Mount Jefferson

Last events 10 km from summit of Mount Jefferson

Mount Jefferson is a stratovolcano, and the second highest peak in Oregon State. It is located 169 km E of Corvallis, OR.

Details regarding eruptive events at Mount Jefferson are poorly known for several reasons. The last major eruption occurred around 7,600 years ago, and since that time the volcano has been covered by large glaciers that have eroded away many deposits. Mount Jefferson has a history that extends back for several hundred thousand years, and it has exhibited a wide range of eruptive styles from highly explosive events to lava flows and lava domes.

More background information on Mount Jefferson

Background Seismicity

The PNSN operates 1 seismometer near Mount Jefferson. On average, we locate 0 earthquakes within 10 km of the volcano per decade.