Previous earthquakes that rivalled the March 2011 Tohoku tremor in size may be recorded in sediment samples just recovered from the seafloor off Japan.
A German-led scientific cruise obtained the cores from 16 different locations, some of them at a water depth of 7.5km.
The sediments hint at three major disturbances on the ocean bed that could be the result of the submarine landslides often seen with big quakes.
The researchers are currently trying to identify and date the events.
Read the rest of the story: Japan sea sediments tell of past ‘Tohoku quakes’.