Subduction of young plates: A case of the Philippine Sea plate beneath the Chugoku region, Japan

An analysis of seismic waves from regional microearthquake networks shows that the seismic leading edge of the Philippine Sea plate may have reached the uppermost mantle beneath the southern to central part of the western Chugoku region, Japan. The epicenters are located close to the volcanic front in the region. The most possible cause of the very low seismicity may be the initiation of melting of the Philippine Sea plate.