Polarization anomalies at various stations


The table below shows the results from polarization analysis of long-period surface waves using the method described by Ekstrom and Busby (SRL, 2008). The horizontal components have been rotated to maximize the correlation between the observed and predicted seismograms for moderate and large earthquakes. The table shows the median (aqua blue) of the rotation angle (the anomaly), as well as the range (navy blue) for the second and third quartiles of the distribution of angles.

The table below gives the channel names and station orientation for the horizontal components, the wave type (Surface-wave or Mantle-wave), a response epoch identifier, the times of the first and last observations used, the total number of observations, and the number of polarization measurements used in the estimate of the sensor orientation. Estimates based on fewer than 5 measurements are less reliable. The orientation anomaly is measured against the reported orientation (Az-1, Az-2). A positive value for the anomaly reflects a counter-clockwise rotation of the sensor compared to the reported value.

Ranked by polarization anomaly

Ascii file with the data

Arrival-angle anomalies
Station Channels T Epoch min time max time Az-1 Az-2 # obs. # used -90- -26 -25- -21 -20- -16 -15- -11 -10- -8 -7- -5 -4- -2 -1- 1 2- 4 5- 7 8- 10 11- 15 16- 20 21- 25 26- 90
BDFB-GT LHN LHE M 0001 1993.219 1996.345 0.0 90.0 140 13 x x x x x x -2 x x x x x x x x
BDFB-GT LHN LHE M 0002 1997.011 1997.011 90.0 0.0 1 0 x x x x x x x x x x x x x x x
BDFB-GT LHN LHE M 0003 1997.035 1998.030 0.0 90.0 33 12 x x x x x -6 x x x x x x x x x
BDFB-GT LHN LHE M 0004 1998.073 1998.216 0.0 90.0 17 7 x x x x x -5 x x x x x x x x x
BDFB-GT LHN LHE M 0005 1998.245 2002.311 0.0 90.0 119 27 x x x x x x x -1 x x x x x x x
BGCA-GT LHN LHE M 0001 1994.202 1998.271 0.0 90.0 128 40 x x x -12 x x x x x x x x x x x
BGCA-GT LHN LHE M 0002 1998.301 2002.116 0.0 90.0 120 33 x x x -11 x x x x x x x x x x x
BOSA-GT BHN-00 BHE-00 M 0001 2002.311 2012.356 0.0 90.0 377 2 x x x -13 x x x x x x x x x x x
BOSA-GT LHN LHE M 0002 1993.106 1998.216 0.0 90.0 199 46 x x x x x x x x 3 x x x x x x
BOSA-GT LHN LHE M 0003 1998.232 2002.178 0.0 90.0 103 20 x x x x x x x x 3 x x x x x x
CPUP-GT BHN-00 BHE-00 M 0001 2002.311 2005.272 0.0 90.0 100 25 x x x x x x x x x x x x 20 x x
CPUP-GT BHN-00 BHE-00 M 0002 2005.302 2010.064 15.0 105.0 150 40 x x x x x x x x 2 x x x x x x
CPUP-GT BHN-00 BHE-00 M 0004 2010.116 2012.356 0.0 90.0 134 39 x x x x x x x x 4 x x x x x x
CPUP-GT LHN LHE M 0001 1994.202 1999.234 0.0 90.0 94 7 x x x x x x x x x x x x 20 x x
CPUP-GT LHN LHE M 0002 1999.312 2002.108 0.0 90.0 14 2 x x x x x x x x x x x 11 x x x
DBIC-GT BHN-00 BHE-00 M 0001 2002.311 2012.356 0.0 90.0 443 189 x x -18 x x x x x x x x x x x x
DBIC-GT LHN LHE M 0001 1994.194 1998.216 0.0 90.0 159 40 x x -18 x x x x x x x x x x x x
DBIC-GT LHN LHE M 0002 1998.232 2002.168 0.0 90.0 34 3 x x -18 x x x x x x x x x x x x
LBTB-GT BHN-00 BHE-00 M 0001 2002.311 2012.345 0.0 90.0 444 1 x x x x x x x x x 6 x x x x x
LBTB-GT LHN LHE M 0001 1993.131 1993.169 0.0 90.0 3 0 x x x x x x x x x x x x x x x
LBTB-GT LHN LHE M 0002 1993.219 1995.184 0.0 90.0 62 2 x x x x x x x x x 6 x x x x x
LBTB-GT LHN LHE M 0003 1995.211 1995.231 180.0 270.0 6 2 x x x x x x x 0 x x x x x x x
LBTB-GT LHN LHE M 0004 1995.257 1998.235 0.0 90.0 107 24 x x x x x x x x x x x 11 x x x
LBTB-GT LHN LHE M 0005 1998.245 2002.116 0.0 90.0 109 24 x x x x x x x x x x x 11 x x x
LPAZ-GT BHN-00 BHE-00 M 0001 2002.319 2012.356 0.0 90.0 419 73 x x x x x x -3 x x x x x x x x
LPAZ-GT LHN LHE M 0001 1993.246 1996.218 0.0 90.0 129 44 x x x x x x -2 x x x x x x x x
LPAZ-GT LHN LHE M 0002 1996.311 2002.064 0.0 90.0 62 11 x x x x x x -2 x x x x x x x x
PLCA-GT BHN-00 BHE-00 M 0001 2002.311 2010.079 0.0 90.0 246 33 x x x x x x x -1 x x x x x x x
PLCA-GT BHN-00 BHE-00 M 0002 2010.089 2010.195 0.0 90.0 14 2 x x x x x x x 0 x x x x x x x
PLCA-GT BHN-00 BHE-00 M 0003 2010.294 2012.356 340.0 70.0 108 15 x x x x x x x 1 x x x x x x x
PLCA-GT LHN LHE M 0001 1994.318 1998.216 0.0 90.0 150 39 x x x x x x x -1 x x x x x x x
PLCA-GT LHN LHE M 0002 1998.232 2002.116 0.0 90.0 113 29 x x x x x x -3 x x x x x x x x
SBA-GT LHN LHE M 0001 1994.230 1997.220 0.0 90.0 105 6 x x x x x x x -1 x x x x x x x
SBA-GT LHN LHE M 0002 1997.301 1998.271 0.0 90.0 38 0 x x x x x x x x x x x x x x x
VNDA-GT BHN BHE M 0002 2002.306 2002.321 0.0 90.0 5 2 x x x x x x x x 3 x x x x x x
VNDA-GT BHN-00 BHE-00 M 0001 2003.010 2012.356 0.0 90.0 380 1 x x x x x x -2 x x x x x x x x
VNDA-GT LHN LHE M 0001 1994.010 1998.150 0.0 90.0 95 13 x x x x x x x x 2 x x x x x x
VNDA-GT LHN LHE M 0002 1998.313 2002.321 0.0 90.0 107 22 x x x x x x x x 2 x x x x x x