West Crater volcano is a small andesitic lava dome with lava flows in southern Washington, belonging to a volcanic field extending from Marble Mountain, north of Swift Reservoir, to south of Trout Creek Hill. The field consists mainly of small basaltic and basaltic andesite cinder cones and small shield volcanoes, oriented along a NW-SE zone SE of Mount St. Helens.
The most recent activity occurred about 8,000 years ago and formed the West Crater lava dome, a small cone at Hackamore Creek, and a phreatic crater at the summit of Bare Mountain.
The older, basaltic Trout Creek Hill shield volcano erupted a lava flow about 340,000 years ago that traveled 20 km SE and temporarily dammed the Columbia River.
Clear view onto the lava lake inside Marum's west crater. (Photo: Tom Pfeiffer)
The lava lake in Marum's west crater. (Photo: Tom Pfeiffer)
Lava lake inside Kilauea volcano's West Gap crater. The whole crust covering the lake has just been overturned, exposing the red hot glowing interior. hawaii_e7837 (Photo...
The complex of Marum crater and its surrounding pit craters: Mbwelesu (l), Marum's west pit with the lava lake (a.l.), smoking Niri Mbwelesu (c), and Niri Mbwelesu Tatem ...
View onto the western crater wall of the 2002 flank cone, the SE crater behind in the background. (Photo: Tom Pfeiffer)
The lava lake in Marum's west crater, and smoking Niri Mbwelesu crater containing another active vent to the right. (Photo: Tom Pfeiffer)
