Hidden slippery clay on seafloor may have worsened devastating 2011 tsunami in Japan

The 2011 earthquake — the largest ever recorded in Japan — triggered a 130-foot-high tsunami that caused huge devastation. The event killed more than 18,000 people. A thick layer of slippery clay on the ocean floor may have formed the weak spot that enabled a magnitude 9.1 quake to make such a devastating tsunami.

A thick layer of slippery clay on the ocean floor may have formed the weak spot that enabled a magnitude 9.1 quake to make such a devastating tsunami.