Whose work first described oceanic trenches as subduction zones?

Japanese seismologist Kiyoo Wadati and American geophysicist Hugo Benioff independently identified patterns of deep earthquakes beneath island arcs and continental margins. These earthquake zones form a sloping plane now called the Wadati-Benioff zone. Later, this pattern was understood as evidence that one tectonic plate is being forced beneath another in subduction zones. Their work was central to modern plate tectonics and our understanding of deep-ocean trenches.