Ultra-long periodicity in eruption activity at Klyuchevskoi volcano (Kamchatka)

Thursday, 17 December 2015
Poster Hall (Moscone South)
Evgenii Gordeev, Institute of Volcanology and Seismology, Petropavlovsk Kamcha, Russia, Hiroaki Takahashi, Hokkaido University, Sapporo-Shi, Japan, Hiroki Miyamachi, Kagoshima University, Kagoshima, Japan, Hiroshi Aoyama, Hokkaido University, Sapporo, Japan, Takeshi Matsushima, Kyushu University, Fukuoka, Japan, Sergey Serovetnikov, Kamchatka branch of Geophysical survey, Petropavlovsk-Kamchatsky, Russia and Yaroslav D. Muravyev, Institute of Volcanology and Seismology, Petropavlovsk-Kamchatsky, Russia
During the eruption of Klyuchevskoi volcano in September – November 2010, long-period (10-15 min.) ground deformations were recorded on the slopes. The changes in tilt of the ground surface were recorded by tiltmeters at four observation points located 10-15 km next to the active crater. A spectral analysis of both the tilt and seismic data revealed that ground deformations data is positively correlated with the intensity of seismic signals at the same observation points. Variation in volcanic tremor amplitude of long –period signals is related to the intensity of gas emissions during the eruption. Therefore, we suggest that the long-period tilt of the ground surface are caused by the deformation of walls in a channel due to variations of pressure in the magmatic melt during gas expansion.