2009/01/04 15:30:30 47.20 9.30 10 4.6 Germany
USGS Felt map for this earthquake
USGS/SLU Moment Tensor Solution
ENS 2009/01/04 15:30:30:0 47.20 9.30 10.0 4.6 Germany
Stations used:
CZ.KHC G.ECH GE.FLT1 GE.MORC GE.STU GR.ASSE GR.BFO GR.BRG
GR.CLL GR.GRA2 GR.GRA3 GR.GRB1 GR.GRB2 GR.MOX GR.UBBA
GR.WET IV.BRMO MN.TUE OE.ABTA OE.DAVA OE.FETA OE.KBA
OE.MYKA OE.OBKA OE.RETA OE.SOKA SX.TANN SX.WIMM TH.PLN
Filtering commands used:
cut a -30 a 180
rtr
taper w 0.1
hp c 0.02 n 3
lp c 0.06 n 3
Best Fitting Double Couple
Mo = 4.95e+21 dyne-cm
Mw = 3.73
Z = 9 km
Plane Strike Dip Rake
NP1 200 90 25
NP2 110 65 180
Principal Axes:
Axis Value Plunge Azimuth
T 4.95e+21 17 68
N 0.00e+00 65 200
P -4.95e+21 17 332
Moment Tensor: (dyne-cm)
Component Value
Mxx -2.89e+21
Mxy 3.44e+21
Mxz -7.16e+20
Myy 2.89e+21
Myz 1.97e+21
Mzz -1.83e+14
--------------
-- ------------#####
----- P ------------########
------ -----------##########
---------------------#############
----------------------##############
----------------------############ #
#---------------------############# T ##
##--------------------############# ##
#####-----------------####################
#######--------------#####################
#########------------#####################
############--------######################
###############---######################
##################-#####################
################-----------#######----
##############----------------------
#############---------------------
##########--------------------
########--------------------
#####-----------------
--------------
Global CMT Convention Moment Tensor:
R T P
-1.83e+14 -7.16e+20 -1.97e+21
-7.16e+20 -2.89e+21 -3.44e+21
-1.97e+21 -3.44e+21 2.89e+21
Details of the solution is found at
http://www.eas.slu.edu/eqc/eqc_mt/MECH.EU/20090104153030/index.html
|
STK = 200
DIP = 90
RAKE = 25
MW = 3.73
HS = 9.0
The NDK file is 20090104153030.ndk The waveform inversion is preferred.
The following compares this source inversion to others
USGS/SLU Moment Tensor Solution
ENS 2009/01/04 15:30:30:0 47.20 9.30 10.0 4.6 Germany
Stations used:
CZ.KHC G.ECH GE.FLT1 GE.MORC GE.STU GR.ASSE GR.BFO GR.BRG
GR.CLL GR.GRA2 GR.GRA3 GR.GRB1 GR.GRB2 GR.MOX GR.UBBA
GR.WET IV.BRMO MN.TUE OE.ABTA OE.DAVA OE.FETA OE.KBA
OE.MYKA OE.OBKA OE.RETA OE.SOKA SX.TANN SX.WIMM TH.PLN
Filtering commands used:
cut a -30 a 180
rtr
taper w 0.1
hp c 0.02 n 3
lp c 0.06 n 3
Best Fitting Double Couple
Mo = 4.95e+21 dyne-cm
Mw = 3.73
Z = 9 km
Plane Strike Dip Rake
NP1 200 90 25
NP2 110 65 180
Principal Axes:
Axis Value Plunge Azimuth
T 4.95e+21 17 68
N 0.00e+00 65 200
P -4.95e+21 17 332
Moment Tensor: (dyne-cm)
Component Value
Mxx -2.89e+21
Mxy 3.44e+21
Mxz -7.16e+20
Myy 2.89e+21
Myz 1.97e+21
Mzz -1.83e+14
--------------
-- ------------#####
----- P ------------########
------ -----------##########
---------------------#############
----------------------##############
----------------------############ #
#---------------------############# T ##
##--------------------############# ##
#####-----------------####################
#######--------------#####################
#########------------#####################
############--------######################
###############---######################
##################-#####################
################-----------#######----
##############----------------------
#############---------------------
##########--------------------
########--------------------
#####-----------------
--------------
Global CMT Convention Moment Tensor:
R T P
-1.83e+14 -7.16e+20 -1.97e+21
-7.16e+20 -2.89e+21 -3.44e+21
-1.97e+21 -3.44e+21 2.89e+21
Details of the solution is found at
http://www.eas.slu.edu/eqc/eqc_mt/MECH.EU/20090104153030/index.html
|
Cesca et al 2010 JGR Vol 115 B06304 do1:10.1029/JB006450
ENS 2009/01/04 15:30:30:0 47.30 9.04 8.4 4.4 Feldkirch, Germany
Best Fitting Double Couple
Mo = 8.91e+21 dyne-cm
Mw = 3.90
Z = 8 km
Plane Strike Dip Rake
NP1 110 75 163
NP2 205 74 16
Principal Axes:
Axis Value Plunge Azimuth
T 8.91e+21 22 68
N 0.00e+00 68 249
P -8.91e+21 0 158
Moment Tensor: (dyne-cm)
Component Value
Mxx -6.54e+21
Mxy 5.79e+21
Mxz 1.26e+21
Myy 5.24e+21
Myz 2.89e+21
Mzz 1.30e+21
--------------
------------------####
-------------------#########
-------------------###########
-------------------###############
-------------------#################
-------------------############## ##
#------------------############### T ###
###---------------################ ###
#######-----------########################
##########-------#########################
#############---##########################
###############--#########################
##############-------###################
#############---------------############
############--------------------------
##########--------------------------
#########-------------------------
######------------------------
#####-----------------------
##-------------- ---
------------ P
Global CMT Convention Moment Tensor:
R T P
1.30e+21 1.26e+21 -2.89e+21
1.26e+21 -6.54e+21 -5.79e+21
-2.89e+21 -5.79e+21 5.24e+21
|
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.
|
|
|
|
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 a -30 a 180 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 25 80 -5 3.43 0.3648
WVFGRD96 2.0 20 75 -10 3.52 0.4598
WVFGRD96 3.0 20 75 -15 3.58 0.5062
WVFGRD96 4.0 20 85 -25 3.62 0.5392
WVFGRD96 5.0 20 85 -25 3.64 0.5684
WVFGRD96 6.0 200 90 20 3.66 0.5912
WVFGRD96 7.0 200 90 20 3.68 0.6099
WVFGRD96 8.0 20 90 -25 3.72 0.6238
WVFGRD96 9.0 200 90 25 3.73 0.6255
WVFGRD96 10.0 20 90 -20 3.74 0.6225
WVFGRD96 11.0 20 90 -20 3.75 0.6165
WVFGRD96 12.0 20 90 -20 3.76 0.6084
WVFGRD96 13.0 20 90 -20 3.76 0.5989
WVFGRD96 14.0 200 90 20 3.77 0.5896
WVFGRD96 15.0 20 90 -20 3.78 0.5819
WVFGRD96 16.0 20 90 -20 3.78 0.5750
WVFGRD96 17.0 200 75 15 3.80 0.5736
WVFGRD96 18.0 200 75 15 3.80 0.5697
WVFGRD96 19.0 200 75 15 3.81 0.5651
WVFGRD96 20.0 200 75 15 3.82 0.5599
WVFGRD96 21.0 200 75 15 3.83 0.5539
WVFGRD96 22.0 200 75 15 3.83 0.5473
WVFGRD96 23.0 200 75 15 3.84 0.5405
WVFGRD96 24.0 200 75 15 3.84 0.5337
WVFGRD96 25.0 200 80 15 3.85 0.5268
WVFGRD96 26.0 200 80 15 3.85 0.5197
WVFGRD96 27.0 200 80 15 3.86 0.5121
WVFGRD96 28.0 200 80 15 3.87 0.5053
WVFGRD96 29.0 195 75 -10 3.86 0.4993
The best solution is
WVFGRD96 9.0 200 90 25 3.73 0.6255
The mechanism correspond to the best fit is
|
|
|
The best fit as a function of depth is given in the following figure:
|
|
|
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 a -30 a 180 rtr taper w 0.1 hp c 0.02 n 3 lp c 0.06 n 3
|
|
|
|
| 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. |
A check on the assumed source location is possible by looking at the time shifts between the observed and predicted traces. The time shifts for waveform matching arise for several reasons:
Time_shift = A + B cos Azimuth + C Sin Azimuth
The time shifts for this inversion lead to the next figure:
The derived shift in origin time and epicentral coordinates are given at the bottom of 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=Thu Jul 3 03:24:39 CDT 2014