Re: Ventura shaking
Posted by Joan {jcblaine[110AT6]home[10DOT61]com} on October 06, 1999 at 20:04:13:

Hi Pat
I looked that up earlier.... and the activity appears to be on the Arroyo Parida fault. Here's the scoop from SCEC.
Joan


MISSION RIDGE, ARROYO PARIDA, and SANTA ANA FAULTS

TYPE OF FAULTING: left-lateral with varied vertical slip
LENGTH: about 70 km

NEAREST COMMUNITIES: Ojai, Santa Barbara, Goleta

LAST KNOWN SURFACE RUPTURE: 30,000 years ago

SLIP RATE: 0.37 mm/yr

INTERVAL BETWEEN MAJOR RUPTURES: 8000 years (?)

PROBABLE MAGNITUDES: MW6.5 - 7.3


The Mission Ridge, Arroyo Parida, and Santa Ana faults make up an essentially continuous fault system running west to east from Goleta to Ojai, on the southern flank of the Santa Ynez Mountains. It has most likely ruptured in Holocene times, though the youngest dated surface rupture is roughly 30,000 years old. Prior to that, the fault ruptured about 38,000 years before present. Between these two rupture times there is about 3 meters of offset. Between the last measured rupture and the present, there has been about 11 meters of offset, so an average time between quakes of about 8,000 years, with an average slip of about 3 meters per major quake, seems quite possible.

MISSION RIDGE, ARROYO PARIDA, and SANTA ANA FAULTS

TYPE OF FAULTING: left-lateral with varied vertical slip
LENGTH: about 70 km

NEAREST COMMUNITIES: Ojai, Santa Barbara, Goleta

LAST KNOWN SURFACE RUPTURE: 30,000 years ago

SLIP RATE: 0.37 mm/yr

INTERVAL BETWEEN MAJOR RUPTURES: 8000 years (?)

PROBABLE MAGNITUDES: MW6.5 - 7.3


The Mission Ridge, Arroyo Parida, and Santa Ana faults make up an essentially continuous fault system running west to east from Goleta to Ojai, on the southern flank of the Santa Ynez Mountains. It has most likely ruptured in Holocene times, though the youngest dated surface rupture is roughly 30,000 years old. Prior to that, the fault ruptured about 38,000 years before present. Between these two rupture times there is about 3 meters of offset. Between the last measured rupture and the present, there has been about 11 meters of offset, so an average time between quakes of about 8,000 years, with an average slip of about 3 meters per major quake, seems quite possible.


Follow Ups:
     ● Re: Ventura shaking - HRH  20:29:15 - 10/6/1999  (900307)  (1)
        ● Re: Ventura shaking - Canie  22:23:30 - 10/6/1999  (900312)  (1)
           ● Re: Ventura shaking - Pat in Petaluma  23:12:02 - 10/6/1999  (900314)  (0)