Mashu

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 43.572°N
  • 144.561°E

  • 857 m
    2811 ft

  • 285081
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Mashu.

The Global Volcanism Program has no Weekly Reports available for Mashu.

The Global Volcanism Program has no Bulletin Reports available for Mashu.

Eruptive History


Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1080 ± 100 years Unknown Confirmed 5 Radiocarbon (corrected) Kamuinupuri, Tephra layer Ma-b
0350 ± 100 years Unknown Confirmed 2 Radiocarbon (corrected) Kamuinupuri, Tephra layer Ma-c1
0150 ± 100 years Unknown Confirmed 4 Radiocarbon (corrected) Kamuinupuri, Tephra layers Ma-c4-c2
2050 BCE ± 40 years Unknown Confirmed 4 Radiocarbon (corrected) Kamuinupuri, Tephra layer Ma-d
2800 BCE ± 750 years Unknown Confirmed 3 Tephrochronology Kamuinupuri, Tephra layer Ma-e'
3550 BCE ± 40 years Unknown Confirmed 4 Radiocarbon (corrected) Kamuinupuri, Tephra layer Ma-e
5550 BCE ± 100 years Unknown Confirmed 6 Radiocarbon (corrected) Tephra layers Ma-j-f

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Photo Gallery


Kamuinupuri, its top in the clouds, is a small stratovolcano constructed on the SE rim of Mashu caldera. Growth of Kamuinupuri postdated the roughly 7000-year-old collapse of Mashu caldera. The steep scarp below the summit is the NE wall of a small, 1.2 x 1.5 km caldera that formed at the summit of Kamuinupuri about 1000 years ago, during the last eruption of Mashu volcano.

Photo by Lee Siebert, 1977 (Smithsonian Institution).
See title for photo information.
Mashu is a 6-km-wide caldera on the northernmost Japanese island of Hokkaido. It truncates a stratovolcano constructed on the ESE rim of the larger Kutcharo caldera. Mashu caldera is seen here from its SW rim with the small island of Kamuishi, a mostly submerged lava dome, in the center of the lake. The steep-walled caldera is one of the scenic highlights of Hokkaido. The latest eruption of Mashu took place about 1000 years from Kamuinupuri, whose lower flanks appear at the extreme right.

Photo by Lee Siebert, 1977 (Smithsonian Institution).
See title for photo information.
The deep blue waters of 6-km-wide Mashu caldera are seen here from its western rim. The small island of Kamuishu in the center of Lake Mashu (right-center) represents the tip of a mostly submerged lava dome. Mashu is a Holocene caldera that truncates a stratovolcano constructed on the ESE rim of the large Kutcharo caldera. Following caldera collapse, a small stratovolcano, Kamuinupuri (whose lower flanks are visible at the far right), was formed beginning about 4000 years ago.

Copyrighted photo by Shun Nakano, 2001 (Japanese Quaternary Volcanoes database, RIODB, http://riodb02.ibase.aist.go.jp/strata/VOL_JP/EN/index.htm and Geol Surv Japan, AIST, http://www.gsj.jp/).
See title for photo information.

Smithsonian Sample Collections Database


There are no samples for Mashu in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

Affiliated Sites