MacKenney cone, the historically active vent of Pacaya volcano in Guatemala, was constructed within a horseshoe-shaped crater produced by collapse of the summit of an ancestral volcano about 1,100 years ago. The SW crater rim forms the steep-sided scarp at the right. The blocky hill in the foreground is a hummock from the debris avalanche produced by the collapse. The avalanche extended for 25 km.

Photo by Lee Siebert, 1988 (Smithsonian Institution).

Keywords: debris avalanche | deposit | hummock

Pacaya