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 S 0001 1993.205 1997.003 0.0 90.0 417 28 x x x x x x x x 2 x x x x x x
BDFB-GT LHN LHE S 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 S 0003 1997.017 1998.038 0.0 90.0 112 26 x x x x x x -4 x x x x x x x x
BDFB-GT LHN LHE S 0004 1998.062 1998.217 0.0 90.0 45 8 x x x x x x -3 x x x x x x x x
BDFB-GT LHN LHE S 0005 1998.239 2002.316 0.0 90.0 400 38 x x x x x x -3 x x x x x x x x
BGCA-GT LHN LHE S 0001 1994.202 1998.271 0.0 90.0 357 59 x x x x -9 x x x x x x x x x x
BGCA-GT LHN LHE S 0002 1998.276 2002.148 0.0 90.0 403 50 x x x -11 x x x x x x x x x x x
BOSA-GT BHN-00 BHE-00 S 0001 2002.311 2012.356 0.0 90.0 1206 173 x x x x x x x 1 x x x x x x x
BOSA-GT LHN LHE S 0002 1993.106 1998.217 0.0 90.0 593 115 x x x x x x x x 2 x x x x x x
BOSA-GT LHN LHE S 0003 1998.232 2002.184 0.0 90.0 332 70 x x x x x x x 1 x x x x x x x
CPUP-GT BHN-00 BHE-00 S 0001 2002.311 2005.272 0.0 90.0 289 21 x x x x x x x x x x x x x 22 x
CPUP-GT BHN-00 BHE-00 S 0002 2005.288 2010.067 15.0 105.0 514 50 x x x x x x x 0 x x x x x x x
CPUP-GT BHN-00 BHE-00 S 0004 2010.107 2012.356 0.0 90.0 411 46 x x x x x x x x 3 x x x x x x
CPUP-GT LHN LHE S 0001 1994.202 1999.240 0.0 90.0 255 9 x x x x x x x x x x x x 19 x x
CPUP-GT LHN LHE S 0002 1999.296 2002.108 0.0 90.0 45 1 x x x x x x x x x x x 15 x x x
DBIC-GT BHN-00 BHE-00 S 0001 2002.311 2012.356 0.0 90.0 1377 123 x x -17 x x x x x x x x x x x x
DBIC-GT LHN LHE S 0001 1994.185 1998.216 0.0 90.0 442 42 x x -16 x x x x x x x x x x x x
DBIC-GT LHN LHE S 0002 1998.232 2002.169 0.0 90.0 115 7 x x x -12 x x x x x x x x x x x
LBTB-GT BHN-00 BHE-00 S 0001 2002.311 2012.352 0.0 90.0 1398 215 x x x x x x x x x x 10 x x x x
LBTB-GT LHN LHE S 0001 1993.107 1993.169 0.0 90.0 11 0 x x x x x x x x x x x x x x x
LBTB-GT LHN LHE S 0002 1993.219 1995.184 0.0 90.0 161 9 x x x x x x x x x 5 x x x x x
LBTB-GT LHN LHE S 0003 1995.207 1995.231 180.0 270.0 17 1 x x x x x x -4 x x x x x x x x
LBTB-GT LHN LHE S 0004 1995.243 1998.235 0.0 90.0 309 59 x x x x x x x x x x 10 x x x x
LBTB-GT LHN LHE S 0005 1998.239 2002.148 0.0 90.0 367 68 x x x x x x x x x x x 11 x x x
LPAZ-GT BHN-00 BHE-00 S 0001 2002.313 2012.356 0.0 90.0 1361 151 x x x x x x x -1 x x x x x x x
LPAZ-GT LHN LHE S 0001 1993.233 1996.232 0.0 90.0 366 23 x x x x x x x x 3 x x x x x x
LPAZ-GT LHN LHE S 0002 1996.311 2002.078 0.0 90.0 178 17 x x x x x x x -1 x x x x x x x
PLCA-GT BHN-00 BHE-00 S 0001 2002.311 2010.087 0.0 90.0 824 127 x x x x x x x -1 x x x x x x x
PLCA-GT BHN-00 BHE-00 S 0002 2010.089 2010.281 0.0 90.0 48 5 x x x x x x x x 3 x x x x x x
PLCA-GT BHN-00 BHE-00 S 0003 2010.294 2012.356 340.0 70.0 331 46 x x x x x x x x 3 x x x x x x
PLCA-GT LHN LHE S 0001 1994.318 1998.217 0.0 90.0 454 75 x x x x x x -3 x x x x x x x x
PLCA-GT LHN LHE S 0002 1998.232 2002.135 0.0 90.0 382 62 x x x x x x x -1 x x x x x x x
SBA-GT LHN LHE S 0001 1994.003 1997.225 0.0 90.0 288 20 x x x x x x -3 x x x x x x x x
SBA-GT LHN LHE S 0002 1997.301 1998.284 0.0 90.0 110 0 x x x x x x x x x x x x x x x
VNDA-GT BHN BHE S 0002 2002.306 2002.330 0.0 90.0 11 2 x x x x x x x 0 x x x x x x x
VNDA-GT BHN-00 BHE-00 S 0001 2003.010 2012.356 0.0 90.0 1228 182 x x x x x x -3 x x x x x x x x
VNDA-GT LHN LHE S 0001 1994.003 1998.180 0.0 90.0 261 26 x x x x x x -2 x x x x x x x x
VNDA-GT LHN LHE S 0002 1998.312 2002.330 0.0 90.0 331 54 x x x x x x -3 x x x x x x x x