Cenozoic Volcanisms and Mantle Dynamics in Japan: Progress in the Last 10 Years

The Japanese Islands have experienced subduction of the old Pacific Plate and the young Philippine Sea Plate, as well as back-arc basin opening, such as at the Kurile basin, Japan Sea, Shikoku basin, and Okinawa trough. This paper summarizes progress in understanding mantle dynamics beneath Japan in the past similar to 10 years in terms of igneous petrology and geochemistry, seismology, and numerical simulation. The discussion is separated into four regions: Hokkaido, northeast and central Japan, southwest Japan (Chugoku and Shikoku districts), and Kyushu, from northeast to the southwest. Now that a massive amount of volcanic eruption age data and high-resolution seismic analyses have been accumulated for every region, we can discuss mantle dynamics within mantle wedge and back arc mantle in more detail than in the 20th century. Constraints related to water content, temperature, and melting process in the mantle from a natural sample are, however, still missing despite the importance of these factors when modeling mantle dynamics.