Mount Murphy is a massive, snow-covered and highly eroded shield volcano in Marie Byrd Land of West Antarctica with steep, rocky slopes. It is directly south of Bear Peninsula and is bounded by the Smith, Pope and Haynes Glaciers. Volcanic activity began in the Miocene with the eruption of basaltic and trachytic lava. Volcanism on the slopes of the volcano resumed much later during the Pleistocene, with a parasitic cone having been K-Ar dated to 0.9 million years old.