Nuovo progetto di ricerca nell'area sismogenetica della Fossa di Nankai (Giappone sud occidentale)

 

In the Nankai trough, mega thrust earthquakes are occurring with an interval of 100-200 years. Many researches are focusing on the Nankai trough to elucidate the recurrence system of mega thrust earthquakes. In the past, initial ruptures of mega thrust earthquakes 1854 and 1944/1946 were starting from the Tonankai seismogenic zone ahead of the Nankai seismogenic zone with intervals of 32 hours and 2 years in each event. Now, we are focusing on the recurrence pattern of the next mega thrust earthquake. New project for next mega thrust earthquakes around the Nankai trough is starting in 2008 as a national project.
New project is focusing on the time difference between the Tonankai EQ and the Nankai EQ and the pattern of next mega thrust earthquakes.
New project includes research planes as follows:

1) construct the detailed crustal structure around the Nankai trough using seismic surveys with controlled sources and seismic tomography;
2) construct the crustal medium model for understanding the detailed crustal activities and advanced simulation researches;
3) as a preceding research, observations of crustal activities will be carried out off Miyagi and Nemuro seismogenic zones in northeastern Japan;
4) develop and improve simulation researches using physical properties with conditions of mega thrust EQs coupling;
5) construct data base to understand the crustal deformation in the past 120 years;
6) analyse the past records of mega-thrust EQs using tsunami sediments;
7) improve the hazard maps of earthquake and tsunamis.

I will introduce the detailed scientific proposal for next mega thrust earthquake around the Nankai trough.