DECEMBER 21, 1812 (M=7) [c6, p157-158]

The second major episode of earthquake activity in 1812 damaged the missions along the Santa Barbara Channel and western Transverse Ranges just 13 days later, on December 21 ( Figure 6.3). All investigators place this event in the Santa Barbara Channel and assign a magnitude of about 7 (see Toppozada and others, 1981, and Evernden and Thompson, 1985, for two recent analyses). This sequence appears to have involved two events of comparable magnitude separated in time by about 15 minutes. A vigorous aftershock sequence accompanied the earthquakes and lasted until the end of the year at Mission Santa Barbara and Mission La Purisima Concepcion. Reports of a tsunami appear to be exaggerated, although some kind of wave activity probably accompanied the earthquake (Toppozada and others, 1981; McCulloch, 1985).