Three‐Dimensional Seismic Attenuation Structure of Central Japan and Deep Sources of Arc Magmatism

We estimate the 3‐D P wave attenuation ( Q p −1 ) structure of central Japan to investigate arc magmatism. We first determine the corner frequencies of the earthquakes and then conduct a joint inversion to determine attenuation terms. The 3‐D Q p −1 structure is finally obtained via a tomographic inversion. High‐attenuation areas are located in the uppermost mantle along the volcanic front, which are interpreted as zones of partial melting at 30‐ to 100‐km depth due to the supply of slab‐derived fluids. The subducted Philippine Sea plate acts as a barrier to the upward migration of melt, resulting in the volcanic gap. The distribution of volcanoes is controlled primarily by the geometry of the subducted Philippine Sea plate. The attenuation structures beneath Mount Fuji and Mount Hakone show contrasting melt transport pathways, which are separated at ≤50‐km depth, suggesting that the independent melt supply system results in the distinct activities of these volcanoes.