Greenland is located between the Arctic Ocean and the North Atlantic Ocean, northeast of Canada and northwest of Iceland. The territory comprises the island of Greenland—the largest island in the world—and more than a hundred other smaller islands. Greenland has a 1.2 kilometre long border with Canada on Hans Island. A sparse population is confined to small settlements along certain sectors of the coast. Greenland possesses the world's second-largest ice sheet.
A canyon, or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency to cut through underlying surfaces, eventually wearing away rock layers as sediments are removed downstream. A river bed will gradually reach a baseline elevation, which is the same elevation as the body of water into which the river drains. The processes of weathering and erosion will form canyons when the river's headwaters and estuary are at significantly different elevations, particularly through regions where softer rock layers are intermingled with harder layers more resistant to weathering.
Lake Vostok is the largest of Antarctica's almost 400 known subglacial lakes. Lake Vostok is located at the southern Pole of Cold, beneath Russia's Vostok Station under the surface of the central East Antarctic Ice Sheet, which is at 3,488 m (11,444 ft) above mean sea level. The surface of this fresh water lake is approximately 4,000 m (13,100 ft) under the surface of the ice, which places it at approximately 500 m (1,600 ft) below sea level.
An ice shelf is a large 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, Northern Canada, and the Russian Arctic. The boundary between the floating ice shelf and the anchor ice that feeds it is the grounding line. The thickness of ice shelves can range from about 100 m (330 ft) to 1,000 m (3,300 ft).
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi). The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Last Glacial Maximum, the Laurentide Ice Sheet covered much of North America, the Weichselian ice sheet covered Northern Europe and the Patagonian Ice Sheet covered southern South America.
The Greenland ice sheet is a vast body of ice covering 1,710,000 square kilometres (660,000 sq mi), roughly near 80% of the surface of Greenland. It is sometimes referred to as an ice cap, or under the term inland ice, or its Danish equivalent, indlandsis. An acronym, GIS, is frequently used in the scientific literature.
The Greenland Ice Core Project (GRIP) was a research project organized through the European Science Foundation (ESF). The project ran from 1989 to 1995, with drilling seasons from 1990 to 1992. In 1988, the project was accepted as an ESF-associated program, and in the summer of 1989, the fieldwork was started in Greenland.
A subglacial lake is a lake that is found under a glacier, typically beneath an ice cap or ice sheet. Subglacial lakes form at the boundary between ice and the underlying bedrock, where gravitational pressure decreases the pressure melting point of ice. Over time, the overlying ice gradually melts at a rate of a few millimeters per year. Meltwater flows from regions of high to low hydraulic pressure under the ice and pools, creating a body of liquid water that can be isolated from the external environment for millions of years.
Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica. It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy (USN) air photos, 1960–66, and named by the Advisory Committee on Antarctic Names (US-ACAN) in association with Pine Island Bay.
An ice stream is a region of fast-moving ice within an ice sheet. It is a type of glacier, a body of ice that moves under its own weight. They can move upwards of 1,000 metres (3,300 ft) a year, and can be up to 50 kilometres (31 mi) in width, and hundreds of kilometers in length. They tend to be about 2 km (1.2 mi) deep at the thickest, and constitute the majority of the ice that leaves the sheet. In Antarctica, the ice streams account for approximately 90% of the sheet's mass loss per year, and approximately 50% of the mass loss in Greenland.
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.
Whillans Ice Stream is a glaciological feature of the West Antarctic Ice Sheet, formerly known as Ice Stream B, renamed in 2001 in honor of Ohio State University glaciologist Ian Whillans.
Greenland's climate is a tundra climate on and near the coasts and an ice cap climate in inland areas. It typically has short, cool summers and long, moderately cold winters.
Petermann Glacier is a large glacier located in North-West Greenland to the east of Nares Strait. It connects the Greenland ice sheet to the Arctic Ocean at 81°10' north latitude, near Hans Island.
Nioghalvfjerdsbrae, sometimes referred to as "79 N Glacier", is a large glacier located in King Frederick VIII Land, northeastern Greenland. It drains an area of 103,314 km2 (39,890 sq mi) of the Greenland Ice Sheet with a flux of 14.3 km3 (3.4 cu mi) per year, as measured for 1996. The glacier has two calving fronts where the glacier meets the ocean, separated by Hovgaard Island. In July 2020, the northern offshoot, the Spalte Glacier broke away from Nioghalvfjerdsbrae and completely disintegrated.
Operation IceBridge is an ongoing NASA mission to monitor changes in polar ice. It is an airborne follow-on mission to the ICESat satellite, continuing until after the ICESat-2 mission launch in September 2018.
There are hundreds of antarctic lakes in Antarctica. In 2018 researchers at the Alfred Wegener Institute for Polar and Marine Research published a study they claimed cast doubt on the earlier estimate that there were almost 400 subglacial antarctic lakes. Antarctica also has some relatively small regions that are clear of ice and snow, and there are some surface lakes in these regions. They called for on the ground seismic studies, or drilling, to determine a more reliable number.
Lake Whillans is a subglacial lake in Antarctica. The lake is located under the Whillans Ice Stream at the southeastern edge of the Ross Ice Shelf in the west of the continent. The lake surface is 800 m (2,600 ft) beneath the surface of the ice and the lake covers an estimated area of 60 km2 (20 sq mi). Lake depths measured thus far have been around 2 metres. Its temperature is −0.49 °C, below 0 °C because of the high pressure.
Jemma L Wadham is a British glacial biogeochemist.
Jonathan Louis Bamber is a British physicist known for his work on satellite remote sensing of the polar regions and especially the Antarctic and Greenland ice sheets. He has authored more than 180 refereed scientific publications about the cryosphere and its interaction with the rest of the Earth System, and is recognised by the Institute for Scientific Information as a "highly cited researcher”. In 2019 he was elected a fellow of the American Geophysical Union "For pioneering satellite remote sensing in glaciology and building bridges to other disciplines of the geoscience community." He is the first non-US scientist in the Cryosphere division to receive this honour.
