Ibusuki volcanic field


The Ibusuki volcanic field, also known as the Ibusuki Volcano or Ibusuki Volcanic Group, is an area of current volcanic and geothermal activity at the tip of the Satsuma Peninsula, Kagoshima prefecture, Kyushu, Japan. It is administered as part of Ibusuki City and Kirishima-Kinkowan National Park.

Geology

The Ibusuki volcanic field is at the eastern margins of the Ata Caldera and has been estimated to contain of volcanic material. The Ibusuki volcanic field includes the following recent active volcanoes and their vents:
There are about 800 hot springs within of the sea at the southeastern tip of the Satsuma Peninsula. The relatively recently commissioned Yamagawa Binary Power Station uses local geothermal power to generate up to 4990 kW.

Tectonics

The north western sector of the zone is limited by the Onkadobira fault scarp which has been interpreted as part of the rim of the Ata Caldera. The volcanism is associated with the subduction of the Philippine Sea Plate under the Eurasian Plate.

Risk

The field has both tectonic and volcanic risks. With regard to volcanic risks currently the area is in the longest period between eruptions for the last 4000 years. Earthquake swarms that do not appear to be related to the volcanoes have been described. Seismic activation of local faults in the area occurred immediately after the megathrust 2011 [Tōhoku earthquake and tsunami|2011 Tōhoku earthquake] which had its epicenter away.