For a small segment of a scientific community to make a significant impact on the broader community, the segment needs to gain strength by developing a consensus within itself. Earthquake seismologists reached a consensus about the existence of deep-focus earthquakes about 1930 and accepted the first quantitative measure of earthquake magnitude in the 1940s. Benioff (1949, 1954) was able to present this consensus to the geological community by publishing a coherent picture of deep tectonic processes in the Bulletin of the Geological Society of America. The next major impact from earthquake seismology after the Benioff zone came from the final acceptance of Reid’s elastic rebound theory in the early 1960s after two controversies were resolved. The mathematical framework for determining the earthquake fault process from observed seismograms was firmly established and has been extensively used in the past two decades. One outcome was the new measure of the size of an earthquake, seismic moment, which directly links geological observations of faults with the seismic ground motions. The latest impact which has begun to be felt by the geological community comes from the consensus about “seismic tomography” which represents the commitment of the seismological community to go beyond the classic one-dimensional earth model to search for a three-dimensional image of Earth’s interior.