Record-breaking ocean drilling reveals why Japan's 2011 tsunami was so deadly
Summary
Deep seafloor drilling off Japan found a thin, slippery layer of ancient clay along the fault that ruptured in 2011. The layer likely let the quake’s slip propagate to the seafloor, amplifying vertical displacement and generating an unusually large tsunami.
Why it matters
If similar weak layers exist elsewhere, some coastlines may face larger tsunamis than current forecasts assume.