West Antarctica, or Lesser Antarctica, one of the two major regions of Antarctica, is the part of the continent that lies within the Western Hemisphere including the Antarctic Peninsula. It is separated from East Antarctica by the Transantarctic Mountains and is covered by the West Antarctic Ice Sheet.
Location and description 
Lying on the Pacific Ocean side of the Transantarctic Mountains, West Antarctica comprises the Antarctic Peninsula (with Graham Land and Palmer Land) and Ellsworth Land, Marie Byrd Land and King Edward VII Land, offshore islands such as Adelaide Island, and ice shelves, notably the Filchner-Ronne Ice Shelf on the Weddell Sea, and the Ross Ice Shelf on the Ross Sea. West Antarctica is separated from the main land mass of the continent by the icy waters of the Ross Sea and Weddell Sea, and resembles a giant peninsula that stretches roughly from the South Pole towards the southern tip of South America.
The name has existed for more than 100 years (Balch, 1902; Nordenskiöld, 1905), but its greatest use followed the International Geophysical Year (1957–58) and explorations disclosing that the Transantarctic Mountains provide a useful regional separation of West Antarctica and East Antarctica. The name was approved by Advisory Committee on Antarctic Names (US-ACAN) in 1962.
Marielandia Antarctic Tundra 
The parts of West Antarctica not covered with ice (Antarctic oasis), which are the coasts of the Antarctic Peninsula, constitute a biodiversity region known as Marielandia Antarctic tundra (after Marie Byrd Land). This area has the warmest climate in Antarctica and the moss and lichen-covered rocks are free of snow during the summer months, although the weather is still intensely cold and the growing season very short.
See also 
- "Antarctic ice sheet is an 'awakened giant'". New Scientist. 2 February 2005. Retrieved 2008-01-26.
- Western Antarctica warming confirmed December 23, 2012 USA Today
- World Wildlife Fund (2001). "Marielandia Antarctic tundra". WildWorld Ecoregion Profile. National Geographic Society. Archived from the original on 2010-03-08. Retrieved 2008-01-26.