Five volcanoes in northeastern Japan sank in some places following the March 2011 Great East Japan Earthquake, seismologists at Kyoto University said.
Five volcanoes in northeastern Japan sank in some places following the March 2011 Great East Japan Earthquake, seismologists at Kyoto University said.
While a swollen volcano surface may indicate an approaching eruption, the scientists said they cannot tell whether the sinking signals a future disaster and called for continued monitoring.
The seismologists, Youichiro Takada and Yo Fukushima, at the university’s Disaster Prevention Research Institute, analyzed data gathered by the observation satellite Daichi and the Global Positioning System, to look at crustal deformation caused by the earthquake.
Takada and Fukushima, both assistant professors, found that the surface of some parts of five volcanoes sank 5 to 15 centimeters in ellipse-shaped rings extending 15 to 20 kilometers.
The mountains--Akita-Komagatake, Kurikomayama, Zaozan, Azumayama and Nasudake--are located close to the tectonic plate boundary where the magnitude-9.0 earthquake occurred.
The earthquake and subsequent tsunami devastated the Pacific coastal areas of the northeastern Tohoku region.
The finding was to be published in the June 30 online edition of the British science journal Nature Geoscience.