The ANSS event ID is usp00005uz and the event page is at https://earthquake.usgs.gov/earthquakes/eventpage/usp00005uz/executive.
1974/04/03 23:05:02 38.592 -88.094 11 4.34 Illinois
USGS/SLU Moment Tensor Solution ENS 1974/04/03 23:05:02:0 38.592 -88.094 11.0 4.3 Illinois Stations used: Filtering commands used: Best Fitting Double Couple Mo = 4.07e+22 dyne-cm Mw = 4.34 Z = 15 km Plane Strike Dip Rake NP1 40 90 -160 NP2 310 70 0 Principal Axes: Axis Value Plunge Azimuth T 4.07e+22 14 173 N 0.00e+00 70 40 P -4.07e+22 14 267 Moment Tensor: (dyne-cm) Component Value Mxx 3.77e+22 Mxy -6.65e+21 Mxz -8.96e+21 Myy -3.77e+22 Myz 1.07e+22 Mzz 0.00e+00 ############## ###################### ###########################- ###########################--- -------####################------- ------------###############--------- ----------------##########------------ --------------------#####--------------- ----------------------##---------------- -----------------------###---------------- - ------------------######-------------- - P ----------------#########------------- - ---------------############----------- ----------------###############--------- ---------------##################------- ------------#####################----- ---------########################--- -------##########################- ---########################### -############## ########## ############ T ####### ######## ### Global CMT Convention Moment Tensor: R T P 0.00e+00 -8.96e+21 -1.07e+22 -8.96e+21 3.77e+22 6.65e+21 -1.07e+22 6.65e+21 -3.77e+22 Details of the solution is found at http://www.eas.slu.edu/eqc/eqc_mt/MECH.NA/19740403230502/index.html |
STK = 310 DIP = 70 RAKE = 0 MW = 4.34 HS = 15
The NDK file is 19740403230502.ndk
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Older earthquake were studied using analog seismograms, which were digitized and analyzed. The original data are not longer available. However focal mechanism solutions based on the waveforms are given in published literature. At the same time, a given earthquake may have been analyzed independently, and the reference is given here.
For this earthquake the source reference is the following:
Herrmann, R. B. (1979). Surface wave focal mechanisms for eastern North American earthquakes with tectonic implications, J. Geophys. Res.84, 3543-3552.
The CUS model used for the waveform synthetic seismograms and for the surface wave eigenfunctions and dispersion is as follows (The format is in the model96 format of Computer Programs in Seismology).
MODEL.01 CUS Model with Q from simple gamma values ISOTROPIC KGS FLAT EARTH 1-D CONSTANT VELOCITY LINE08 LINE09 LINE10 LINE11 H(KM) VP(KM/S) VS(KM/S) RHO(GM/CC) QP QS ETAP ETAS FREFP FREFS 1.0000 5.0000 2.8900 2.5000 0.172E-02 0.387E-02 0.00 0.00 1.00 1.00 9.0000 6.1000 3.5200 2.7300 0.160E-02 0.363E-02 0.00 0.00 1.00 1.00 10.0000 6.4000 3.7000 2.8200 0.149E-02 0.336E-02 0.00 0.00 1.00 1.00 20.0000 6.7000 3.8700 2.9020 0.000E-04 0.000E-04 0.00 0.00 1.00 1.00 0.0000 8.1500 4.7000 3.3640 0.194E-02 0.431E-02 0.00 0.00 1.00 1.00