Will a volcanic eruption be triggered by an earthquake?


In general, will a volcanic eruption be triggered by an earthquake? (Male, 50s, Kanagawa)


Though there is a possibility, there has been no eruptions directly connected to the 2011 Tohoku Earthquake as of March 27. Yet it is necessary to continue observations.

Here is a case study of a huge earthquake (Magnitude 8.4 on the Richter scale) called Tokai-Tonankai-Nankai in 1707 (the Hoei era) which triggered a Mt. Fuji eruption after 49 days. Tons of volcanic ash piled up all over the Kanto area. The Hoei vent is now visible on the south east side of Mt. Fuji. Naturally there was no seismometer or any observation net at that time. It is possible to assume the magnitude and how the earthquake and the eruption went on by delving into the archives and geological survey. A historical novel “Angry Fuji” by Jiro Nitta, is the story of aforementioned Hoei earthquake and it triggered Mt. Fuji eruption.

The Earthquake Research Institute, The University of Tokyo, which has volumes of earthquake and volcano research data, released the following:
Q: Is it true that the volcanoes in Tohoku and Kanto are becoming active?
A: It is true. Just after a huge earthquake, it is usual for the surrounding volcanoes to become active for a while. So far, these volcanoes are coming to its end, but monitoring will be still continued.

Science Communicator: Yuko Okayama
Supervised by Japan Geoscience Union


Earthquake Research Institute