Location

2006/04/10 11:25:59 43.74 144.68 121

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=6.4 2006/04/10 11:25:59 EVID: LAT: 43.74N, LON: 144.68E, DEPTH: 240 Mw: 6.4, mb: 0.0, Ms: 0.0 Mo= 0.434E+26 (dyne-cm) No. of Stations: 37, GAP: 166 Error (clvd/dc)*100= 51.60 Bandpass: 12 - 60 sec Nodal plane parameters strike dip rake NP1: 43 85 -170 NP2: 312 80 -5 ############### ##################### ########################### --##########################--- ------######################----- ----------#################-------- --------------#############---------- -----------------#########------------- -------------------######-------------- ------------------##---------------- P ------------------##---------------- -----------------#####-------------- ------------------#########------------ ----------------############----------- -------------################-------- ----------###################------ -------#######################--- ----##########################- ########################### ########## ######## ####### T ##### Stat Dist Az Misfit Stat Dist Az Misfit ACSO 86 34 0.94 AML 50 294 3.43 ARU 53 316 3.13 BLA 89 34 0.96 BMN 68 54 1.07 CBKS 79 45 0.98 CHUM 40 37 0.99 COLA 42 36 1.00 ENH 30 256 4.60 EUO 62 54 0.84 F04A 62 52 0.92 FOR 88 28 0.97 GRA 70 57 0.97 GRFO 78 331 1.25 H05A 63 52 0.99 IRM 73 58 1.04 KSM 52 225 1.14 KSU1 80 43 0.93 KURK 44 303 10.31 LSA 44 270 9.18 LTX 84 54 0.98 M05C 65 55 1.01 MEGW 61 52 0.97 MUR 72 59 0.98 N02C 64 57 1.10 ORV 66 57 1.08 OXF 87 42 0.97 R08A 69 56 0.95 TKM2 48 294 2.47 TNA 33 33 1.23 TRF 41 38 0.97 TUC 77 57 0.89 UCH 49 294 1.44 VCS 71 59 0.90 VOS 47 308 2.21 WENL 67 59 0.97 X14A 74 56 1.02 Misfit > 1 heavily downweighted

April 10, 2006, HOKKAIDO, JAPAN REGION, MW=5.1 Natasha Maternovskaya CENTROID, MOMENT TENSOR SOLUTION HARVARD EVENT-FILE NAME C041006B DATA USED: GSN L.P. BODY WAVES: 31S, 37C, T= 40 SURFACE WAVES: 51S,100C, T= 50 CENTROID LOCATION: ORIGIN TIME 11:26: 1.3 0.3 LAT 43.74N 0.02;LON 144.84E 0.03 DEP 128.4 2.7;HALF-DURATION 0.9 MOMENT TENSOR; SCALE 10**23 D-CM MRR= 3.17 0.19; MTT= 1.58 0.20 MPP=-4.75 0.21; MRT= 0.33 0.13 MRP=-3.41 0.16; MTP=-2.32 0.18 PRINCIPAL AXES: 1.(T) VAL= 4.87;PLG=58;AZM= 47 2.(N) 1.68; 25; 186 3.(P) -6.54; 18; 285 BEST DOUBLE COUPLE:M0=5.7*10**23 NP1:STRIKE= 49;DIP=35;SLIP= 138 NP2:STRIKE=175;DIP=68;SLIP= 63 ----####### -------############ --------############### ----------################- ----------##################- -----------######## #######-- - -------######## T #######-- -- P -------######## #######--- -- -------#################---- ------------#################---- ------------################----- ------------##############----- ------------############------- -----------##########-------- -----------#######--------- #---------##----------- #########---------- ######-----

Deviatoric Moment Tensor Solution

The following broadband stations were used for the source inversion: ACSO AML ARU BLA BMN CBKS CHUM COLA ENH EUO F04A FOR GRA GRFO H05A IRM KSM KSU1 KURK LSA LTX M05C MEGW MUR N02C ORV OXF R08A TKM2 TNA TRF TUC UCH VCS VOS WENL X14A

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
br c 0.12 0.25 n 4 p 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  240.0   43.   85. -170.   6.39    -0.028 0.100E-05     0.077     0.134 0.209E-06  51.6

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