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Holocene Glacial Retreat
The Holocene glacial retreat is a geographical phenomenon that involved the global retreat of glaciers ( deglaciation) that previously had advanced during the Last Glacial Maximum. Ice sheet retreat initiated ca. 19,000 years ago and accelerated after ca. 15,000 years ago. The Holocene, starting with abrupt warming 11,700 years ago, resulted in rapid melting of the remaining ice sheets of North America and Europe. Geographical alterations Antarctica Radiocarbon dating has been used to date the start of glacial retreat on Alexander Island 18,000 years ago. The outermost locations like Marguerite Bay were fully deglaciated 12,000 years ago and the further inland locations continued deglaciating for an additional 3,000 years. The Larsen ice shelf was formed in the early Holocene at the latest estimation of 10,700 years ago. Certain segments of the ice shelf have collapsed as recently as 1995 for Larsen A and a large segment of Larsen B collapsed in 2002. Europe The many valley ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Ice Age
The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Matthes described glaciers in the Sierra Nevada (U.S.), Sierra Nevada of California that he believed could not have survived the hypsithermal; his usage of "Little Ice Age" has been superseded by "Neoglaciation". The period has been conventionally defined as extending from the 16th to the 19th centuries, (noted in Grove 2004: 4). but some experts prefer an alternative time-span from about 1300 to about 1850. The NASA Earth Observatory notes three particularly cold intervals. One began about 1650, another about 1770, and the last in 1850, all of which were separated by intervals of slight warming. The Intergovernmental Panel on Climate Change IPCC Third Assessment Report, Third Assessment Report considered that the timing and the areas affecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Svalbard
Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norway, Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of continental Europe, mainland Europe, it lies about midway between the northern coast of Norway and the North Pole. The islands of the group range from 74th parallel north, 74° to 81st parallel north, 81° north latitude, and from 10th meridian east, 10° to 35th meridian east, 35° east longitude. The largest island is Spitsbergen (37,673 km2), followed in size by Nordaustlandet (14,443 km2), (5,073 km2), and Barentsøya (1,288 km2). Bear Island (Norway), Bjørnøya or Bear Island (178 km2) is the most southerly island in the territory, situated some 147 km south of Spitsbergen. Other small islands in the group include Hopen (Svalbard), Hopen to the southeast of Edgeøya, Kongsøya and Svenskøya in the east, and Kvitøya to the northeast. The largest settlement is Longyearbyen, situated in Isfjor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teays River
The Teays River (pronounced taze) was a major preglacial river that drained much of the present Ohio River watershed, but took a more northerly downstream course. Traces of the Teays across northern Ohio and Indiana are represented by a network of river valleys. The largest still existing contributor to the former Teays River is the Kanawha River in West Virginia, which is itself an extension of the New River. The name "Teays," from the much smaller Teays Valley still extant above the surface, has been associated with the river and the remainder of its related buried valley since 1910.The Glacial Boundary in Western Pennsylvania, Ohio, Kentucky, Indiana, and Illinois; George Frederick Weight; Bulletin of the United States Geological Survey No. 58; Washington, Government Printing Office; 1890; pg 86-88 The more appropriate name would be the Ancestral Kanawha Valley.Glacial Geology of Wabash County, Indiana: William J. Wayne and William D. Thornbury; Indiana Department of Conser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisville, Kentucky
Louisville is the List of cities in Kentucky, most populous city in the Commonwealth of Kentucky, sixth-most populous city in the Southeastern United States, Southeast, and the list of United States cities by population, 27th-most-populous city in the United States. By land area, it is the country's List of United States cities by area, 24th-largest city; however, by population density, it is the 265th most dense city. Louisville is the historical county seat and, since 2003, the nominal seat of Jefferson County, Kentucky, Jefferson County, on the Indiana border. Since 2003, Louisville and Jefferson County have shared the same borders following a consolidated city-county, city-county merger. The consolidated government is officially called the Louisville/Jefferson County Metro Government, commonly known as Louisville Metro. The term "Jefferson County" is still used in some contexts, especially for Louisville neighborhoods#Incorporated places, incorporated cities outside the "Lou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohio River
The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its river mouth, mouth on the Mississippi River in Cairo, Illinois, Cairo, Illinois. It is the third largest river by discharge volume in the United States and the largest tributary by volume of the Mississippi River. It is also the sixth oldest river on the North American continent. The river flows through or along the border of six U.S. state, states, and its drainage basin includes parts of 14 states. Through its largest tributary, the Tennessee River, the basin includes several states of the southeastern United States. It is the source of drinking water for five million people. The river became a primary transportation route for pioneers during the westward expansion of the early U.S. The lower Ohio River just below Louisville was obstructed by rapids known as the Falls of the Oh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Labrador Sea
The Labrador Sea (; ) is an arm of the North Atlantic Ocean between the Labrador Peninsula and Greenland. The sea is flanked by continental shelf, continental shelves to the southwest, northwest, and northeast. It connects to the north with Baffin Bay through the Davis Strait. It is a marginal sea of the Atlantic. The sea formed upon separation of the North American Plate and Greenland Plate that started about 60 million years ago and stopped about 40 million years ago. It contains one of the world's largest turbidity current channel systems, the Northwest Atlantic Mid-Ocean Channel (NAMOC), that runs for thousands of kilometers along the sea bottom toward the Atlantic Ocean. The Labrador Sea is a major source of the North Atlantic Deep Water, a cold water mass that flows at great depth along the western edge of the North Atlantic. History The Labrador Sea formed upon separation of the North American Plate and Greenland Plate that started about 60 million years ago (Paleocene) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland
Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenland are full Danish nationality law, citizens of Denmark and European Union citizenship, of the European Union. Greenland is one of the Special territories of members of the European Economic Area#Overseas countries and territories, Overseas Countries and Territories of the European Union and is part of the Council of Europe. It is the List of islands by area, world's largest island, and lies between the Arctic Ocean, Arctic and Atlantic oceans, east of the Arctic Archipelago, Canadian Arctic Archipelago. It is the location of the northernmost point of land in the world; Kaffeklubben Island off the northern coast is the world's Northernmost point of land, northernmost undisputed point of land—Cape Morris Jesup on the mainland was thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sermilik
Sermilik () is a fjord in eastern Greenland. It is part of the Sermersooq municipality. The settlement of Tasiilaq is located about 15 km to the east of the mouth of the fjord. Geography This fjord, whose Greenlandic name 'Sermilik' means 'place with glaciers' is located at the southern end of King Christian IX Land, west of Ammassalik Fjord. It is one of the largest fjords in the southeastern coast of Greenland. Its waters are fed by the Helheim Glacier, Fenris Glacier and Midgard Glacier among others. The fjord stretches inland in a roughly northern direction and splits into two branches at its head —at the southern limit of Schweizerland, the western one being the Helheim Fjord and the right one the Ningerti. Sermilik's mouth is located between Kitak Island and Cape Tycho Brahe in the Denmark Strait area of the Atlantic Ocean. Kangersivartikajik is the next fjord to the east along the coast. Near the fjord's entrance on the western side there is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuup Kangerlua
Nuup Kangerlua is a long fjord in the Sermersooq municipality in southwestern Greenland. It was formerly known by its colonial name as Godthaab Fjord (), Gilbert Sound and Baal's River.Nicoll, James. An Historical and Descriptive Account of Iceland, Greenland and the Faroe Islands'. Oliver & Boyd, 1840. Located by the island's capital, Nuuk, it is the longest fjord on the Labrador Sea coast of Greenland, and one of the longest in the inhabited part of the country. Geography The fjord head is located deep inland, with the fjord beginning as an icefjord at , with two glaciers draining the Greenland ice sheet () flowing into the fjord. Initially, the fjord flows to the northwest, to then turn southwest at , splitting into three arms in its lower run, with three large, mountainous islands in between the arms: Sermitsiaq Island with the Sermitsiaq mountain visible from most of Nuuk, Qeqertarsuaq Island, and Qoornuup Qeqertarsua Island. The fjord widens into a bay dotted wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoglaciation
The neoglaciation ("renewed glaciation") describes the documented cooling trend in the Earth's climate during the Holocene, following the retreat of the Wisconsin glaciation, the most recent glacial period. Neoglaciation has followed the Hypsithermal or Holocene Climatic Optimum, the warmest point in the Earth's climate during the current interglacial stage, excluding the global warming-induced temperature increase starting in the 20th century. The neoglaciation has no well-marked universal beginning: local conditions and ecological inertia affected the onset of detectably cooler (and wetter) conditions. Driven inexorably by the Milankovitch cycle, cooler summers in higher latitudes of North America, which would cease to melt the annual snowfall completely, were masked at first by the presence of the slowly disappearing continental ice sheets, which persisted long after the astronomically calculated moment of maximum summer warmth: "the neoglaciation can be said to have begun wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Agassiz
Lake Agassiz ( ) was a large proglacial lake that existed in central North America during the late Pleistocene, fed by meltwater from the retreating Laurentide Ice Sheet at the end of the last glacial period. At its peak, the lake's area was larger than all of the modern Great Lakes combined. It eventually drained into what is now Hudson Bay, leaving behind Lake Winnipeg, Lake Winnipegosis, Lake Manitoba, and Lake of the Woods. First postulated in 1823 by William H. Keating, it was named by Warren Upham in 1879 after Louis Agassiz, the then recently deceased (1873) founder of glaciology, when Upham recognized that the lake was formed by glacial action. Geological progression During the last glacial maximum, northern North America was covered by an ice sheet, which alternately advanced and retreated with variations in the climate. This continental ice sheet formed during the period now known as the Wisconsin glaciation, and covered much of central North America betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proglacial Lakes
In geology, a proglacial lake is a lake formed either by the damming action of a moraine during the retreat of a melting glacier, a glacial ice dam, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around the ice. At the end of the last ice age about 10,000 years ago, large proglacial lakes were a widespread feature in the northern hemisphere. Moraine-dammed The receding glaciers of the tropical Andes have formed a number of proglacial lakes, especially in the Cordillera Blanca of Peru, where 70% of all tropical glaciers are. Several such lakes have formed rapidly during the 20th century. These lakes may burst, creating a hazard for zones below. Many natural dams (usually moraines) containing the lake water have been reinforced with safety dams. Some 34 such dams have been built in the Cordillera Blanca to contain proglacial lakes. Several proglacial lakes have also formed in recent decades at the end of glaciers on the eastern side of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
