This is a preliminary UCB moment tensor solution for the event 16 km SSE of
Tres Pinos, CA (36.6478 N, 121.2677 W; z=10.9km; ML=4.3; USGS/UCB Joint
Notification System) on January 18,1999 at 08:48:36UTC. A Mw4.3 and depth of
11 km were obtained from long-period waves recorded at BKS, MHC and JRSC.

Best Fitting Double-Couple:
COMPLETE WAVEFORMS SURFACE WAVES
Mo = 2.96E+22 Dyne-cm 5.20E+22
Mw = 4.28 4.44
Z = 11 km
Plane Strike Rake Dip
NP1 48 -4 88 NP1 131 175 88
NP2 138 -178 86 NP2 221 2 85
Principal Axes:
Axis Value Plunge Azimuth
T 2.960 1 93
N 0.000 86 201
P -2.960 4 3

Best regards,

Doug Dreger
Hrvoje Tkalcic
UCB Seismological Laboratory



Berkeley Moment Tensor Solution (COMPLETE WAVEFORMS SOLUTION)

Event Date/Time: prel

Moment Tensor: Scale = 10**22 Dyne-cm
Component Value
Mxx -2.928
Mxy -0.301
Mxz -0.222
Myy 2.943
Myz 0.062
Mzz -0.014


--- P -
--------- -------
-------------------------
#----------------------------
####---------------------------##
#######-----------------------#####
#########--------------------########
############----------------###########
#############-------------#############
################---------################
##################-----##################
###################--##################
###################--################## T
#################------################
##############---------################
############-------------##############
#########-----------------###########
######---------------------########
##--------------------------#####
----------------------------#
-------------------------
-------------------
-------

Lower Hemisphere Equiangle Projection