日本海溝
In 2013, the Integrated Ocean Drilling Program (IODP) Expedition 343 collected sediment samples from drilling at the plate boundary fault zone along the Japan Trench. The sediment cores collected exhibited low friction at coseismic slip velocities as well as at low slip velocities. These studies and samples have supported the idea that these frictional properties of the fault zone possibly triggered the shallow and large slip during the Tohoku earthquake.