Keywords:subduction zone, megathrust earthquake, ocean current
Slow earthquake  including very low-frequency earthquake migrates along strike direction at depth about 30 km, which has been detected from inland seismic observation networks . This migration of slow earthquake is thought to occur in the shallower part near the trench , which would be important to monitor the generation process of megathrust earthquakes, in order to classify hydraulic pressure change on the sea bottom into crustal deformation and oceanic oscillation. Toward the monitoring, we have conducted simultaneous observations from seafloor to atmosphere by using DONET and Scientific Deep Sea Drilling Vessel “Chikyu”. In our presentation, we will introduce our observations and collaboration with other related observational campaigns.
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