Mount Sidley

Mount Sidley is a massive dormant shield volcano in Antarctica’s Executive Committee Range and the continent’s highest volcano. Its broad summit caldera lies beneath the polar climate of Marie Byrd Land.

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Shield volcano: A broad volcano built mainly from fluid lava flows that spread over wide areas. Mount Sidley’s low, expansive profile is characteristic of this volcanic form.
Richard E. Byrd: An American naval officer and polar explorer who led expeditions to Antarctica. The 1934 expedition he led discovered Mount Sidley.
Lava flow: Molten rock that erupts onto the surface and moves across the ground before solidifying. Repeated lava flows built Mount Sidley’s broad shield shape.
Mount Sidley summit caldera: The broad volcanic depression at the summit of Mount Sidley. It is the volcano’s most distinctive summit feature.
Executive Committee Range: A mountain range in Marie Byrd Land, West Antarctica, containing several major volcanoes. Mount Sidley is the range’s highest peak and one of its volcanoes.
Marie Byrd Land: A large region of West Antarctica named for the wife of explorer Richard E. Byrd. The region’s exploration and naming provide the historical setting for Mount Sidley’s discovery.
Magma: Molten or partially molten rock beneath Earth’s surface, containing crystals and dissolved gases. Magma supplied the eruptive material that constructed the volcano.
Mount Sidley West Face: The steep western side of Mount Sidley, a route used by climbing expeditions. Its ascent illustrates the practical challenges of reaching the remote peak.
Antarctica: Earth’s southernmost continent, almost entirely covered by a vast ice sheet. The continent’s polar conditions shape access to Mount Sidley and its surroundings.
West Antarctic Rift System: A major extensional geological province beneath West Antarctica, associated with volcanism and crustal stretching. Regional tectonic extension helps explain volcanism in Mount Sidley’s part of Antarctica.