Calculated vertical movement of the seafloor during the Sendai earthquake

© GFZ

The source of the earthquake, i.e. the relative displacement between the continental shelves during the quake, can be reconstructed using GPS measurements. If this is known, the vertical displacement on the sea floor can in turn be calculated, which in this case occured over an area about 500 km long and 100 km wide. This rise of the sea floor of up to 7 meters was the cause of the tsunami. With new Japanese data after the quake it was possible to calculate an offset between the tectonic plates ​​of up to 60 meters in 15 kilometers depth. Image: Andreas Hoechner, GFZ