Seismologists are divided over whether a spate of weak tremors and apparent volcanic activity are warning signs of a much-anticipated major earthquake in the Tokai region.
Low-frequency earthquakes focused 15 km beneath Mount Fuji began in October and as many as 221 were recorded the following month. This number has dropped to less than 20 since June.
Mount Hakone in Kanagawa Prefecture has triggered a series of quiet tremors since June, with more than 200 of magnitude 1 or stronger registered by late August, according to the Japan Meteorological Agency and the Geographical Survey Institute.