Location

2006/04/11 17:29:29 37.96 21.23 10

Moment Tensor Comparison

The following compares this source inversion to the USGS Rapid Moment Tensor Solution and to the Harvard CMT solutions, if they are available.

Mw=5.5 2006/04/11 17:29:29 EVID: LAT: 37.96N, LON: 21.23E, DEPTH: 15 Mw: 5.5, mb: 0.0, Ms: 0.0 Mo= 0.231E+25 (dyne-cm) No. of Stations: 21, GAP: 88 Error (clvd/dc)*100= 9.51 Bandpass: 12 - 60 sec Nodal plane parameters strike dip rake NP1: 357 73 -133 NP2: 249 46 -25 #######-------- ###########---------- ###############------------ ##################------------- #################--########------ ############---------############-- ##########------------############### ########---------------################ ######-----------------################ #####-------------------############### ###---------------------############### ##----------------------############### ##----------------------############### #--------- -----------######### ### --------- P -----------######### T ## -------- ----------########## # --------------------############# -------------------############ -----------------########## -------------######## ---------###### Stat Dist Az Misfit Stat Dist Az Misfit ARU 30 41 0.50 BILL 71 13 0.93 BJT 70 54 0.63 BRVK 36 49 0.64 DBIC 39 223 4.42 EGMT 83 329 0.80 KSM 88 89 0.73 KURK 41 53 0.37 LSA 57 75 0.44 MA2 74 24 0.60 MDJ 75 44 0.97 MSEY 53 135 0.86 PALK 61 103 0.59 SDV 86 278 2.34 TIXI 59 20 0.64 TKM2 41 65 0.33 TNA 76 3 0.94 ULN 60 50 0.44 USP 40 65 0.36 YAK 65 29 0.60 YHNB 82 64 0.87 Misfit > 1 heavily downweighted

April 11, 2006, SOUTHERN GREECE, MW=5.5 Natasha Maternovskaya CENTROID, MOMENT TENSOR SOLUTION HARVARD EVENT-FILE NAME C041106B DATA USED: GSN L.P. BODY WAVES: 58S,101C, T= 40 SURFACE WAVES: 75S,166C, T= 50 CENTROID LOCATION: ORIGIN TIME 17:29:35.3 0.2 LAT 37.66N 0.02;LON 20.84E 0.01 DEP 21.1 0.8;HALF-DURATION 1.4 MOMENT TENSOR; SCALE 10**24 D-CM MRR= 1.44 0.06; MTT= 1.31 0.05 MPP=-2.76 0.05; MRT= 0.36 0.09 MRP=-0.90 0.09; MTP=-0.11 0.04 PRINCIPAL AXES: 1.(T) VAL= 1.87;PLG=55;AZM= 17 2.(N) 1.06; 33; 173 3.(P) -2.95; 12; 270 BEST DOUBLE COUPLE:M0=2.4*10**24 NP1:STRIKE= 35;DIP=44;SLIP= 141 NP2:STRIKE=155;DIP=64;SLIP= 53 ########### --################# ----##################- ------##################--- -------######## ########--- --------######## T ########---- --------######## ########---- -------#################------ P -------#################------ --------###############------- ------------#############-------- ------------###########-------- -------------#########--------- -------------######---------- --------------##----------- -----------###--------- ##############----- ###########

Date 6 4 11 Time 17 29 27.2 Loc 37.72 20.94 18. Dur 9.0 SED http://www.seismo.ethz.ch/mt/armt/all_armt.html ScMom 0.361E+25 Mw 5.64 MT 0.174E+25 0.148E+25 -0.322E+25 -0.239E+25 0.896E+23 0.679E+23 Err 0.777E+23 0.469E+23 0.528E+23 0.869E+23 0.954E+23 0.494E+23 Principal Axes: T - val 0.400E+01 plg 46 azi 180 N - -0.773E+00 43 356 P - -0.323E+01 1 88 Best Double Couple: NP1 - str 213 dip 57 slp 144 NP2 - 324 60 37 Isotropic component 0.000 Deviation from Double Couple 0.193 Freq range 0.0100 0.020 ########## ****#######***** ------** **------- ---------- n ----------- ----------- ------------ -----------**-**------------ ----------*--#--**---------- ----------*########*-------- ---------*##########*------- p --------*############*------ -------*##############*------- -----#*##############*#----- -----*###### #######*----- ----*###### t #######*---- ---*###### #######*--- -*################*- ################ ##########

Deviatoric Moment Tensor Solution

The following broadband stations were used for the source inversion: ARU BILL BJT BRVK DBIC EGMT KSM KURK LSA MA2 MDJ MSEY PALK SDV TIXI TKM2 TNA ULN USP YAK YHNB

Location of the earthquake (yellow star) and great circle path from the epicenter to each station (red) [created using GMT (Wessel, P., and W. H. F. Smith, New version of Generic Mapping Tools released, EOS Trans. AGU, 76 329, 1995.)]

All observed and Greens function waveforms are corrected to instrument response to ground velocity in meters/sec for the passband of 0.01 - 5 Hz. Next tre traces were bandpass filtered by the application of the following high- and low-pass stages:

hp c 0.0167 2
lp c 0.0833 2

The source inversion is a multipass operation since a lower frequency filter band is used for larger earthquakes and since a search is made over depth. Up to three passed of the outer loop are made, after which the moment magnitude is determined and filter settings readjusted. The inner loop over depth samples all depths from 0 to 800 km with 5 km increments in depth to 50 km, followed by 10 km depth sampling for the remaining range.

The following filter ranges are used according to the moment magnitude Mw:

   FILTER_BAND   FH(s)  FL(s)
       1           60     12      Mw < 6.4
       2          100     20      6.4 < Mw <= 6.9
       3          120     40      Mw > 6.9

For this data set the favored solution is

WVFMTD96   15.0  357.   73. -133.   5.54     0.228 0.110E-06     0.417     0.490 0.526E-07   9.5

The following figures show the sensitivity of the goodness of fit parameter so source depth, the waveform comparison as a function of epicentral distance in degrees and the source to station azimuth

Depth Sensitivity

Goodness of fit as a function of source depth. The measure is 1 - SUM (o -p)2 / SUM o2. A value of 1.0 is the best fit. The best double couple mechanism for the solution depth is plotted above goodness of fit value to indicate how the mefhanism may change with depth.

Fit with Distance

Fit with Azimuth

Comparison of the observed traces (red) and solution predicted traces (blue) as a function of source to station azimuth in degrees (D). The purpose of this display is to highlight the azimuthal dependence on the first motion. The traces are annotated with the station name at the top.

Inversion Details