Location

2006/04/12 01:06:59 56.26 164.15 20

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=5.9 2006/04/12 01:06:59 EVID: LAT: 56.26N, LON: 164.15E, DEPTH: 10 Mw: 5.9, mb: 0.0, Ms: 0.0 Mo= 0.709E+25 (dyne-cm) No. of Stations: 32, GAP: 158 Error (clvd/dc)*100= 20.11 Bandpass: 12 - 60 sec Nodal plane parameters strike dip rake NP1: 294 88 162 NP2: 25 72 2 ------------ --- P -------------## ------ -------------##### ------------------------####### -------------------------######## -------------------------########## ###-----------------------########### ########------------------############# #############-------------############# #################--------############## #####################---############### #######################--############## ## #################-------########## ## T #################----------####### # ###############----------------## #################------------------ ###############------------------ #############------------------ #########------------------ ####----------------- --------------- Stat Dist Az Misfit Stat Dist Az Misfit AAK 55 296 0.76 ACCN 69 41 0.92 BFO 73 343 0.80 BMN 51 72 0.88 BNI 77 343 0.93 C03A 42 69 0.52 C04A 43 69 0.33 CBKS 61 61 0.57 CCM 66 56 0.58 CRAG 34 64 0.42 DBO 46 74 0.92 DGR 56 78 0.82 DPC 70 338 0.83 EIL 84 317 0.98 G04A 45 71 0.69 I06A 47 71 0.74 ISP 78 324 0.82 KBS 44 352 0.57 KKM 62 236 0.50 KSU1 63 59 0.81 MALT 75 318 0.80 MNTX 64 70 0.60 O04C 49 75 0.87 P05C 50 75 0.90 STU 73 342 0.84 ULN 35 280 0.79 VSU 60 335 0.66 VTS 76 331 0.78 WDC 48 76 0.93 WMOK 65 63 0.52 X13A 57 74 0.75 X15A 58 73 0.67 Misfit > 1 heavily downweighted

MANDORSKIYE OSTROVA REGION 2006/04/12 01:06:59.45 EVID: LKAC LAT: 56.26N, LON: 164.15E, DEPTH: 20 Mw: 5.8, mb: 5.8, Ms: 5.8 Mo= 0.548E+25 (dyne-cm) No. of Stations: 4, GAP: 254 Error (clvd/dc)*100= 93.80 Nodal plane parameters strike dip rake NP1: 358 45 -53 NP2: 131 56 239 ------#### -------------####### ------------------######## ----------------------######## #-----------------------######## ##------------------------######## ###------------------------######### #####------------------------######### #####------------------------######### #######------------------------######### ########-----------------------######### ##########---------------------######### ###########--------------------######### ############-----------------######### ##############---------------######### ###############-------------######## #################---------######## ####################----######## ######################-------- ###################------- ##############------ #######--- Stat Dist Az Misfit Stat Dist Az Misfit EIL 84 317 0.95 INK 29 41 0.54 KBS 44 352 0.84 SIT 32 62 0.70 Median of misfit: 0.77 Average misfit: 0.76

April 12, 2006, KOMANDORSKIYE OSTROVA REGION, MW=6.0 Natasha Maternovskaya CENTROID, MOMENT TENSOR SOLUTION HARVARD EVENT-FILE NAME C041206A DATA USED: GSN L.P. BODY WAVES: 77S,185C, T= 40 MANTLE WAVES: 71S,117C, T=125 CENTROID LOCATION: ORIGIN TIME 01:07: 1.6 0.1 LAT 56.18N 0.02;LON 164.27E 0.02 DEP 39.1 1.4;HALF-DURATION 2.5 MOMENT TENSOR; SCALE 10**25 D-CM MRR= 0.04 0.01; MTT=-0.62 0.02 MPP= 0.58 0.02; MRT= 0.00 0.03 MRP= 0.17 0.03; MTP=-1.19 0.01 PRINCIPAL AXES: 1.(T) VAL= 1.33;PLG= 7;AZM=239 2.(N) 0.03; 82; 28 3.(P) -1.36; 4; 148 BEST DOUBLE COUPLE:M0=1.3*10**25 NP1:STRIKE=283;DIP=83;SLIP= 178 NP2:STRIKE= 14;DIP=88;SLIP= 7 ---------## -------------###### ---------------######## ----------------########### -----------------############ -----------------############## -----------------############## ###########-------############### #################--############## #################--------######## ################--------------### ###############---------------- # ##########----------------- T ##########---------------- #########---------------- #########--------- -- ######---------- P ##---------

Deviatoric Moment Tensor Solution

The following broadband stations were used for the source inversion: AAK ACCN BFO BMN BNI C03A C04A CBKS CCM CRAG DBO DGR DPC EIL G04A I06A ISP KBS KKM KSU1 MALT MNTX O04C P05C STU ULN VSU VTS WDC WMOK X13A X15A

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   10.0  294.   88.  162.   5.87     0.143 0.197E-06     0.210     0.382 0.820E-07  20.1

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