Loess is a clastic, predominantly silt-sized sediment, formed by the accumulation of wind-blown dust. Ten percent of the Earth's land area is covered by similar deposits. Loess is an aeolian sediment formed by the accumulation of wind-blown silt in the 20–50 micrometer size range, twenty percent or less clay and the balance equal parts sand and silt that are loosely cemented by calcium carbonate, it is homogeneous and porous and is traversed by vertical capillaries that permit the sediment to fracture and form vertical bluffs. The word loess, with connotations of origin by wind-deposited accumulation, came into English from German Löss, which can be traced back to Swiss German and is cognate with the English word loose and the German word los, it was first applied to Rhine River valley loess about 1821. Loess is homogeneous, friable, pale yellow or buff coherent non-stratified and calcareous. Loess grains are angular with little polishing or rounding and composed of crystals of quartz, feldspar and other minerals.
Loess can be described as a dust-like soil. Loess deposits may become thick, more than a hundred meters in areas of China and tens of meters in parts of the Midwestern United States, it occurs as a blanket deposit that covers areas of hundreds of square kilometers and tens of meters thick. Loess stands in either steep or vertical faces; because the grains are angular, loess will stand in banks for many years without slumping. This soil has a characteristic called vertical cleavage which makes it excavated to form cave dwellings, a popular method of making human habitations in some parts of China. Loess will erode readily. In several areas of the world, loess ridges have formed that are aligned with the prevailing winds during the last glacial maximum; these are called "paha ridges" in "greda ridges" in Europe. The form of these loess dunes has been explained by a combination of tundra conditions. Loess comes from the German Löss or Löß, from Alemannic lösch meaning drop as named by peasants and masons along the Rhine Valley.
The term "Löß" was first described in Central Europe by Karl Cäsar von Leonhard who reported yellowish brown, silty deposits along the Rhine valley near Heidelberg. Charles Lyell brought this term into widespread usage by observing similarities between loess and loess derivatives along the loess bluffs in the Rhine and Mississippi. At that time it was thought that the yellowish brown silt-rich sediment was of fluvial origin being deposited by the large rivers, it wasn't until the end of the 19th century that the aeolian origin of loess was recognized the convincing observations of loess in China by Ferdinand von Richthofen. A tremendous number of papers have been published since focusing on the formation of loess and on loess/palaeosol sequences as archives of climate and environment change; these water conservation works were carried out extensively in China and the research of Loess in China has been continued since 1954. Much effort was put into the setting up of regional and local loess stratigraphies and their correlation.
But the chronostratigraphical position of the last interglacial soil correlating to marine isotope substage 5e has been a matter of debate, owing to the lack of robust and reliable numerical dating, as summarized for example in Zöller et al. and Frechen, Horváth & Gábris for the Austrian and Hungarian loess stratigraphy, respectively. Since the 1980s, thermoluminescence, optically stimulated luminescence and infrared stimulated luminescence dating are available providing the possibility for dating the time of loess deposition, i.e. the time elapsed since the last exposure of the mineral grains to daylight. During the past decade, luminescence dating has improved by new methodological improvements the development of single aliquot regenerative protocols resulting in reliable ages with an accuracy of up to 5 and 10% for the last glacial record. More luminescence dating has become a robust dating technique for penultimate and antepenultimate glacial loess allowing for a reliable correlation of loess/palaeosol sequences for at least the last two interglacial/glacial cycles throughout Europe and the Northern Hemisphere.
Furthermore, the numerical dating provides the basis for quantitative loess research applying more sophisticated methods to determine and understand high-resolution proxy data, such as the palaeodust content of the atmosphere, variations of the atmospheric circulation patterns and wind systems, palaeoprecipitation and palaeotemperature. According to Pye, four fundamental requirements are necessary for the formation of loess: a dust source, adequate wind energy to transport the dust, a suitable accumulation area, a sufficient amount of time. Periglacial loess is derived from the floodplains of glacial braided rivers that carried large volumes of glacial meltwater and sediments from the annual melting of continental icesheets and mountain icecaps during the spring and summer. During the autumn and winter, when melting of the icesheets and icecaps ceased, the flow of meltwater down these rivers either ceased or was reduced; as a consequence, large parts of the submerged and unvegetated floodplains of these braided rivers dried out and were exposed to the wind.
Because these floodplains consist of sediment containing a high content of glacial
United States congressional delegations from Iowa
These are tables of congressional delegations from Iowa to the United States House of Representatives and the United States Senate. List of members of the Iowan United States House delegation, their terms in office, district boundaries, the district political ratings according to the CPVI; the delegation has a total including 1 Republican and 3 Democrats. On July 4, 1838, the Iowa Territory was organized. Most of the area comprising the territory was part of the Louisiana Purchase and was a part of the Missouri Territory; when Missouri became a state in 1821, this area became unorganized territory. The area was closed to white settlers until the 1830s, it was attached to the Michigan Territory on June 28, 1834, was split off with the Wisconsin Territory in 1836 when Michigan became a state. The Iowa Territory was the "Iowa District" of western Wisconsin Territory – the region west of the Mississippi River; the original boundaries of the territory, as established in 1838, included part of Minnesota and parts of the Dakotas, covering about 194,000 square miles of land.
As of December 2018, there are three living former senators from Iowa. List of United States congressional districts Iowa's congressional districts
Last Glacial Period
The Last Glacial Period occurred from the end of the Eemian interglacial to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. This most recent glacial period is part of a larger pattern of glacial and interglacial periods known as the Quaternary glaciation extending from c. 2,588,000 years ago to present. The definition of the Quaternary as beginning 2.58 Ma is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, in the mid-Cenozoic; the term Late Cenozoic Ice Age is used to include this early phase. During this last glacial period there were alternating episodes of glacier retreat. Within the last glacial period the Last Glacial Maximum was 22,000 years ago. While the general pattern of global cooling and glacier advance was similar, local differences in the development of glacier advance and retreat make it difficult to compare the details from continent to continent. 13,000 years ago, the Late Glacial Maximum began.
The end of the Younger Dryas about 11,700 years ago marked the beginning of the Holocene geological epoch, which includes the Holocene glacial retreat. From the point of view of human archaeology, the last glacial period falls in the Paleolithic and early Mesolithic periods; when the glaciation event started, Homo sapiens were confined to lower latitudes and used tools comparable to those used by Neanderthals in western and central Eurasia and by Homo erectus in Asia. Near the end of the event, Homo sapiens migrated into Australia. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived the last glacial period in sparsely wooded areas and dispersed through areas of high primary productivity while avoiding dense forest cover; the last glacial period is sometimes colloquially referred to as the "last ice age", though this use is incorrect because an ice age is a longer period of cold temperature in which year-round ice sheets are present near one or both poles.
Glacials are colder phases within an ice age. Thus, the end of the last glacial period, about 11,700 years ago, is not the end of the last ice age since extensive year-round ice persists in Antarctica and Greenland. Over the past few million years the glacial-interglacial cycles have been "paced" by periodic variations in the Earth's orbit via Milankovitch cycles; the last glacial period is the best-known part of the current ice age, has been intensively studied in North America, northern Eurasia, the Himalaya and other glaciated regions around the world. The glaciations that occurred during this glacial period covered many areas in the Northern Hemisphere and to a lesser extent in the Southern Hemisphere, they have different names developed and depending on their geographic distributions: Fraser, Wisconsinan or Wisconsin, Midlandian, Würm, Mérida, Weichselian or Vistulian, Valdai in Russia and Zyryanka in Siberia, Llanquihue in Chile, Otira in New Zealand. The geochronological Late Pleistocene includes the late glacial and the preceding penultimate interglacial period.
Canada was nearly covered by ice, as well as the northern part of the United States, both blanketed by the huge Laurentide Ice Sheet. Alaska remained ice free due to arid climate conditions. Local glaciations existed in the Rocky Mountains and the Cordilleran Ice Sheet and as ice fields and ice caps in the Sierra Nevada in northern California. In Britain, mainland Europe, northwestern Asia, the Scandinavian ice sheet once again reached the northern parts of the British Isles, Germany and Russia, extending as far east as the Taymyr Peninsula in western Siberia; the maximum extent of western Siberian glaciation was reached by 16,000–15,000 BC and thus than in Europe. Northeastern Siberia was not covered by a continental-scale ice sheet. Instead, but restricted, icefield complexes covered mountain ranges within northeast Siberia, including the Kamchatka-Koryak Mountains; the Arctic Ocean between the huge ice sheets of America and Eurasia was not frozen throughout, but like today was only covered by shallow ice, subject to seasonal changes and riddled with icebergs calving from the surrounding ice sheets.
According to the sediment composition retrieved from deep-sea cores there must have been times of seasonally open waters. Outside the main ice sheets, widespread glaciation occurred on the highest mountains of the Alps−Himalaya mountain chain. In contrast to the earlier glacial stages, the Würm glaciation was composed of smaller ice caps and confined to valley glaciers, sending glacial lobes into the Alpine foreland; the [, the highest massifs of the Carpathian Mountains and the Balkanic peninsula mountains and to the east the Caucasus and the mountains of Turkey and Iran were capped by local ice fields or small ice sheets. In the Himalaya and the Tibetan Plateau, glaciers advanced particularly between 45,000 and 25,000 BC, but these datings are controversial; the formation of a contiguous ice sheet on the Tibetan Plateau is controversial. Other areas of the Northern Hemisphere did not bear extensive ice sheets, but local glaciers in high areas. Parts of Taiwan, for example, were glaciated between 42,250 and 8,680 BCE as well as the Japanese Alps
Rochester is a city founded in 1854 in the U. S. State of Minnesota and is the county seat of Olmsted County located on the Zumbro River's south fork in Southeast Minnesota, it is Minnesota's third-largest city and the largest city located outside the Minneapolis-St. Paul Metropolitan Statistical Area; as of 2015, the Rochester metropolitan area has a population of 215,884. According to the 2010 United States Census the city has a population of 106,769; the U. S. Census Bureau estimated that the 2017 population was 115,733, it is the home of the Mayo Clinic and an IBM facility one of the company's largest. The city has long been rated as one of the best places to live in the United States by multiple publications such as Money; the area developed as a stagecoach stop between Saint Paul and Dubuque, Iowa near the Zumbro River. The community was founded by George Head and his wife Henrietta who built log cabin Head's Tavern in 1854 and named the city after his hometown of Rochester, New York; when the Winona and St Peter Railroad initiated service in October 1864, it brought new residents and business opportunities further spurring growth and expansion.
In 1863, Dr. William W. Mayo arrived as the examining surgeon for Union draftees in the Civil War. Rochester celebrated its sesquicentennial in 2004. On August 21, 1883, the Great Tornado demolished much of Rochester, leaving 37 dead and 200 injured; as there was no medical facility in the immediate area at the time, Dr. Mayo and his two sons worked together to care for the wounded. Donations of US$60,000 were collected and the Sisters of St. Francis, assisted by Mayo, opened a new facility named St. Marys Hospital in 1889; the Mayo practice grew and is today among the largest and most well-respected medical facilities in the world. Many notable people from around the world, including former Presidents Franklin D. Roosevelt, Harry S. Truman, George H. W. Bush, Gerald Ford, Ronald Reagan, have visited Rochester as patients of the Mayo Clinic. Rochester has been hit by two F4 tornadoes since 1950. Rochester lies alongside the South Fork of the Zumbro River, 57.6 miles long and is ringed by gentle hills and surrounded by farmland within a deciduous forest biome.
The Zumbro Watershed flows through 1,422 square miles of urban lands. Located in southeast Minnesota, the City of Rochester falls within the Driftless Area: the only region in North America, never glaciated and contains deeply-carved river valleys; the rugged terrain is due both to the lack of glacial deposits, or drift, to the incision of the upper Mississippi River and its tributaries into bedrock. According to the United States Census Bureau, the city has a total area of 54.75 square miles, of which 54.59 square miles of it is land and 0.16 square miles is water. The city is located 85 miles southeast of Minneapolis-St. Paul. Rochester is in one of only four counties in Minnesota without a natural lake. Artificial lakes exist in the area, including Silver Lake, a dammed portion of the South Fork Zumbro River just below the convergence with Silver Creek near the city center. Silver Lake was once used as a cooling pond when the coal-burning power plant was operated by Rochester Public Utilities at the lake.
When operational, the RPU coal plant's heated water output prevented the lake from freezing over during the winter months. Rochester has an extensive parks system, the largest of which are Silver Lake and Soldiers Field in the central part of the city. A major flood in 1978 led the city to embark on an expensive and successful flood-control project that involved altering many nearby rivers and streams; the Zumbro river flowing through the center of the city is presently being readdressed for increased development and use as part of city planning in conjunction with funding from the Destination Medical Center project. Rochester features a humid continental climate, with hot summers and cold winters; the city features four distinct seasons. Rochester sees on 48 inches of snowfall per year. Significant snow accumulation is common during the winter months. Spring and fall are transitional seasons, with a general warming trend during the spring and a general cooling trend during the fall. However, it is not uncommon to see some snowfall during the early months of spring and the months of fall.
Rochester is the second windiest city in the United States, with wind speeds averaging 12.6 mph. January to April are the windiest months on average, according to The Weather Channel; as of the census of 2010, there were 106,769 people, 43,025 households, 26,853 families residing in the city. The population density was 1,955.8 inhabitants per square mile. There were 45,683 housing units at an average density of 836.8 per square mile. The racial makeup of the city was 82.0% White, 6.3% African American, 0.3% Native American, 6.8% Asian, 2.0% from other races, 2.6% from two or more races. Hispanic or Latino of any race were 7.2% of the population. In terms of ancestry, the 2005–2007 American Community Survey found German Americans to be the largest single ethnic group in Rochester, making up 35.5% of the city's population. Norwegian Americans made up 15.9%, while Irish Americans contributed to 11.6% of the city's populace. English Americans made up 8.2% of the populatio
A glacier is a persistent body of dense ice, moving under its own weight. Glaciers deform and flow due to stresses induced by their weight, creating crevasses and other distinguishing features, they abrade rock and debris from their substrate to create landforms such as cirques and moraines. Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. On Earth, 99% of glacial ice is contained within vast ice sheets in the polar regions, but glaciers may be found in mountain ranges on every continent including Oceania's high-latitude oceanic island countries such as New Zealand and Papua New Guinea. Between 35°N and 35°S, glaciers occur only in the Himalayas, Rocky Mountains, a few high mountains in East Africa, New Guinea and on Zard Kuh in Iran. Glaciers cover about 10 percent of Earth's land surface. Continental glaciers cover nearly 13 million km2 or about 98 percent of Antarctica's 13.2 million km2, with an average thickness of 2,100 m.
Greenland and Patagonia have huge expanses of continental glaciers. Glacial ice is the largest reservoir of fresh water on Earth. Many glaciers from temperate and seasonal polar climates store water as ice during the colder seasons and release it in the form of meltwater as warmer summer temperatures cause the glacier to melt, creating a water source, important for plants and human uses when other sources may be scant. Within high-altitude and Antarctic environments, the seasonal temperature difference is not sufficient to release meltwater. Since glacial mass is affected by long-term climatic changes, e.g. precipitation, mean temperature, cloud cover, glacial mass changes are considered among the most sensitive indicators of climate change and are a major source of variations in sea level. A large piece of compressed ice, or a glacier, appears blue, as large quantities of water appear blue; this is. The other reason for the blue color of glaciers is the lack of air bubbles. Air bubbles, which give a white color to ice, are squeezed out by pressure increasing the density of the created ice.
The word glacier is a loanword from French and goes back, via Franco-Provençal, to the Vulgar Latin glaciārium, derived from the Late Latin glacia, Latin glaciēs, meaning "ice". The processes and features caused by or related to glaciers are referred to as glacial; the process of glacier establishment and flow is called glaciation. The corresponding area of study is called glaciology. Glaciers are important components of the global cryosphere. Glaciers are categorized by their morphology, thermal characteristics, behavior. Cirque glaciers form on the slopes of mountains. A glacier that fills a valley is called a valley glacier, or alternatively an alpine glacier or mountain glacier. A large body of glacial ice astride a mountain, mountain range, or volcano is termed an ice cap or ice field. Ice caps have an area less than 50,000 km2 by definition. Glacial bodies larger than 50,000 km2 are called continental glaciers. Several kilometers deep, they obscure the underlying topography. Only nunataks protrude from their surfaces.
The only extant ice sheets are the two that cover most of Greenland. They contain vast quantities of fresh water, enough that if both melted, global sea levels would rise by over 70 m. Portions of an ice sheet or cap that extend into water are called ice shelves. Narrow, fast-moving sections of an ice sheet are called ice streams. In Antarctica, many ice streams drain into large ice shelves; some drain directly into the sea with an ice tongue, like Mertz Glacier. Tidewater glaciers are glaciers that terminate in the sea, including most glaciers flowing from Greenland, Antarctica and Ellesmere Islands in Canada, Southeast Alaska, the Northern and Southern Patagonian Ice Fields; as the ice reaches the sea, pieces break off, or calve. Most tidewater glaciers calve above sea level, which results in a tremendous impact as the iceberg strikes the water. Tidewater glaciers undergo centuries-long cycles of advance and retreat that are much less affected by the climate change than those of other glaciers.
Thermally, a temperate glacier is at melting point throughout the year, from its surface to its base. The ice of a polar glacier is always below the freezing point from the surface to its base, although the surface snowpack may experience seasonal melting. A sub-polar glacier includes both temperate and polar ice, depending on depth beneath the surface and position along the length of the glacier. In a similar way, the thermal regime of a glacier is described by its basal temperature. A cold-based glacier is below freezing at the ice-ground interface, is thus frozen to the underlying substrate. A warm-based glacier is above or at freezing at the interface, is able to slide at this contact; this contrast is thought to a large extent to govern the ability of a glacier to erode its bed, as sliding ice promotes plucking at rock from the surface below. Glaciers which are cold-based and warm-based are known as polythermal. Glaciers form where the accumulation of ice exceeds ablation. A glacier originates from a landform called'cirque' – a armchair-shaped geological feature (such as a depressio
Attorney General of Iowa
The Attorney General of Iowa is the state attorney general of the Government of Iowa, United States. Office holders include people elected as the Constitution of Iowa requires it and appointed by the Governor of Iowa to fill a vacancy; the office was created February 9, 1853. The Office of the Attorney General is housed in the Lucas State Office Building in Des Moines; as stated in Iowa law, the powers and duties of the office include: representing the departments and agencies of state government. The Attorney General issues legal opinions on questions of law submitted by elected or appointed state officials and defends all tort claim actions against the state. Iowa is unique in that its Attorney General belongs to the judicial branch of government, as opposed to the executive branch of government, as do 48 of the other 50 states. Iowa Attorney General official website Iowa Attorney General articles at Legal Newsline Legal Journal Iowa Attorney General articles at ABA Journal News and Commentary at FindLaw Iowa Code at Law.
Justia.com U. S. Supreme Court Opinions - "Cases with title containing: State of Iowa" at FindLaw The Iowa State Bar Association Iowa Attorney General Tom Miller profile at National Association of Attorneys General Press releases at Iowa Attorney General
Minnesota is a state in the Upper Midwest and northern regions of the United States. Minnesota was admitted as the 32nd U. S. state on May 11, 1858, created from the eastern half of the Minnesota Territory. The state has a large number of lakes, is known by the slogan the "Land of 10,000 Lakes", its official motto is L'Étoile du Nord. Minnesota is the 12th largest in area and the 22nd most populous of the U. S. states. This area is the center of transportation, industry and government, while being home to an internationally known arts community; the remainder of the state consists of western prairies now given over to intensive agriculture. Minnesota was inhabited by various indigenous peoples for thousands of years prior to the arrival of Europeans. French explorers and fur traders began exploring the region in the 17th century, encountering the Dakota and Ojibwe/Anishinaabe tribes. Much of what is today Minnesota was part of the vast French holding of Louisiana, purchased by the United States in 1803.
Following several territorial reorganizations, Minnesota in its current form was admitted as the country's 32nd state on May 11, 1858. Like many Midwestern states, it remained centered on lumber and agriculture. During the 19th and early 20th centuries, a large number of European immigrants from Scandinavia and Germany, began to settle the state, which remains a center of Scandinavian American and German American culture. In recent decades, immigration from Asia, the Horn of Africa, the Middle East, Latin America has broadened its demographic and cultural composition; the state's economy has diversified, shifting from traditional activities such as agriculture and resource extraction to services and finance. Minnesota's standard of living index is among the highest in the United States, the state is among the best-educated and wealthiest in the nation; the word Minnesota comes from the Dakota name for the Minnesota River: The river got its name from one of two words in the Dakota language,'Mní sóta' which means "clear blue water", or'Mnißota', which means cloudy water.
Native Americans demonstrated the name to early settlers by dropping milk into water and calling it mnisota. Many places in the state have similar names, such as Minnehaha Falls, Minneota, Minnetonka and Minneapolis, a combination of mni and polis, the Greek word for "city". Minnesota is the second northernmost U. S. state and northernmost contiguous state. Its isolated Northwest Angle in Lake of the Woods county is the only part of the 48 contiguous states lying north of the 49th parallel; the state is part of the U. S. region known as part of North America's Great Lakes Region. It shares a Lake Superior water border with Michigan and a land and water border with Wisconsin to the east. Iowa is to the south, North Dakota and South Dakota are to the west, the Canadian provinces of Ontario and Manitoba are to the north. With 86,943 square miles, or 2.25% of the United States, Minnesota is the 12th-largest state. Minnesota has gneisses that are about 3.6 billion years old. About 2.7 billion years ago, basaltic lava poured out of cracks in the floor of the primordial ocean.
The roots of these volcanic mountains and the action of Precambrian seas formed the Iron Range of northern Minnesota. Following a period of volcanism 1.1 billion years ago, Minnesota's geological activity has been more subdued, with no volcanism or mountain formation, but with repeated incursions of the sea, which left behind multiple strata of sedimentary rock. In more recent times, massive ice sheets at least one kilometer thick ravaged the state's landscape and sculpted its terrain; the Wisconsin glaciation left 12,000 years ago. These glaciers covered all of Minnesota except the far southeast, an area characterized by steep hills and streams that cut into the bedrock; this area is known as the Driftless Zone for its absence of glacial drift. Much of the remainder of the state outside the northeast has 50 feet or more of glacial till left behind as the last glaciers retreated. Gigantic Lake Agassiz formed in the northwest 13,000 years ago, its bed created the fertile Red River valley, its outflow, glacial River Warren, carved the valley of the Minnesota River and the Upper Mississippi downstream from Fort Snelling.
Minnesota is geologically quiet today. The state's high point is Eagle Mountain at 2,301 feet, only 13 miles away from the low of 601 feet at the shore of Lake Superior. Notwithstanding dramatic local differences in elevation, much of the state is a rolling peneplain. Two major drainage divides meet in Minnesota's northeast in rural Hibbing, forming a triple watershed. Precipitation can follow the Mississippi River south to the Gulf of Mexico, the Saint Lawrence Seaway east to the Atlantic Ocean, or the Hudson Bay watershed to the Arctic Ocean; the state's nickname, "Land of 10,000 Lakes", is apt, as there are 11,842 Minnesota lakes over 10 acres in size. Minnesota's portion of Lake Superior is the largest at 962,700 acres and deepest body of wate