Kiyoo Wadati

Kiyoo Wadati was a pioneering Japanese seismologist who worked for the Japan Meteorological Agency in the early 20th century. He is most famous for his groundbreaking research on deep earthquakes occurring beneath the Earth's surface.

In 1928, Wadati discovered deep-focus earthquakes occurring hundreds of kilometers beneath the Earth's surface. By plotting the depths of these earthquakes, he mapped out the inclined planes of seismic activity that define subduction zones.

The Wadati-Benioff zone is the scientific term for the sloping plane of deep earthquakes found along a subducting tectonic plate. It is named in honor of Kiyoo Wadati and the American seismologist Hugo Benioff, who independently mapped the phenomenon in the 1940s.

Wadati's mapping of deep-focus earthquakes provided crucial early evidence for continental drift and plate tectonics. His data proved that massive portions of the Earth's crust were being forced deep into the mantle, decades before the theory of plate tectonics was fully accepted.