Volcano Live

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.

Further Reading
Donnelly-Nolan, J.M., Champion, D.E., Miller, C.D., Grove, T.L. and Trimble, D.A., 1990. Post-11,000-year volcanism at Medicine Lake Volcano, Cascade Range, northern California. Journal of Geophysical Research: Solid Earth, 95(B12), pp.19693-19704.

Donnelly-Nolan, J.M., 1988. A magmatic model of Medicine Lake volcano, California. Journal of Geophysical Research: Solid Earth, 93(B5), pp.4412-4420.

Grove, T.L. and Donnelly-Nolan, J.M., 1986. The evolution of young silicic lavas at Medicine Lake Volcano, California: Implications for the origin of compositional gaps in calc-alkaline series lavas. Contributions to Mineralogy and Petrology, 92(3), pp.281-302.