Related Research Articles
A glacier is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
A moraine is any accumulation of unconsolidated debris, sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice sheet. It may consist of partly rounded particles ranging in size from boulders down to gravel and sand, in a groundmass of finely-divided clayey material sometimes called glacial flour. Lateral moraines are those formed at the side of the ice flow, and terminal moraines were formed at the foot, marking the maximum advance of the glacier. Other types of moraine include ground moraines and medial moraines.
Lamoille County is a county located in the U.S. state of Vermont. As of the 2020 census, the population was 25,945, and it is the third-least populous county in Vermont. Its shire town is the town of Hyde Park, while Morristown is the county's largest town by population as well as its main commercial center. The county was created in 1835 from portions of Orleans, Franklin, Washington, and Chittenden Counties and organized the following year.
A kame delta is a glacial landform formed by a stream of melt water flowing through or around a glacier and depositing material, known as kame deposits. Upon entering a proglacial lake at the end (terminus) of a glacier, the river/stream deposit these sediments. This landform can be observed after the glacier has melted and the delta's asymmetrical triangular shape is visible. Once the glacier melts, the edges of the delta may subside as ice under it melts. Glacial till is deposited on the lateral sides of the delta, as the glacier melts.
Post-glacial rebound is the rise of land masses after the removal of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression. Post-glacial rebound and isostatic depression are phases of glacial isostasy, the deformation of the Earth's crust in response to changes in ice mass distribution. The direct raising effects of post-glacial rebound are readily apparent in parts of Northern Eurasia, Northern America, Patagonia, and Antarctica. However, through the processes of ocean siphoning and continental levering, the effects of post-glacial rebound on sea level are felt globally far from the locations of current and former ice sheets.
Jökulsárlón is a large glacial lake in southern part of Vatnajökull National Park, Iceland. Situated at the head of the Breiðamerkurjökull glacier, it developed into a lake after the glacier started receding from the edge of the Atlantic Ocean. The lake has grown since then at varying rates because of melting of the glaciers. The glacial front is now about 8 km (5.0 mi) away from the ocean's edge and the lake covers an area of about 18 km2 (6.9 sq mi). In 2009 it was reported to be the deepest lake in Iceland, at over 284 m (932 ft), as glacial retreat extended its boundaries. The size of the lake has increased fourfold since the 1970s.
A jökulhlaup is a type of glacial outburst flood. It is an Icelandic term that has been adopted in glaciological terminology in many languages. It originally referred to the well-known subglacial outburst floods from Vatnajökull, Iceland, which are triggered by geothermal heating and occasionally by a volcanic subglacial eruption, but it is now used to describe any large and abrupt release of water from a subglacial or proglacial lake/reservoir.
A kettle is a depression or hole in an outwash plain formed by retreating glaciers or draining floodwaters. The kettles are formed as a result of blocks of dead ice left behind by retreating glaciers, which become surrounded by sediment deposited by meltwater streams as there is increased friction. The ice becomes buried in the sediment and when the ice melts, a depression is left called a kettle hole, creating a dimpled appearance on the outwash plain. Lakes often fill these kettles; these are called kettle hole lakes. Another source is the sudden drainage of an ice-dammed lake and when the block melts, the hole it leaves behind is a kettle. As the ice melts, ramparts can form around the edge of the kettle hole. The lakes that fill these holes are seldom more than 10 m (33 ft) deep and eventually fill with sediment. In acid conditions, a kettle bog may form but in alkaline conditions, it will be kettle peatland.
Glacial motion is the motion of glaciers, which can be likened to rivers of ice. It has played an important role in sculpting many landscapes. Most lakes in the world occupy basins scoured out by glaciers. Glacial motion can be fast or slow, but is typically around 25 centimetres per day (9.8 in/d).
Lake Hitchcock was a glacial lake that formed approximately 15,000 years ago in the late Pleistocene epoch. After the Laurentide Ice Sheet retreated, glacial ice melt accumulated at the terminal moraine and blocked up the Connecticut River, creating the long, narrow lake. The lake existed for approximately 3,000 years, after which a combination of erosion and continuing geological changes likely caused it to drain. At its longest, Lake Hitchcock stretched from the moraine dam at present-day Rocky Hill, Connecticut, to St. Johnsbury, Vermont. Although the rift valley through which the river flows above Rocky Hill actually continues south to New Haven, on Long Island Sound, the obstructing moraine at Rocky Hill diverted the river southeast to its present mouth at Old Saybrook.
A subglacial volcano, also known as a glaciovolcano, is a volcanic form produced by subglacial eruptions or eruptions beneath the surface of a glacier or ice sheet which is then melted into a lake by the rising lava. Today they are most common in Iceland and Antarctica; older formations of this type are found also in British Columbia and Yukon Territory, Canada.
A moulin is a roughly circular, vertical well-like shaft formed where a surface meltstream exploits a weakness in the ice. The term is derived from the French word for mill.
A glacial lake outburst flood (GLOF) is a type of outburst flood caused by the failure of a dam containing a glacial lake. An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier, is called a jökulhlaup. The dam can consist of glacier ice or a terminal moraine. Failure can happen due to erosion, a buildup of water pressure, an avalanche of rock or heavy snow, an earthquake or cryoseism, volcanic eruptions under the ice, or massive displacement of water in a glacial lake when a large portion of an adjacent glacier collapses into it.
The retreat of glaciers since 1850 is well documented and is one of the effects of climate change. The retreat of mountain glaciers, notably in western North America, Asia, the Alps and tropical and subtropical regions of South America, Africa and Indonesia, provide evidence for the rise in global temperatures since the late 19th century. The acceleration of the rate of retreat since 1995 of key outlet glaciers of the Greenland and West Antarctic ice sheets may foreshadow a rise in sea level, which would affect coastal regions. Excluding peripheral glaciers of ice sheets, the total cumulated global glacial losses over the 26-year period from 1993 to 2018 were likely 5500 gigatons, or 210 gigatons per yr.
Meltwater is water released by the melting of snow or ice, including glacial ice, tabular icebergs and ice shelves over oceans. Meltwater is often found during early spring when snow packs and frozen rivers melt with rising temperatures, and in the ablation zone of glaciers where the rate of snow cover is reducing. Meltwater can be produced during volcanic eruptions, in a similar way in which the more dangerous lahars form. It can also be produced by the heat generated by the flow itself.
A cryoseism, ice quake or frost quake, is a seismic event caused by a sudden cracking action in frozen soil or rock saturated with water or ice, or by stresses generated at frozen lakes. As water drains into the ground, it may eventually freeze and expand under colder temperatures, putting stress on its surroundings. This stress builds up until relieved explosively in the form of a cryoseism. The requirements for a cryoseism to occur are numerous; therefore, accurate predictions are not entirely possible and may constitute a factor in structural design and engineering when constructing in an area historically known for such events. Speculation has been made between global warming and the frequency of cryoseisms.
Glacial Lake Albany was a prehistoric North American proglacial lake that formed during the end of the Wisconsinan glaciation. It existed between 15,000 and 12,600 years ago and was created when meltwater from a retreating glacier, along with water from rivers such as the Iromohawk, became ice dammed in the Hudson Valley. Organic materials in Lake Albany deposits have been carbon dated to approximately 11,700 years ago. The lake spanned approximately 160 miles (260 km) from present-day Poughkeepsie to Glens Falls.
New England is a region in the North Eastern United States consisting of the states Rhode Island, Connecticut, Massachusetts, New Hampshire, Vermont, and Maine. Most of New England consists geologically of volcanic island arcs that accreted onto the eastern edge of the Laurentian Craton in prehistoric times. Much of the bedrock found in New England is heavily metamorphosed due to the numerous mountain building events that occurred in the region. These events culminated in the formation of Pangaea; the coastline as it exists today was created by rifting during the Jurassic and Cretaceous periods. The most recent rock layers are glacial conglomerates.
Lake Vermont, also called Glacial Lake Vermont, was a temporary lake created by the retreating glaciers during the close of the last ice age. The lake once included land in the Canadian province of Quebec and the American states Vermont and New York. It was a geologic predecessor of Lake Champlain. Once the glacier retreated far enough north, it drained into Glacial Lake Candona, a geologic predecessor of the St. Lawrence River.
Lake Merrimack was a glacial lake that formed during the late Pleistocene epoch. After the Laurentide Ice Sheet retreated, glacial ice melt accumulated at the terminal moraine and blocked up the Merrimack River, creating the narrow lake. The lake extended from Manchester to Plymouth, New Hampshire. It is unknown when the lake was drained.
References
- ↑ New England Intercollegiate Geological Conference (16 June 1972). "Guide book". [S.l. : s.n. – via Internet Archive.
- ↑ "Native Americans in Vermont: The Abenaki". Archived from the original on 2006-07-14. Retrieved 2011-10-01.
- ↑ "Archived copy" (PDF). Archived from the original (PDF) on 2006-09-18. Retrieved 2011-10-01.
{{cite web}}: CS1 maint: archived copy as title (link)
| Africa | |||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Antarctica | |||||||||||||||||||||||||||||
| Asia | |||||||||||||||||||||||||||||
| Europe |
| ||||||||||||||||||||||||||||
| North America |
| ||||||||||||||||||||||||||||
| South America | |||||||||||||||||||||||||||||
| Summary | |||||||||||||||||||||||||||||
 | This article about a location in Vermont is a stub. You can help Wikipedia by expanding it. |