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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. Glaciers slowly deform and flow under stresses induced by their weight, creating crevasses, seracs, and other distinguishing features. They also abrade rock and debris from their substrate to create landforms such as cirques, moraines, or fjords. Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that forms on the surface of bodies of water.
A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a very long period of time. Some valleys are formed through erosion by glacial ice. These glaciers may remain present in valleys in high mountain or polar areas. At lower latitudes and altitudes, these glacially-formed valleys may have been created or enlarged during ice ages but now are ice-free and occupied by streams or rivers. In desert areas, valleys may be entirely dry or carry a watercourse only rarely. In areas of limestone bedrock, dry valleys may also result from drainage taking place underground rather than at the surface. Rift valleys arise principally from earth movements, rather than erosion. Many different types of valley are described by geographers, using terms that may be global in use or else applied only locally.
In geology, a fjord or fiord is a long, narrow inlet with steep sides or cliffs, created by a glacier. There are many fjords on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Greenland, the Faroe Islands, Iceland, Ireland, Kamchatka, the Kerguelen Islands, New Zealand, Norway, Novaya Zemlya, Labrador, Nunavut, Newfoundland, Quebec, Scotland, South Georgia Island, Staten Island (Argentina), and Washington state. Norway's coastline is estimated at 29,000 kilometres (18,000 mi) with nearly 1,200 fjords, but only 2,500 kilometres (1,600 mi) when fjords are excluded.
A glacial erratic is glacially-deposited rock differing from the size and type of rock native to the area in which it rests. "Erratics" take their name from the Latin word errare, and are carried by glacial ice, often over distances of hundreds of kilometres. Erratics can range in size from pebbles to large boulders such as Big Rock in Alberta.
A cirque is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie and cwm. A cirque may also be a similarly shaped landform arising from fluvial erosion.
Eden Riegel is an American actress. She portrayed Bianca Montgomery in the daytime drama All My Children, and propelled the character into a gay icon, as well as a popular figure within the medium. Nominated previously on multiple occasions, she received a Daytime Emmy Award for the role in 2005.
The Driftless Area is a region in southwestern Wisconsin, southeastern Minnesota, northeastern Iowa, and the extreme northwestern corner of Illinois, of the American Midwest. The region escaped the flattening effects of glaciation during the last ice age and is consequently characterized by steep, forested ridges, deeply carved river valleys, and karst geology characterized by spring-fed waterfalls and cold-water trout streams. Ecologically, the Driftless Area's flora and fauna are more closely related to those of the Great Lakes region and New England than those of the broader Midwest and central Plains regions. Colloquially, the term includes the incised Paleozoic Plateau of southeastern Minnesota and northeastern Iowa. The region includes elevations ranging from 603 to 1,719 feet at Blue Mound State Park, and covers 24,000 square miles (62,200 km2). The rugged terrain is due both to the lack of glacial deposits, or drift, and to the incision of the upper Mississippi River and its tributaries into bedrock.
Glacial landforms are landforms created by the action of glaciers. Most of today's glacial landforms were created by the movement of large ice sheets during the Quaternary glaciations. Some areas, like Fennoscandia and the southern Andes, have extensive occurrences of glacial landforms; other areas, such as the Sahara, display rare and very old fossil glacial landforms.
In glaciology, a roche moutonnée is a rock formation created by the passing of a glacier. The passage of glacial ice over underlying bedrock often results in asymmetric erosional forms as a result of abrasion on the "stoss" (upstream) side of the rock and plucking on the "lee" (downstream) side. These erosional features are seen on scales of less than a metre to several hundred metres.
Riegel may refer to:
Plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock, especially large "joint blocks". This occurs in a type of glacier called a "valley glacier". As a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock. The freezing and thawing action of the ice enlarges, widens, or causes further cracks in the bedrock as it changes volume across the ice/water phase transition, gradually loosening the rock between the joints. This produces large pieces of rock called joint blocks. Eventually these joint blocks come loose and become trapped in the glacier.
Bianca Montgomery is a fictional character from the American daytime drama All My Children. Until Eden Riegel assumed the role, portraying the character from July 2000 to January 2010, the character was portrayed solely by child actresses: Lacey Chabert, Nathalie Paulding, Gina Gallagher, Caroline Wilde and Jessica Leigh Falborn. When Riegel decided to permanently exit the role, plans to recast were confirmed; in June 2010, Christina Bennett Lind replaced Riegel, and remained on the series through the original television finale episode, which aired September 23, 2011. In February 2013, it was announced that Riegel would be reprising her role as Bianca in a guest-arc on Prospect Park's continuation of All My Children.
A tunnel valley is a U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages. They can be as long as 100 km (62 mi), 4 km (2.5 mi) wide, and 400 m (1,300 ft) deep.
U-shaped valleys, trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom. Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice, called glacial till or glacial erratic.
The geology of Minnesota comprises the rock, minerals, and soils of the U.S. state of Minnesota, including their formation, development, distribution, and condition.
Abrasion is a process of erosion which occurs when material being transported wears away at a surface over time. It is the process of friction caused by scuffing, scratching, wearing down, marring, and rubbing away of materials. The intensity of abrasion depends on the hardness, concentration, velocity and mass of the moving particles. Abrasion generally occurs four ways. Glaciation slowly grinds rocks picked up by ice against rock surfaces. Solid objects transported in river channels make abrasive surface contact with the bed and walls. Objects transported in waves breaking on coastlines cause abrasion. And, finally, abrasion can be caused by wind transporting sand or small stones against surface rocks.
The geography of Iowa includes the study of bedrock, landforms, rivers, geology, paleontology and urbanisation of the U.S. state of Iowa. The state covers an area of 56,272.81 sq mi (145,746 km2).
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.
Overdeepening is a characteristic of basins and valleys eroded by glaciers. An overdeepened valley profile is often eroded to depths which are hundreds of metres below the deepest continuous line along a valley or watercourse. This phenomenon is observed under modern day glaciers, in salt-water fjords and fresh-water lakes remaining after glaciers melt, as well as in tunnel valleys which are partially or totally filled with sediment. When the channel produced by a glacier is filled with debris, the subsurface geomorphic structure is found to be erosionally cut into bedrock and subsequently filled by sediments. These overdeepened cuts into bedrock structures can reach a depth of several hundred metres below the valley floor.
The Edaga Arbi Glacials are a Palaeozoic geological formation in Tigray and in Eritrea. The matrix is composed of grey, black and purple clays, that contains rock fragments up to 6 metres across. Pollen dating yields a Late Carboniferous to Early Permian age.