USGS/SLU Moment Tensor Solution ENS 2021/08/13 11:57:35:0 35.88 84.90 0.0 3.0 Tennessee Stations used: CO.CASEE CO.HODGE CO.PAULI ET.CPCT IM.TKL IU.WCI IU.WVT N4.R49A N4.R50A N4.S51A N4.T47A N4.T50A N4.U49A N4.V48A N4.V53A N4.V55A N4.W50A N4.W52A N4.X48A N4.X51A N4.Y52A NM.BLO NM.USIN US.GOGA US.LRAL US.TZTN Filtering commands used: cut o DIST/3.3 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3 Best Fitting Double Couple Mo = 8.04e+21 dynecm Mw = 3.87 Z = 4 km Plane Strike Dip Rake NP1 245 81 95 NP2 35 10 60 Principal Axes: Axis Value Plunge Azimuth T 8.04e+21 53 161 N 0.00e+00 5 65 P 8.04e+21 36 331 Moment Tensor: (dynecm) Component Value Mxx 1.44e+21 Mxy 1.36e+21 Mxz 6.99e+21 Myy 9.41e+20 Myz 3.09e+21 Mzz 2.38e+21   #    P #  # # ######### ############## ################## ###################### ########################## ############################# ############################### ################# ############## #################### T ############# ################### ############ ################################ ############################ ######################### ################### ####### Global CMT Convention Moment Tensor: R T P 2.38e+21 6.99e+21 3.09e+21 6.99e+21 1.44e+21 1.36e+21 3.09e+21 1.36e+21 9.41e+20 Details of the solution is found at http://www.eas.slu.edu/eqc/eqc_mt/MECH.NA/20210813115735/index.html 
STK = 35 DIP = 10 RAKE = 60 MW = 3.87 HS = 4.0
The NDK file is 20210813115735.ndk The waveform inversion is preferred.
The following compares this source inversion to others
USGS/SLU Moment Tensor Solution ENS 2021/08/13 11:57:35:0 35.88 84.90 0.0 3.0 Tennessee Stations used: CO.CASEE CO.HODGE CO.PAULI ET.CPCT IM.TKL IU.WCI IU.WVT N4.R49A N4.R50A N4.S51A N4.T47A N4.T50A N4.U49A N4.V48A N4.V53A N4.V55A N4.W50A N4.W52A N4.X48A N4.X51A N4.Y52A NM.BLO NM.USIN US.GOGA US.LRAL US.TZTN Filtering commands used: cut o DIST/3.3 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3 Best Fitting Double Couple Mo = 8.04e+21 dynecm Mw = 3.87 Z = 4 km Plane Strike Dip Rake NP1 245 81 95 NP2 35 10 60 Principal Axes: Axis Value Plunge Azimuth T 8.04e+21 53 161 N 0.00e+00 5 65 P 8.04e+21 36 331 Moment Tensor: (dynecm) Component Value Mxx 1.44e+21 Mxy 1.36e+21 Mxz 6.99e+21 Myy 9.41e+20 Myz 3.09e+21 Mzz 2.38e+21   #    P #  # # ######### ############## ################## ###################### ########################## ############################# ############################### ################# ############## #################### T ############# ################### ############ ################################ ############################ ######################### ################### ####### Global CMT Convention Moment Tensor: R T P 2.38e+21 6.99e+21 3.09e+21 6.99e+21 1.44e+21 1.36e+21 3.09e+21 1.36e+21 9.41e+20 Details of the solution is found at http://www.eas.slu.edu/eqc/eqc_mt/MECH.NA/20210813115735/index.html 
Moment (dynecm) 8.01E+21 dynecm Magnitude (Mw) 3.87 Principal Axes: Axis Value Plunge Azimuth T 8.01E+21 53. 161. N 1.30E+18 5. 65. P 8.01E+21 36. 331. Moment Tensor: (dynecm) AkiRichards Component Value Mxx 1.43E+21 Mxy 1.35E+21 Mxz 6.97E+21 Myy 9.39E+20 Myz 3.08E+21 Mzz 2.37E+21   #    P #  # # ######### ############## ################## ###################### ########################## ############################# ############################### ################# ############## ################### T ############# ################### ############ ################################ ############################ ######################### ################### ####### Global CMT Convention Moment Tensor: (dynecm) R T F R 2.37E+21 6.97E+21 3.08E+21 T 6.97E+21 1.43E+21 1.35E+21 F 3.08E+21 1.35E+21 9.39E+20 
Moment (dynecm) 1.07E+22 dynecm Magnitude (Mw) 3.95 Principal Axes: Axis Value Plunge Azimuth T 6.67E+21 5. 88. N 5.70E+21 8. 179. P 1.23E+22 81. 328. Moment Tensor: (dynecm) AkiRichards Component Value Mxx 5.39E+21 Mxy 2.31E+20 Mxz 2.33E+21 Myy 6.54E+21 Myz 1.56E+21 Mzz 1.19E+22 ############## ###################### ############################ ################## ################ ############### ############## ############### ###### ######## ####### P ###### ####### ###### T ############# ################# ################ ################## #################### ###################### ################################## ############################## ############################ ###################### ############## Global CMT Convention Moment Tensor: (dynecm) R T F R 1.19E+22 2.33E+21 1.56E+21 T 2.33E+21 5.39E+21 2.31E+20 F 1.56E+21 2.31E+20 6.54E+21 
Moment (dynecm) 1.48E+22 dynecm Magnitude (Mw) 4.05 Principal Axes: Axis Value Plunge Azimuth T 3.77E+21 10. 140. N 5.72E+21 0. 230. P 1.98E+22 80. 320. Moment Tensor: (dynecm) AkiRichards Component Value Mxx 4.86E+21 Mxy 7.24E+20 Mxz 2.10E+21 Myy 5.11E+21 Myz 1.76E+21 Mzz 1.93E+22 Global CMT Convention Moment Tensor: (dynecm) R T F R 1.93E+22 2.10E+21 1.76E+21 T 2.10E+21 4.86E+21 7.24E+20 F 1.76E+21 7.24E+20 5.11E+21 Moment (dynecm) 1.48E+22 dynecm Magnitude (Mw) 4.05 Principal Axes: Axis Value Plunge Azimuth T 3.77E+21 10. 140. N 5.72E+21 0. 230. P 1.98E+22 80. 320. Moment Tensor: (dynecm) AkiRichards Lune parameters Component Value Mxx 4.86E+21 beta: 143.82 Mxy 7.24E+20 gamma: 23.58 Mxy 7.24E+20 Mxz 2.10E+21 Myy 5.11E+21 Myz 1.76E+21 Mzz 1.93E+22  .  ..  .....  ..  .......  .. .. .  ..  . . . ..   . . . . .  P  ..   . . . . .  . . . . .  ..  . . . . .  ..  . . . . .  . . . ..   ..  T  .. .. .  .....#.  ..  ..... .. . 
Moment (dynecm) 8.40E+21 dynecm Magnitude (Mw) 3.88 Principal Axes: Axis Value Plunge Azimuth T 5.15E+21 4. 106. N 4.55E+21 16. 15. P 9.70E+21 74. 209. Moment Tensor: (dynecm) AkiRichards Component Value Mxx 3.75E+21 Mxy 6.15E+20 Mxz 3.32E+21 Myy 4.85E+21 Myz 1.85E+21 Mzz 8.60E+21 Global CMT Convention Moment Tensor: (dynecm) R T F R 8.60E+21 3.32E+21 1.85E+21 T 3.32E+21 3.75E+21 6.15E+20 F 1.85E+21 6.15E+20 4.85E+21 Moment (dynecm) 8.40E+21 dynecm Magnitude (Mw) 3.88 Principal Axes: Axis Value Plunge Azimuth T 5.15E+21 4. 106. N 4.55E+21 16. 15. P 9.70E+21 74. 209. Moment Tensor: (dynecm) AkiRichards Lune parameters Component Value Mxx 3.75E+21 beta: 90.00 Mxy 6.15E+20 gamma: 27.96 Mxy 6.15E+20 Mxz 3.32E+21 Myy 4.85E+21 Myz 1.85E+21 Mzz 8.60E+21 ############## . ###################### .. ############################ ..... ############################## .. ################################## ....... ############################### .. .. . ######################## .. ##################### . . . .. ################## . . . . . ################## .. ################ . . . . . ###### ########## . . . . . ###### P ###### .# ##### ###### T . . . . . ############ .. ############# . . . . . ############# . . . .. ############# .. ############# .. .. . ################# ....... ###################### .. ############## ..... .. . 
Moment (dynecm) 1.03E+22 dynecm Magnitude (Mw) 3.94 Principal Axes: Axis Value Plunge Azimuth T 9.26E+19 3. 110. N 4.52E+20 18. 19. P 1.46E+22 71. 209. Moment Tensor: (dynecm) AkiRichards Component Value Mxx 1.50E+21 Mxy 7.27E+20 Mxz 3.71E+21 Myy 4.78E+20 Myz 2.10E+21 Mzz 1.31E+22 Global CMT Convention Moment Tensor: (dynecm) R T F R 1.31E+22 3.71E+21 2.10E+21 T 3.71E+21 1.50E+21 7.27E+20 F 2.10E+21 7.27E+20 4.78E+20 Moment (dynecm) 1.03E+22 dynecm Magnitude (Mw) 3.94 Principal Axes: Axis Value Plunge Azimuth T 9.26E+19 3. 110. N 4.52E+20 18. 19. P 1.46E+22 71. 209. Moment Tensor: (dynecm) AkiRichards Lune parameters Component Value Mxx 1.50E+21 beta: 126.77 Mxy 7.27E+20 gamma: 28.75 Mxy 7.27E+20 Mxz 3.71E+21 Myy 4.78E+20 Myz 2.10E+21 Mzz 1.31E+22  .  ..  .....  ..  .......  .. .. .  ..  . . . ..  . . . . .  ..  . . . . .  . . . . .   ..  P  . . . . .   T ..  . . . . .  . . . ..  .#  .. .. .  .......  ..  ..... .. . 
(a) mLg computed using the IASPEI formula; (b) mLg residuals ; the values used for the trimmed mean are indicated.
(a) ML computed using the IASPEI formula for Horizontal components; (b) ML residuals computed using a modified IASPEI formula that accounts for path specific attenuation; the values used for the trimmed mean are indicated. The ML relation used for each figure is given at the bottom of each plot.
(a) ML computed using the IASPEI formula for Vertical components (research); (b) ML residuals computed using a modified IASPEI formula that accounts for path specific attenuation; the values used for the trimmed mean are indicated. The ML relation used for each figure is given at the bottom of each plot.
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 o DIST/3.3 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3The results of this grid search from 0.5 to 19 km depth are as follow:
DEPTH STK DIP RAKE MW FIT WVFGRD96 1.0 230 15 90 3.95 0.3836 WVFGRD96 2.0 30 5 55 3.96 0.4577 WVFGRD96 3.0 30 10 55 3.90 0.4904 WVFGRD96 4.0 35 10 60 3.87 0.5010 WVFGRD96 5.0 30 5 50 3.85 0.4963 WVFGRD96 6.0 260 10 80 3.84 0.4858 WVFGRD96 7.0 235 20 100 3.86 0.4800 WVFGRD96 8.0 50 60 80 3.90 0.4789 WVFGRD96 9.0 45 55 80 3.91 0.4729 WVFGRD96 10.0 45 60 85 3.92 0.4484 WVFGRD96 11.0 40 55 85 3.93 0.4347 WVFGRD96 12.0 40 55 85 3.93 0.4173 WVFGRD96 13.0 40 55 90 3.92 0.3972 WVFGRD96 14.0 30 55 95 3.92 0.3758 WVFGRD96 15.0 220 40 80 3.93 0.3545 WVFGRD96 16.0 225 45 80 3.93 0.3348 WVFGRD96 17.0 225 50 80 3.93 0.3178 WVFGRD96 18.0 225 50 80 3.93 0.3022 WVFGRD96 19.0 225 50 75 3.94 0.2862 WVFGRD96 20.0 225 50 80 3.96 0.2649 WVFGRD96 21.0 225 50 80 3.96 0.2523 WVFGRD96 22.0 35 65 90 3.97 0.2429 WVFGRD96 23.0 215 25 85 3.98 0.2350 WVFGRD96 24.0 215 25 85 3.99 0.2279 WVFGRD96 25.0 215 25 85 4.00 0.2202 WVFGRD96 26.0 215 25 85 4.00 0.2121 WVFGRD96 27.0 70 80 85 4.01 0.2049 WVFGRD96 28.0 75 80 85 4.02 0.2032 WVFGRD96 29.0 305 20 70 4.06 0.2023
The best solution is
WVFGRD96 4.0 35 10 60 3.87 0.5010
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 observedpredicted 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 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.
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 wvfmtd96 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3The results of this grid search over depth are as follow:
MT Program H(km) Mxx(dynecm) Myy Mxy Mxz Myz Mzz Mw Fit WVFMTD96 0.5 113. 78. 89. 4.00 0.485 0.150E06 0.504 0.697 0.109E06 58.7 WVFMTD96 1.0 111. 76. 89. 4.02 0.464 0.153E06 0.483 0.682 0.111E06 65.6 WVFMTD96 2.0 101. 72. 93. 3.97 0.359 0.167E06 0.370 0.599 0.123E06 78.8 WVFMTD96 3.0 109. 78. 95. 3.93 0.344 0.169E06 0.361 0.586 0.121E06 59.9 WVFMTD96 4.0 310. 65. 96. 3.91 0.288 0.176E06 0.302 0.537 0.130E06 70.4 WVFMTD96 5.0 326. 57. 98. 3.96 0.390 0.163E06 0.408 0.624 0.120E06 88.3 WVFMTD96 6.0 351. 53. 103. 3.96 0.454 0.154E06 0.474 0.674 0.113E06 90.7 WVFMTD96 7.0 2. 51. 105. 3.95 0.485 0.150E06 0.505 0.696 0.109E06 88.6 WVFMTD96 8.0 4. 50. 106. 3.94 0.490 0.149E06 0.509 0.700 0.109E06 87.8 WVFMTD96 9.0 11. 48. 107. 3.93 0.486 0.150E06 0.505 0.697 0.109E06 82.5 WVFMTD96 10.0 14. 48. 108. 3.96 0.472 0.152E06 0.490 0.687 0.111E06 85.6
The best solution is
WVFMTD96 4.0 310. 65. 96. 3.91 0.288 0.176E06 0.302 0.537 0.130E06 70.4
The complete moment tensor decomposition using the program mtdinfo is given in the text file MTDinfo.txt. (Jost, M. L., and R. B. Herrmann (1989). A student's guide to and review of moment tensors, Seism. Res. Letters 60, 3757. SRL_60_2_3757.pdf.
The Pwave first motion mechanism corresponding 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 observedpredicted 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3

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.
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 wvfmt96 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3The results of this grid search over depth are as follow:
MT Program H(km) Mxx(dynecm) Myy Mxy Mxz Myz Mzz Mw Fit WVFMT96 0.5 112. 85. 89. 4.00 0.487 0.149E06 0.507 0.698 0.108E06 33.9 WVFMT96 1.0 293. 86. 89. 4.06 0.486 0.149E06 0.508 0.698 0.108E06 2.9 WVFMT96 2.0 286. 75. 90. 4.07 0.498 0.148E06 0.514 0.706 0.108E06 42.2 WVFMT96 3.0 293. 69. 90. 4.08 0.506 0.147E06 0.523 0.712 0.107E06 66.0 WVFMT96 4.0 298. 66. 91. 4.06 0.514 0.145E06 0.531 0.717 0.106E06 84.1 WVFMT96 5.0 344. 58. 109. 4.04 0.519 0.145E06 0.537 0.720 0.106E06 99.4 WVFMT96 6.0 5. 51. 114. 4.01 0.518 0.145E06 0.537 0.720 0.106E06 92.9 WVFMT96 7.0 10. 49. 114. 3.99 0.513 0.146E06 0.534 0.716 0.106E06 86.2 WVFMT96 8.0 13. 48. 112. 3.96 0.505 0.147E06 0.525 0.711 0.107E06 82.1 WVFMT96 9.0 14. 48. 111. 3.94 0.494 0.148E06 0.513 0.703 0.108E06 81.2 WVFMT96 10.0 14. 48. 110. 3.96 0.478 0.151E06 0.495 0.691 0.110E06 85.2
The best solution is
WVFMT96 10.0 14. 48. 110. 3.96 0.478 0.151E06 0.495 0.691 0.110E06 85.2
The complete moment tensor decomposition using the program mtinfo is given in the text file MTinfo.txt. (Jost, M. L., and R. B. Herrmann (1989). A student's guide to and review of moment tensors, Seism. Res. Letters 60, 3757. SRL_60_2_3757.pdf.
The Pwave first motion mechanism corresponding 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 observedpredicted 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3

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.
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 wvfmtgrd96 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3The results of this grid search over depth are as follow:
MT Program H(km) Mxx(dynecm) Myy Mxy Mxz Myz Mzz Mw Fit WVFMTGRD96 1.0 0.105E+23 0.112E+23 0.315E+21 0.701E+21 0.210E+22 0.176E+23 4.0808 0.5303 WVFMTGRD96 2.0 0.105E+23 0.103E+23 0.908E+21 0.233E+22 0.383E+22 0.201E+23 4.1063 0.5465 WVFMTGRD96 3.0 0.778E+22 0.800E+22 0.903E+21 0.445E+22 0.269E+22 0.193E+23 4.0803 0.5656 WVFMTGRD96 4.0 0.704E+22 0.772E+22 0.684E+21 0.361E+22 0.118E+22 0.196E+23 4.0720 0.5769 WVFMTGRD96 5.0 0.486E+22 0.511E+22 0.724E+21 0.210E+22 0.176E+22 0.193E+23 4.0467 0.5823 WVFMTGRD96 6.0 0.354E+22 0.261E+22 0.703E+21 0.284E+22 0.141E+22 0.173E+23 4.0098 0.5820 WVFMTGRD96 7.0 0.457E+21 0.326E+21 0.354E+21 0.301E+22 0.142E+22 0.152E+23 3.9677 0.5749 WVFMTGRD96 8.0 0.125E+22 0.172E+22 0.663E+21 0.240E+22 0.393E+18 0.147E+23 3.9560 0.5637 WVFMTGRD96 9.0 0.355E+22 0.428E+22 0.640E+21 0.250E+22 0.219E+21 0.130E+23 3.9434 0.5480 WVFMTGRD96 10.0 0.267E+22 0.384E+22 0.421E+21 0.355E+22 0.122E+21 0.144E+23 3.9690 0.5255
The best solution is
WVFMTGRD96 5.0 0.486E+22 0.511E+22 0.724E+21 0.210E+22 0.176E+22 0.193E+23 4.0467 0.5823
The complete moment tensor decomposition using the program mtinfo is given in the text file MTGRDinfo.txt. (Jost, M. L., and R. B. Herrmann (1989). A student's guide to and review of moment tensors, Seism. Res. Letters 60, 3757. SRL_60_2_3757.pdf.
The Pwave first motion mechanism corresponding 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 observedpredicted 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3

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.
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 wvfmtgrd96 DC 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3The results of this grid search over depth are as follow:
MT Program H(km) Mxx(dynecm) Myy Mxy Mxz Myz Mzz Mw Fit WVFMTGRD96 1.0 0.312E+22 0.220E+22 0.262E+22 0.705E+22 0.592E+22 0.532E+22 3.9511 0.3836 WVFMTGRD96 2.0 0.863E+21 0.693E+21 0.947E+21 0.983E+22 0.452E+22 0.156E+22 3.9593 0.4577 WVFMTGRD96 3.0 0.139E+22 0.110E+22 0.152E+22 0.779E+22 0.342E+22 0.250E+22 3.8999 0.4904 WVFMTGRD96 4.0 0.143E+22 0.939E+21 0.135E+22 0.697E+22 0.308E+22 0.237E+22 3.8692 0.5010 WVFMTGRD96 5.0 0.605E+21 0.379E+21 0.634E+21 0.690E+22 0.247E+22 0.985E+21 3.8463 0.4963 WVFMTGRD96 6.0 0.233E+22 0.151E+21 0.633E+21 0.649E+22 0.242E+22 0.248E+22 3.8447 0.4858 WVFMTGRD96 7.0 0.379E+22 0.120E+22 0.219E+22 0.562E+22 0.236E+22 0.500E+22 3.8648 0.4800 WVFMTGRD96 8.0 0.312E+22 0.443E+22 0.395E+22 0.384E+22 0.221E+22 0.756E+22 3.8983 0.4789 WVFMTGRD96 9.0 0.299E+22 0.565E+22 0.432E+22 0.288E+22 0.157E+22 0.865E+22 3.9137 0.4729 WVFMTGRD96 10.0 0.341E+22 0.485E+22 0.413E+22 0.367E+22 0.308E+22 0.826E+22 3.9206 0.4484
The best solution is
WVFMTGRD96 4.0 0.143E+22 0.939E+21 0.135E+22 0.697E+22 0.308E+22 0.237E+22 3.8692 0.5010
The complete moment tensor decomposition using the program mtinfo is given in the text file MTGRDDCinfo.txt. (Jost, M. L., and R. B. Herrmann (1989). A student's guide to and review of moment tensors, Seism. Res. Letters 60, 3757. SRL_60_2_3757.pdf.
The Pwave first motion mechanism corresponding 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 observedpredicted 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3

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.
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 wvfmtgrd96 DEV 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3The results of this grid search over depth are as follow:
MT Program H(km) Mxx(dynecm) Myy Mxy Mxz Myz Mzz Mw Fit WVFMTGRD96 1.0 0.438E+22 0.479E+22 0.364E+21 0.434E+22 0.367E+22 0.917E+22 3.9266 0.4966 WVFMTGRD96 2.0 0.220E+22 0.334E+22 0.436E+21 0.958E+22 0.433E+22 0.555E+22 3.9758 0.4821 WVFMTGRD96 3.0 0.168E+22 0.283E+22 0.287E+21 0.791E+22 0.347E+22 0.451E+22 3.9184 0.5049 WVFMTGRD96 4.0 0.338E+22 0.453E+22 0.988E+20 0.622E+22 0.340E+22 0.791E+22 3.9296 0.5195 WVFMTGRD96 5.0 0.551E+22 0.458E+22 0.732E+21 0.394E+22 0.409E+22 0.101E+23 3.9464 0.5253 WVFMTGRD96 6.0 0.568E+22 0.692E+22 0.577E+21 0.317E+22 0.148E+22 0.126E+23 3.9735 0.5332 WVFMTGRD96 7.0 0.584E+22 0.645E+22 0.328E+21 0.271E+22 0.120E+22 0.123E+23 3.9623 0.5553 WVFMTGRD96 8.0 0.539E+22 0.654E+22 0.231E+21 0.233E+22 0.156E+22 0.119E+23 3.9534 0.5563 WVFMTGRD96 9.0 0.553E+22 0.630E+22 0.669E+21 0.262E+22 0.229E+21 0.118E+23 3.9503 0.5462 WVFMTGRD96 10.0 0.590E+22 0.696E+22 0.413E+21 0.301E+22 0.201E+21 0.129E+23 3.9753 0.5244
The best solution is
WVFMTGRD96 8.0 0.539E+22 0.654E+22 0.231E+21 0.233E+22 0.156E+22 0.119E+23 3.9534 0.5563
The complete moment tensor decomposition using the program mtinfo is given in the text file MTGRDDEVinfo.txt. (Jost, M. L., and R. B. Herrmann (1989). A student's guide to and review of moment tensors, Seism. Res. Letters 60, 3757. SRL_60_2_3757.pdf.
The Pwave first motion mechanism corresponding 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 observedpredicted 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 20 o DIST/3.3 +50 rtr taper w 0.1 hp c 0.06 n 3 lp c 0.10 n 3

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.
Thanks also to the many seismic network operators whose dedication make this effort possible: University of Nevada Reno, University of Alaska, University of Washington, Oregon State University, University of Utah, Montana Bureau of Mines, UC Berkely, Caltech, UC San Diego, Saint Louis University, University of Memphis, Lamont Doherty Earth Observatory, the Oklahoma Geological Survey, TexNet, the Iris stations, the Transportable Array of EarthScope and other networks.
The CUS model used for the waveform synthetic seismograms and for the surface wave eigenfunctions and dispersion is as follows:
MODEL.01 CUS Model with Q from simple gamma values ISOTROPIC KGS FLAT EARTH 1D CONSTANT VELOCITY LINE08 LINE09 LINE10 LINE11 H(KM) VP(KM/S) VS(KM/S) RHO(GM/CC) QP QS ETAP ETAS FREFP FREFS 1.0000 5.0000 2.8900 2.5000 0.172E02 0.387E02 0.00 0.00 1.00 1.00 9.0000 6.1000 3.5200 2.7300 0.160E02 0.363E02 0.00 0.00 1.00 1.00 10.0000 6.4000 3.7000 2.8200 0.149E02 0.336E02 0.00 0.00 1.00 1.00 20.0000 6.7000 3.8700 2.9020 0.000E04 0.000E04 0.00 0.00 1.00 1.00 0.0000 8.1500 4.7000 3.3640 0.194E02 0.431E02 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: