Detailed Subduction Structure of the Philippine Sea Plate off Tokai District Deduced by Airgun-Ocean Bottom Seismograph Profiling

Upper boundaries of the Pacific and Philippine Sea plates near the triple junction off the Boso Peninsula deduced from ocean-bottom seismic observations

We determined hypocenter distributions and focal mechanisms of earthquakes off the Boso Peninsula, Japan, based on seafloor observations using ocean-bottom seismometers (OBSs). From OBS data, we detected and located earthquakes that were closer to the trenches than had previously been reported. The determined focal depths of relocated hypocenters were systematically shallower than those in the ...

Slab interactions in 3-D subduction settings: The Philippine Sea Plate region

Earthquake Mechanisms at the Head of the Philippine Sea Plate beneath the Southern Kanto District, Japan

An analysis has been made of the rupture mechanism of two earthquakes which occurred in the vicinity of the oblique collision beneath the tip of the descending Philippine Sea plate and the Pacific plate beneath Chiba, Japan. The M=6.5 1956 Chiba earthquake occurred in a dense nest of seismicity at a depth of between 70 and 80km beneath Chiba city, and may represent deformation at the tip of the...

Tomographic image of crust and upper mantle off the Boso Peninsula using data from an ocean-bottom seismograph array

We determined the three-dimensional structure of the crust and upper mantle off the Boso Peninsula, Japan, by analyzing seismograms recorded by ocean-bottom seismometers and land stations between 2011 and 2013. We employed seismic tomography to determine the Pand S-wave velocity structures and earthquake locations simultaneously. The tomographic image shows that the mantle parts of the Pacific ...

Isolated intermediate-depth seismicity north of the Izu peninsula, Japan: implications for subduction of the Philippine Sea Plate

The subduction of the Philippine Sea (PHS) Plate toward the north of Izu peninsula, Japan, is of great interest because intraslab seismicity is absent where the buoyant Izu volcanic arc has been subducting over the past 15 Myr. This study analyzes 42 earthquakes in an isolated seismic cluster that occurred ~ 100 km north of Izu peninsula at depths of 40–90 km and discusses seismogenesis in the ...