1.
Gulf of Alaska
–
The entire shoreline of the Gulf is a rugged combination of forest, mountain, and a number of tidewater glaciers. Alaskas largest glaciers, the Malaspina Glacier and Bering Glacier, spill out onto the line along the Gulf of Alaska. The coast is indented, with Cook Inlet and Prince William Sound the two largest connected bodies of water. It includes Yakutat Bay and Cross Sound, lituya Bay is the site of the largest recorded tsunami in history. It is customarily a popular sheltered anchorage for fishing boats, the Gulf of Alaska is considered a Class I, highly productive ecosystem based on SeaWiFS data. Many deep water corals can be found in the Gulf of Alaska, primnoa pacifica has contributed to the location being labeled as Habitat Areas of Particular Concern. P. pacifica is typically a deep water coral normally found between 150 metres and 900 metres here, the Gulf is a great generator of storms. Much of the rainfall and snowfall in the Pacific Northwest. The International Hydrographic Organization defines the limits of the Gulf of Alaska as follows, a line drawn from Cape Spencer, the Northern limit of to Kabuch Point, the Southeast limit of, in such a way that all the adjacent islands are included in the Gulf of Alaska
Gulf of Alaska
–
Map showing the Gulf of Alaska.
2.
Anchorage, Alaska
–
Anchorage is a unified home rule municipality in the U. S. state of Alaska. All together, the Anchorage metropolitan area, which combines Anchorage with the neighboring Matanuska-Susitna Borough, had a population of 401,635 in 2016. Anchorage is located in the portion of Alaska at the terminus of the Cook Inlet on a peninsula formed by the Knik Arm to the north. The city limits span 1,961.1 square miles encompass the urban core. Due to its location on the globe, being almost equidistant from New York City, Tokyo, Anchorage has been named an All-America City four times, in 1956,1965, 1984–85, and 2002, by the National Civic League. It has also named by Kiplinger as the most tax-friendly city in the United States. Russian presence in south central Alaska was well established in the 19th century, in 1867, U. S. Secretary of State William H. Seward brokered a deal to purchase Alaska from Imperial Russia for $7.2 million. His political rivals lampooned the deal as Sewards folly, Sewards icebox, by 1888, gold was discovered along Turnagain Arm. Alaska became a United States territory in 1912, Anchorage, unlike every other large town in Alaska south of the Brooks Range, was neither a fishing nor mining camp. The area surrounding Anchorage lacks significant economic metal minerals, a number of Denaina settlements existed along Knik Arm for years. By 1911 the families of J. D. Bud Whitney, jack Brown, and his bride, Nellie, in 1912 to have lived in the Ship Creek valley in the 1910s prior to the large influx of settlers. The city grew from its choice as the site, in 1914, under the direction of Frederick Mears. The area near the mouth of Ship Creek, where the headquarters was located. A town site was mapped out on higher ground to the south of the tent city, greatly noted in the years since for its order and rigidity compared with other Alaska town sites. In 1915, territorial governor John Franklin Alexander Strong encouraged residents to change the name to one that had more significance. In the summer of year, residents held a vote to change the citys name. However, the government ultimately declined to change the citys name. Anchorage was incorporated on November 23,1920, construction of the Alaska Railroad continued until its completion in 1923
Anchorage, Alaska
–
Anchorage skyline and
Bootleggers Cove as photographed from
Point Woronzof Park on an April evening.
Anchorage, Alaska
–
The tent city (called "The White City" in the handwritten caption) in Ship Creek, photographed by Alberta Pyatt on July 1, 1915.
Anchorage, Alaska
–
Panorama of Anchorage, May 1, 1916
Anchorage, Alaska
–
Fourth Avenue in 1953, looking east from near I Street. Just ten years before, the retail area shown in the foreground was mostly an industrial area, housing lumber yards and similar uses.
3.
Alaska
–
Alaska is a U. S. state located in the northwest extremity of North America. To the north are the Chukchi and Beaufort seas–the southern parts of the Arctic Ocean, the Pacific Ocean lies to the south and southwest. Alaska is the largest state in the United States by area, the 3rd least populous, approximately half of Alaskas residents live within the Anchorage metropolitan area. Alaskas economy is dominated by the fishing, natural gas, military bases and tourism are also a significant part of the economy. The United States purchased Alaska from the Russian Empire on March 30,1867, the area went through several administrative changes before becoming organized as a territory on May 11,1912. It was admitted as the 49th state of the U. S. on January 3,1959, the name Alaska was introduced in the Russian colonial period when it was used to refer to the peninsula. It was derived from an Aleut, or Unangam idiom, which refers to the mainland of Alaska. Literally, it means object to which the action of the sea is directed, Alaska is the northernmost and westernmost state in the United States and has the most easterly longitude in the United States because the Aleutian Islands extend into the Eastern Hemisphere. Alaska is the only non-contiguous U. S. state on continental North America and it is technically part of the continental U. S. but is sometimes not included in colloquial use, Alaska is not part of the contiguous U. S. often called the Lower 48. The capital city, Juneau, is situated on the mainland of the North American continent but is not connected by road to the rest of the North American highway system. Alaskas territorial waters touch Russias territorial waters in the Bering Strait, as the Russian Big Diomede Island, Alaska has a longer coastline than all the other U. S. states combined. Alaska is the largest state in the United States by total area at 663,268 square miles, over twice the size of Texas, Alaska is larger than all but 18 sovereign countries. Counting territorial waters, Alaska is larger than the area of the next three largest states, Texas, California, and Montana. It is also larger than the area of the 22 smallest U. S. states. Also referred to as the Panhandle or Inside Passage, this is the region of Alaska closest to the rest of the United States, as such, this was where most of the initial non-indigenous settlement occurred in the years following the Alaska Purchase. The region is dominated by the Alexander Archipelago as well as the Tongass National Forest and it contains the state capital Juneau, the former capital Sitka, and Ketchikan, at one time Alaskas largest city. The Alaska Marine Highway provides a vital transportation link throughout the area. The Interior is the largest region of Alaska, much of it is uninhabited wilderness, Fairbanks is the only large city in the region
Alaska
–
Denali is the highest peak in North America.
Alaska
–
Flag
Alaska
–
Grizzly bear fishing for
salmon at
Brooks Falls, part of
Katmai National Park and Preserve.
Alaska
–
Augustine Volcano erupting on January 12, 2006
4.
Knik Arm
–
Knik Arm is a waterway into the northwestern part of the Gulf of Alaska. It is one of two branches of Cook Inlet, the other being Turnagain Arm. Knik Glacier empties into the Knik Arm, the Port of Anchorage is located on the Arm. Knik is the Eskimo–Aleut language word for fire and it has been written Kinik, Kneep, Kneik, Kook, Knuyk, and Kweek. Knik Arm begins at the Inlets northern edge, near Anchorage, before heading north and it is about 15 miles long, and at its upper end, receives the waters of the Matanuska River. West of Knik Arm is the delta of the Susitna River, at the head of Knik Arm, at the mouth of Knik River, was the village of Knik. Knik Arm receives two or three small streams from the east, of which Yukla Creek,35 miles long, is one of the largest. Its western tributaries are not notable, the part of the plain. The upper part of Knik Arm merges into the delta of the Knik and Matanuska rivers, knakatnuk and Nitak were historic native villages on the arms shore. The 1964 Alaska earthquake destroyed or significantly damaged most of the Anchorage neighborhoods adjacent to the Arm, the proposed Knik Arm Bridge would measure approximately 2 miles from Point MacKenzie on the west in the Matanuska-Susitna Borough to Anchorage on the east. The Knik Arm ferry was a proposed year-round passenger and auto ferry across the arm which was to use the M/V Susitna SWATH / barge convertible expedition craft
Knik Arm
–
Mount Susitna (background); Susitna River Delta (middle distance); Knik Arm (foreground)
Knik Arm
–
Port of Anchorage on Knik Arm
Knik Arm
–
Cook Inlet with Knik and Turnagain arms
Knik Arm
–
Mudflats on Knik Arm
5.
Turnagain Arm
–
Turnagain Arm is a waterway into the northwestern part of the Gulf of Alaska. It is one of two branches at the north end of Cook Inlet, the other being Knik Arm. Turnagain is subject to extremes and large tide ranges. Turnagain extends in an east-west direction, and is between 40–45 miles long and it forms part of the northern boundary of Kenai Peninsula, and reaches on the east to within 12 miles of Portage Bay, a western branch of Prince William Sound. Turnagain is characterized by remarkably large tides of up to 40 feet which are the largest tides in the United States. The flood tide often begins with a tidal bore especially on large tides with a strong east wind, which has a height of 6 feet at times, at low tide, the arm becomes a broad mud flat, cut by the stream channels. Historically small steamers entered and left on high water though the practice is rare at best since most if not all the places that they went are now connected by road, the region adjacent to Turnagain Arm is very rugged. South Suicide Peak is the tallest mountain rising from the side of Turnagain. Mountains rise precipitously on both sides of the arm and reach altitudes of 5, 000–6,000 feet and their tops are ragged and bare. The timber rarely reaches higher than 1, 500–2,000 feet feet, the smaller valleys are narrow and steep, but the larger ones frequently show by their U-shaped cross section the former presence of glaciers. Glaciers may be seen at a number of places. Chief among them are Portage Glacier, occupying the pass between the head of Turnagain Arm and Portage Bay, and the two neighboring glaciers on Glacier River and Twentymile Creek, besides these there are several smaller ones on tributaries of Glacier Creek. The Seward Highway follows a portion of the edge of the Chugach State Park along Turnagain Arm. Turnagain Arm boasts the second highest tides in North America after the Bay of Fundy and these tides, which can reach 40 feet, come in so quickly that they produce a wave known as a bore tide. Adventurous kayakers and surfers have taken to riding the tide as an extreme sport, hikers should take care not to get stuck in the quicksand-like mudflats that otherwise make up the beaches along Turnagain Arm. Turnagain Arm communities within the Municipality of Anchorage include Indian, Bird, Portage, at the eastern tip or head of the Arm, is a former settlement destroyed in the 1964 Alaska earthquake. Tributaries of Turnagain include Resurrection Creek, Bear Creek, Sixmile Creek, Resurrection Creek flows in a direction slightly east of north. The town of Hope is located near its mouth, Palmer Creek is its largest tributary
Turnagain Arm
–
Turnagain Arm from
Anchorage.
Turnagain Arm
–
Cook Inlet with Knik and Turnagain arms.
Turnagain Arm
–
South Suicide Peak.
Turnagain Arm
–
Turnagain Arm mudflats.
6.
Shelikof Strait
–
Shelikof Strait is a strait on the southwestern coast of the U. S. state of Alaska between the Alaska mainland to the west and Kodiak and Afognak islands to the east. Shelikof Strait separates the coastal strip of the Kodiak Island Borough from its Kodiak Island portion and is about 150 statute miles long and 25 to 30 statute miles wide. Cook Inlet is at its northern end, the strait is well known for its extreme tidal flow due to its close proximity to Cook Inlet, which can have maximum tidal variances of up to 40 feet. The strait is named after Grigory Shelikhov, also spelled Shelikof, the United States Navy seaplane tender USS Shelikof, in commission from 1944 to 1947 and from 1952 to 1954, was named for Shelikof Strait. This article incorporates text from the public domain Dictionary of American Naval Fighting Ships, the entry can be found here. Merriam Websters Geographical Dictionary, Third Edition
Shelikof Strait
–
Notes [edit]
7.
Drainage basin
–
A drainage basin or catchment area is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. Drainage basins connect into other drainage basins at elevations in a hierarchical pattern, with smaller sub-drainage basins. Other terms used to describe drainage basins are catchment, catchment basin, drainage area, river basin and water basin. In closed drainage basins the water converges to a point inside the basin, known as a sink, which may be a permanent lake. The drainage basin acts as a funnel by collecting all the water within the covered by the basin. Each drainage basin is separated topographically from adjacent basins by a perimeter, drainage basins are similar but not identical to hydrologic units, which are drainage areas delineated so as to nest into a multi-level hierarchical drainage system. Hydrologic units are defined to allow multiple inlets, outlets, or sinks, in a strict sense, all drainage basins are hydrologic units but not all hydrologic units are drainage basins. Drainage basins of the oceans and seas of the world. Grey areas are endorheic basins that do not drain to the oceans, the following is a list of the major ocean basins, About 48. 7% of the worlds land drains to the Atlantic Ocean. The two major mediterranean seas of the world also flow to the Atlantic, The Caribbean Sea and Gulf of Mexico basin includes most of the U. S. The Mediterranean Sea basin includes much of North Africa, east-central Africa, Southern, Central, and Eastern Europe, Turkey, and the areas of Israel, Lebanon. Just over 13% of the land in the world drains to the Pacific Ocean, the Indian Oceans drainage basin also comprises about 13% of Earths land. It drains the eastern coast of Africa, the coasts of the Red Sea and the Persian Gulf, the Indian subcontinent, Burma, antarctica comprises approximately eight percent of the Earths land. The five largest river basins, from largest to smallest, are the basins of the Amazon, the Río de la Plata, the Congo, the Nile, and the Mississippi. The three rivers that drain the most water, from most to least, are the Amazon, Ganga, endorheic drainage basins are inland basins that do not drain to an ocean. Around 18% of all land drains to endorheic lakes or seas or sinks, the largest of these consists of much of the interior of Asia, which drains into the Caspian Sea, the Aral Sea, and numerous smaller lakes. Some of these, such as the Great Basin, are not single drainage basins but collections of separate, in endorheic bodies of standing water where evaporation is the primary means of water loss, the water is typically more saline than the oceans. An extreme example of this is the Dead Sea, drainage basins have been historically important for determining territorial boundaries, particularly in regions where trade by water has been important
Drainage basin
–
Animation of
Latoriţa River drainage basin,
Romania
Drainage basin
–
Example of a drainage basin. The dashed line is the main water divide of the hydrographic basin.
Drainage basin
–
Endorheic basin in
Central Asia
Drainage basin
–
The
Mississippi River drains the largest area of any
U.S. river, much of it
agricultural regions. Agricultural runoff and other water pollution that flows to the outlet is the cause of the
hypoxic, or dead zone in the
Gulf of Mexico.
8.
Aleutian Range
–
The Aleutian Range is a major mountain range located in southwest Alaska, and it extends from Chakachamna Lake to Unimak Island, which is at the tip of the Alaska Peninsula. It includes all of the mountains of the peninsula, and what makes it so special is its number of active volcanoes. The mainland part of the range is about 600 miles long, however the official designation Aleutian Range includes only the mainland peaks and the peaks on Unimak Island. The range is almost entirely roadless wilderness, and Katmai National Park and Preserve, the core Aleutian Range can be divided into three mountain groups. Just to the north of the Aleutian Range are the Tordrillo Mountains, on July 12,2008, Mount Okmok erupted, and it continued to erupt for a month. A giant, rapidly moving ash and gas cloud shot up to a height of 15,240 m as a result of this eruption, Mount Kasatochi was home to the other eruption, which occurred on August 7 and 8. This eruption also sent up a gas cloud about 15,000 high, together, these two power volcanic eruptions deposited emissions of trace gases an aerosols into the atmosphere. These emissions formed a sulfate aerosol layer that totaled a transfer of 1.6 Tg of SO2 into the stratosphere, the 7.9 Mw Aleutian Islands earthquake occurred in June 2014 at an intermediate depth of 107 km. The quake was caused by normal faulting along the Aleutian Trench. List of earthquakes in Alaska U. S. Geological Survey Geographic Names Information System, Aleutian Range
Aleutian Range
–
Alaska Peninsula, Peulik Volcano and Ukinrek Maars
Aleutian Range
–
Blockade Glacier in the Neacola Mountains
Aleutian Range
–
Aleutian Range
9.
Alaska Range
–
The highest mountain in North America, Denali, is in the Alaska Range. It is part of the American Cordillera, the range is the highest in the world outside of Asia and the Andes. The mountains act as a barrier to the flow of moist air from the Gulf of Alaska northwards. The heavy snowfall also contributes to a number of glaciers, including the Canwell, Castner, Black Rapids, Susitna, Yanert, Muldrow, Eldridge, Ruth, Tokositna. Four major rivers cross the Range, including the Delta River, and Nenana River in the center of the range and the Nabesna and Chisana Rivers to the east. The range is part of the Pacific Ring of Fire, mount Spurr is a stratovolcano located in the northeastern end of the Aleutian Volcanic Arc of Alaska, USA which has two vents, the summit and nearby Crater Peak. Parts of the range are protected within Wrangell-St, elias National Park and Preserve, Denali National Park and Preserve, and Lake Clark National Park and Preserve. The George Parks Highway from Anchorage to Fairbanks, the Richardson Highway from Valdez to Fairbanks, the Alaska Pipeline parallels the Richardson Highway. The name Alaskan Range appears to have been first applied to mountains in 1869 by naturalist W. H. Dall. The name eventually became Alaska Range through local use, in 1849 Constantin Grewingk applied the name Tschigmit to this mountain range. A map made by the General Land Office in 1869 calls the southwestern part of the Alaska Range the Chigmit Mountains, however the Chigmit Mountains are now considered part of the Aleutian Range. Canada to Lake Clark, Roman Dial, Carl Tobin, and Paul Adkins by mountain bike and packraft, Tok to Lake Clark, Kevin Armstrong, Doug Woody, and Jeff Ottmers by snowshoe, foot, and packraft, first foot traverse. Lake Clark to Mentasta Lake, Gavin McClurg by paraglider and foot, summit Lake, Alaska Churkin, M. Jr. and C. Stratigraphy, structure, and graptolites of an Ordovician and Silurian sequence in the Terra Cotta Mountains, Alaska Range, U. S. Department of the Interior, U. S. Geological Survey
Alaska Range
–
Rugged peaks of the Alaska Range near
Denali
Alaska Range
–
View from Denali National Park
Alaska Range
–
Alaska Range Glacier
Alaska Range
–
Denali, on a rare clear day
10.
Tributaries
–
A tributary or affluent is a stream or river that flows into a larger stream or main stem river or a lake. A tributary does not flow directly into a sea or ocean, tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean. A confluence, where two or more bodies of water together, usually refers to the joining of tributaries. The opposite to a tributary is a distributary, a river or stream that branches off from, distributaries are most often found in river deltas. Right tributary and left tributary are terms stating the orientation of the relative to the flow of the main stem river. These terms are defined from the perspective of looking downstream, where tributaries have the same name as the river into which they feed, they are called forks. These are typically designated by compass direction, for example, the American River receives flow from its North, Middle, and South forks. The Chicago Rivers North Branch has the East, West, and Middle Fork, the South Branch has its South Fork, forks are sometimes designated as right or left. Here, the handedness is from the point of view of an observer facing upstream, for instance, Steer Creek has a left tributary which is called Right Fork Steer Creek. Tributaries are sometimes listed starting with those nearest to the source of the river, the Strahler Stream Order examines the arrangement of tributaries in a hierarchy of first, second, third, and higher orders, with the first-order tributary being typically the least in size. For example, a second-order tributary would be the result of two or more first-order tributaries combining to form the second-order tributary, another method is to list tributaries from mouth to source, in the form of a tree structure, stored as a tree data structure
Tributaries
–
Biała Lądecka, a right tributary of Nysa Kłodzka in Poland, located in the village of
Bielice in
Lower Silesia.
Tributaries
–
The
Pfinz, a right tributary of the
Rhine, located in
Baden-Württemberg.
Tributaries
–
Walton Creek, a small tributary of the
Lochsa River in
northeastern Idaho, flowing slightly
upstream of its confluence with a larger stream.
Tributaries
–
In Norway, the river
Glomma meets its main tributary
Vorma.
11.
Susitna River
–
The Susitna River /suːˈsɪtnə/ is a 313-mile long river in the Southcentral Alaska. It is the 15th largest river in the United States, ranked by average discharge volume at its mouth, the river stretches from the Susitna Glacier to Cook Inlets Knik Arm. Denaina Indian name meaning sandy river published by the Russian Hydrog, dept. as R Sushitna, meaning Sushitna River, on Chart 1378 dated 1847. The Susitna River appears to have been first explored in 1834, by a Creole named Malakov, the present spelling of the name has evolved due to euphemistic reasons. The Susitna River heads at Susitna Glacier, in Alaska Range, flows southwest to Cook Inlet,24 miles west of Anchorage, there are several rivers flowing into the Susitna River including East Fork Susitna River and West Fork Susitna River. The Little Susitna River is a river system which flows into the Cook Inlet on the other side of Susitna Flats. The Susitna along with the Matanuska River, drains the broad Matanuska-Susitna Valley south of the Alaska Range and it rises in the Susitna Glacier on Mount Hayes in the Alaska Range near 63°30′N 147°15′W. It receives the Yentna River from the northwest approximately 5 miles north of Susitna and it is navigable to 85 mile upstream from its mouth to Talkeetna. Valdez Creek, notable for its 1903 gold mining, is one of the headwater tributaries of Susitna River. The Susitna River is one of Southcentral Alaskas premier sport fishing streams, with significant runs of Chinook and Coho salmon, along with resident grayling, burbot, located within a roadless area, access to the river is difficult and is made usually by power boat or by floatplane. Matanuska-Susitna Borough owns much of the land along the Susitna and Deshka Rivers, however, the borough currently lacks either regulations to prevent further damage or the means to enforce such regulations. Susitna River was named by the Dena’ina Alaska Native people meaning sandy river, the Denaina language name is Susitnu. The Susitna appears to have been first explored in 1834 by a Creole Indian named Malakor, the 1890 census reported that Susitna Village on the east bank of the river had 146 Kenai Natives and 27 houses. Susitna River is on the North side of Cook Inlet 22 miles North-East of North Foreland, Mount Susitna, a prominent landmark along the upper part of the inlet, is about 6 miles West of the Susitna River at a point 13 miles above the mouth. The channels across the flats at the mouth of Susitna River have depths of 2 feet or less at low water and change during the winter and spring because of ice, the channels above the mouth are said to change frequently in the spring and early summer. Launches navigate Susitna River to Yentna River, about 20 miles above Cook Inlet, the tides are not felt more than 7 miles from the inlet, and above this the current is swift. Overhead power cables with a least clearance of 37 feet cross the Susitna River about 5 miles above its mouth, alexander, Alaska is a small settlement on the west side of Susitna River 10 miles above the mouth. Susitna, Alaska is on the East side 18 miles above the mouth and just below the mouth of the Yentna River, launches run to and from Anchorage, mail is delivered to both settlements twice monthly by airplane from Anchorage, Alaska
Susitna River
–
Susitna River in
Southcentral Alaska
Susitna River
–
Susitna River on a clear sunny day in June 2015 near Talkeetna.
Susitna River
Susitna River
–
The
Denali Highway crosses the upper Susitna river
12.
Matanuska River
–
The Matanuska River is a 75-mile long stream in Southcentral Alaska, United States. The river drains a valley south of the Alaska Range eponymously known as the Matanuska Valley. Formed by the confluence of its east and south forks, the Matanuska River flows generally southwest to the Knik Arm of Cook Inlet, downstream of its source, the river is joined by meltwater from Matanuska Glacier in the northern Chugach Mountains. From there it continues through the Matanuska Valley, between the Chugach Mountains to the south and the Talkeetna Mountains to the north, population centers along its course include Chickaloon, Sutton, Palmer, and Butte. It enters the Knik Arm of Cook Inlet about 9.5 miles southwest of Palmer, the Glenn Highway runs roughly parallel to the river for much of its length. Highway bridges over the river, listed from source to mouth, include Glacier Park Bridge, Chickaloon River Bridge, King River Bridge, Old Glenn Highway Bridge, an Alaska Railroad bridge crosses the river parallel to the Glenn Highway Bridge at Palmer Hay Flats State Game Refuge. In addition to the glacier, named and unnamed streams drain the Talkeetna. These include Glacier, Hicks, Purinton, Caribou, and Coal creeks, and the Chickaloon and King rivers, the main stem is silty with glacial run-off from spring through fall but at lower flows beneath winter ice, it runs relatively clear. The Mat-Su Valley is one of the most settled regions of Alaska, erosion by the glacial braided river has damaged roads, farms, houses, and houses for decades. The United States Geological Survey operates a stream gauge near Palmer, mean monthly discharge at this gauge varies from 500 cubic feet per second in March to 13,000 cubic feet per second in July. The maximum recorded flow was 82,100 cubic feet per second on August 10,1971, the minimum recorded flow of 234 cubic feet per second occurred on April 25,1956. The river is a destination for whitewater enthusiasts who float mainly in rafts or kayaks. Accessible at several bridges and other points along the Glenn Highway, expert paddlers sometimes run a tributary, Caribou Creek, that flows past Matanuska Glacier and is rated Class II to IV. Hazards along the main stem include swift, cold water, big standing waves and holes along some sections, overhanging or submerged vegetation on the lower reaches, and upriver winds. The indigenous Denaina Athabascan name for the river is Chatanhtnu, based on the root -tanh trail extends out, list of rivers of Alaska Matanuska Formation Kari, James M. et al. Shem Petes Alaska, The Territory of the Upper Cook Inlet Denaina, 2nd ed. Fairbanks, Alaska, media related to Matanuska River at Wikimedia Commons
Matanuska River
–
Silt-laden waters of the Chickaloon River (right center) enter the Matanuska River at mile 76 (km 123) of the
Glenn Highway (upper right), a major highway connecting
Anchorage to the rest of the state. The valley is forested with
black cottonwood,
balsam poplar,
white spruce and
paper birch.
Matanuska River
–
South-central Alaska, near
Anchorage
13.
River
–
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water, small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the term river as applied to geographic features. Many names for small rivers are specific to geographic location, examples are run in parts of the United States, burn in Scotland and northeast England. Sometimes a river is defined as being larger than a creek, but not always, Rivers are part of the hydrological cycle. Potamology is the study of rivers while limnology is the study of inland waters in general. Extraterrestrial rivers of liquid hydrocarbons have recently found on Titan. Channels may indicate past rivers on other planets, specifically outflow channels on Mars and rivers are theorised to exist on planets, a river begins at a source, follows a path called a course, and ends at a mouth or mouths. The water in a river is confined to a channel. In larger rivers there is also a wider floodplain shaped by flood-waters over-topping the channel. Floodplains may be wide in relation to the size of the river channel. This distinction between river channel and floodplain can be blurred, especially in areas where the floodplain of a river channel can become greatly developed by housing. Rivers can flow down mountains, through valleys or along plains, the term upriver refers to the direction towards the source of the river, i. e. against the direction of flow. Likewise, the term describes the direction towards the mouth of the river. The term left bank refers to the bank in the direction of flow. The river channel typically contains a stream of water, but some rivers flow as several interconnecting streams of water. Extensive braided rivers are now found in only a few regions worldwide and they also occur on peneplains and some of the larger river deltas. Anastamosing rivers are similar to braided rivers and are quite rare
River
–
Melting toe of Athabasca Glacier,
Jasper National Park,
Alberta, Canada
River
–
The River Cam from the Green Dragon Bridge, Cambridge (United Kingdom)
River
–
Nile River delta, as seen from Earth orbit. The Nile is an example of a wave-dominated delta that has the classic Greek letter delta (Δ) shape after which river deltas were named.
River
–
A radar image of a 400-kilometre (250 mi) river of methane and ethane near the north pole of Saturn's moon
Titan
14.
Denali
–
Denali is the highest mountain peak in North America, with a summit elevation of 20,310 feet above sea level. With a topographic prominence of 20,156 feet and an isolation of 4,629 miles, Denali is the third most prominent and third most isolated peak after Mount Everest. Located in the Alaska Range in the interior of the U. S. state of Alaska, Denali is the centerpiece of Denali National Park, the Koyukon people who inhabit the area around the mountain have referred to the peak as Denali for centuries. In August 2015, following the 1975 lead of the state of Alaska, prior to this, most Alaskans already referred to the mountain as Denali. In 1903, James Wickersham recorded the first attempt at climbing Denali, in 1906, Frederick Cook claimed the first ascent, which was later proven to be false. The first verifiable ascent to Denalis summit was achieved on June 7,1913, by climbers Hudson Stuck, Harry Karstens, Walter Harper, and Robert Tatum, who went by the South Summit. In 1951, Bradford Washburn pioneered the West Buttress route, considered to be the safest and easiest route, and therefore the most popular currently in use. On September 2,2015, the U. S. Geological Survey announced that the mountain is 20,310 feet high, not 20,320 feet, the forces that lifted Denali also cause many deep earthquakes in Alaska and the Aleutian Islands. The Pacific Plate is seismically active beneath Denali, a region that is known as the McKinley cluster. Denali has an elevation of 20,310 feet above sea level, making it the highest peak in North America. Measured from base to peak at some 18,000 ft, Denali rises from a sloping plain with elevations from 1,000 to 3,000 ft, for a base-to-peak height of 17,000 to 19,000 ft. By comparison, Mount Everest rises from the Tibetan Plateau at a higher base elevation. Denali has two significant summits, the South Summit is the one, while the North Summit has an elevation of 19,470 ft. The North Summit is sometimes counted as a peak and sometimes not, it is rarely climbed. Five large glaciers flow off the slopes of the mountain, the Peters Glacier lies on the northwest side of the massif, while the Muldrow Glacier falls from its northeast slopes. Just to the east of the Muldrow, and abutting the eastern side of the massif, is the Traleika Glacier, the Ruth Glacier lies to the southeast of the mountain, and the Kahiltna Glacier leads up to the southwest side of the mountain. With a length of 44 mi, the Kahiltna Glacier is the longest glacier in the Alaska Range, the Koyukon Athabaskans who inhabit the area around the mountain have for centuries referred to the peak as Dinale or Denali. The name is based on a Koyukon word for high or tall, during the Russian ownership of Alaska, the common name for the mountain was Bolshaya Gora, which is the Russian translation of Denali
Denali
–
From the north, with Wonder Lake in the foreground
Denali
–
Hudson Stuck and
Harry Karstens, co-leaders of the first successful summit of Denali in 1913
Denali
–
The reverse side of the Denali National Park quarter
Denali
–
High camp (17,200 ft or 5,200 m) of the West Buttress Route pioneered by
Bradford Washburn, photographed in 2001
15.
National park
–
A national park is a park in use for conservation purposes. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns, although individual nations designate their own national parks differently, there is a common idea, the conservation of wild nature for posterity and as a symbol of national pride. An international organization, the International Union for Conservation of Nature, although Yellowstone was not officially termed a national park in its establishing law, it was always termed such in practice and is widely held to be the first and oldest national park in the world. The first area to use national park in its legislation was the USs Mackinac Island. Australias Royal National Park, established in 1879, was the third official national park. In 1895 ownership of Mackinac Island was transferred to the State of Michigan as a state park, as a result, Australias Royal National Park is by some considerations the second oldest national park now in existence. The largest national park in the meeting the IUCN definition is the Northeast Greenland National Park. According to the IUCN,6,555 national parks worldwide met its criteria in 2006, IUCN is still discussing the parameters of defining a national park. National parks are almost always open to visitors, in 1971, these criteria were further expanded upon leading to more clear and defined benchmarks to evaluate a national park. In 1810, the English poet William Wordsworth described the Lake District as a sort of property, in which every man has a right and interest who has an eye to perceive. It was known as Hot Springs Reservation, but no authority was established. Federal control of the area was not clearly established until 1877, John Muir is today referred to as the Father of the National Parks due to his work in Yosemite. He published two articles in The Century Magazine, which formed the base for the subsequent legislation. President Abraham Lincoln signed an Act of Congress on July 1,1864, ceding the Yosemite Valley, according to this bill, private ownership of the land in this area was no longer possible. The state of California was designated to manage the park for use, resort. Leases were permitted for up to ten years and the proceeds were to be used for conservation, a public discussion followed this first legislation of its kind and there was a heated debate over whether the government had the right to create parks. The perceived mismanagement of Yosemite by the Californian state was the reason why Yellowstone at its establishment six years later was put under national control, in 1872, Yellowstone National Park was established as the United States first national park, being also the worlds first national park. In some European countries, however, national protection and nature reserves already existed, such as Drachenfels, Yellowstone was part of a federally governed territory
National park
–
An elephant safari through the
Jaldapara National Park in
West Bengal,
India
National park
–
The
Teide National Park in
Tenerife,
Spain
National park
–
Manuel Antonio National Park in
Costa Rica was listed by
Forbes as one of the world's 12 most beautiful national parks.
National park
–
A
salt marsh in
Schiermonnikoog National Park,
Netherlands
16.
Mount Redoubt (Alaska)
–
Redoubt Volcano, or Mount Redoubt, is an active stratovolcano in the largely volcanic Aleutian Range of the U. S. state of Alaska. At 10,197 feet, in just over 5 miles Mount Redoubt attains 9,150 feet of prominence over its surrounding terrain and it is the highest summit in the Aleutian Range. Active for millennia, Mount Redoubt has erupted four times since it was first observed, in 1902,1966,1989 and 2009, the eruption in 1989 spewed volcanic ash to a height of 45,000 ft. It caught KLM Flight 867, a Boeing 747 aircraft, in its plume, after the plane descended 13,000 feet, the pilots restarted the engines and landed the plane safely at Anchorage. The ash blanketed an area of about 7,700 sq mi, as of August 2015, the Alaska Volcano Observatory has rated Redoubt as Aviation Alert Level Green and Volcano Alert Level Normal. The official name of the mountain is Redoubt Volcano, a translation of the Russian name Sopka Redutskaya, referring to, as does the word redoubt, a fortified place. A local name, Ujakushatsch, also means fortified place, the Board on Geographic Names decided on the name Redoubt Volcano in 1891. The Alaska Volcano Observatory also uses simply Redoubt, it lists the alternate names in addition to the following, Goryalaya, Redoute Mtn. and Redutskaya. The volcano is about 3.7 miles in diameter at its base with a volume of 7.2 to 8.4 cu mi. The sides of the cone are relatively steep. The current main vent is on the side of the crater by the head of the Drift glacier. Also present on the mountain are Holocene lahar deposits that extend as far as the Cook Inlet and this mountain has produced andesite, basalt and dacite, with relatively silicic andesite dominant in recent eruptions. But this besides being too small for one of those clouds, however, several sources call this a discredited eruption. There are several other of these activities that are not called eruptions, in 1819, smoke was observed at the mountain. However, this is not recorded as an eruption as the information was insufficient to identify it as such. Similarly, in 2003, a cloud of snow was mistaken by an employee of the ConocoPhillips Building in Anchorage for an ash plume. Possible steam-vapor let off was observed in 1933 at the mountain, there was apparently an eruption described as to the eastward, Redoubt Volcano,11,060 feet high, is constantly smoking, with periods of exaggerated activity. Fire has been seen issuing from its summit far out at sea, a great eruption took place in 1881, when a party of native hunters half-way up its slopes were overwhelmed by a lava-flow and only two escaped
Mount Redoubt (Alaska)
–
Steaming at the active summit lava dome on May 8, 2009
Mount Redoubt (Alaska)
–
A chunk of
andesite thrown from the volcano in 2009 is seen on display at the
Anchorage Museum in March 2011.
Mount Redoubt (Alaska)
–
North face in 1980
Mount Redoubt (Alaska)
–
April 21, 1990 eruption cloud from Redoubt Volcano as viewed to the west from the
Kenai Peninsula
17.
Volcano
–
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earths volcanoes occur because its crust is broken into 17 major, therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging. This type of volcanism falls under the umbrella of plate hypothesis volcanism, Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called hotspots, for example Hawaii, are postulated to arise from upwelling diapirs with magma from the boundary,3,000 km deep in the Earth. Volcanoes are usually not created where two plates slide past one another. Erupting volcanoes can pose hazards, not only in the immediate vicinity of the eruption. Historically, so-called volcanic winters have caused catastrophic famines, the word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is called volcanology, sometimes spelled vulcanology, at the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock. Most divergent plate boundaries are at the bottom of the oceans, therefore, most volcanic activity is submarine, black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed, for example, subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. In this case, the plate subducts, or submerges under the continental plate forming a deep ocean trench just offshore. In a process called flux melting, water released from the subducting plate lowers the temperature of the overlying mantle wedge. This magma tends to be very viscous due to its high content, so it often does not reach the surface. When it does reach the surface, a volcano is formed, typical examples of this kind of volcano are Mount Etna and the volcanoes in the Pacific Ring of Fire. Because tectonic plates move across them, each volcano becomes dormant and is eventually re-formed as the plate advances over the postulated plume and this theory is currently under criticism, however. The most common perception of a volcano is of a mountain, spewing lava and poisonous gases from a crater at its summit, however. The features of volcanoes are more complicated and their structure. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have features such as massive plateaus
Volcano
–
Cleveland Volcano in the
Aleutian Islands of
Alaska photographed from the
International Space Station, May 2006
Volcano
–
Ash plumes reached a height of 19 kilometres (12 mi) during the climactic
explosive eruption at
Mount Pinatubo, Philippines in 1991.
Volcano
–
A 2007 eruptive column at
Mount Etna producing volcanic ash, pumice and lava bombs
Volcano
–
Ubinas Volcano
18.
Port
–
A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land. Port locations are selected to optimize access to land and navigable water, for commercial demand, Ports with deeper water are rarer, but can handle larger ships. Since ports throughout history handled every kind of traffic, support and storage facilities vary widely, may extend for miles, some ports have an important military role. One of the worlds oldest known artificial harbors is at Wadi al-Jarf on the Red Sea, along with the finding of harbor structures, ancient anchors have also been found. Guangzhou was an important port during the ancient times as far back as the Qin Dynasty, canopus was the principal port in Egypt for Greek trade before the foundation of Alexandria. Athens port of Piraeus was the base for the Athenian fleet, lothal is one of the most prominent cities of the ancient Indus valley civilisation, located in the Bhāl region of the modern state of Gujarāt and dating from 3700 BCE. Ostia Antica was the port of ancient Rome with Portus established by Claudius, Ports often have cargo-handling equipment, such as cranes and forklifts for use in loading ships, which may be provided by private interests or public bodies. Often, canneries or other processing facilities will be located nearby, some ports feature canals, which allow ships further movement inland. Access to intermodal transportation, such as railroads and highways, is critical to a port, so that passengers, Ports with international traffic have customs facilities. Harbor pilots and tugboats may maneuver large ships in tight quarters when near docks, the terms port and seaport are used for different types of port facilities that handle ocean-going vessels, and river port is used for river traffic, such as barges and other shallow-draft vessels. An inland port is a port on a lake, river, or canal with access to a sea or ocean. An example of this is the St. Lawrence Seaway which allows ships to travel from the Atlantic Ocean several thousand kilometers inland to Great Lakes ports like Duluth-Superior, a fishing port is a port or harbor for landing and distributing fish. It may be a facility, but it is usually commercial. A fishing port is the port that depends on an ocean product. In recent decades, regulations to save fishing stock may limit the use of a fishing port, a dry port is an inland intermodal terminal directly connected by road or rail to a seaport and operating as a centre for the transshipment of sea cargo to inland destinations. A warm-water port is one where the water does not freeze in wintertime, because they are available year-round, warm-water ports can be of great geopolitical or economic interest. A seaport is further categorized as a port or a cargo port. Additionally, cruise ports are known as a home port or a port of call
Port
–
The
Port of New York and New Jersey grew from the original
harbor at the convergence of the
Hudson River and the
East River at the
Upper New York Bay.
Port
–
Seaport, a 17th-century depiction by
Claude Lorrain, 1638
Port
–
Shanghai Port is the
world's busiest container port
Port
–
Port of Hamburg
19.
Homer, Alaska
–
Homer is a city located in Kenai Peninsula Borough in the U. S. state of Alaska. It is two hundred and eighteen miles southwest of Anchorage, according to the 2010 Census, the population is 5,003. Long known as The Halibut Fishing Capital of the World, Homer is also nicknamed the end of the road, and more recently, the cosmic hamlet by the sea. Homer is located at 59°3835 North, 151°3133 West, the only road into Homer is the Sterling Highway. Homer is on the shore of Kachemak Bay on the southwest side of the Kenai Peninsula and its distinguishing feature is the Homer Spit, a narrow 4.5 mi ) long gravel bar that extends into the bay, on which is located the Homer Harbor. Much of the coastline as well as the Homer Spit sank dramatically during the Good Friday earthquake in March 1964, after the earthquake, very little vegetation was able to survive on the Homer Spit. According to the United States Census Bureau, the town has an area of 22.4 square miles. The total area is 52. 83% water, as with much of South Central Alaska, Homer has a moderate subarctic coastal climate which causes its weather to be moderate compared to interior Alaska. Winters are snowy and long but not particularly cold, considering the latitude, snow averages 50 inches per season, falling primarily from November through March, with some accumulation in October and April, and rarely in May. Homer receives only about 25 inches of rainfall due to the influence of the Chugach Mountains to the southeast which shelter it from the Gulf of Alaska. There are 7 nights of sub-0 °F lows annually, and the area straddles the border between USDA Plant Hardiness Zones 5B and 6A, indicating an average minimum of around −10 °F. Summers are cool due to the influence, with 75 °F highs or 55 °F lows being extremely rare. Extreme temperatures have ranged from −24 °F on January 28–29,1989 up to 84 °F on July 22,2011, tiller digs indicate that early Alutiiq people probably camped in the Homer area although their villages were on the far side of Kachemak Bay. Coal was discovered in the area in the 1890s, the Cook Inlet Coal Fields Company built a town, dock, coal mine, and a railroad at Homer. Coal mining in the area continued until World War II, there are an estimated 400 million tons of coal deposits still in the area. Homer was named for Homer Pennock, a company promoter. However, gold mining was never profitable in the area, another earlier settlement was Millers Landing. Millers Landing is named after a Charles Miller who homesteaded in the neighborhood around 1915, according to local historian Janet Klein, he was an employee of the Alaska Railroad and had wintered company horses on the beach grasses on the Homer Spit
Homer, Alaska
–
Downtown Homer seen from Beluga Slough
Homer, Alaska
–
Location of Homer, Alaska
Homer, Alaska
–
Homer City Hall, located on Pioneer Avenue
Homer, Alaska
–
Landmark: the
Salty Dawg Saloon.
20.
Knik-Fairview, Alaska
–
Knik-Fairview is a census-designated place in Matanuska-Susitna Borough, Alaska, United States. It is part of the Anchorage, Alaska Metropolitan Statistical Area, at the 2010 census the population was 14,923. Knik-Fairview is located at 61°31′39″N 149°35′53″W,17.5 miles northeast of Anchorage on the west bank of the Knik Arm of Cook Inlet,13 miles south of Wasilla. According to the United States Census Bureau, the CDP has an area of 180 km2. Two percent, or 1 square mile, of it is water, as of the 2000 census, there were 7,050 people,2,380 households, and 1,800 families residing in the CDP. There were 2,590 housing units at a density of 37/sq mi. The racial makeup of the CDP was 88% white, 6% Native American, 3% of the population were Hispanic or Latino of any race. Blacks, Asians, and Pacific Islanders all have less than 1%, 18% of all households were made up of individuals and 3% had someone living alone who was 65 years of age or older. The average household size was 3.0 and the family size was 3.4. In the CDP, the population was out with 34% under the age of 18, 6% from 18 to 24, 33% from 25 to 44, 23% from 45 to 64. The median age was 33 years, for every 100 females there were 108 males. For every 100 females age 18 and over, there were 107 males, the median income for a household in the CDP was $52,100, and the median income for a family was $60,100. Males had an income of $46,300 versus $29,800 for females. The per capita income for the CDP was $20,900, 11% of the population and 9% of families were below the poverty line. 13% of those under the age of 18 and 4% of those 65 and older were living below the poverty line
Knik-Fairview, Alaska
–
Location in
Matanuska-Susitna Borough and the state of
Alaska.
21.
Clam Gulch
–
Clam Gulch is a census-designated place in Kenai Peninsula Borough, Alaska, United States. At the 2000 census the population was 173, Clam Gulch is located at 60°13′40″N 151°23′38″W on the shores of Cook Inlet. The only road access is via the Sterling Highway, according to the United States Census Bureau, the CDP has a total area of 13.7 square miles, all of it land. //www. google. com/maps/@60.2258704, -151.402415, 1626m/data=. 3m1. 1e3 As of the census of 2000, there were 173 people,67 households, the population density was 12.6 people per square mile. There were 115 housing units at a density of 8. 4/sq mi. The racial makeup of the CDP was 92. 49% White,2. 89% Native American,1. 16% Asian,28. 4% of all households were made up of individuals and 6. 0% had someone living alone who was 65 years of age or older. The average household size was 2.58 and the family size was 3.21. In the CDP, the population was out with 31. 8% under the age of 18,5. 8% from 18 to 24,27. 2% from 25 to 44,24. 3% from 45 to 64. The median age was 38 years, for every 100 females there were 106.0 males. For every 100 females age 16 and over, there were 103.4 males, the median income for a household in the CDP was $37,500, and the median income for a family was $44,375. Males had an income of $25,625 versus $27,083 for females. The per capita income for the CDP was $17,983, about 7. 0% of families and 8. 1% of the population were below the poverty line, including 10. 2% of those under the age of eighteen and none of those sixty five or over. Clam Gulch is visited by tourists who participate in clam digging on the beach during low tides, there is a State Recreation Area with a large campground and access to the clamming beaches. In the winter there are many poker runs by snow-machine enthusiasts and in the past Clam Gulch has been the half-way point for the Tustumena 200 Sled Dog Race
Clam Gulch
–
Waves on the rocky beach at Clam Gulch
22.
Augustine Volcano
–
Augustine Volcano is a central lava dome and lava flow complex, surrounded by pyroclastic debris. It forms Augustine Island in southwestern Cook Inlet in the Kenai Peninsula Borough of southcentral coastal Alaska,280 kilometers southwest of Anchorage. Augustine Island has an area of 83.872 square kilometers, while West Island. The island is made up mainly of past eruption deposits, scientists have been able to discern that past dome collapse has resulted in large avalanches. The nearly circular uninhabited island formed by Augustine Volcano is 12 km wide east-west,10 km north-south, Augustines summit consists of several overlapping lava dome complexes formed during many historic and prehistoric eruptions. The surface of such deposits is skeet, a field of steep conical mounds, en route to Katmai in 1913, Robert F. Helens. The deposit of that landslide revealed the origin of coarse diamicts with hummocky topography at other strato volcanic cones, since 1980 many hummocky coarsely fragmental deposits on Augustines lower flanks have come to be interpreted as deposits of numerous great landslides and debris avalanches. A March 27,1986 eruption deposited ash over Anchorage and disrupted air traffic in southcentral Alaska, on January 11,1994, Augustine erupted at 13,44 and 14,13 UTC. The eruption consisted of four phases, continuing from December to March 2006, the initial stage of the eruption began when microearthquake activity increased steadily from May to December 2005. At first, they started out at around 2 each day to around 15 each day, microearthquakes are tiny earthquake that suggest a volcanic eruption could possibly occur. The volcano erupted on January 11,2006, entering a second stage, tectonic earthquakes began early in January, resulting in an explosive Volcanic Explosivity Index 3 eruption later in that day. Several ash columns were generated, each 9 km above sea level, samples of the tephra were dense, insinuating that the lava released was mature. Six explosions were recorded by seismic instruments between January 13, the first of these consuming a seismograph and a CPGS located on the northwestern flank, ash columns now reached 14 km and Kenai Peninsula residents reported ash deposits. On January 16, a new dome was observed on the summit. This explosion created a 20-30 meter wide crater in the new lava dome, on September 22,2007, the Alaska Volcano Observatory reported that shallow earthquake activity had increased over the week of September 22. However, the activity was less than its level during the leading up to the 2005-2006 eruption. The Plate Boundary Observatory, operated by UNAVCO has a network of 10 high-precision GPS instruments on the flanks of Augustine, activity two years ago claimed two of these sites. The Alaska Volcano Observatory also operates a number of seismometers and tiltmeters all around the volcano, including four webcams
Augustine Volcano
–
Augustine Volcano, 1976
Augustine Volcano
–
Thermal image after the January 2006 eruptions. White parts of the image are warmer than dark areas.
Augustine Volcano
–
2006 eruption
23.
Mount Redoubt
–
Redoubt Volcano, or Mount Redoubt, is an active stratovolcano in the largely volcanic Aleutian Range of the U. S. state of Alaska. At 10,197 feet, in just over 5 miles Mount Redoubt attains 9,150 feet of prominence over its surrounding terrain and it is the highest summit in the Aleutian Range. Active for millennia, Mount Redoubt has erupted four times since it was first observed, in 1902,1966,1989 and 2009, the eruption in 1989 spewed volcanic ash to a height of 45,000 ft. It caught KLM Flight 867, a Boeing 747 aircraft, in its plume, after the plane descended 13,000 feet, the pilots restarted the engines and landed the plane safely at Anchorage. The ash blanketed an area of about 7,700 sq mi, as of August 2015, the Alaska Volcano Observatory has rated Redoubt as Aviation Alert Level Green and Volcano Alert Level Normal. The official name of the mountain is Redoubt Volcano, a translation of the Russian name Sopka Redutskaya, referring to, as does the word redoubt, a fortified place. A local name, Ujakushatsch, also means fortified place, the Board on Geographic Names decided on the name Redoubt Volcano in 1891. The Alaska Volcano Observatory also uses simply Redoubt, it lists the alternate names in addition to the following, Goryalaya, Redoute Mtn. and Redutskaya. The volcano is about 3.7 miles in diameter at its base with a volume of 7.2 to 8.4 cu mi. The sides of the cone are relatively steep. The current main vent is on the side of the crater by the head of the Drift glacier. Also present on the mountain are Holocene lahar deposits that extend as far as the Cook Inlet and this mountain has produced andesite, basalt and dacite, with relatively silicic andesite dominant in recent eruptions. But this besides being too small for one of those clouds, however, several sources call this a discredited eruption. There are several other of these activities that are not called eruptions, in 1819, smoke was observed at the mountain. However, this is not recorded as an eruption as the information was insufficient to identify it as such. Similarly, in 2003, a cloud of snow was mistaken by an employee of the ConocoPhillips Building in Anchorage for an ash plume. Possible steam-vapor let off was observed in 1933 at the mountain, there was apparently an eruption described as to the eastward, Redoubt Volcano,11,060 feet high, is constantly smoking, with periods of exaggerated activity. Fire has been seen issuing from its summit far out at sea, a great eruption took place in 1881, when a party of native hunters half-way up its slopes were overwhelmed by a lava-flow and only two escaped
Mount Redoubt
–
Steaming at the active summit lava dome on May 8, 2009
Mount Redoubt
–
A chunk of
andesite thrown from the volcano in 2009 is seen on display at the
Anchorage Museum in March 2011.
Mount Redoubt
–
North face in 1980
Mount Redoubt
–
April 21, 1990 eruption cloud from Redoubt Volcano as viewed to the west from the
Kenai Peninsula
24.
Eruption
–
Several types of volcanic eruptions—during which lava, tephra, and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed, some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three different types of eruptions, the most well-observed are magmatic eruptions, which involve the decompression of gas within magma that propels it forward. Phreatomagmatic eruptions are another type of eruption, driven by the compression of gas within magma. Within these wide-defining eruptive types are several subtypes, the weakest are Hawaiian and submarine, then Strombolian, followed by Vulcanian and Surtseyan. The stronger eruptive types are Pelean eruptions, followed by Plinian eruptions, subglacial and phreatic eruptions are defined by their eruptive mechanism, and vary in strength. An important measure of strength is Volcanic Explosivity Index, an order of magnitude scale ranging from 0 to 8 that often correlates to eruptive types. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra, effusive eruptions, meanwhile, are characterized by the outpouring of lava without significant explosive eruption. Volcanic eruptions vary widely in strength, on the one extreme there are effusive Hawaiian eruptions, which are characterized by lava fountains and fluid lava flows, which are typically not very dangerous. On the other extreme, Plinian eruptions are large, violent, volcanoes are not bound to one eruptive style, and frequently display many different types, both passive and explosive, even the span of a single eruptive cycle. Volcanoes do not always erupt vertically from a crater near their peak. Some volcanoes exhibit lateral and fissure eruptions, notably, many Hawaiian eruptions start from rift zones, and some of the strongest Surtseyan eruptions develop along fracture zones. Scientists believed that pulses of magma mixed together in the chamber before climbing upward—a process estimated to several thousands of years. But Columbia University volcanologists found that the eruption of Costa Rica’s Irazú Volcano in 1963 was likely triggered by magma that took a route from the mantle over just a few months. The volcanic explosivity index is a scale, from 0 to 8 and it is used by the Smithsonian Institutions Global Volcanism Program in assessing the impact of historic and prehistoric lava flows. It operates in a way similar to the Richter scale for earthquakes, the vast majority of volcanic eruptions are of VEIs between 0 and 2. Volcanic eruptions by VEI index Magmatic eruptions produce juvenile clasts during explosive decompression from gas release, Hawaiian eruptions are a type of volcanic eruption, named after the Hawaiian volcanoes with which this eruptive type is hallmark. Hawaiian eruptions are the calmest types of events, characterized by the effusive eruption of very fluid basalt-type lavas with low gaseous content
Eruption
–
Some of the eruptive structures formed during volcanic activity: a
Plinian eruption column,
Hawaiian pahoehoe flows, and a lava arc from a
Strombolian eruption.
Eruption
–
Ropey
pahoehoe lava from
Kilauea,
Hawaiʻi.
Eruption
–
An example of the lava arcs formed during Strombolian activity. This image is of
Stromboli itself.
Eruption
–
Tavurvur in
Papua New Guinea erupting.
25.
Earthquake
–
An earthquake is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earths lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to people around. The seismicity or seismic activity of an area refers to the frequency, type, Earthquakes are measured using measurements from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe and these two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly imperceptible or weak and magnitude 7 and over potentially cause damage over larger areas. The largest earthquakes in historic times have been of magnitude slightly over 9, intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the damage to structures it causes. At the Earths surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground, when the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity, in its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of faults, but also by other events such as volcanic activity, landslides, mine blasts. An earthquakes point of rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter, tectonic earthquakes occur anywhere in the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane. The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the surface that increase the frictional resistance. Most fault surfaces do have such asperities and this leads to a form of stick-slip behavior, once the fault has locked, continued relative motion between the plates leads to increasing stress and therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the portion of the fault. This energy is released as a combination of radiated elastic strain seismic waves, frictional heating of the fault surface and this process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory. It is estimated that only 10 percent or less of a total energy is radiated as seismic energy. Most of the energy is used to power the earthquake fracture growth or is converted into heat generated by friction
Earthquake
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Global plate tectonic movement
Earthquake
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Global earthquake
epicenters, 1963–1998
Earthquake
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Aerial photo of the San Andreas Fault in the
Carrizo Plain, northwest of Los Angeles
Earthquake
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Collapsed Gran Hotel building in the
San Salvador metropolis, after the shallow
1986 San Salvador earthquake during mid civil war El Salvador.
26.
Tsunami
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A tsunami or tidal wave, also known as a seismic sea wave, is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Unlike normal ocean waves which are generated by wind, or tides which are generated by the pull of the Moon and Sun. Tsunami waves do not resemble normal undersea currents or sea waves, Tsunamis generally consist of a series of waves with periods ranging from minutes to hours, arriving in a so-called internal wave train. Wave heights of tens of metres can be generated by large events, numerous terms are used in the English language to describe waves created in a body of water by the displacement of water, however, none of the terms in frequent use are entirely accurate. The term tsunami, meaning harbour wave in literal translation, comes from the Japanese 津波, while not entirely accurate, as tsunami are not restricted to harbours, tsunami is currently the term most widely accepted by geologists and oceanographers. Tsunami are sometimes referred to as tidal waves and this once-popular term derives from the most common appearance of tsunami, which is that of an extraordinarily high tidal bore. Although the meanings of tidal include resembling or having the form or character of the tides, use of the tidal wave is discouraged by geologists. The term seismic sea wave also is used to refer to the phenomenon, prior to the rise of the use of the term tsunami in English-speaking countries, scientists generally encouraged the use of the term seismic sea wave rather than tidal wave. The Sumatran region is not unused to tsunamis either, with earthquakes of varying magnitudes regularly occurring off the coast of the island, Tsunamis are an often underestimated hazard in the Mediterranean Sea and parts of Europe. The tsunami claimed more than 123,000 lives in Sicily, the Storegga Slide in the Norwegian sea and some examples of tsunamis affecting the British Isles refer to landslide and meteotsunamis predominantly and less to earthquake-induced waves. The cause, in my opinion, of this phenomenon must be sought in the earthquake, at the point where its shock has been the most violent the sea is driven back, and suddenly recoiling with redoubled force, causes the inundation. Without an earthquake I do not see how such an accident could happen, the principal generation mechanism of a tsunami is the displacement of a substantial volume of water or perturbation of the sea. This displacement of water is attributed to either earthquakes, landslides, volcanic eruptions, glacier calvings or more rarely by meteorites. The waves formed in this way are then sustained by gravity, tides do not play any part in the generation of tsunamis. Tsunami can be generated when the sea floor abruptly deforms and vertically displaces the overlying water and they grow in height when they reach shallower water, in a wave shoaling process described below. A tsunami can occur in any state and even at low tide can still inundate coastal areas. On April 1,1946, the 8.6 Mw Aleutian Islands earthquake occurred with a maximum Mercalli intensity of VI and it generated a tsunami which inundated Hilo on the island of Hawaii with a 14-metre high surge. Between 165 and 173 were killed, the area where the earthquake occurred is where the Pacific Ocean floor is subducting under Alaska
Tsunami
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2011 Tōhoku earthquake and tsunami, An aerial view of damage in the
Sendai region with black smoke coming from the Nippon Oil Sendai oil refinery
Tsunami
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Taken at
Ao Nang,
Krabi Province,
Thailand, during the
2004 Indian Ocean earthquake and tsunami in
Thailand
Tsunami
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Tsunami warning bilingual sign in Ulee Lheue,
Banda Aceh in
Acehnese and
Indonesian
Tsunami
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Tsunami aftermath in
Aceh,
Indonesia.
27.
Avalanche
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An avalanche is a rapid flow of snow down a sloping surface. Avalanches are typically triggered in a zone from a mechanical failure in the snowpack when the forces on the snow exceed its strength. After initiation, avalanches usually accelerate rapidly and grow in mass, if the avalanche moves fast enough some of the snow may mix with the air forming a powder snow avalanche, which is a type of gravity current. Slides of rocks or debris, behaving in a way to snow, are also referred to as avalanches. The remainder of this article refers to snow avalanches, the load on the snowpack may be only due to gravity, in which case failure may result either from weakening in the snowpack or increased load due to precipitation. Avalanches that occur in this way are known as spontaneous avalanches, Avalanches can also be triggered by other loads such as skiers, snowmobilers, animals or explosives. Seismic activity may trigger the failure in the snowpack and avalanches. A popular myth is that avalanches can be triggered by loud noise or shouting, Avalanches are not rare or random events and are endemic to any mountain range that accumulates a standing snowpack. Avalanches are most common during winter or spring but glacier movements may cause ice, there is no universally accepted classification of avalanches—different classifications are useful for different purposes. Avalanches can be described by their size, their potential, their initiation mechanism, their composition. Most avalanches occur spontaneously during storms under increased load due to snowfall, the second largest cause of natural avalanches is metamorphic changes in the snowpack such as melting due to solar radiation. Other natural causes include rain, earthquakes, rockfall and icefall, artificial triggers of avalanches include skiers, snowmobiles, and controlled explosive work. Avalanche initiation can start at a point with only an amount of snow moving initially. A snowpack will fail when the load exceeds the strength, the load is straightforward, it is the weight of the snow. However, the strength of the snowpack is much more difficult to determine and is extremely heterogenous and it varies in detail with properties of the snow grains, size, density, morphology, temperature, water content, and the properties of the bonds between the grains. These properties may all metamorphose in time according to the humidity, water vapour flux, temperature. The top of the snowpack is also influenced by incoming radiation. One of the aims of research is to develop and validate computer models that can describe the evolution of the seasonal snowpack over time
Avalanche
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The toe of an avalanche in
Alaska 's
Kenai Fjords.
Avalanche
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A powder snow avalanche in the
Himalayas near
Mount Everest.
Avalanche
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A crown fracture from a slab avalanche near the Neve Glacier in the
North Cascades mountains. Extensive fracture propagation is evident.
Avalanche
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Loose snow avalanches (far left) and slab avalanches (near center) near
Mount Shuksan in the
North Cascades mountains. Fracture propagation is relatively limited.
28.
Lahar
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A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley, lahars are extremely destructive, they can flow tens of metres per second, be 140 metres deep, and destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the word lahar is the Javanese term for flowing lava. A lahar is a volcanic mudflow or debris flow, lahars have the consistency, viscosity and approximate density of wet concrete, fluid when moving, solid at rest. Lahars can be huge.3 cubic kilometres, a lahar of sufficient size and intensity can erase virtually any structure in its path, and is capable of carving its own pathway, making the prediction of its course difficult. Conversely, a lahar quickly loses force when it leaves the channel of its flow, even frail huts may remain standing, a lahars viscosity decreases with time, and can be further thinned by rain, but it nevertheless solidifies quickly when coming to a stop. Lahars vary in size and speed, small lahars less than a few metres wide and several centimetres deep may flow a few metres per second. Large lahars hundreds of metres wide and tens of metres deep can flow tens of metres per second. With the potential to flow at speeds up to 100 kilometres per hour, and flow distances of more than 300 kilometres, a lahar can cause catastrophic destruction in its path. Lahars from the 1985 Nevado del Ruiz eruption in Colombia caused the Armero tragedy, which killed an estimated 23,000 people, a lahar caused New Zealands Tangiwai disaster, where 151 people died after a Christmas Eve express train fell into the Whangaehu River in 1953. Lahars have been responsible for 17% of volcano-related deaths between 1783 and 1997, a lahar can cause fatalities years after its precipitating eruption. For example, the Cabalantian tragedy occurred four years subsequent to the 1991 eruption of Mount Pinatubo, the word lahar is of Indonesian origin. Lahars have several causes, Snow and glaciers can be melted by lava or pyroclastic flows during an eruption. Lava flows out of vents and can mix with wet soil and mud on the slope of the volcano making a very viscous. A flood caused by a glacier, lake breakout, or heavy rainfall can release a lahar, also called glacier run or jökulhlaup Water from a crater lake, heavy rainfall on unconsolidated pyroclastic deposits. Snow and glaciers can melt during periods of mild weather Earthquakes underneath or close to the volcano can shake material loose and cause it to collapse triggering a lahar avalanche. Rainfall can cause the still-hanging slabs of solidified mud to come rushing down the slopes at a speed of more than 30 kilometres per hour, causing devastating results. Several towns in the Puyallup River valley in Washington state, including Orting, are built on top of lahar deposits that are only about 500 years old
Lahar
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A hot lahar rushes down a river valley in Guatemala near the
Santa Maria volcano, 1989.
Lahar
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This
mudline left behind on the trees on the banks of the
Muddy River after the
1980 eruption of Mount St. Helens shows how high the lahars reached here.
Lahar
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The aftermath of a lahar from the 1982 eruption of
Galunggung, Indonesia.
Lahar
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The lahar from the 1985 eruption of
Nevado del Ruiz that
wiped out the town of Armero in
Colombia.
29.
Drift River oil terminal
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The Drift River Terminal Facility, also known as the Drift River Oil Terminal, is a tank farm which holds crude oil before it is loaded onto oil tankers and transported to refineries. It is located in Alaska along Cook Inlet, at the terminus of the Drift River, the facility is owned and operated by Cook Inlet Pipeline Company, a Delaware-based corporation owned 50% by Chevron and 50% by Pacific Energy Resources. Oil is collected into the tanks via the submerged Cook Inlet Pipeline, Oil tankers load crude from the tanks via a pump station located approximately one mile off shore, known as the Christy Lee Platform. The tank farms location has been controversial since the 1989/1990 eruption of Mount Redoubt, concerns were renewed during the 2009 eruptions of Redoubt. Dikes built after the 89/90 eruptions have kept the 2009 flooding away from the tanks, while the facility was again surrounded by lahars, the tank farm itself was not flooded and workers at the facility were not injured. The workers on site were evacuated to a safe room complete with food and sleeping quarters, as well as bathrooms, instead, the oil will simply be removed and sent to refineries, with damage to the tanks from further flooding still possible. The Coast Guard will coordinate the oil removal with the Alaska Volcano Observatory, Chevron Corporation official site Pacific Energy Resources website Alaska Division of Environmental Conservation Alaska Volcano Observatory Mount Redoubt activity page
Drift River oil terminal
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Location of the Drift River Terminal Facility
30.
Promyshlenniki
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Initially the Russians in Russian America were Siberian fur hunters, although many later worked as sailors, carpenters, artisans and craftsmen. Promyshlenniki formed the backbone of Russian trading operations in Alaska, after the Russian Conquest of Siberia, as a part of the regional fur trade, colonists began to exploit the vast populations of sables. The opportunities offered by this newly available luxury product drew many Russians eager to make a profit in the newly conquered Siberia, service-men that arrived, rarely able to receive a stable salary from the state, nonetheless had certain legal rights and duties while nominally a servant to Tsar. Merchants began to visit the Russian settlements, interested in selling the gathered furs at various markets, Promyshlenniki were free men who made their living any way they could. A minor group were sworn-men, agreeing to an oath in order to certain rights. In practice the groups blended into each other and the distinction was most important when dealing with the government, when petitioning the tsar, a service-man would call himself your slave and a promishlenik your orphan. These people were often called cossacks, but only in the sense of being neither land-owners nor peasants. As the Russian Empire expanded its network into Siberia, Russian colonists were able to be placed under Imperial regulations. The fierce competition between promyshlenniki led to the overexploitation of sable populations, continually forcing them to go further east, Promyshlenniki began to gather sable pelts located in the Amur basin during the early 17th century. Trappers based out of Nerchinsk regularly crossed the Qing border into Outer Manchuria by the 1730s to pursue sable populations residing there, Russian officials were aware of these operations, but tolerated any breach of the Russian-Chinese treaties which might occur. The Great Northern Expedition expanded Russian geographical knowledge to many of the Aleutian Islands, news of the many Sea otter populations along these lands quickly drew the attention of many Siberian based promyshlenniki. Few had naval experience, though began to travel the Bering Sea on kochs made from timber adjacent to the Sea of Okhotsk. The first Russian promyshlenniki to travel east was Emelian Basov, who sailed to Bering Island in 1743, Promyshlenniki based out of Okhotsk or Petropavlovsk, made provisions for their yearly operations in the Aleutians by killing sea cows of the Commander Islands to extinction. The Sea otters of the Aleutians were progressively exploited by Russians, as these early trappers had no knowledge of navigation, they consequently took no observations, made no surveys. And greatly limited geographical information for outsiders, the Lebedev-Lastochkin Company sent the first Russian promyshlenniki to investigate the resources of the lower Yukon River in 1790. The party, led by the hunter Ivanov, traveled from Iliamna Lake to the Kuskokwim, Ivanov reported on the extensive fish and game resources and the many people inhabiting the region. At first the traders returned to Kamchatka after every season but eventually trading posts were established in the territory and these posts began in the Aleutians and moved eastward toward the Alaska Peninsula rather than north to the Yukon delta and Bering Strait. Promyshlenniki were adept at hunting on land but they lacked the skills to hunt on water, the Promyshlenniki then turned to the native Aleut and Alutiiq men to do their hunting for them
Promyshlenniki
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Advancement of the Promyshlenniki to the East
