Ross Ice Shelf in the context of "Transantarctic Mountains"

The Ross Dependency is a region of Antarctica defined by a sector originating at the South Pole, passing along longitudes 160° east to 150° west, and terminating at latitude 60° south. It is claimed by New Zealand, a claim mutually accepted only by Australia, the UK, France and Norway, which are countries that also have territorial claims in Antarctica. Under the 1961 Antarctic Treaty, of which all territorial claimants are signatories, including New Zealand, all claims are held in abeyance. Article IV states: "No acts or activities taking place while the present Treaty is in force shall constitute a basis for asserting, supporting or denying a claim to territorial sovereignty in Antarctica or create any rights of sovereignty in Antarctica".

The Dependency takes its name from Sir James Clark Ross, who discovered the Ross Sea and includes part of Victoria Land, and most of the Ross Ice Shelf. Ross, Balleny, Scott and Roosevelt Islands also form part of the Dependency.

Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of 1,610,000 km (620,000 sq mi), it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century.

The territory lies in West Antarctica, east of the Ross Ice Shelf and the Ross Sea and south of the Pacific Ocean portion of the Antarctic or Southern Ocean, extending eastward approximately to a line between the head of the Ross Ice Shelf and Eights Coast. It stretches between 158°W and 103°24'W. The inclusion of the area between the Rockefeller Plateau and Eights Coast is based upon Byrd's exploration.

An ice shelf is a large platform of glacial ice floating on the ocean, fed by one or multiple tributary glaciers. Ice shelves form along coastlines where the ice thickness is insufficient to displace the more dense surrounding ocean water. The boundary between the ice shelf (floating) and grounded ice (resting on bedrock or sediment) is referred to as the grounding line; the boundary between the ice shelf and the open ocean (often covered by sea ice) is the ice front or calving front.

Ice shelves are found in Antarctica and the Arctic (Greenland, Northern Canada, and the Russian Arctic), and can range in thickness from about 100–1,000 m (330–3,280 ft). The world's largest ice shelves are the Ross Ice Shelf and the Filchner-Ronne Ice Shelf in Antarctica.

79°S 100°W / 79°S 100°W / -79; -100

West Antarctica, or Lesser Antarctica, one of the two major regions of Antarctica, is the part of that continent that lies within the Western Hemisphere, and includes the Antarctic Peninsula. It is separated from East Antarctica by the Transantarctic Mountains and is covered by the West Antarctic Ice Sheet. It lies between the Ross Sea (partly covered by the Ross Ice Shelf), and the Weddell Sea (largely covered by the Filchner-Ronne Ice Shelf). It may be considered a giant peninsula, stretching from the South Pole towards the tip of South America.

78°44′03″S 133°16′41″W / 78.73417°S 133.27806°W / -78.73417; -133.27806

The West Antarctic Ice Sheet (WAIS) is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. It is classified as a marine-based ice sheet, meaning that its bed lies well below sea level and its edges flow into floating ice shelves. The WAIS is bounded by the Ross Ice Shelf, the Ronne Ice Shelf, and outlet glaciers that drain into the Amundsen Sea.

The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who visited this area in 1841. To the west of the sea lies Ross Island and Victoria Land, to the east Roosevelt Island and Edward VII Peninsula in Marie Byrd Land, while the southernmost part is covered by the Ross Ice Shelf, and is about 200 miles (320 km) from the South Pole. Its boundaries and area have been defined by the New Zealand National Institute of Water and Atmospheric Research as having an area of 637,000 square kilometres (246,000 sq mi).

The circulation of the Ross Sea is dominated by a wind-driven ocean gyre and the flow is strongly influenced by three submarine ridges that run from southwest to northeast. The circumpolar deep water current is a relatively warm, salty and nutrient-rich water mass that flows onto the continental shelf at certain locations. The Ross Sea is covered with ice for most of the year.

Iceberg B 15 was the largest recorded iceberg by area. It measured around 295 by 37 kilometres (159 by 20 nautical miles), with a surface area of 11,000 square kilometres (3,200 square nautical miles), about the size of the island of Jamaica. Calved from the Ross Ice Shelf of Antarctica in March 2000, Iceberg B-15 broke up into smaller icebergs, the largest of which was named Iceberg B-15-A. In 2003, B-15A drifted away from Ross Island into the Ross Sea and headed north, eventually breaking up into several smaller icebergs in October 2005. In 2018, a large piece of the original iceberg was steadily moving northward, located between the Falkland Islands and South Georgia Island. As of August 2023, the U.S. National Ice Center (USNIC) still lists one extant piece of B-15 that meets the minimum threshold for tracking (70 km or 20 sq nmi). This iceberg, B-15AB, measures 20 km × 7 km (11 nmi × 4 nmi); it is currently grounded off the coast of Antarctica in the western sector of the Amery region.

Victoria Land is a region in eastern Antarctica which fronts the western side of the Ross Sea and the Ross Ice Shelf, extending southward from about 70°30'S to 78°00'S, and westward from the Ross Sea to the edge of the Antarctic Plateau. It was discovered by Captain James Clark Ross in January 1841 and named after Queen Victoria. The rocky promontory of Minna Bluff is often regarded as the southernmost point of Victoria Land, and separates the Scott Coast to the north from the Hillary Coast of the Ross Dependency to the south.

Roosevelt Island is the second largest ice rise of Antarctica and world-wide, after Berkner Island. Despite its name, it is not an island, since the bedrock below the ice at its highest part is below sea level. It is about 130 km (81 mi) long in a NW-SE direction, 65 km (40 mi) wide and about 7,500 km (2,896 sq mi) in area, lying under the eastern part of the Ross Ice Shelf of Antarctica. Its central ridge rises to about 550 m (1,804 ft) above sea level, but this and all other elevations of the ice rise are completely covered by ice, so that it is invisible at ground level.

Examination of how the ice flows above it establishes the existence and extent of the ice rise. Radar surveying carried out between 1995 and 2013 showed that the Raymond Effect was operating beneath the ice divide.The ice rise has become a focus of the Roosevelt Island Climate Evolution (RICE) research using ice coring.