And each number on the Richter Scale involves an energy release about 32 times as great. Measures the earthquake source. Rattled doors in Washington, DC and rang bells in Boston. Strongest earthquake to hit US this century. Some occur far from plate edges.
Thixotropic sediment causes ground to flow Tsunami - seismic sea waves.
When they enter shallow water, they slow down, the water stacks up. Earthquake Prediction Monitor to look for patterns Parkfield, California had earthquakes every 22 years in anticipation of the next one, seismographs were put into place, but it has not yet occurred. Changes in animal behavior Radio emissions from the Earth - first noticed 1989 San Francisco.