1.
Jerome County, Idaho
–
Jerome County is a county in the U. S. state of Idaho. As of the 2010 Census the county had a population of 22,374, the county seat and largest city is Jerome. The county was created by the Idaho Legislature on February 8,1919, the Minidoka Relocation Camp, one of ten Japanese American internment camps set up during World War II, was located in Jerome County, six miles north of Eden. According to the U. S. Census Bureau, the county has an area of 602 square miles. Jerome countys settlements are among Idahos youngest, while Jerome County was located quite close to the Oregon Trail and subsequent stagecoach lines, it was also divided from them by the 500-ft deep Snake River Canyon. The depth of the canyon also eliminated the possibility of drawing water for farming operations, together, those factors made the area unattractive to early Idahoans looking to settle during the territorial and early statehood era. Construction of the railroad across Idaho in the 1880s also bypassed the Jerome area with the route being run 16 miles north of the present center of Jerome City. A ferry commenced operation at Shoshone Falls on April 15,1884, the Schodde settlement on Jerome Countys western border north of Milner was established as the Schoddie Precinct under Lincoln County with a 1900 census population of 24. Completion of the Milner Dam and associated Northside Canal in 1905 brought a supply to the north side of the Snake River that also brought farmers to the region. Eden and Hazelton were settled starting in 1905, settlement at Jerome commenced September 30,1907 and the Idaho Southern Railway reached Jerome on December 28,1908. By the 1910 Census, Jerome Village contained 970 residents having been incorporated in 1909, also by that time, Lincoln County established two precincts of Hillsdale and Jerome. The towns of Eden and Hazelton were part of the Hillsdale precinct, by the 1920 Census, Eden and Hazelton also were incorporated as villages. Jerome, Eden, and Hazelton were all part of Lincoln County at their formation, Eden and Hazelton became part of Minidoka County at its creation in 1913. Jerome County became the 43rd of Idahos 44 counties on February 8,1911 and it is 3 days older than Caribou County. The population density was 31 people per square mile, there were 6,713 housing units at an average density of 11 per square mile. The racial makeup of the county was 86. 99% White,0. 23% Black or African American,0. 69% Native American,0. 27% Asian,0. 05% Pacific Islander,9. 84% from other races, and 1. 94% from two or more races. 17. 17% of the population were Hispanic or Latino of any race,15. 4% were of English,15. 3% German,11. 6% American and 6. 2% Irish ancestry according to Census 2000. 19. 50% of all households were made up of individuals and 8. 70% had someone living alone who was 65 years of age or older, the average household size was 2.89 and the average family size was 3.33
Jerome County, Idaho
–
Jerome County Courthouse
2.
Twin Falls County, Idaho
–
Twin Falls County is a county in the south central part of the U. S. state of Idaho. As of the 2010 Census, the county had a population of 77,230, the county seat and largest city is Twin Falls. Twin Falls County is part of the Twin Falls, ID Micropolitan Statistical Area, prior to the 1860s, the Twin Falls County area was an unorganized part of Shoshone lands, then as part of the Oregon Country. The area was first organized as part of the original Owyhee County in 1864 as part of Idaho Territory, in 1879 it was partitioned away from Owyhee County to form part of Cassia County. The county is named for a waterfall on the Snake River of the same name. The Snake River is the northern boundary. Even after Idaho became a state in 1890, the Twin Falls area was sparsely populated. That changed after the city of Twin Falls was founded in 1904, most of the countys other towns were established during this period as well. According to the U. S. Census Bureau, the county has an area of 1,928 square miles. The population density was 33 people per square mile, there were 25,595 housing units at an average density of 13 per square mile. The racial makeup of the county was 92. 47% White,0. 19% Black or African American,0. 71% Native American,0. 76% Asian,0. 08% Pacific Islander,3. 77% from other races, and 2. 02% from two or more races. 9. 37% of the population were Hispanic or Latino of any race,17. 9% were of German,17. 7% English,10. 9% American and 7. 3% Irish ancestry according to Census 2000. 23. 60% of all households were made up of individuals and 10. 40% had someone living alone who was 65 years of age or older, the average household size was 2.64 and the average family size was 3.13. In the county, the population was out with 27. 90% under the age of 18,10. 40% from 18 to 24,26. 00% from 25 to 44,21. 50% from 45 to 64. The median age was 35 years, for every 100 females there were 96.50 males. For every 100 females age 18 and over, there were 93.70 males, the median income for a household in the county was $34,506, and the median income for a family was $39,886. Males had an income of $30,058 versus $20,825 for females. The per capita income for the county was $16,678, about 9. 10% of families and 12. 70% of the population were below the poverty line, including 16. 00% of those under age 18 and 9. 30% of those age 65 or over
Twin Falls County, Idaho
–
Location in the state of
Idaho
3.
Idaho
–
Idaho is a state in the northwestern region of the United States. It borders the state of Montana to the east and northeast, Wyoming to the east, Nevada and Utah to the south, to the north, it shares a small portion of the Canadian border with the province of British Columbia. With a population of around 1.7 million people and an area of 83,569 square miles, Idaho is the 14th largest, the states capital and largest city is Boise. Idaho prior to European settlement was inhabited solely by Native American peoples, in the early 19th century, Idaho was considered part of the Oregon Country, an area disputed between the U. S. and the United Kingdom. Idaho was eventually admitted to the Union on July 3,1890, forming part of the Pacific Northwest, Idaho is divided into several distinct geographic and climatic regions. In the states north, the relatively isolated Idaho Panhandle is closely linked with Eastern Washington, the states south includes the Snake River Plain, while the south-east incorporates part of the Great Basin. Idaho is quite mountainous, and contains several stretches of the Rocky Mountains, additionally, around 38 percent of Idahos land is held by the United States Forest Service, the most of any state. Industries significant for the economy include manufacturing, agriculture, mining, forestry. Idahos agricultural sector supplies a number of different products, but the state is best known for its potato crop, the official state nickname is the Gem State, which references Idahos reputation for gemstones and, more broadly, its many wilderness areas. The exact origin of the remains a mystery. Willing later claimed that he had invented the name. Congress ultimately decided to name the area Colorado Territory when it was created in February 1861, thinking they would get a jump on the name, locals named a community in Colorado Idaho Springs. However, the name Idaho did not fall into obscurity, the same year Congress created Colorado Territory, a county called Idaho County was created in eastern Washington Territory. The county was named after a steamship named Idaho, which was launched on the Columbia River in 1860 and it is unclear whether the steamship was named before or after Willings claim was revealed. Regardless, a portion of Washington Territory, including Idaho County, was used to create Idaho Territory in 1863. Despite this lack of evidence for the origin of the name, the name Idaho may be derived from the Plains Apache word ídaahę́, which means enemy. The Comanches used this word to refer to the Idaho Territory, a 1956 Idaho history textbook says, Idaho is a Shoshoni Indian exclamation. The word consists of three parts, the first is Ee, which in English conveys the idea of coming down
Idaho
–
Digitally colored elevation map of Idaho.
Idaho
–
Flag
Idaho
–
Shoshone Falls in south central Idaho.
Idaho
–
Reynolds Creek Experimental Watershed in the Owyhee Mountains, about 50 miles (80 km) southwest of
Boise, Idaho
4.
United States
–
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
United States
–
Native Americans meeting with Europeans, 1764
United States
–
Flag
United States
–
The signing of the
Mayflower Compact, 1620.
United States
–
The
Declaration of Independence: the
Committee of Five presenting their draft to the
Second Continental Congress in 1776
5.
Geographic coordinate system
–
A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
Geographic coordinate system
–
Longitude lines are perpendicular and latitude lines are parallel to the equator.
6.
Waterfall
–
A waterfall is a place where water flows over a vertical drop or a series of drops in the course of a stream or river. Waterfalls also occur where meltwater drops over the edge of an iceberg or ice shelf. Waterfalls are commonly formed in the course of a river. At these times the channel is narrow and deep. When the river courses over resistant bedrock, erosion happens slowly, as the watercourse increases its velocity at the edge of the waterfall, it plucks material from the riverbed. Whirlpools created in the turbulence as well as sand and stones carried by the increase the erosion capacity. This causes the waterfall to carve deeper into the bed and to recede upstream, often over time, the waterfall will recede back to form a canyon or gorge downstream as it recedes upstream, and it will carve deeper into the ridge above it. The rate of retreat for a waterfall can be as high as one, eventually, the outcropping, more resistant cap rock will collapse under pressure to add blocks of rock to the base of the waterfall. Waterfalls normally form in an area due to erosion. After a long period of being formed, the water falling off the ledge will retreat. Eventually, as the pit grows deeper, the waterfall collapses to be replaced by a steeply sloping stretch of river bed, a river sometimes flows over a large step in the rocks that may have been formed by a fault line. Waterfalls can occur along the edge of a trough, where a stream or river flowing into a glacier continues to flow into a valley after the glacier has receded or melted. The large waterfalls in Yosemite Valley are examples of this phenomenon, another reason hanging valleys may form is where two rivers join and one is flowing faster than the other. Waterfalls can be grouped into ten classes based on the average volume of water present on the fall using a logarithmic scale. Class 10 waterfalls include Niagara Falls, Paulo Afonso Falls and Khone Falls, young Wrote Waterfalls, form and process this work made waterfalls a much more serious topic for research for modern Geoscientists. Ledge waterfall, Water descends vertically over a cliff, maintaining partial contact with the bedrock. Block/Sheet. Classical, Ledge waterfalls where fall height is equal to stream width. Curtain, Ledge waterfalls which descend over a larger than the width of falling water stream
Waterfall
–
Angel Falls in
Venezuela is the world's tallest at 979 m (3,212 ft).
Waterfall
–
Aerial view of
Victoria Falls on the
Zambezi River in southern Africa
Waterfall
–
Aerial view of
Iguazu Falls on the Iguazu River between Brazil and Argentina
Waterfall
–
Aerial view of
Niagara Falls in the state of
New York,
US, and province of
Ontario,
Canada
7.
Snake River
–
The Snake River is a major river of the greater Pacific Northwest in the United States. At 1,078 miles long, it is the largest tributary of the Columbia River and its drainage basin encompasses parts of six U. S. states, and its average discharge is over 54,000 cubic feet per second. Rugged mountains divided by rolling plains characterize the physiographically diverse watershed of the Snake River, the Snake River Plain was created by a volcanic hotspot which now lies underneath Yellowstone National Park, where the headwaters of the Snake River arise. Two of these flooding events significantly affected the river and its surrounds. More than 11,000 years ago, prehistoric Native Americans lived along the Snake, Salmon from the Pacific Ocean spawned by the millions in the river. These fish were central to the lives of the people along the Snake below Shoshone Falls, by the time Lewis and Clark crossed the Rockies and sighted the valley of a Snake tributary, the Nez Perce and Shoshone were the most powerful peoples in the region. Some tribes adopted use of horses after contact with Europeans, which reshaped their hunting, later explorers and fur trappers further changed and used the resources of the Snake River basin. At one point, a sign made by the Shoshones representing fish was misinterpreted to represent a snake. By the middle 19th century, the Oregon Trail, a trail of which a major portion followed the Snake River, had been established by aspiring settlers and traders. Steamboats and railroads moved agricultural products and minerals along the river throughout the 19th, several of these have been proposed for removal in order to restore some of the rivers once-tremendous salmon runs. Its first 50-mile run through the valley of Jackson Hole, which cuts between the Teton Range and the Continental Divide, there it is also met by the Salt River at the mouth of Star Valley. Southwest of the city of Rexburg, the Snake receives from the right the Henrys Fork, the confluence with the Henrys Fork takes the river southwards through downtown Idaho Falls, rounding the Fort Hall Indian Reservation and into American Falls Reservoir, receiving the Portneuf River. Close to Twin Falls, the Snake approaches the southernmost point in its entire course, after which it starts to flow generally northwest. Shortly after it passes within 30 miles of the Idaho state capital of Boise, there were hundreds of rapids in Hells Canyon, some of which have been stilled by the three dams of the Hells Canyon Hydroelectric Project, Hells Canyon, Oxbow, and Brownlee. The Salmon River, the largest tributary of the Snake River, meets it in one of the most remote areas of its entire course, the confluence of the Snake and Columbia rivers has been submerged in Lake Wallula, the reservoir of McNary Dam. The Columbia River flows about 325 miles further west to the Pacific Ocean, as recently as 165 million years ago, most of western North America was still part of the Pacific Ocean. Even larger lava flows of Columbia River basalts issued over eastern Washington, forming the Columbia Plateau southeast of the Columbia River, separate volcanic activity formed the northwestern portion of the plain, an area far from the path of the hotspot which now lies beneath Yellowstone National Park. At this point, the Snake River watershed was beginning to take shape, the Snake River Plain and the gap between the Sierra Nevada and Cascade Range formed a moisture channel, running as far inland as the headwaters of the Snake River
Snake River
–
The Snake River flowing through the Palouse region about 10 miles (16 km) above its mouth on the Columbia River
Snake River
–
Map of the Snake River watershed
Snake River
–
The Snake River exits
Jackson Lake and winds southwards through
Jackson Hole.
Snake River
–
Tourist feels cold waters of the Snake River in
Grand Teton National Park (1974 photograph).
8.
Twin Falls, Idaho
–
Twin Falls is the county seat and largest city of Twin Falls County, Idaho, United States. The city had a population of 44,125 as of the 2010 census, Twin Falls is the largest city of Idahos Magic Valley region. As the largest city in a 100-mile radius, Twin Falls serves as a commercial center for both south-central Idaho and northeastern Nevada. Twin Falls is the city of the Twin Falls, ID Micropolitan Statistical Area. The resort community of Jackpot, Nevada, in Elko County is unofficially considered part of the greater Twin Falls area, located on a broad plain, Twin Falls is near the site where Evel Knievel attempted to jump across the Snake River Canyon in 1974 with a rocket-powered motorcycle. Excavations at Wilson Butte Cave near Twin Falls in 1959 revealed evidence of activity, including arrowheads. Later Native American tribes predominant in the area included the Northern Shoshone, Louis, Missouri, to Astoria, Oregon, in 1811 and 1812. Hunts expedition met with disaster, much of his expedition was destroyed, hunt and the surviving members of his expedition completed the journey to Astoria by land. In 1812 and 1813, Robert Stuart successfully led an expedition eastward from Astoria to St. Louis. Stuarts route formed the basis of what became the Oregon Trail, some 150 years later, Robert Stuart Middle School in Twin Falls was named in his honor. The first permanent settlement in the area was a stage stop established in 1864 at Rock Creek near the present-day townsite, to address this issue, in 1900 I. B. Perrine founded the Twin Falls Land and Water Company, largely to build a canal system for the area. After an August 1900 area survey of 244,025 acres, several lots in the surveyed area were set aside specifically for future townsites. These lots eventually became the settlements of Twin Falls, Kimberly, Buhl, Filer, Hansen, in 1902 the project nearly failed as most of the original investors pulled out, with only Salt Lake businessman Stanley Milner maintaining a stake in the company. Completed in 1905, Milner Dam and its accompanying canals made commercial irrigation outside the Snake River Canyon practical for the first time, as a result, Perrine is generally credited as the founder of Twin Falls. A land drawing was held for the townsite in July 1903 with disappointing results. A much more successful drawing was held in October 1904, Twin Falls was incorporated as a village on April 12,1905. The city is named for a waterfall on the Snake River of the same name
Twin Falls, Idaho
–
Downtown Twin Falls
Twin Falls, Idaho
–
Snake River Canyon
Twin Falls, Idaho
–
Shoshone Falls along
Snake River
Twin Falls, Idaho
–
View of the Perrine Bridge from the south side of the canyon.
9.
Niagara Falls
–
They form the southern end of the Niagara Gorge. From largest to smallest, the three waterfalls are the Horseshoe Falls, the American Falls and the Bridal Veil Falls, the Horseshoe Falls lies on the border of the United States and Canada with the American Falls entirely on the American side, separated by Goat Island. The smaller Bridal Veil Falls are also on the American side, the international boundary line was originally drawn through Horseshoe Falls in 1819, but the boundary has long been in dispute due to natural erosion and construction. Located on the Niagara River, which drains Lake Erie into Lake Ontario, Horseshoe Falls is the most powerful waterfall in North America, as measured by vertical height and flow rate. The falls are 17 miles north-northwest of Buffalo, New York, while not exceptionally high, the Niagara Falls are very wide. More than six cubic feet of water falls over the crest line every minute in high flow. The Niagara Falls are famed both for their beauty and as a source of hydroelectric power. Balancing recreational, commercial, and industrial uses has been a challenge for the stewards of the falls since the 19th century. The Horseshoe Falls drop about 188 feet, while the height of the American Falls varies between 70 and 100 feet because of the presence of giant boulders at its base. The larger Horseshoe Falls are about 2,600 feet wide, the distance between the American extremity of the Niagara Falls and the Canadian extremity is 3,409 feet. The volume of water approaching the falls during peak season may sometimes be as much as 225,000 cubic feet per second. The average annual rate is 85,000 cubic feet per second. Since the flow is a function of the Lake Erie water elevation. This is accomplished by employing a weir – the International Control Dam – with movable gates upstream from the Horseshoe Falls. The falls flow is further halved at night, and, during the low tourist season in the winter, water diversion is regulated by the 1950 Niagara Treaty and is administered by the International Niagara Board of Control. The current rate of erosion is approximately 1 foot per year and it is estimated that 50,000 years from now, even at this reduced rate of erosion, the remaining 20 miles to Lake Erie will have been undermined and the falls will cease to exist. The features that became Niagara Falls were created by the Wisconsin glaciation about 10,000 years ago, the same forces also created the North American Great Lakes and the Niagara River. All were dug by an ice sheet that drove through the area, deepening some river channels to form lakes
Niagara Falls
–
Niagara Falls
Niagara Falls
–
Louis Rémy Mignot, Niagara (Brooklyn Museum)
Niagara Falls
–
Niagara Falls, New York
Niagara Falls
–
American Falls (large waterfall on the left) and
Bridal Veil Falls (smaller waterfall on the right)
10.
Outburst flood
–
In geomorphology, an outburst flood, which is a type of megaflood, is a high-magnitude, low-frequency catastrophic flood involving the sudden release of water. During the last deglaciation, numerous glacial lake outburst floods were caused by the collapse of ice sheets or glaciers that formed the dams of proglacial lakes. Examples of older outburst floods are known from the geological past of the Earth, landslides, lahars, and volcanic dams can also block rivers and create lakes, which trigger such floods when the rock or earthen barrier collapses or is eroded. Lakes also form behind glacial moraines, which can collapse and create outburst floods, megafloods are paleofloods that involved rates of water flow larger than those in the historical record. They are studied through the deposits and the erosional and constructional landforms that individual megafloods have created. Floods that are known to us through historical descriptions are related to meteorological events, such as heavy rains, rapid melting of snowpacks. In the geological past of the Earth, however, geological research has shown much larger events have occurred. In the case of outburst floods, such floods are typically linked to the collapse of the forming a lake. They fall in the classification according to the mechanism responsible. Rapid erosion, melting of ice sheets, Collapse of volcanic dams created by lava flows, lahars, or pyroclastic flows. Overtopping of earthen or rock barriers Lake overtopping, Ocean spilling over a dividing ridge into a landlocked basin. A smaller scale example would be the Pantai Remis landslide, a landslide dam on Sichuans Dadu River, created by an earthquake ten days earlier, burst and caused a flood that extended 1400 km downstream and killed 100,000 people. The marine incursion, caused by the level of the Mediterranean. In North America, during glacial maximum, there were no Great Lakes as we know them and they lay in the areas of the modern lakes, but their drainage sometimes passed south, into the Mississippi system, sometimes into the Arctic, or east into the Atlantic. The most famous of these lakes was Lake Agassiz. As ice-dam configurations failed, a series of floods were released from Lake Agassiz. The Missoula Floods of Oregon and Washington states were caused by breaking ice dams. Lake Bonneville was not a lake, but glacial age climate change determined the lake level
Outburst flood
–
Black Sea today (light blue) and in
5600 BC (dark blue) according to Ryan's and Pitman's theories
11.
Pleistocene
–
The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the worlds most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period, the Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, all of these stages were defined in southern Europe. In addition to this subdivision, various regional subdivisions are often used. Charles Lyell introduced the term pleistocene in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today and this distinguished it from the older Pliocene Epoch, which Lyell had originally thought to be the youngest fossil rock layer. The Pleistocene has been dated from 2.588 million to 11,700 years before present and it covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell. The end of the Younger Dryas has been dated to about 9640 BC, the IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point, for the upper Pleistocene/Holocene boundary. The proposed section is the North Greenland Ice Core Project ice core 75°06 N 42°18 W, the lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils, Discoaster pentaradiatus, the Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age. The revised definition of the Quaternary, by pushing back the date of the Pleistocene to 2.58 Ma. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places and it is estimated that, at maximum glacial extent, 30% of the Earths surface was covered by ice. In addition, a zone of permafrost stretched southward from the edge of the sheet, a few hundred kilometres in North America. The mean annual temperature at the edge of the ice was −6 °C, during interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions. The effects of glaciation were global, antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap, there were glaciers in New Zealand and Tasmania. The current decaying glaciers of Mount Kenya, Mount Kilimanjaro, glaciers existed in the mountains of Ethiopia and to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one, the Cordilleran ice sheet covered the North American northwest, the east was covered by the Laurentide
Pleistocene
–
The maximum extent of
glacial ice in the north polar area during the Pleistocene period.
Pleistocene
–
Ice ages as reflected in atmospheric CO 2, stored in bubbles from glacial ice of
Antarctica.
Pleistocene
–
Pleistocene of
Northern Spain showing
woolly mammoth,
cave lions eating a
reindeer,
tarpans, and
woolly rhinoceros.
Pleistocene
–
Pleistocene of
South America showing
Megatherium and two
Glyptodon.
12.
Last glacial period
–
The last glacial period, popularly known as the Ice Age, was the most recent glacial period, which occurred from c. 110,000 – c. 11,700 years ago. This most recent glacial period is part of a pattern of glacial and interglacial periods known as the Quaternary glaciation. From this point of view, scientists consider this ice age to be merely the latest glaciation event in a larger ice age. During this last glacial period, there were changes between glacier advance and retreat. The Last Glacial Maximum, the extent of glaciation within the last glacial period, was approximately 22,000 years ago. Approximately 13,000 years ago, the Late Glacial Maximum began, around 11,700 years ago marked the beginning of the Holocene geological epoch, which includes the Holocene glacial retreat. From the point of view of archaeology, it falls in the Paleolithic and Mesolithic periods. When the glaciation event started, Homo sapiens were confined to Africa and used tools comparable to those used by Neanderthals in western and central Eurasia, near the end of the event, Homo sapiens spread into Eurasia and Australia. The retreat of the glaciers allowed groups of Asians to migrate to the Americas, glacials, on the other hand, refer to colder phases within an ice age that separate interglacials. Thus, the end of the last glacial period is not the end of the last ice age, the end of the last glacial period was about 11,700 years ago, while the end of the last ice age has not yet come. Over the past few years the glacial-interglacial cycle has been paced by periodic variations in the Earths orbit via Milankovitch cycles which are thus the cause of ice ages. The glaciations that occurred during this period covered many areas, mainly in the Northern Hemisphere. The geochronological Late Pleistocene comprises the late glacial and the immediately preceding penultimate interglacial preiond, the last glaciation centered on the huge ice sheets of North America and Eurasia. Considerable areas in the Alps, the Himalaya and the Andes were ice-covered, Canada was nearly completely covered by ice, as well as the northern part of the United States, both blanketed by the huge Laurentide ice sheet. Alaska remained mostly ice free due to climate conditions. Local glaciations existed in the Rocky Mountains and the Cordilleran ice sheet and as ice fields, the maximum extent of western Siberian glaciation was reached by approximately 16, 000–15,000 BCE and thus later than in Europe. Northeastern Siberia was not covered by an ice sheet. Instead, large, but restricted, icefield complexes covered mountain ranges within northeast Siberia, according to the sediment composition retrieved from deep-sea cores there must even have been times of seasonally open waters
Last glacial period
–
An artist's impression of the last glacial period at glacial maximum.
Last glacial period
–
Chronology of climatic events of importance for the Last Glacial Period (about the last 120 000 years)
Last glacial period
–
Map showing the extent of the
Patagonian Ice Sheet in the
Strait of Magellan area during the last glacial period. Selected modern settlements are shown with yellow dots.
13.
Pacific salmon
–
Oncorhynchus is a genus of fish in the family Salmonidae, it contains the Pacific salmon and Pacific trout. The name of the genus is derived from the Greek onkos and rynchos, Salmon and trout with native ranges in waters draining to the Pacific Ocean are members of the genus. Their range extends from Beringia southwards, roughly to Taiwan in the west, in North America, some subspecies of O. Several species of Oncorhynchus have been introduced into waters around the globe establishing self-sustaining wild populations. The six Pacific salmons of Oncorhynchus are anadromous and semelparous, migration can be affected by parasites. Infected individuals can become weak and probably have shortened lifespans, infection with parasites creates an effect known as culling whereby fish that are infected are less likely to complete the migration. Anadromous forms of Oncorhynchus mykiss known as steelhead are iteroparus, the Coastal cutthroat trout form of Oncorhynchus clarki is considered semi-anadromous as it spends short periods of time in marine environments. Several late Miocene trout-like fossils in Idaho, in the Clarkia Lake beds, consequently, the split between Oncorhynchus and Salmo must have occurred well before the Pliocene. Suggested dates ions have gone back as far as the early Miocene, one fossil species assigned to this genus, O. rastrosus, the sabertooth salmon, is a 9-foot -long species known from Late Miocene to Pleistocene fossils. Speciation among Oncorhynchus has been examined for decades, and a tree is not yet completely developed for the Pacific salmonids. Mitochondrial DNA research has been completed on a variety of Pacific trout and salmonid species, Chum, pink and sockeye salmon lineages are generally agreed to have diverged in the sequence after other species. Montgomery discusses the pattern of the record as compared to tectonic shifts in the plates of the Pacific Northwest of America. The divergence in Onchorhyncus lineages appear to follow the uprising of the Pacific Rim, the climatic and habitat changes that would follow such a geologic event are discussed, in the context of potential stressors leading to adaptation and speciation. One interesting case involving speciation with salmon is that of the kokanee sockeye, kokanee sockeye evolve differently from anadromous sockeye—they reach the level of biological species. Biological species—as opposed to morphological species—are defined by the capacity to maintain themselves in sympatry as independent genetic entities and this definition can be vexing because it apparently applies only to sympatry, and this limitation makes the definition difficult to apply. Examples in Washington State, Canada, and elsewhere have two living in the same lake, but spawning in different substrates at different times. There is no pressure to compete or interbreed and these types of kokanee salmon show the principal attributes of a biological species, they are reproductively isolated and show strong resources partitioning. A general decline in overall Pacific salmon populations began in the mid 19th century, as the result of western expansion and development in the U. S. experts estimate salmon populations in the Columbia River basin had been reduced to less than 20% of their pre-1850 levels by 1933
Pacific salmon
–
Oncorhynchus Temporal range: Late
Miocene - Recent
14.
Native Americans in the United States
–
In the United States, Native Americans are people descended from the Pre-Columbian indigenous population of the land within the countrys modern boundaries. These peoples were composed of distinct tribes, bands, and ethnic groups. Most Native American groups had historically preserved their histories by oral traditions and artwork, at the time of first contact, the indigenous cultures were quite different from those of the proto-industrial and mostly Christian immigrants. Some of the Northeastern and Southwestern cultures in particular were matrilineal, the majority of Indigenous American tribes maintained their hunting grounds and agricultural lands for use of the entire tribe. Europeans at that time had patriarchal cultures and had developed concepts of property rights with respect to land that were extremely different. Assimilation became a consistent policy through American administrations, during the 19th century, the ideology of manifest destiny became integral to the American nationalist movement. Expansion of European-American populations to the west after the American Revolution resulted in increasing pressure on Native American lands and this resulted in the ethnic cleansing of many tribes, with the brutal, forced marches coming to be known as The Trail of Tears. As American expansion reached into the West, settler and miner migrants came into increasing conflict with the Great Basin, Great Plains and these were complex nomadic cultures based on horse culture and seasonal bison hunting. Over time, the United States forced a series of treaties and land cessions by the tribes, in 1924, Native Americans who were not already U. S. citizens were granted citizenship by Congress. Contemporary Native Americans have a relationship with the United States because they may be members of nations, tribes. The terms used to refer to Native Americans have at times been controversial, by comparison, the indigenous peoples of Canada are generally known as First Nations. It is not definitively known how or when the Native Americans first settled the Americas and these early inhabitants, called Paleoamericans, soon diversified into many hundreds of culturally distinct nations and tribes. The archaeological periods used are the classifications of archaeological periods and cultures established in Gordon Willey and Philip Phillips 1958 book Method and they divided the archaeological record in the Americas into five phases, see Archaeology of the Americas. The Clovis culture, a hunting culture, is primarily identified by use of fluted spear points. Artifacts from this culture were first excavated in 1932 near Clovis, the Clovis culture ranged over much of North America and also appeared in South America. The culture is identified by the distinctive Clovis point, a flaked flint spear-point with a notched flute, dating of Clovis materials has been by association with animal bones and by the use of carbon dating methods. Recent reexaminations of Clovis materials using improved carbon-dating methods produced results of 11,050 and 10,800 radiocarbon years B. P, other tribes have stories that recount migrations across long tracts of land and a great river, believed to be the Mississippi River. Genetic and linguistic data connect the people of this continent with ancient northeast Asians
Native Americans in the United States
–
Pushmataha
Native Americans in the United States
Native Americans in the United States
–
Charles Eastman
Native Americans in the United States
–
Wilma Mankiller
15.
Magic Valley
–
The Magic Valley is a region in south-central Idaho consisting of Blaine, Camas, Cassia, Gooding, Jerome, Lincoln, Minidoka and Twin Falls Counties. It is particularly associated with the region in the Snake River Plain located in the area. The northern Magic Valley region — particularly Blaine and Camas Counties — is also known as the Wood River Valley after the Big Wood River. According to the 2010 Census the counties of the Magic Valley region had a population of 185,790. Twin Falls is the regions largest city and micropolitan area, burley is the principal city of the regions other micropolitan area. Other cities include Jerome, Rupert, Gooding, Wendell, Bliss, Hagerman, the name Magic Valley is a reference to the construction of Milner and Minidoka Dams and a series of irrigation canal systems on the Snake River during the first decade of the 20th century. In a short time these projects magically transformed what had been considered a nearly uninhabitable area into some of the most productive farmland in the northwestern U. S, many cities and towns in the region were founded between 1900 and 1910 as a direct result of these projects. The College of Southern Idaho in Twin Falls is the Magic Valleys only college, most of the regions cities and towns support separate public school districts. Cultural events are held at CSI. County fairs are held throughout the region in the late summer, the Sun Valley resort in Blaine County hosts several attractions throughout the year. The town of Hagerman hosts a large blues fest in September, the Magic Valley is home to the Magic Valley Arts Council, a non-profit umbrella arts organization that serves the greater Twin Falls area and surrounding 8-county Magic Valley region. The organizations mission is to foster and promote experiences in the arts for all people in the Greater Twin Falls, popular leisure activities in the Magic Valley include camping, hunting and fishing. Skiing at several resorts throughout the region is one of the most popular winter activities, jackpot, Nevada, which is closely associated with the Magic Valley region, offers casino gaming. The Perrine Bridge draws many BASE jumpers from around the world and it is the only man-made structure in the USA that is legally jumpable without a permit. Important agricultural commodities in the Magic Valley include beans, sugar beets, corn, dairy production is also significant, especially in Jerome and Gooding Counties
Magic Valley
–
Perrine Bridge spanning the
Snake River Canyon at Twin Falls
16.
Hydroelectricity
–
Hydroelectricity is electricity produced from hydropower. In 2015 hydropower generated 16. 6% of the total electricity and 70% of all renewable electricity. Hydropower is produced in 150 countries, with the Asia-Pacific region generating 33 percent of global hydropower in 2013, China is the largest hydroelectricity producer, with 920 TWh of production in 2013, representing 16.9 percent of domestic electricity use. The cost of hydroelectricity is relatively low, making it a source of renewable electricity. The hydro station consumes no water, unlike coal or gas plants, the average cost of electricity from a hydro station larger than 10 megawatts is 3 to 5 U. S. cents per kilowatt-hour. With a dam and reservoir it is also a source of electricity since the amount produced by the station can be changed up or down very quickly to adapt to changing energy demands. Once a hydroelectric complex is constructed, the project produces no direct waste, Hydropower has been used since ancient times to grind flour and perform other tasks. In the mid-1770s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique which described vertical-, by the late 19th century, the electrical generator was developed and could now be coupled with hydraulics. The growing demand for the Industrial Revolution would drive development as well, in 1878 the worlds first hydroelectric power scheme was developed at Cragside in Northumberland, England by William George Armstrong. It was used to power an arc lamp in his art gallery. The old Schoelkopf Power Station No.1 near Niagara Falls in the U. S. side began to produce electricity in 1881. The first Edison hydroelectric power station, the Vulcan Street Plant, began operating September 30,1882, in Appleton, Wisconsin, by 1886 there were 45 hydroelectric power stations in the U. S. and Canada. By 1889 there were 200 in the U. S. alone, at the beginning of the 20th century, many small hydroelectric power stations were being constructed by commercial companies in mountains near metropolitan areas. Grenoble, France held the International Exhibition of Hydropower and Tourism with over one million visitors, by 1920 as 40% of the power produced in the United States was hydroelectric, the Federal Power Act was enacted into law. The Act created the Federal Power Commission to regulate hydroelectric power stations on federal land, as the power stations became larger, their associated dams developed additional purposes to include flood control, irrigation and navigation. Federal funding became necessary for development and federally owned corporations, such as the Tennessee Valley Authority. Hydroelectric power stations continued to become larger throughout the 20th century, Hydropower was referred to as white coal for its power and plenty. Hoover Dams initial 1,345 MW power station was the worlds largest hydroelectric station in 1936
Hydroelectricity
–
The
Three Gorges Dam in Central China is the
world's largest power producing facilitiy of any kind.
Hydroelectricity
–
Museum Hydroelectric power plant ″Under the Town″ in
Serbia, built in 1900.
Hydroelectricity
–
Turbine row at Los Nihuiles Power Station in
Mendoza, Argentina
17.
Snake River Canyon (Idaho)
–
The canyon ranges up to 500 feet deep and 0.25 miles wide, and runs for just over 50 miles. Perrine Bridge crosses the canyon north of the city of Twin Falls. Shoshone Falls is located approximately 5 miles east of Perrine Bridge along the canyon, in the late 19th century I. B. Perrine and others founded the Magic Valleys first successful agricultural operations on the Snake River Canyon floor, the canyons value as a farming area diminished after irrigation projects made agriculture practical in the surrounding areas in the early 20th Century. Today the canyon floor is a tourist attraction and features several parks, in the past it was generally believed the Snake River Canyon was created by a cataclysmic flood caused by water released from Lake Bonneville approximately 15,000 years ago. However, as of 2000, geologists believe that while the canyon was shaped by the flood, the canyon is well known as the site of an unsuccessful 1974 attempt by Evel Knievel to jump across it in the Skycycle X-2 rocket. The dirt ramp built for that jump is still there and remains a tourist attraction, on September 16,2016, stuntman Eddie Braun successfully jumped the canyon using technology similar to that used by Evel Knievel 42 years previously
Snake River Canyon (Idaho)
–
View east up the Snake River Canyon from the
Perrine Bridge
Snake River Canyon (Idaho)
–
Looking west down the Snake River Canyon from the Perrine Bridge
Snake River Canyon (Idaho)
–
View west down the Snake River Canyon from
Shoshone Falls
Snake River Canyon (Idaho)
–
View up the Snake River Gorge above Shoshone Falls
18.
Columbia River
–
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada and it flows northwest and then south into the US state of Washington, then turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is 1,243 miles long, and its largest tributary is the Snake River and its drainage basin is roughly the size of France and extends into seven US states and a Canadian province. By volume, the Columbia is the fourth-largest river in the United States, the rivers heavy flow and relatively steep gradient gives it tremendous potential for the generation of electricity. The Columbia and its tributaries have been central to the regions culture and they have been used for transportation since ancient times, linking the many cultural groups of the region. The river system hosts many species of fish, which migrate between freshwater habitats and the saline waters of the Pacific Ocean. In the following decades, fur trading companies used the Columbia as a key transportation route, steamships along the river linked communities and facilitated trade, the arrival of railroads in the late 19th century, many running along the river, supplemented these links. Since the late 19th century, public and private sectors have developed the river. The development, commonly referred to as taming or harnessing of the river, has been massive, to aid ship and barge navigation, locks have been built along the lower Columbia and its tributaries, and dredging has opened, maintained, and enlarged shipping channels. Since the early 20th century, dams have been built across the river for the purposes of power generation, navigation, irrigation, and flood control. Today, a reservoir lies along nearly every US mile of the once free-flowing river. Production of nuclear power has taken place at two sites along the river, plutonium for nuclear weapons was produced for decades at the Hanford Site, which is now the most contaminated nuclear site in the US. All these developments have had a impact on river environments, mainly through industrial pollution. The Columbia begins its 1, 243-mile journey in the southern Rocky Mountain Trench in British Columbia, Columbia Lake –2,690 feet above sea level – and the adjoining Columbia Wetlands form the rivers headwaters. The trench is a broad, deep, and long glacial valley between the Canadian Rockies and the Columbia Mountains in BC. Rounding the northern end of the Selkirk Mountains, the river turns south through a region known as the Big Bend Country, passing through Revelstoke Lake. Revelstoke, the Big Bend, and the Columbia Valley combined are referred to in BC parlance as the Columbia Country. Below the Arrow Lakes, the Columbia passes the cities of Castlegar, located at the Columbias confluence with the Kootenay River, the Pend Oreille River joins the Columbia about 2 miles north of the US–Canada border
Columbia River
–
Bonneville Dam, in the Columbia River Gorge
Columbia River
–
Course of the Columbia River
Columbia River
–
The
Columbia River Gorge in May 2009, facing east toward
Beacon Rock
Columbia River
–
Drumheller Channels, part of the
Channeled Scablands formed by the
Missoula Floods
19.
Horseshoe
–
A horseshoe is a fabricated product, normally made of metal, although sometimes made partially or wholly of modern synthetic materials, designed to protect a horses hoof from wear. Shoes are attached on the surface of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toenail. However, there are cases where shoes are glued. In some countries, such as the United Kingdom, horseshoeing is legally restricted to people with specific qualifications. In others, such as the United States, where licensing is not legally required. Horseshoes are available in a variety of materials and styles, developed for different types of horse. The most common materials are steel and aluminium, but specialized shoes may use of rubber, plastic, magnesium, titanium. Steel tends to be preferred in sports where a strong, long-wearing shoe is needed, such as polo, eventing, show jumping, and western riding events. Aluminium shoes are lighter, making them common in racing, where a lighter shoe is desired, and often facilitate certain types of movement. Some horseshoes have caulkins, caulks, or calks, protrusions at the toe or heels of the shoe, when kept as a talisman, a horseshoe is said to bring good luck. Others believe that the horseshoe should be hung the other way, a stylized variation of the horseshoe is used for a popular throwing game, horseshoes. Since the early history of domestication of the horse, working animals were found to be exposed to conditions that created breakage or excessive hoof wear. Ancient people recognized the need for the walls of domestic horses hooves to have additional protection over, an early form of hoof protection was seen in ancient Asia, where horses hooves were wrapped in rawhide, leather or other materials for both therapeutic purposes and protection from wear. Historians have expressed differing opinions on the origin of the horseshoe, because iron was a valuable commodity, and any worn out items were generally melted down and reused, it is difficult to locate clear archaeological evidence. Although some credit the Druids, there is no evidence to support this claim. In 1897 four bronze horseshoes with what are apparently nail holes were found in an Etruscan tomb dated around 400 B. C. The assertion by some historians that the Romans invented the mule shoes sometime after 100 BC is supported by a reference by Catullus who died in 54 BC. However, these references to use of horseshoes and muleshoes in Rome, may have been to the boots, reinforced by an iron plate
Horseshoe
–
Modern horseshoes are most commonly made of
steel and nailed into the hoof wall.
Horseshoe
–
A variety of horseshoes, including aluminium racing plates (light coloured) and shoes used on cattle in lower right.
Horseshoe
–
A
hipposandal, a predecessor to the horseshoe
Horseshoe
–
English horseshoes from the 11th to the 19th centuries
20.
Rocky Mountains
–
The Rocky Mountains, commonly known as the Rockies, are a major mountain range in western North America. The Rocky Mountains stretch more than 3,000 miles from the northernmost part of British Columbia, in western Canada, to New Mexico, in the Southwestern United States. Within the North American Cordillera, the Rockies are somewhat distinct from the Pacific Coast Ranges, the Rocky Mountains were initially formed from 80 million to 55 million years ago during the Laramide orogeny, in which a number of plates began to slide underneath the North American plate. The angle of subduction was shallow, resulting in a belt of mountains running down western North America. Since then, further tectonic activity and erosion by glaciers have sculpted the Rockies into dramatic peaks, at the end of the last ice age, humans started to inhabit the mountain range. The first mention of their present name by a European was in the journal of Jacques Legardeur de Saint-Pierre in 1752, the Rocky Mountains are commonly defined as stretching from the Liard River in British Columbia south to the Rio Grande in New Mexico. The United States definition of the Rockies includes the Cabinet and Salish Mountains of Idaho and their counterparts north of the Kootenai River, the Columbia Mountains, are considered a separate system in Canada, lying to the west of the huge Rocky Mountain Trench. This runs the length of British Columbia from its beginnings in the middle Flathead River valley in western Montana to the bank of the Liard River. The Rockies vary in width from 70 to 300 miles, also west of the Rocky Mountain Trench, farther north and facing the Muskwa Range across the trench, are the Stikine Ranges and Omineca Mountains of the Interior Mountains system of British Columbia. A small area east of Prince George, British Columbia on the side of the Trench. In Canada geographers define three main groups of ranges, the Continental Ranges, Hart Ranges and Muskwa Ranges, the Muskwa and Hart Ranges together comprise what is known as the Northern Rockies. The western edge of the Rockies includes ranges such as the Wasatch near Salt Lake City, the Great Basin and Columbia River Plateau separate these sub-ranges from distinct ranges further to the west, most prominent among which are the Sierra Nevada, Cascade Range and Coast Mountains. The Rocky Mountain System within the United States is a United States physiographic region, the Rocky Mountains are notable for containing the highest peaks in central North America. The ranges highest peak is Mount Elbert located in Colorado at 14,440 feet above sea level, Mount Robson in British Columbia, at 12,972 feet, is the highest peak in the Canadian Rockies. The Continental Divide of the Americas is located in the Rocky Mountains, triple Divide Peak in Glacier National Park is so named because water that falls on the mountain reaches not only the Atlantic and Pacific, but Hudson Bay as well. Farther north in Alberta, the Athabasca and other rivers feed the basin of the Mackenzie River, see Rivers of the Rocky Mountains for a list of rivers. Human population is not very dense in the Rocky Mountains, with an average of four people per square kilometer, however, the human population grew rapidly in the Rocky Mountain states between 1950 and 1990. The 40-year statewide increases in range from 35% in Montana to about 150% in Utah
Rocky Mountains
–
Moraine Lake, and the
Valley of the Ten Peaks,
Banff National Park,
Alberta,
Canada
Rocky Mountains
–
The Front Range of the Rocky Mountains near
Denver, Colorado
Rocky Mountains
–
The
Tetons are a rugged subrange in Wyoming
Rocky Mountains
–
Mount Robson in
British Columbia.
21.
Wyoming
–
Wyoming /waɪˈoʊmɪŋ/ is a state in the mountain region of the western United States. The state is the tenth largest by area, the least populous, Wyoming is bordered on the north by Montana, on the east by South Dakota and Nebraska, on the south by Colorado, on the southwest by Utah, and on the west by Idaho. Cheyenne is the capital and the most populous city in Wyoming, the state population was estimated at 586,107 in 2015, which is less than the population of 31 of the largest U. S. cities. The Crow, Arapaho, Lakota, and Shoshone were some of the inhabitants of the region. Southwestern Wyoming was included in the Spanish Empire and then Mexican territory until it was ceded to the United States in 1848 at the end of the Mexican–American War. The region acquired the name Wyoming when a bill was introduced to Congress in 1865 to provide a government for the territory of Wyoming. The territory was named after the Wyoming Valley in Pennsylvania, with the name ultimately being derived from the Munsee word xwé, wamənk, the mineral extraction industry—especially coal, oil, natural gas, and trona—along with the travel and tourism sector are the main drivers behind Wyomings economy. Agriculture has historically been an important component of the economy with the main commodities being livestock, hay, sugar beets, grain. The climate is generally semi-arid and continental, being drier and windier in comparison to the rest of the United States, except for the 1964 election, Wyoming has been a politically conservative state since the 1950s, with the Republican party winning every presidential election. Wyoming is one of three states to have borders along only straight latitudinal and longitudinal lines, rather than being defined by natural landmarks. Wyoming is bordered on the north by Montana, on the east by South Dakota and Nebraska, on the south by Colorado, on the southwest by Utah, and on the west by Idaho. It is the tenth largest state in the United States in total area, from the north border to the south border it is 276 miles, and from the east to the west border is 365 miles at its south end and 342 miles at the north end. The Great Plains meet the Rocky Mountains in Wyoming, the state is a great plateau broken by many mountain ranges. Surface elevations range from the summit of Gannett Peak in the Wind River Mountain Range, at 13,804 feet, to the Belle Fourche River valley in the states northeast corner, at 3,125 feet. In the northwest are the Absaroka, Owl Creek, Gros Ventre, Wind River, in the north central are the Big Horn Mountains, in the northeast, the Black Hills, and in the southern region the Laramie, Snowy and Sierra Madre ranges. The Snowy Range in the central part of the state is an extension of the Colorado Rockies in both geology and appearance. The Wind River Range in the west central part of the state is remote and includes more than 40 mountain peaks in excess of 13,000 ft tall in addition to Gannett Peak, the highest peak in the state. The Big Horn Mountains in the central portion are somewhat isolated from the bulk of the Rocky Mountains
Wyoming
–
Wind River Canyon
Wyoming
–
Flag
Wyoming
–
Thunder Basin National Grassland close to
Douglas, Wyoming
Wyoming
–
Seedskadee National Wildlife Refuge
22.
Yellowstone National Park
–
Yellowstone National Park is a national park located in the U. S. states of Wyoming, Montana and Idaho. It was established by the U. S. Congress and signed into law by President Ulysses S. Grant on March 1,1872. Yellowstone was the first National Park in the U. S. and is widely held to be the first national park in the world. The park is known for its wildlife and its many features, especially Old Faithful Geyser. It has many types of ecosystems, but the subalpine forest is the most abundant and it is part of the South Central Rockies forests ecoregion. Native Americans have lived in the Yellowstone region for at least 11,000 years, aside from visits by mountain men during the early-to-mid-19th century, organized exploration did not begin until the late 1860s. Management and control of the park fell under the jurisdiction of the Secretary of the Interior. However, the U. S. Army was subsequently commissioned to oversee management of Yellowstone for a 30-year period between 1886 and 1916, in 1917, administration of the park was transferred to the National Park Service, which had been created the previous year. Hundreds of structures have been built and are protected for their architectural and historical significance, Yellowstone National Park spans an area of 3,468.4 square miles, comprising lakes, canyons, rivers and mountain ranges. Yellowstone Lake is one of the largest high-elevation lakes in North America and is centered over the Yellowstone Caldera, the caldera is considered an active volcano. It has erupted with tremendous force several times in the last two million years, half of the worlds geothermal features are in Yellowstone, fueled by this ongoing volcanism. Lava flows and rocks from volcanic eruptions cover most of the area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining nearly-intact ecosystem in the Earths northern temperate zone, hundreds of species of mammals, birds, fish, and reptiles have been documented, including several that are either endangered or threatened. The vast forests and grasslands also include species of plants. Yellowstone Park is the largest and most famous location in the Continental United States. Grizzly bears, wolves, and free-ranging herds of bison and elk live in the park, the Yellowstone Park bison herd is the oldest and largest public bison herd in the United States. Forest fires occur in the each year, in the large forest fires of 1988. Yellowstone has numerous opportunities, including hiking, camping, boating, fishing and sightseeing
Yellowstone National Park
–
Grand Canyon of Yellowstone
Yellowstone National Park
Yellowstone National Park
–
Aerial view, 3D computer generated image
Yellowstone National Park
–
Detailed pictorial map from 1904
23.
Grand Teton National Park
–
Grand Teton National Park is a United States National Park in northwestern Wyoming. At approximately 310,000 acres, the park includes the peaks of the 40-mile-long Teton Range as well as most of the northern sections of the valley known as Jackson Hole. It is only 10 miles south of Yellowstone National Park, to which it is connected by the National Park Service-managed John D. Rockefeller, in the early 19th century, the first White explorers encountered the eastern Shoshone natives. Between 1810 and 1840, the region attracted fur trading companies that vied for control of the beaver pelt trade. U. S. Government expeditions to the commenced in the mid-19th century as an offshoot of exploration in Yellowstone. Efforts to preserve the region as a national park commenced in the late 19th century, against public opinion and with repeated Congressional efforts to repeal the measures, much of Jackson Hole was set aside for protection as Jackson Hole National Monument in 1943. The monument was abolished in 1950 and most of the monument land was added to Grand Teton National Park, Grand Teton National Park is named for Grand Teton, the tallest mountain in the Teton Range. The naming of the mountains is attributed to early 19th-century French-speaking trappers—les trois tétons was later anglicized and shortened to Tetons. At 13,775 feet, Grand Teton abruptly rises more than 7,000 feet above Jackson Hole, almost 850 feet higher than Mount Owen, the second-highest summit in the range. The park has numerous lakes, including 15-mile-long Jackson Lake as well as streams of varying length, though in a state of recession, a dozen small glaciers persist at the higher elevations near the highest peaks in the range. Some of the rocks in the park are the oldest found in any U. S. National Park and have been dated at nearly 2.7 billion years. Grand Teton National Park is an almost pristine ecosystem and the species of flora. More than 1,000 species of plants, dozens of species of mammals,300 species of birds, more than a dozen fish species. Grand Teton National Park is a destination for mountaineering, hiking, fishing. There are more than 1,000 drive-in campsites and over 200 miles of hiking trails provide access to backcountry camping areas. Noted for world-renowned trout fishing, the park is one of the few places to catch Snake River fine-spotted cutthroat trout, Grand Teton has several National Park Service-run visitor centers, and privately operated concessions for motels, lodges, gas stations and marinas. Paleo-Indian presence in what is now Grand Teton National Park dates back more than 11,000 years, along the shores of Jackson Lake, fire pits, tools and what are thought to have been fishing weights have been discovered. One of the tools found is of an associated with the Clovis culture
Grand Teton National Park
–
The John Moulton Barn and Teton Range
Grand Teton National Park
–
A
Shoshone encampment in Wyoming, photographed by W. H. Jackson, 1870
Grand Teton National Park
–
The enigmatic Colter Stone, with the inscription "John Colter", was found in a field in eastern Idaho in 1931.
Grand Teton National Park
–
"The Three Tetons" as seen from west of the Teton Range by members of the Hayden Geological Survey of 1872. One of the earliest photographs of the Teton Range taken by William Henry Jackson in 1872.
24.
Spring (hydrology)
–
A spring is any natural situation where water flows from an aquifer to the Earths surface. It is a component of the hydrosphere, a spring may be the result of karst topography where surface water has infiltrated the Earths surface, becoming part of the area groundwater. The groundwater then travels through a network of cracks and fissure—openings ranging from intergranular spaces to large caves, the water eventually emerges from below the surface, in the form of a karst spring. The forcing of the spring to the surface can be the result of an aquifer in which the recharge area of the spring water table rests at a higher elevation than that of the outlet. Spring water forced to the surface by elevated sources are artesian wells and this is possible even if the outlet is in the form of a 300-foot-deep cave. In this case the cave is used like a hose by the higher elevated area of groundwater to exit through the lower elevation opening. Non-artesian springs may simply flow from a higher elevation through the earth to a lower elevation, still other springs are the result of pressure from an underground source in the earth, in the form of volcanic activity. The result can be water at elevated temperature such as a hot spring, the action of the groundwater continually dissolves permeable bedrock such as limestone and dolomite, creating vast cave systems. The term seep refers to springs with small flow rates in which the water has filtered through permeable earth. Fracture springs, discharge from faults, joints, or fissures in the earth, tubular springs, in which the water flows from underground caverns. Spring discharge, or resurgence, is determined by the springs recharge basin, factors that affect the recharge include the size of the area in which groundwater is captured, the amount of precipitation, the size of capture points, and the size of the spring outlet. Water may leak into the system from many sources including permeable earth, sinkholes. In some cases entire creeks seemingly disappear as the water sinks into the ground via the stream bed, grand Gulf State Park in Missouri is an example of an entire creek vanishing into the groundwater system. The water emerges 9 miles away, forming some of the discharge of Mammoth Spring in Arkansas, human activity may also affect a springs discharge--withdrawal of groundwater reduces the water pressure in an aquifer, decreasing the volume of flow. Springs are often classified by the volume of the water they discharge, the largest springs are called first-magnitude, defined as springs that discharge water at a rate of at least 2800 liters or 100 cubic feet of water per second. The scale for spring flow is as follows, Minerals become dissolved in the water as it moves through the underground rocks and this may give the water flavor and even carbon dioxide bubbles, depending on the nature of the geology through which it passes. This is why spring water is bottled and sold as mineral water. Springs that contain significant amounts of minerals are sometimes called mineral springs, Springs that contain large amounts of dissolved sodium salts, mostly sodium carbonate, are called soda springs
Spring (hydrology)
–
On an average day nearly 303 million US gallons (1,150,000 m 3) of water flow from
Big Spring in
Missouri at a rate of 469 cubic feet per second (13.3 m 3 /s).
Spring (hydrology)
–
A natural spring on
Mackinac Island in
Michigan
Spring (hydrology)
–
Sunrise at Middle Spring,
Fish Springs National Wildlife Refuge, Utah
Spring (hydrology)
–
Fontaine de Vaucluse or Spring of Vaucluse in France discharges about 470 million US gallons (1,800,000 m 3) of water per day at a rate of 727 cubic feet (21 m 3) per second.
25.
Stream gauge
–
A stream gauge, streamgage or gauging station is a location used by hydrologists or environmental scientists to monitor and test terrestrial bodies of water. Hydrometric measurements of water surface elevation and/or volumetric discharge are generally taken and observations of biota. The location of gauging stations are found on topographical maps. Some gauging stations are automated and may include telemetry capability transmitted to a central data logging facility. Automated direct measurement of streamflow discharge is difficult at present, in place of the direct measurement of streamflow discharge, one or more surrogate measurements can be used to produce discharge values. In the majority of cases, a measurement is used as the surrogate. Low gradient streams are influenced by variable downstream channel conditions. For these streams, a stream gauge would be installed. This value would be used along with the measurement to more accurately determine the streamflow discharge. These sensors are mounted in the stream and measure velocity at a particular location in the stream. In those instances where only a stage measurement is used as the surrogate, a rating curve is the functional relation between stage and discharge. Once the rating curve is established, it can be used in conjunction with measurements to determine the volumetric streamflow discharge. This record then serves as an assessment of the volume of water passes by the stream gauge and is useful for many tasks associated with hydrology. In those instances where a velocity measurement is used as a surrogate. This analysis uses a velocity sensor, often either magnetic or acoustic, once again, discrete measurements of streamflow discharge are made by the technician or hydrologist at a variety of stages. For each discrete determination of streamflow discharge, the velocity of the cross section is determined by dividing streamflow discharge by the cross-sectional area. A rating curve, similar to that used for stage-discharge determinations, is constructed using the mean velocity, an additional rating curve is constructed that relates stage of the stream to cross-sectional area. The streamflow discharge is computed as the estimate of the cross section area, electromagnetic gauges Discharge measurements of a stream or canal without an established stream gage can be made using a current meter or Acoustic Doppler current profiler
Stream gauge
–
Brant Broughton Gauging Station on the
River Brant in Lincolnshire, England. The most recent hydrometric data for this station are available here: [2].
Stream gauge
–
Stream Gaging Station,
Carnation, Washington data available at [3].
Stream gauge
–
December 12, 2001 photo of the
USGS streamflow-gaging station at
Huey Creek,
McMurdo Dry Valleys,
Antarctica.
Stream gauge
–
Stream gauge B62, a
combination weir at Doddieburn, on the
Mzingwane River,
Zimbabwe
26.
Idaho Falls, Idaho
–
Idaho Falls is a city in and the county seat of Bonneville County, Idaho, United States, and is the largest city in Eastern Idaho. As of the 2010 census, the population of Idaho Falls was 56,813, as of 2013, the population was estimated at 58,292. Idaho Falls serves as a hub to all of eastern Idaho, due to its relative economic vitality, high quality of life, and proximity to world-class outdoor recreation, it is often featured in various publications lists of best places to live. What became Idaho Falls was the site of Taylor’s Crossing on the Montana Trail which was a frame bridge built across the Snake River. Mail service postmarks indicate that by 1866 the emerging town had become known as Eagle Rock. The name was derived from an isolated island in the Snake River,7 miles upstream at 43°36. 112′N 112°3. 528′W in the Snake River that was the nesting site for approximately twenty eagles. A private bank, a hotel, a livery stable, and an eating house also developed at the bridge in 1865 along with the post office. There had been a few cattle and sheep ranchers in the area for years, in 1874 water rights were established on nearby Willow Creek and the first grain harvested. Settlement was sparse and consisted of only a couple of families, the first child of European descent was born at Eagle Rock being delivered in 1874. The winds of change arrived in the form of the Utah and Northern Railway that came north from Utah through Eagle Rock and crossed the Snake River at the same narrow gorge as the wooden bridge. The U&NR was building its road to the new copper mines at Butte. The railroad company had 16 locomotives and 300 train cars working between Logan, Utah at the once quiet stage stop. A new iron bridge was fabricated in Athens, Pennsylvania at a cost of $30,000 and was shipped, by rail, to the site and erected in April. The bridge was 800 feet long and in two spans with an island in the center, as soon as the railroad came through settlers began homesteading the Upper Snake River Valley. The first of the new settlers carved out homesteads to the north at Egin, large scale settlement ensued and in a decade there appeared roads, bridges, dams as well as irrigation canals which brought most of the Upper Snake River Valley under cultivation. In 1891 the town voted to change its name to Idaho Falls, some years later, the construction of a retaining wall for a hydroelectric power plant enhanced the rapids into falls. The area grew sugar beets, potatoes, peas, grains, there have been more than 50 unique nuclear reactors built at the facility for testing. All but three are shut down now, the site was the scene of the only fatal nuclear reactor incident in U. S. history on the night of January 3,1961
Idaho Falls, Idaho
–
Taylor's Bridge, c.1870
Idaho Falls, Idaho
–
Idaho Falls
Idaho Falls, Idaho
–
Utah & Northern Bridge, c.1880, looking north, or upriver, with railroad shops in background.
Idaho Falls, Idaho
–
Idaho Falls on the Snake River with the
Idaho Falls Idaho Temple in the background
27.
Milner Dam
–
Milner Dam is a rockfill dam near Burley in south central Idaho. It impounds the Snake River in a reservoir named Milner Lake, the dam spans the river across two islands, with three embankments. Milner Dam was authorized for construction as a privately capitalized venture under the 1894 Carey Act, ira Burton Perrine, a local rancher, chose the site and recruited financial backers, including Salt Lake City banker Stanley B. Milner and eastern investors Frank H. Buhl and Peter L. Kimberly, the Buhl-Kimberly Corporation built the dam and the Twin Falls Canal in 1903-1905. Milner Dams primary purpose is irrigation but it also produces hydroelectricity and it is currently owned and operated by Milner Dam, Inc. The dam is 73 feet high and 2,160 feet long, the storage capacity of its reservoir, Milner Lake, is 36,300 acre feet. Inspections in 1988 indicated a risk of dam failure in an earthquake. The 1992 powerplant has 46 and 11.5 MW generators, water for the powerplant is drawn from the Twin Falls Canal during seasons when water is not needed for irrigation. Milner Dam was placed on the National Register of Historic Places on July 10,1986, gooding Milner canal List of dams in the Columbia River watershed Milner Dam at the Twin Falls Canal Company
Milner Dam
–
Milner Dam
28.
Idaho Power
–
Idaho Power Company is a regulated electrical power utility. Its business involves the purchase, sale, generation, transmission and distribution of electricity in eastern Oregon and it is a subsidiary of IDACORP, Inc. The companys 24, 000-square-mile service area generally follows the area around the Snake River, Idaho Power owns and operates 17 hydroelectric dams and 2 natural gas power plants. IPC also owns shares of three coal-fired power plants, in 2007, electricity sold by IPC was 33% hydroelectric, 39% thermal and 28% was purchased from other generation companies. Idaho Power Company originally filed for incorporation in Maine on May 6,1915 and it was reincorporated in Idaho as a subsidiary of IDACORP, Inc on October 1,1998. Four-fifths of Idaho’s electricity generation is from hydroelectric, Idaho Power built the majority of its hydroelectric facilities during the 1940s, 1950s and 1960s, culminating with completion of the three-dam Hells Canyon Complex in 1968. American Falls Dam power plant at river mile 714.7, milner Dam power plant at river mile 639.1. Twin Falls power plant at river mile 617.4, shoshone Falls power plant at river mile 614.7. Clear Lake power plant at river mile 593.0, thousand Springs power plant at river mile 584.7. Mid-Snakes Project in Central Idaho on the Snake River consisting of the Upper Salmon Falls power plant, the Lower Salmon Falls power plant, the Malads, Upper Malad and Lower Malad power plants at river mile 571.2. Cascade Dam power plant on the Payette River, C. J. Strike Dam power plant at river mile 494.0. Swan Falls Dam power plant at river mile 457.7, Hells Canyon Complex, Brownlee Dam power plant at river mile 285.0, Oxbow Dam power plant at river mile 272, and the Hells Canyon Dam power plant at river mile 251. List of companies based in Idaho http, //www. idahopower. com/
Idaho Power
–
Idaho Power Company
29.
Rainbow trout
–
The rainbow trout is a trout and species of salmonid native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead is a form of the coastal rainbow trout or Columbia River redband trout that usually returns to fresh water to spawn after living two to three years in the ocean. Freshwater forms that have been introduced into the Great Lakes and migrate into tributaries to spawn are also called steelhead, adult freshwater stream rainbow trout average between 1 and 5 lb, while lake-dwelling and anadromous forms may reach 20 lb. Coloration varies widely based on subspecies, forms and habitat, adult fish are distinguished by a broad reddish stripe along the lateral line, from gills to the tail, which is most vivid in breeding males. Wild-caught and hatchery-reared forms of species have been transplanted and introduced for food or sport in at least 45 countries. Introductions to locations outside their range in the United States, Southern Europe, Australia, New Zealand. Some local populations of subspecies, or in the case of steelhead. The steelhead is the state fish of Washington. The scientific name of the trout is Oncorhynchus mykiss. The species was named by German naturalist and taxonomist Johann Julius Walbaum in 1792 based on type specimens from the Kamchatka Peninsula in Siberia. Walbaums original species name, mykiss, was derived from the local Kamchatkan name used for the fish, the name of the genus is from the Greek onkos and rynchos, in reference to the hooked jaws of males in the mating season. In 1855, William P. Gibbons, the curator of Geology and Mineralogy at the California Academy of Sciences, found a population and named it Salmo iridia and these names faded once it was determined that Walbaums description of type specimens was conspecific and therefore had precedence. Thus, in 1989, taxonomic authorities moved the rainbow, cutthroat, Walbaums name had precedence, so the species name Oncorhynchus mykiss became the scientific name of the rainbow trout. The previous species names irideus and gairdneri were adopted as subspecies names for the rainbow and Columbia River redband trout. Anadromous forms of the rainbow trout or redband trout are commonly known as steelhead. Subspecies of Oncorhynchus mykiss are listed below as described by fisheries biologist Robert J. Behnke, resident freshwater rainbow trout adults average between 1 and 5 lb in riverine environments, while lake-dwelling and anadromous forms may reach 20 lb. Coloration varies widely between regions and subspecies, adult freshwater forms are generally blue-green or olive green with heavy black spotting over the length of the body. Adult fish have a reddish stripe along the lateral line, from gills to the tail
Rainbow trout
–
Rainbow trout
Rainbow trout
Rainbow trout
–
Ocean and fresh water forms of coastal rainbow trout; aka "steelhead" O. m. irideus
Rainbow trout
30.
Yellowstone hotspot
–
It formed the eastern Snake River Plain through a succession of caldera forming eruptions. The resulting calderas include the Island Park Caldera, the Henrys Fork Caldera, the hotspot currently lies under the Yellowstone Caldera. The hotspots most recent caldera forming supereruption, known as the Lava Creek eruption, took place 640,000 years ago and created the Lava Creek Tuff, and the most recent Yellowstone Caldera. The Yellowstone hotspot is one of a few volcanic hotspots underlying the North American tectonic plate, others include the Anahim, the eastern Snake River Plain is a topographic depression that cuts across Basin and Range Mountain structures, more or less parallel to North American plate motion. Beneath more recent basalts are rhyolite lavas and ignimbrites that erupted as the lithosphere passed over the hotspot, younger volcanoes that erupted after passing over the hotspot covered the plain with young basalt lava flows in places, including Craters of the Moon National Monument. The central Snake River plain is similar to the eastern plain, three silicic calderas have been newly identified in northwest Nevada, west of the McDermitt volcanic field as well as the Virgin Valley Caldera. The northwest Nevada calderas have diameters ranging from 15–26 km and deposited high temperature rhyolite ignimbrites over approximately 5000 km2, the Bruneau-Jarbidge caldera erupted between ten and twelve million years ago, spreading a thick blanket of ash in the Bruneau-Jarbidge event and forming a wide caldera. There, two hundred fossilized rhinoceros and many animals were preserved in two meters of volcanic ash. The event responsible for fall of volcanic ash was identified as Bruneau-Jarbidge. Prevailing westerlies deposited distal ashfall over a vast area of the Great Plains, Twin Falls volcanic field and Picabo volcanic field were active about 10 million years ago. The Picabo Caldera was notable for producing the Arbon Valley Tuff 10.2 million years ago, the first three caldera-forming rhyolites — Blacktail Tuff, Walcott Tuff and Conant Creek Tuff — totaled at least 2250 km3 of erupted magma. The final, extremely voluminous, caldera-forming eruption — the Kilgore Tuff — which erupted 1800 km3 of ash, the Yellowstone Plateau volcanic field is composed of four adjacent calderas. West Thumb Lake is itself formed by a caldera which erupted 174,000 years ago. The Henrys Fork Caldera in Idaho was formed in an eruption of more than 280 km31.3 million years ago, the Henrys Fork Caldera is nested inside of the Island Park Caldera and the calderas share a rim on the western side. The earlier Island Park Caldera is much larger and more oval, of the many calderas formed by the Yellowstone Hotspot, including the later Yellowstone Caldera, the Henrys Fork Caldera is the only one that is currently clearly visible. The Henrys Fork of the Snake River flows through the Henrys Fork Caldera and drops out at Upper and Lower Mesa Falls. The caldera is bounded by the Ashton Hill on the south, Big Bend Ridge and Bishop Mountain on the west, by Thurburn Ridge on the North and by Black Mountain, the Henrys Fork caldera is in an area called Island Park. Harriman State Park is situated in the caldera, the Island Park Caldera is older and much larger than the Henrys Fork Caldera with approximate dimensions of 58 miles by 40 miles
Yellowstone hotspot
–
Past locations of the hotspot in
millions of years
Yellowstone hotspot
–
Schematic of the hotspot and the Yellowstone Caldera
Yellowstone hotspot
–
Yellowstone sits on top of four overlapping calderas.
Yellowstone hotspot
–
Map of recent Yellowstone eruption fields, in comparison with a recent
Long Valley Caldera eruption and
Mount St. Helens.
31.
Rhyolite
–
Rhyolite is an igneous, volcanic rock, of felsic composition. It may have any texture from glassy to aphanitic to porphyritic, the mineral assemblage is usually quartz, sanidine and plagioclase. Biotite and hornblende are common accessory minerals and it is the extrusive equivalent to granite. Rhyolite can be considered as the equivalent to the plutonic granite rock. Due to their content of silica and low iron and magnesium contents, rhyolite melts are highly polymerized. They also occur as breccias or in volcanic plugs and dikes, rhyolites that cool too quickly to grow crystals form a natural glass or vitrophyre, also called obsidian. Slower cooling forms microscopic crystals in the lava and results in such as flow foliations, spherulitic, nodular. Some rhyolite is highly vesicular pumice, many eruptions of rhyolite are highly explosive and the deposits may consist of fallout tephra/tuff or of ignimbrites. Eruptions of rhyolite are relatively rare compared to eruptions of less felsic lavas, etsch Valley Vulcanite Group near Bolzano and the surrounding area Gréixer rhyolitic complex at Moixeró range Vosges Iceland, all active and extinct central volcanoes, e. g. g. Wichita Mountains within the Southern Oklahoma Aulacogen St, in North American pre-historic times, rhyolite was quarried extensively in eastern Pennsylvania in the United States. Among the leading quarries was the Carbaugh Run Rhyolite Quarry Site in Adams County, comendite List of rock types Pantellerite Thunderegg University of North Dakota description of rhyolite Information from rocks-rock. com
Rhyolite
–
Rhyolite
Rhyolite
–
Top:
obsidian (vitrophyre), below:
pumice, lower right: is rhyolite (light colour)
Rhyolite
–
Old rhyolite quarry in the
Hohburg Hills
Rhyolite
–
Rhyolite quarry,
Löbejün, Saxony-Anhalt
32.
Basalt
–
Basalt is a common extrusive igneous rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Flood basalt describes the formation in a series of basalt flows. By definition, basalt is an igneous rock with generally 45-55% silica and less than 10% feldspathoid by volume. Basalt commonly features a very fine-grained or glassy matrix interspersed with visible mineral grains, the average density is 3.0 gm/cm3. Basalt is defined by its content and texture, and physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its mafic minerals into hematite, although usually characterized as dark, basaltic rocks exhibit a wide range of shading due to regional geochemical processes. Due to weathering or high concentrations of plagioclase, some basalts can be quite light-coloured and these phenocrysts usually are of olivine or a calcium-rich plagioclase, which have the highest melting temperatures of the typical minerals that can crystallize from the melt. Basalt with a texture is called vesicular basalt, when the bulk of the rock is mostly solid. Gabbro is often marketed commercially as black granite and these ultramafic volcanic rocks, with silica contents below 45% are usually classified as komatiites. Agricola applied basalt to the black rock of the Schloßberg at Stolpen. Tholeiitic basalt is relatively rich in silica and poor in sodium, included in this category are most basalts of the ocean floor, most large oceanic islands, and continental flood basalts such as the Columbia River Plateau. Basalt rocks are in some cases classified after their content in High-Ti and Low-Ti varieties. High-Ti and Low-Ti basalts have been distinguished in the Paraná and Etendeka traps and it has greater than 17% alumina and is intermediate in composition between tholeiite and alkali basalt, the relatively alumina-rich composition is based on rocks without phenocrysts of plagioclase. Alkali basalt is relatively poor in silica and rich in sodium and it is silica-undersaturated and may contain feldspathoids, alkali feldspar and phlogopite. Boninite is a form of basalt that is erupted generally in back-arc basins. Ocean island basalt Lunar basalt On Earth, most basalt magmas have formed by melting of the mantle. Basalt commonly erupts on Io, the third largest moon of Jupiter, and has formed on the Moon, Mars, Venus. The crustal portions of oceanic tectonic plates are composed predominantly of basalt, produced from upwelling mantle below, the mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene
Basalt
–
Basalt
Basalt
–
Columnar basalt flows in
Yellowstone National Park, USA.
Basalt
–
Columnar basalt at Szent György Hill, Hungary
Basalt
–
Vesicular basalt at
Sunset Crater, Arizona. US quarter for scale.
33.
Snake River Plain
–
The Snake River Plain is a geologic feature located primarily within the U. S. state of Idaho. It stretches about 400 miles westward from northwest of the state of Wyoming to the Idaho-Oregon border, the plain is a wide, flat bow-shaped depression and covers about a quarter of Idaho. Three major volcanic buttes dot the plain east of Arco, the largest being Big Southern Butte, most of Idahos major cities are in the Snake River Plain, as is much of its agricultural land. The Snake River Plain can be divided into three sections, western, central, and eastern, the western plain began to form around 11–12 Ma with the eruption of rhyolite lavas and ignimbrites. The western plain is not parallel to North American Plate motion and lies at an angle to the central. Its morphology is similar to other volcanic plateaus such as the Chilcotin Group in south-central British Columbia, the eastern Snake River Plain traces the path of the North American Plate over the Yellowstone hotspot, now centered in Yellowstone National Park. The eastern plain is a depression that cuts across Basin and Range mountain structures. It is underlain almost entirely by basalt erupted from large shield volcanoes, beneath the basalts are rhyolite lavas and ignimbrites that erupted as the lithosphere passed over the hotspot. The central Snake River plain is similar to the plain but differs by having thick sections of interbedded lacustrine and fluvial sediments. Island Park and Yellowstone Calderas formed as the result of enormous rhyolite ignimbrite eruptions, henrys Fork Caldera, measuring 18 miles by 23 miles, may be the largest symmetrical caldera in the world. The caldera formed when a dome of magma built up and then drained away, the center of the dome collapsed, leaving a caldera. Henrys Fork Caldera lies within the older and larger Island Park Caldera, younger volcanoes that erupted after passing over the hotspot covered the plain with young basalt lava flows in places, including Craters of the Moon National Monument. The Snake River Plain has a significant effect on the climate of Yellowstone National Park, over time, the Yellowstone hotspot left a 70-mile wide channel through the Rocky Mountains. This channel is in line with the gap between the Cascade Range and the Sierra Nevada, the result is a moisture channel extending from the Pacific Ocean to Yellowstone. Moisture from the Pacific Ocean streams onshore in the form of clouds, the result is a localized climate on the eastern side of the Rockies that is akin to a climate on the west slope of the Cascades or the northern Sierras. Lost streams of Idaho Snake River Snake River Plain Wilson Butte Cave The Snake River Plain Snake River Plain at Digital Atlas of Idaho
Snake River Plain
–
The
Snake River cutting through the Plain leaves many
canyons and
gorges, such as this one near
Twin Falls, Idaho
Snake River Plain
–
Snake River Plain across southern Idaho
Snake River Plain
–
The eastern Snake River Plain, image from NASA's
Aqua satellite, 2008
Snake River Plain
–
Location of Yellowstone Hotspot in Millions of Years Ago
34.
Knickpoint
–
In geomorphology, a knickpoint or nickpoint is part of a river or channel where there is a sharp change in channel slope, such as a waterfall or lake. Knickpoints reflect different conditions and processes on the river, often caused by erosion due to glaciation or variance in lithology. In the cycle of erosion model, knickpoints advance one cycle upstream, or inland, knickpoints are formed by the influence of tectonics, climate history, and/or lithology. For example, uplift along a fault over which a river is flowing will often result in a steep reach along a channel. Glaciation resulting in a valley are often prime spots for knickpoints. If lithology of the varies, such as shale amongst igneous rock, erosion will occur more steadily in the softer rock than the surrounding. Base level is the elevation of the surface of the body into which a river ultimately drains. A drop in base level causes a response by the system to carve into the landscape. This incision begins at the formation of a knickpoint, and its upstream migration depends heavily upon the area, material through which it cuts. Knickpoints include both waterfalls and some lakes and these features are common in rivers with a sufficient slope, i. e. enough change in elevation above sea level over their length to encourage degradation. Variations in stability of the rock influence development of a bedrock-channeled river. Victoria Falls, on the Zambezi River, is an example of this. The gorges visible by satellite imagery illustrate the erosional processes behind the formation of the falls, here, much of the surface rock is a massive basalt sill, with large cracks filled with easily weathered sandstone made visible by the Zambezis course across the land. The gorges downstream of the falls through which it flows were eroded over time by the action of the water, throughout New Zealand, tectonic uplift and faulting are actively contributing to knickpoint initiation and recession. The Waipoua River system, on the North island, has studied and used to create mathematical models to predict the behavior of knickpoints. The study showed a correlation between upstream drainage area and rate of migration, producing modeled data closely approximating the collected data. The Waipoua River system incises through sediments, for the most part, sharp changes in slope are common in rivers flowing through the heavily carved landscape left behind when glaciers retreat. Glacial valleys, as well as isostatic rebound resulting from the removal of the mass of glacial ice contribute to this, niagara Falls, on the border of the United States and Canada, is a characteristic example of knickpoint
Knickpoint
–
The
Horseshoe Falls, one of the three Niagara Falls. The falls are a knickpoint, formed by slower erosion above the falls than below.
35.
Bonneville Flood
–
Unlike the Missoula Floods, which also occurred during the same period in the Pacific Northwest, the Bonneville flood only happened once. The flood is believed to be the second largest in known geologic history, about 14,500 years ago, pluvial Lake Bonneville in northern Utah reached its highest water level since its formation. The lake occupied the basin of the Great Salt Lake, except it was far larger. Ancient Red Rock Pass was the site of two alluvial fans descending from opposite sides of the notch, forming a natural dam, when the dam collapsed, it released a 410-foot -high flood crest down the Portneuf River valley, also spilling into the neighboring Bear River valley. The flood scoured the 600-foot -deep Snake River Canyon through the basalt and loess soil, creating Shoshone Falls. It also carved and increased in many other tributary canyons, including those of the Bruneau River. The flood then entered Hells Canyon, significantly widening the gorge and its waters eventually reached the Pacific Ocean via the Columbia River. Although the peak of the flood lasted a few weeks at most, the flood drained the top 351 feet of Lake Bonneville, which constituted about 1,200 cubic miles of water, and lowered the lake level to a stage known as the Provo shoreline. The flood transformed the Snake River Plain into a series of channeled scablands resembling the Columbia Plateau, also left by the flood were the many melon boulders distributed throughout the canyons in the Snake River Plain. Much of the sediment scoured by the flood was deposited near the mouth of the Snake River, on top of about 20 layers of Missoula Floods deposits
Bonneville Flood
–
Red Rock Pass, Idaho.
36.
Pluvial lake
–
A pluvial lake is a landlocked basin which fills with rainwater during times of glaciation, when precipitation is higher. Pluvial lakes that have since evaporated and dried out may also be referred to as paleolakes, the word pluvial comes from the Latin pluvia, which means rain. Pluvial lakes represent changes in the hydrological cycle — wet cycles generate large lakes, accumulated sediments show the variation in water level. During glacial periods, times when the level is fairly high, mud sediments will settle out. At times in between glaciers, salt deposits may be present due to the climate and evaporation of lake water. Several pluvial lakes formed in what is now the southwestern United States during the glaciation of the late Pleistocene epoch, one of these was Lake Bonneville in western Utah which covered roughly 19,000 square miles. When Lake Bonneville was at its water level, it was 1,000 feet higher than the Great Salt Lake. Fresh water mollusks have been found in mud deposits from Searles Lake in California, radiocarbon dating of the youngest mud beds yield dates from 24,000 to 12,000 years ago. When warm air from arid regions meets chilled air from glaciers, it creates cloudy, cool and this type of humid climate was present during the last glacial period in North America, and causes more precipitation than evaporation. The increase in rainfall fills the basin and forms a lake. During interglacial periods, the climate becomes arid once more and causes these lakes to evaporate, Lake Bonneville Lake Eyre, Australia Lake Lahontan Lake Manix Great Salt Lake Lake Manly Proglacial lake
Pluvial lake
–
Pluvial
Lake Manix sediments (
Pleistocene) in the
Mojave Desert near
Barstow, California.
Pluvial lake
–
Pleistocene pluvial lakes and rivers of the Mojave Desert
37.
Lake Bonneville
–
Lake Bonneville was a prehistoric pluvial lake that covered much of the eastern part of North Americas Great Basin region. Most of the territory it covered was in present-day Utah, though parts of the lake extended into present-day Idaho and Nevada. Formed about 32,000 years ago, Lake Bonneville existed until about 14,500 years ago, following the Bonneville Flood, as the release is now known, the lake receded to a level called the Provo Level. Many of the geological characteristics of the Great Basin are due to the effects of the lake. At more than 1,000 ft deep and more than 19,691 square miles in area, with the change in climate, the lake began drying up, leaving Great Salt Lake, Utah Lake, Sevier Lake, Rush Lake, and Little Salt Lake as remnants. Bonneville was noted for his expeditions to the Oregon Country and the Great Basin, the lake was probably not a singular entity either, geologic evidence suggests that it may have evaporated and reformed as many as 28 times in the last 800,000 years. Great Salt Lake, Utah Lake, and Sevier Lake are the largest remnants of the original Lake Bonneville, several levels of the old shorelines are still visible above Salt Lake City, along the Wasatch Front and elsewhere. The appearance of the shorelines is that of a shelf or bench protruding from the mountainside, four main shorelines are associated with the fluctuating levels of the ancient lake. The Stansbury, Bonneville, Provo and Gilbert shorelines each mark a time when lake level remained constant long enough to deposit massive accumulations of sand, the Bonneville Bench, at about 5,102 feet above sea level, is part of the preserved ice age shoreline. This shoreline marks the highest level attained by the Pleistocene lake approximately 15,500 years ago, during this period, the lake covered over 20,000 sq mi and was over 980 ft deep in places. About 14,500 years ago, the level fell catastrophically as Lake Bonneville overflowed near Red Rock Pass, Idaho. The lake level fell some 344 ft to what is now the lower bench in a flood that geologists estimate to have lasted up to a year. It is estimated that this breach released 1,000 cubic miles of water in the first few weeks, during this period, the Red Rock Pass contained a river carrying water overflowing out of Lake Bonneville into the Snake River. A slight transgression or rise in lake level occurred about 10,900 to 10,300 years ago, in addition to geological traces, the lake has left a legacy of related fish distributed in now-isolated bodies of water
Lake Bonneville
–
Wave-cut platforms from Lake Bonneville preserved on Antelope Island, Great Salt Lake, Utah.
Lake Bonneville
–
Lake Bonneville and other ice age
pluvial lakes (17,500 years before the present), and modern remnants
38.
Great Basin
–
The Great Basin is the largest area of contiguous endorheic watersheds in North America. The region spans several physiographic divisions, biomes/ecoregions, and deserts, the term Great Basin is applied to hydrographic, biological, floristic, physiographic, topographic, and ethnographic geographic areas. The name was coined by John C. Frémont, who, based on information gleaned from Joseph R. Walker as well as his own travels, the hydrographic definition is the most commonly used, and is the only one with a definitive border. The other definitions yield not only different geographical boundaries of Great Basin regions, the Great Basin physiographic section is a geographic division of the Basin and Range Province defined by Nevin Fenneman in 1931. The United States Geological Survey adapted Fennemans scheme in their Physiographic division of the United States, the section is somewhat larger than the hydrographic definition. The culture area covers approximately 400,000 sq mi, or just less than twice the area of the hydrographic Great Basin, the hydrographic Great Basin is a 209,162 square miles area that drains internally. All precipitation in the region evaporates, sinks underground or flows into lakes, as observed by Frémont, creeks, streams, or rivers find no outlet to either the Gulf of Mexico or the Pacific Ocean. The region is bounded by the Wasatch Mountains to the east, the Sierra Nevada and Cascade Ranges to the west, the south rim is less distinct. The Great Basin includes most of Nevada, half of Utah, substantial portions of Oregon and California and small areas of Idaho, Wyoming, the term Great Basin is slightly misleading, the region is actually made up of many small basins. The Great Salt Lake, Pyramid Lake, and the Humboldt Sink are a few of the drains in the Great Basin, the Salton Sink is another closed basin within the Great Basin. The Great Basin Divide separates the Great Basin from the watersheds draining to the Pacific Ocean, the southernmost portion of the Great Basin is the watershed area of the Laguna Salada. The Great Basins longest and largest river is the Bear River of 350 mi, Lake Tahoe, North Americas largest alpine lake, is part of the Great Basins central Lahontan subregion. The hydrographic Great Basin contains multiple deserts and ecoregions, each with its own set of flora. The ecological boundaries and divisions in the Great Basin are unclear, the Great Basin overlaps four different deserts, portions of the hot Mojave and Colorado Deserts to the south, and the cold Great Basin and Oregon High Deserts in the north. The deserts can be distinguished by their plants, the Joshua tree and creosote bush occur in the hot deserts, the cold deserts are generally higher than the hot, and have their precipitation spread throughout the year. The climate and flora of the Great Basin is strongly dependent on elevation, as the elevation increases, because of this, forests occur at higher elevations. Utah juniper/single-leaf pinyon and mountain mahogany form open pinyon-juniper woodland on the slopes of most ranges, stands of limber pine and Great Basin bristlecone pine can be found in some of the higher ranges
Great Basin
–
The hydrographic Great Basin (magenta outline), distinguished from the
Great Basin Desert (black), and the
Basin and Range Geological Province (teal).
Great Basin
–
Relief Map with Great Basin Overlay
Great Basin
–
The
Tule Valley watershed and the
House Range (
Notch Peak) are part of the Great Basin's Great Salt Lake
hydrologic unit
Great Basin
–
Ecoregions as currently delineated by the Environmental Protection Agency and World Wildlife Fund
39.
Red Rock Pass
–
Red Rock Pass is a low mountain pass in eastern Idaho, south of Downey in southern Bannock County. It is geologically significant as the spillway of ancient Lake Bonneville and it is located along highway US-91 at an elevation of 4785 feet above sea level, bounded by two mountain ranges, the Portneuf to the east and the Bannock to the west. The pass was cut through resistant Paleozoic shale, limestone, and dolomite, at one time the pass was 300 feet higher, where the shoreline of Pleistocene Lake Bonneville stood. Red Rock Pass has a deposit of calcareous silty alluvium with topsoil of dark grayish brown silt loam. It is believed that during the last ice age lava flows in the vicinity of Pocatello began to divert the Bear River through Lake Thatcher and this sudden influx caused Bonneville to overflow at Red Rock about 14,500 years ago. This overflow caused an erosion of unconsolidated material on the northern shoreline near Red Rock Pass. As the material gave way, Marsh Creek Valley, immediately downstream, was flooded from wall to wall, the flood then flowed into the Snake River Plain, generally following the path of the present-day Snake River to its outlet in the Pacific Northwest. The Bonneville Flood, as it is known, was a catastrophic event, the maximum discharge was about 15 million cubic feet per second, or about three times the average flow of the Amazon River, the worlds largest river. The speed of flow was approximately 16 mph, and though peak flow lasted only a few days, huge Floods. com – Bonneville Idaho State Univ. – Digital Geology of Idaho – Lake Bonneville
Red Rock Pass
–
Red Rock Pass
.JPG)
.jpg)
