M 6.1 - The 1992 Joshua Tree, California Earthquake

Thirty-two people were treated for minor injuries. Light to moderate damage (VII) at Joshua Tree and (VI) at Angelus Oaks, Banning, Cathedral City, Coachella, Desert Hot Springs, Indio, Palm Desert, Palm Springs, Pioneertown, Rancho Mirage, Twentynine Palms and Yucca Valley. Felt strongly in many parts of southern California. Felt from San Diego, California to Las Vegas, Nevada and from Santa Barbara, California to Yuma, Arizona. Also felt at Phoenix, Arizona and in Baja California, Mexico. Complex event observed on broadband displacement seismograms. FAULT PLANE SOLUTION: P-Waves NP1:Strike=305 Dip=74 Slip=165 NP2:Strike=39 Dip=76 Slip=17 Principal Axes: (T) Plg=22 Azm=262 (P) Plg=1 Azm=172 Comment: The focal mechanism is moderately well controlled and corresponds to right-lateral strike slip faulting with a moderate reverse component. The preferred fault plane is NP1. RADIATED ENERGY No. of sta: 7 Focal mech. F Energy 4.5+1.1*10**13 Nm MOMENT TENSOR SOLUTION Dep 12 No. of sta: 9 Moment Tensor; Scale 10**18 Nm Mrr=0.49 Mtt=-0.98 Mff=0.48 Mrt=-0.63 Mrf=0.25 Mtf=2.22 Principal axes: (T) Val=2.11 Plg=6 Azm=127 (N) Val=0.61 Plg=77 Azm=245 (P) Val=-2.72 Plg=12 Azm=35 Best Double Couple:Mo=2.4*10**18 NP1:Strike=172 Dip=77 Slip=-176 NP2:Strike=81 Dip=86 Slip=-13 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 27S, 72C M.W.: 21S, 42C Centroid Location: Origin Time 04:50:29.5 0.1 Lat 34.07N 0.01 Lon 116.52W 0.02 Dep 15.0 FIX Half-duration 8.3 Moment Tensor; Scale 10**18 Nm Mrr=-0.31 0.02 Mtt=-0.47 0.02 Mff=0.77 0.03 Mrt=-0.03 0.09 Mrf=0.09 0.10 Mtf=2.01 0.02 Principal Axes: (T) Val=2.26 Plg=1 Azm=306 (N) Val=-0.30 Plg=87 Azm=191 (P) Val=-1.96 Plg=3 Azm=36 Best Double Couple:Mo=2.1*10**18 NP1:Strike=81 Dip=87 Slip=-1 NP2:Strike=171 Dip=89 Slip=-177