Ice Shelf

An ice shelf is a thick floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded (resting on bedrock) ice that feeds it is called the grounding line. The thickness of ice shelves ranges from about 100 to 1000 metres.

In contrast, sea ice is formed on water, is much thinner (typically less than 3m), and forms throughout the Arctic Ocean. It also is found in the Southern Ocean around the continent of Antarctica.

Ice shelves are principally driven by gravity-driven pressure from the grounded ice That flow continually moves ice from the grounding line to the seaward front of the shelf. The primary mechanism of mass loss from ice shelves is iceberg calving, in which a chunk of ice breaks off from the seaward front of the shelf. Typically, a shelf front will extend forward for years or decades between major calving events. Snow accumulation on the upper surface and melting from the lower surface are also important to the mass balance of an ice shelf. Ice may also accrete onto the underside of the shelf.

The density contrast between glacial ice, which is denser than normal ice, and liquid water means that only about 1/9 of the floating ice is above the ocean surface. The world's largest ice shelves are the Ross Ice Shelf and the Filchner-Ronne Ice Shelf in Antarctica.

The term captured ice shelf has been used for the ice over a subglacial lake, such as Lake Vostok.

Read more about Ice Shelf:  Canadian Ice Shelves, Antarctic Ice Shelves, Ice Shelf Disruption

Other articles related to "ice shelf, ice":

Prince Gustav Ice Shelf
... Prince Gustav Ice Shelf (64°15′S 58°30′W / 64.250°S 58.500°W / -64.250 -58.500Coordinates 64°15′S 58°30′W / 64.250°S 58.500°W / -64.250 -58.500) was an ice shelf of more than 15 ... The ice shelf has since retreated and collapsed in 1995 Prince Gustav Channel was open throughout its length, and only a remnant in Rohss Bay remained ... domain material from the United States Geological Survey document "Prince Gustav Ice Shelf" (content from the Geographic Names Information System) ...
Arctic Cordillera - Geography - Glaciers and Ice Caps
... Cordillera is largely covered with ice caps while glaciers are more common at the more humid southern end ... Large portions of Ellesmere Island are covered with glaciers and ice, with Manson Icefield and Sydkap in the south Prince of Wales Icefield and Agassiz ... Island was covered by a massive, 500 km (310 mi) long ice shelf until the 20th century ...
List Of Antarctic Ice Shelves
... This is a list of Antarctic ice shelves ... Ice shelves are attached to 44% of the Antarctic coastline ... The ice shelf areas are listed below, clockwise, starting in the west of East Antarctica Filchner Ice Shelf Brunt Ice Shelf Riiser-Larsen Ice Shelf Quar Ice ...
Ice Shelf Disruption
... the last several decades, glaciologists have observed consistent decreases in ice shelf extent through melt, calving, and complete disintegration of some shelves ... The Ellesmere ice shelf reduced by 90 percent in the twentieth century, leaving the separate Alfred Ernest, Ayles, Milne, Ward Hunt, and Markham Ice Shelves ... A 1986 survey of Canadian ice shelves found that 48 km² ...
Mercator Cooper - First Visitor To Antarctica
... Making a quick passage through the belt of pack ice in the Ross Sea, on January 26, 1853, he sighted land, an ice shelf backed by a high mountain some 70 to 100 miles ... The next morning, the ice shelf still in sight, with high mountains looming behind it, he sailed the ship close inshore and ordered a boat to be lowered ... They made a landing on the ice shelf, reportedly seeing numerous penguins, but no seals – their chief objective ...

Famous quotes containing the words shelf and/or ice:

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    Samuel Butler (1835–1902)

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    —Anonymous Antebellum Confederate Women. Previously quoted by Mary Boykin Chesnut in Mary Chesnut’s Civil War, edited by C. Vann Woodward (1981)