SAN JACINTO FAULT ZONE
TYPE OF FAULTING : right-lateral strike-slip; minor right-reverse
LENGTH: 210 km, including Coyote Creek fault
NEARBY COMMUNITIES: Lytle Creek, San Bernardino, Loma Linda, San Jacinto, Hemet, Anza, Borrego Springs, Ocotillo Wells
MOST RECENT SURFACE RUPTURE: within the last few centuries; April 9, 1968, Mw6.5 on Coyote Creek segment
SLIP RATE: typically between 7 and 17 mm/yr
INTERVAL BETWEEN SURFACE RUPTURES: between 100 and 300 years, per segment
PROBABLE MAGNITUDES: Mw6.5 - 7.5
COYOTE CREEK FAULT
TYPE OF FAULT : right-lateral strike-slip
LENGTH: 80 km
NEARBY COMMUNITIES: Borrego Springs, Borrego, Ocotillo Wells
MOST RECENT SURFACE RUPTURE: April 9, 1968, Mw6.5, on southern half; within the last few centuries on northern half
SLIP RATE: between 2 and 6 mm/yr, possibly greater
INTERVAL BETWEEN MAJOR RUPTURES: 100 - 300 years
PROBABLE MAGNITUDES: Mw6.5 - 7.5
HOT SPRINGS and BUCK RIDGE FAULTS
TYPE OF FAULT: right-lateral strike-slip
LENGTH: 75 km
NEARBY COMMUNITIES: Idyllwild, Mountain Center, Thomas Mountain, Anza
MOST RECENT SURFACE RUPTURE: Late Quaternary; Holocene only at extreme northern end
OTHER NOTES: Probably the least active strands of the San Jacinto fault zone, though the southern Buck Ridge fault is associated with a zone of recent active seismicity.
As in other large fault zones, many of the individual fault strands in the San Jacinto fault zone have their own identities. At its extreme northern end, where the San Jacinto meets the San Andreas fault, this fault zone is made up of several parallel fault strands. The farthest east of these is called the Glen Helen fault; the farthest west is known as the Lytle Creek fault.
One of the larger and more active fault segments, the Casa Loma fault, runs from near Perris Reservoir to just north of Anza. Another large and active named segment is the Clark fault, which runs from near Hemet to just 15 km southwest of the shore of the Salton Sea. The 1954 San Jacinto earthquake probably occurred due to rupture on the Clark fault.
REFERENCES
These faults are featured on the following maps: