 Complete the following phrase:  George Plafker is an American geologist and seismologist who has made significant contributions to both fields, with research focused on subduction, tsunami, and the geology of Alaska. Following prolonged study of the region of the 1964 Alaska earthquake, Plafker correctly concluded that the largest earthquakes are the result of fault slip at convergent boundaries. This was at a time when the theory of plate tectonics was still not completely accepted by the scientific community. Additional studies were done in Chile in the late 1960s regarding the series of 