Medicine Lake Volcano | John Seach


California, USA

41.58 N, 121.57 W
summit elevation 2412 m
shield volcano

Medicine Lake Volcano is located in northern California. It is a large shield volcano with a 12 km x 7 km caldera. The volcano has erupted nine times during the past 5,200 years.

Eruptive vents at Medicine Lake extend 55 km north-south and 40 km east-west. Lava from the volcano covers more than 2,000 sq km.

Due to its frequent explosive eruptions, and proximity to regional infrastructure, Medicine Lake Volcano has been designated a “high threat volcano” by the U.S. Geological Survey. The volcano contains a small silicic magma chamber at a depth of 3-7 km, and a volume of 10 cubic km.

1992 Earthquakes
On 28th June 1992 a magnitude 7.5 earthquake 200 km east of Los Angeles, triggered seismicity at Medicine Lake. Twelve earthquakes occurred in the Medicine Lake area (~900 km NNW of the epicenter) in the 30 minutes after the M 7.5 earthquake.

1988 Earthquake swarm
On 29th September 1988, 47 earthquakes occurred at Medicine Lake volcano, which had only experienced one earthquake in the previous 8 years. On 30th September 146 earthquakes were registered, including 66 during a one hour period. Seismic activity continued until December 1988.

Medicine Lake Volcano Eruptions

1910?, 1080, 890 ± 100, 830, 800?, 720?, 50 BC?, 780 BC ±  100, 1080 BC ± 50, 2410 BC ± 100