Mashu
About Mashu
Mashu is a 6-km-wide Holocene caldera that truncates a stratovolcano constructed on the ESE rim of the large Kussharo caldera. The steep-walled caldera, filled by Lake Mashu, is one of the scenic highlights of Hokkaido. Following caldera collapse about 7,000 years ago, a small andesitic stratovolcano, Kamuinupuri, was formed beginning about 4,000 years ago, creating a reentrant into the SE side of the deep caldera lake. A large explosive eruption about 1,000 years ago, the latest dated eruption, created a 1.2 x 1.5 km crater at the summit of Kamuinupuri. The small island of Kamuishu in the center of Lake Mashu represents the tip of a mostly submerged dacitic lava dome.
Eruption reports
Reports from GDACS and NASA EONET linked to this volcano.
No eruption reports in our records yet. New reports appear here automatically.
Earthquakes nearby, 30 days
Within about 50 km. Swarms of small quakes can sometimes accompany volcanic unrest.
No earthquakes recorded nearby in the last 30 days.