From NHK:

The latest research on the March 11 tsunami that slammed into Ofunato city in Iwate Prefecture, northern Japan shows that it was nearly 30 meters high.

A joint research team from Yokohama National University and University of Tokyo surveying the Ofunato city shoreline made the discovery.

They found fishing equipment scattered on the high cliff of the city’s Ryori Bay and have determined the tsunami reached as high as 29.6 meters.

The research group says the great height of the tsunami was formed by the shape of the narrow bay. They will continue to survey traces of the tsunami to clarify the scale the tsunami.