[SCG58-P13] High Fluid Pressure Patch beneath the Décollement as a Potential Source of Slow Earthquakes at the Nankai Trough
Keywords:fluid pressure, slow earthuake, Nankai Trough
In the neighborhood of the drilling site, very low frequency (VLF) earthquakes have been reported (e.g., Obara and Kato, 2016). Seismic survey has suggested a possible linkage between high pore pressure zone and the distribution and generation of slow earthquakes (e.g., Kodaira et al., 2004). Furthermore, high temperature and pressure friction experiments by Sawai et al. (2016) suggested that a transition from stable to unstable slip behavior appears with increasing pore fluid pressure that is a prerequisite for the generation of slow earthquakes. Our result implies that the slow earthquakes at off Cape Muroto can be attributed with slip behaviors along not only décollement but also the patchily distributed high-pore-pressure aquifers in the underthrust sediments.