2016/01/08 13:07:41 42.93 18.52 15 4.5 Bosnia Herzegovina
USGS Felt map for this earthquake
USGS/SLU Moment Tensor Solution
ENS 2016/01/08 13:07:41:0 42.93 18.52 15.0 4.5 Bosnia Herzegovina
Stations used:
GE.PSZ HT.SRS HU.AMBH HU.BSZH HU.BUD HU.EGYH HU.KOVH
HU.LTVH HU.MORH HU.SOP MN.BLY MN.DIVS MN.TIR MN.VTS NI.ACOM
NI.SABO OE.OBKA RO.BAIL RO.BZS RO.COPA RO.HERR RO.LOT
RO.MDVR RO.SIRR SJ.BBLS SJ.FRGS SL.BOJS SL.CRES SL.DOBS
SL.GBRS SL.GCIS SL.JAVS SL.KOGS SL.LJU SL.PERS SL.ROBS
SL.VISS
Filtering commands used:
cut o DIST/3.3 -30 o DIST/3.3 +70
rtr
taper w 0.1
hp c 0.02 n 3
lp c 0.06 n 3
Best Fitting Double Couple
Mo = 5.56e+22 dyne-cm
Mw = 4.43
Z = 24 km
Plane Strike Dip Rake
NP1 270 70 60
NP2 149 36 144
Principal Axes:
Axis Value Plunge Azimuth
T 5.56e+22 55 142
N 0.00e+00 28 281
P -5.56e+22 19 22
Moment Tensor: (dyne-cm)
Component Value
Mxx -3.09e+22
Mxy -2.61e+22
Mxz -3.69e+22
Myy -6.23e+14
Myz 9.51e+21
Mzz 3.09e+22
--------------
---------------- ---
##----------------- P ------
##------------------ -------
###-------------------------------
####--------------------------------
####----------------------------------
#####-----------------------------------
#####--------##############-------------
####################################------
##----##################################--
-------###################################
--------##################################
-------################# #############
--------################ T #############
--------############### ############
---------###########################
----------########################
----------####################
------------################
-------------#########
--------------
Global CMT Convention Moment Tensor:
R T P
3.09e+22 -3.69e+22 -9.51e+21
-3.69e+22 -3.09e+22 2.61e+22
-9.51e+21 2.61e+22 -6.23e+14
Details of the solution is found at
http://www.eas.slu.edu/eqc/eqc_mt/MECH.EU/20160108130741/index.html
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STK = 270
DIP = 70
RAKE = 60
MW = 4.43
HS = 24.0
The NDK file is 20160108130741.ndk The waveform inversion is preferred.
The following compares this source inversion to others
USGS/SLU Moment Tensor Solution
ENS 2016/01/08 13:07:41:0 42.93 18.52 15.0 4.5 Bosnia Herzegovina
Stations used:
GE.PSZ HT.SRS HU.AMBH HU.BSZH HU.BUD HU.EGYH HU.KOVH
HU.LTVH HU.MORH HU.SOP MN.BLY MN.DIVS MN.TIR MN.VTS NI.ACOM
NI.SABO OE.OBKA RO.BAIL RO.BZS RO.COPA RO.HERR RO.LOT
RO.MDVR RO.SIRR SJ.BBLS SJ.FRGS SL.BOJS SL.CRES SL.DOBS
SL.GBRS SL.GCIS SL.JAVS SL.KOGS SL.LJU SL.PERS SL.ROBS
SL.VISS
Filtering commands used:
cut o DIST/3.3 -30 o DIST/3.3 +70
rtr
taper w 0.1
hp c 0.02 n 3
lp c 0.06 n 3
Best Fitting Double Couple
Mo = 5.56e+22 dyne-cm
Mw = 4.43
Z = 24 km
Plane Strike Dip Rake
NP1 270 70 60
NP2 149 36 144
Principal Axes:
Axis Value Plunge Azimuth
T 5.56e+22 55 142
N 0.00e+00 28 281
P -5.56e+22 19 22
Moment Tensor: (dyne-cm)
Component Value
Mxx -3.09e+22
Mxy -2.61e+22
Mxz -3.69e+22
Myy -6.23e+14
Myz 9.51e+21
Mzz 3.09e+22
--------------
---------------- ---
##----------------- P ------
##------------------ -------
###-------------------------------
####--------------------------------
####----------------------------------
#####-----------------------------------
#####--------##############-------------
####################################------
##----##################################--
-------###################################
--------##################################
-------################# #############
--------################ T #############
--------############### ############
---------###########################
----------########################
----------####################
------------################
-------------#########
--------------
Global CMT Convention Moment Tensor:
R T P
3.09e+22 -3.69e+22 -9.51e+21
-3.69e+22 -3.09e+22 2.61e+22
-9.51e+21 2.61e+22 -6.23e+14
Details of the solution is found at
http://www.eas.slu.edu/eqc/eqc_mt/MECH.EU/20160108130741/index.html
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The focal mechanism was determined using broadband seismic waveforms. The location of the event and the and stations used for the waveform inversion are shown in the next figure.
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The program wvfgrd96 was used with good traces observed at short distance to determine the focal mechanism, depth and seismic moment. This technique requires a high quality signal and well determined velocity model for the Green functions. To the extent that these are the quality data, this type of mechanism should be preferred over the radiation pattern technique which requires the separate step of defining the pressure and tension quadrants and the correct strike.
The observed and predicted traces are filtered using the following gsac commands:
cut o DIST/3.3 -30 o DIST/3.3 +70 rtr taper w 0.1 hp c 0.02 n 3 lp c 0.06 n 3The results of this grid search from 0.5 to 19 km depth are as follow:
DEPTH STK DIP RAKE MW FIT
WVFGRD96 1.0 285 50 -90 4.06 0.3078
WVFGRD96 2.0 105 40 -90 4.13 0.3492
WVFGRD96 3.0 260 90 -5 4.17 0.3428
WVFGRD96 4.0 265 90 -5 4.22 0.3389
WVFGRD96 5.0 265 90 -5 4.25 0.3191
WVFGRD96 6.0 75 80 -40 4.24 0.3034
WVFGRD96 7.0 75 80 -45 4.25 0.3196
WVFGRD96 8.0 75 85 -55 4.30 0.3361
WVFGRD96 9.0 75 85 -55 4.31 0.3649
WVFGRD96 10.0 270 80 70 4.29 0.3924
WVFGRD96 11.0 265 80 65 4.31 0.4226
WVFGRD96 12.0 270 75 70 4.32 0.4518
WVFGRD96 13.0 275 70 75 4.33 0.4771
WVFGRD96 14.0 275 70 75 4.33 0.5001
WVFGRD96 15.0 275 70 70 4.35 0.5196
WVFGRD96 16.0 270 70 65 4.36 0.5360
WVFGRD96 17.0 270 70 65 4.37 0.5501
WVFGRD96 18.0 270 70 65 4.38 0.5613
WVFGRD96 19.0 270 70 65 4.38 0.5700
WVFGRD96 20.0 270 70 60 4.40 0.5768
WVFGRD96 21.0 270 70 60 4.41 0.5820
WVFGRD96 22.0 270 70 65 4.41 0.5854
WVFGRD96 23.0 270 70 65 4.42 0.5872
WVFGRD96 24.0 270 70 60 4.43 0.5877
WVFGRD96 25.0 270 70 60 4.44 0.5870
WVFGRD96 26.0 265 75 55 4.46 0.5852
WVFGRD96 27.0 265 75 55 4.46 0.5823
WVFGRD96 28.0 265 75 55 4.47 0.5782
WVFGRD96 29.0 265 75 55 4.48 0.5729
The best solution is
WVFGRD96 24.0 270 70 60 4.43 0.5877
The mechanism correspond to the best fit is
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The best fit as a function of depth is given in the following figure:
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The comparison of the observed and predicted waveforms is given in the next figure. The red traces are the observed and the blue are the predicted. Each observed-predicted component is plotted to the same scale and peak amplitudes are indicated by the numbers to the left of each trace. A pair of numbers is given in black at the right of each predicted traces. The upper number it the time shift required for maximum correlation between the observed and predicted traces. This time shift is required because the synthetics are not computed at exactly the same distance as the observed and because the velocity model used in the predictions may not be perfect. A positive time shift indicates that the prediction is too fast and should be delayed to match the observed trace (shift to the right in this figure). A negative value indicates that the prediction is too slow. The lower number gives the percentage of variance reduction to characterize the individual goodness of fit (100% indicates a perfect fit).
The bandpass filter used in the processing and for the display was
cut o DIST/3.3 -30 o DIST/3.3 +70 rtr taper w 0.1 hp c 0.02 n 3 lp c 0.06 n 3
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| Focal mechanism sensitivity at the preferred depth. The red color indicates a very good fit to thewavefroms. Each solution is plotted as a vector at a given value of strike and dip with the angle of the vector representing the rake angle, measured, with respect to the upward vertical (N) in the figure. |
Should the national backbone of the USGS Advanced National Seismic System (ANSS) be implemented with an interstation separation of 300 km, it is very likely that an earthquake such as this would have been recorded at distances on the order of 100-200 km. This means that the closest station would have information on source depth and mechanism that was lacking here.
Dr. Harley Benz, USGS, provided the USGS USNSN digital data. The digital data used in this study were provided by Natural Resources Canada through their AUTODRM site http://www.seismo.nrcan.gc.ca/nwfa/autodrm/autodrm_req_e.php, and IRIS using their BUD interface.
Thanks also to the many seismic network operators whose dedication make this effort possible: University of Alaska, University of Washington, Oregon State University, University of Utah, Montana Bureas of Mines, UC Berkely, Caltech, UC San Diego, Saint L ouis University, Universityof Memphis, Lamont Doehrty Earth Observatory, Boston College, the Iris stations and the Transportable Array of EarthScope.
The WUS used for the waveform synthetic seismograms and for the surface wave eigenfunctions and dispersion is as follows:
MODEL.01
Model after 8 iterations
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
1.9000 3.4065 2.0089 2.2150 0.302E-02 0.679E-02 0.00 0.00 1.00 1.00
6.1000 5.5445 3.2953 2.6089 0.349E-02 0.784E-02 0.00 0.00 1.00 1.00
13.0000 6.2708 3.7396 2.7812 0.212E-02 0.476E-02 0.00 0.00 1.00 1.00
19.0000 6.4075 3.7680 2.8223 0.111E-02 0.249E-02 0.00 0.00 1.00 1.00
0.0000 7.9000 4.6200 3.2760 0.164E-10 0.370E-10 0.00 0.00 1.00 1.00
Here we tabulate the reasons for not using certain digital data sets
The following stations did not have a valid response files:
DATE=Fri Jan 8 19:14:11 CST 2016