Craters of the Moon Lava Field

November 04, 2012

Craters of the Moon Natl Monument~Arco ID~100912~36med

Photographer: Carl Crumley
Summary Author: Carl Crumley

The photo above shows the visually stunning Craters of the Moon National Monument and Preserve in south central Idaho. This extensive lava field formed thousands of years ago during eight major eruptive periods along the Great Rift volcanic zone. Lava here covers approximately 618 sq mi (1,600 sq km). The Earth's crust is being pulled apart in this region due to basin and range type faulting. On average, there have been lava eruptions in this area every 2,000 years or so -- the last eruption occurred about 2,200 years ago. Craters of the Moon is seismically active as well. In 1983 a magnitude 6.9 earthquake caused Mount Borah to rise about 1 ft (30 cm) and the Lost River Valley to drop about 8 ft (240 cm). Photo taken on October 9, 2012.