The past five years have seen the highest level of regional earthquake activity this century. Nine earthquakes of magnitude 6 or larger have struck the coastal and offshore areas. Seven earthquakes were close enough to coastal communities to cause at least moderate damage. Damaging earthquake activity was not restricted to the coast. Klamath Falls, Ore., experienced its strongest earthquake in historic times.
Recent earthquakes demonstrate both the high activity and the diversity of seismic source areas.
The largest earthquake to occur within a 15-mile radius of Eureka since 1932. The largest earthquake ever recorded along the Mendocino fault. The earthquake was felt from south of San Francisco to Roseburg, Oregon but caused little damage due to its far offshore location. These earthquakes occurred along faults which are part of the northernmost Basin and Range geologic province. Significant damage occurred in older unreinforced brick buildings in the Klamath Falls area.