High pore fluid pressure may cause silent slip in the Nankai Trough.
Silent-slip events have been detected at several subduction zones, but the cause of these events is unknown. Using seismic imaging, we detected a cause of the Tokai silent slip, which occurred at a presumed fault zone of a great earthquake. The seismic image that we obtained shows a zone of high pore fluid pressure in the subducted oceanic crust located down-dip of a subducted ridge. We propose that these structures effectively extend a region of conditionally stable slips and consequently generate the silent slip.
Kodaira
Shuichi
S
Institute for Frontier Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Showa-machi 3175-25 Kanazawa-ku, Yokohama 236-0001, Japan.
Iidaka
Takashi
T
Kato
Aitaro
A
Park
Jin-Oh
JO
Iwasaki
Takaya
T
Kaneda
Yoshiyuki
Y