ⓘ Asahi-dake

                                     

ⓘ Asahi-dake

Mount Asahi is a mountain located in the town of Higashikawa, Hokkaido and the tallest mountain in the Japanese island of Hokkaido. It is part of the Daisetsuzan Volcanic Group of the Ishikari Mountains, it is located in the northern part of the Daisetsuzan National Park.

The mountain is popular with hikers in the summer and can be easily reached from Asahidake Onsen via Asahidake Ropeway. During winter, the mountain is open for use by skiers and snowboarders.

Sugatami Pond, directly below the peak, is famous for its reflection of the peaks, snow, and steam escaping from the volcanic vents.

                                     

1. Geology

Mount Asahi is an active stratovolcano, 2.291 metres 7.516 ft in height that arose 3 kilometres 1.9 mi southwest of the Ohachi-Daira caldera. The Japan Meteorological Agency gave the region rank C in volcanic activity. The volcano consists mainly of andesite and dacite, Holocene volcanic non-alkali mafic rock less than 18.000 years old. In addition to the main peak, there is a smaller volcano emerging from the southeast shoulder of the mountain, Mount Ushiro Asahi or Rear Mount Asahi 後旭岳, Ushiro-Asahi-dake.

                                     

1.1. Geology Eruptive history

There is no historical record of the eruptions of Mount Asahi. Tephrochronology and radiocarbon dating have determined the following events:

  • 1450 BC ± 50 years, As-B tephra, uncorrected radiocarbon dating, explosive eruption and phreatic explosions
  • 3200 BC ± 75 years, Asahi Soria deposit, corrected radiocarbon dating, explosive eruption
  • 1739, tephrochronology, explosive eruption and phreatic explosions with possible eruption of the central vent and radial good
  • 2800 BC ± 100 years, As-A tephra, corrected radiocarbon dating, explosive eruption and phreatic explosions
  • 500 BC ± 50 years, Ash-b tephra, tephrochonology, explosive eruption and phreatic explosions and debris avalanches

Mount Asahi currently exhibits steam activity in the form of fumaroles.