Usas Escarpment () is an expansive but discontinuous north-facing

escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...

in Marie Byrd Land,

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

. It is about long, extending roughly west to east along the

76th parallel south The 76th parallel south is a circle of latitude that is 76 degrees south of the Earth's equatorial plane in the Antarctic. The parallel passes through the Southern Ocean and Antarctica. Around the world Starting at the Prime Meridian and ...

from where the elevation of the snow surface descends toward the

Ruppert Coast Ruppert Coast () is that portion of the coast of Marie Byrd Land, Antarctica, between Brennan Point and Cape Burks, or between Saunders Coast in the west and Hobbs Coast in the east. It stretches from 146°31'W to 136°50'W. It was named by R. Adm ...

and

Hobbs Coast Hobbs Coast () is that portion of the coast of Marie Byrd Land, Antarctica extending from Cape Burks to a point on the coast opposite eastern Dean Island, at , or between the Ruppert Coast in the west and the Bakutis Coast in the east. It stretch ...

. The position of the escarpment coincides with the north slopes of the

Flood Range The Flood Range () is an Antarctic range of large snow-covered mountains extending in an E-W direction for about 96 km (60 mi) and forming a right angle with the southern end of the Ames Range in Marie Byrd Land. Discovered by the Byrd ...

Ames Range The Ames Range is an Antarctic range of snow-covered, flat-topped, steep-sided mountains, extending in a N-S direction for 32 km (20 mi) and forming a right angle with the eastern end of the Flood Range in Marie Byrd Land. They were di ...

McCuddin Mountains The McCuddin Mountains are a small cluster of mountains in Antarctica consisting mainly of two large mountains, Mount Flint and Mount Petras, along with several scattered peaks and nunataks. Located in Marie Byrd Land, east of the Ames Range, ...

, and the eastern peaks of Mount Galla, Mount Aldaz and Benes Peak. The escarpment was observed by members of the

United States Antarctic Service The United States Antarctic Program (or USAP; formerly known as the United States Antarctic Research Program or USARP and the United States Antarctic Service or USAS) is an organization of the United States government which has presence in the A ...

, 1939–41, and in ensuing scientific reports was referred to as 76th Parallel Escarpment. The approved name is an acronym for the discovery expedition.

References

Landforms of Marie Byrd Land Escarpments of Antarctica {{MarieByrdLand-geo-stub