I don't know the earthquake history of the onshore Malibu Coast fault, except I've seen papers that indicate some strands may have had a quake or 2 in the last 10,000 yrs. The Malibu Coast fault merges with the Santa Monica fault to the east. The Santa Monica fault was trenched (Dolan and othesr 2000). It has had Holocene (last 10,000 years) earthquakes, but I recall they are rare: only about every 5000 (?) years. I've walked large parts of the Santa Cruz Island fault and everytime a gully/stream crosses it, it is offset by 3 or 4 m, which suggests that the last earthquake there slipped that much, or that there was more than 1 quake not too far apart in time that slipped a combined 3 or 4 m. This was noticed in the thesis by Patterson (1979). The fault system is certainly long and continuous enough to be capable of a M7+ quake. But, if it slips at 1 or 2 mm/yr (left-lateral), and there is 4 m in an earthquake, then that would be one every 2000 to 4000 years. of couse, if it breaks in smaller quakes, they would be more frequent somewhere along the fault system'

The Santa Monica-Dume fault sits offshore and dips about 45 deg north under this earthquake. It seems to be the more important and more active fault.

Chris