Location

2006/01/31 19:15:50 2.74 96.06 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=6.0 2006/01/31 19:15:50 EVID: LAT: 2.74N, LON: 96.06E, DEPTH: 25 Mw: 6.0, mb: 0.0, Ms: 0.0 Mo= 0.111E+26 (dyne-cm) No. of Stations: 26, GAP: 73 Error (clvd/dc)*100= 17.05 Bandpass: 12 - 60 sec Nodal plane parameters strike dip rake NP1: 326 80 -100 NP2: 192 14 -45 ----########### ---################## ###--###################### ###------###################### ###--------###################### ###-----------##################### ###-------------############# ##### ###----------------########### T ###### ###-----------------########## ###### ##-------------------################## ##--------------------################# ##----------------------############### ##---------- ----------############## ###--------- P -----------############# ##--------- ------------########### ##------------------------######### ##------------------------####### ##-----------------------###### ##----------------------### #-------------------- #-------------- Stat Dist Az Misfit Stat Dist Az Misfit BILL 80 21 0.44 CASY 69 173 0.56 CTAO 54 117 0.41 GNI 59 315 0.71 GRFO 84 319 0.78 GUMO 49 74 0.58 HNR 64 101 0.69 INCN 44 35 0.41 KBS 86 348 0.63 KEV 80 340 0.67 KMBO 58 267 3.59 LSZ 69 252 1.78 MA2 70 26 0.43 MAJO 51 43 0.51 MBWA 33 136 0.73 NWAO 40 152 4.21 PET 71 34 0.57 PMG 52 104 0.43 QSPA 92 179 0.75 SBA 88 168 0.90 SNZO 83 131 0.78 TATO 33 45 0.72 TIXI 71 10 0.53 ULN 45 10 0.47 YAK 64 16 0.50 YSS 59 35 0.35 Misfit > 1 heavily downweighted

06/01/31 19:15:50.38 SIMEULUE, INDONESIA Epicenter: 2.744 96.059 MW 5.9 USGS MOMENT TENSOR SOLUTION Depth 17 No. of sta: 31 Moment Tensor; Scale 10**17 Nm Mrr= 4.14 Mtt=-3.33 Mff=-0.82 Mrt= 5.05 Mrf=-4.06 Mtf= 1.77 Principal axes: T Val= 7.73 Plg=61 Azm= 45 N -0.03 5 305 P -7.71 29 212 Best Double Couple:Mo=7.7*10**17 NP1:Strike=288 Dip=17 Slip= 72 NP2: 127 74 96 ------- ----------------- ----###########------ --###################---- #########################---- #---########################--- -----############# ########-- --------########### T #########-- ----------######### ##########- ------------####################- --------------################### ----------------################# ------------------############# -------- -----------######### ------- P ---------------#### ----- ----------------- --------------------- ----------------- ------- `

Harvard CMT ------------- ----------------- P -- -------------------- ----- ------------------------------ #--------------------------------- ##---------------------------------- ##----###############----------------- ############################------------ ----############################-------- -----##############################------- -----################################----- ------#################################--- -------############### ###############-- -------############## T ################ --------############# ################ ---------############################# ----------########################## ------------###################### -------------################# -------------------####----- ---------------------- -------------- Region name: KALIMANTAN, INDONESIA Date (y/m/d): 2006/1/31 Information on data used in inversion Wave nsta nrec cutoff Body 59 111 40 Mantle 0 0 0 Surface 68 138 50 Timing and location information hr min sec lat lon depth mb Ms PDE 16 40 53.00 1.65 117.98 24.5 5.4 5.4 CMT 16 40 54.50 1.68 117.95 12.0 Error 0.20 0.01 0.02 0.0 Assumed half duration: 1.3 Mechanism informationExponent for moment tensor: 24 units: dyne-cm Mrr Mtt Mpp Mrt Mrp Mtp CMT 1.480 -1.180 -0.290 -0.640 -0.160 0.650 Error 0.030 0.020 0.030 0.070 0.080 0.020 Mw = 5.4 Scalar Moment = 1.64e+24 Fault plane: strike=132 dip=38 slip=114 Fault plane: strike=283 dip=56 slip=72 Eigenvector: eigenvalue: 1.68 plunge: 73 azimuth: 147 Eigenvector: eigenvalue: -0.07 plunge: 14 azimuth: 293 Eigenvector: eigenvalue: -1.60 plunge: 9 azimuth: 25

Deviatoric Moment Tensor Solution

The following broadband stations were used for the source inversion: BILL CASY CTAO GNI GRFO GUMO HNR INCN KBS KEV KMBO LSZ MA2 MAJO MBWA NWAO PET PMG QSPA SBA SNZO TATO TIXI ULN YAK YSS

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   25.0  326.   80. -100.   6.00     0.396 0.318E-06     0.441     0.637 0.270E-06  17.0

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