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
ANWB-CU LH1-00 LH2-00 S 0001 2010.044 2015.149 0.0 90.0 781 50 x x x x x x x 1 x x x x x x x
ANWB-CU LHN LHE S 0001 2007.253 2010.040 0.0 90.0 395 21 x x x x x x x -1 x x x x x x x
BBGH-CU LH1-00 LH2-00 S 0001 2010.044 2013.167 0.0 90.0 524 37 x x x x x x x x 2 x x x x x x
BBGH-CU LH1-00 LH2-00 S 0002 2013.175 2015.149 0.0 90.0 290 34 x x x x x x x x 3 x x x x x x
BBGH-CU LHN LHE S 0001 2006.252 2007.306 330.0 60.0 202 15 x x x x -8 x x x x x x x x x x
BBGH-CU LHN LHE S 0002 2007.314 2010.040 0.0 90.0 360 27 x x x x x x x 0 x x x x x x x
BCIP-CU LH1-00 LH2-00 S 0001 2010.044 2015.053 0.0 90.0 736 35 x x x x x x -3 x x x x x x x x
BCIP-CU LH1-00 LH2-00 S 0002 2015.058 2015.149 0.0 90.0 42 1 x x x x x x x x 3 x x x x x x
BCIP-CU LHN LHE S 0001 2006.341 2010.040 0.0 90.0 523 14 x x x x -8 x x x x x x x x x x
GRGR-CU LH1-00 LH2-00 S 0001 2010.044 2015.149 0.0 90.0 803 36 x x x x x x x x 2 x x x x x x
GRGR-CU LHN LHE S 0001 2006.346 2010.040 0.0 90.0 521 16 x x x x x x x 1 x x x x x x x
GRTK-CU LH1-00 LH2-00 S 0001 2010.044 2015.149 0.0 90.0 775 37 x x x x x x x x 2 x x x x x x
GRTK-CU LHN LHE S 0001 2007.355 2010.040 0.0 90.0 283 11 x x x x x x x 1 x x x x x x x
GTBY-CU LH1-00 LH2-00 S 0001 2010.044 2015.047 0.0 90.0 730 72 x x x x x x x x x 7 x x x x x
GTBY-CU LH1-00 LH2-00 S 0002 2015.049 2015.149 0.0 90.0 44 3 x x x x x x x x x x x x x x x
GTBY-CU LHN LHE S 0001 2007.244 2010.040 0.0 90.0 398 36 x x x x x x x x x 6 x x x x x
MTDJ-CU LH1-00 LH2-00 S 0001 2010.044 2015.149 0.0 90.0 792 91 x x x x x x x 0 x x x x x x x
MTDJ-CU LHN LHE S 0001 2007.347 2010.040 0.0 90.0 326 36 x x x x x x x 0 x x x x x x x
SDDR-CU LH1-00 LH2-00 S 0001 2010.044 2015.149 0.0 90.0 775 88 x x x x x x x 1 x x x x x x x
SDDR-CU LHN LHE S 0001 2006.244 2010.040 0.0 90.0 442 45 x x x x x x x 1 x x x x x x x
TGUH-CU LH1-00 LH2-00 S 0001 2010.160 2015.149 24.0 114.0 738 84 x x x x x x x x x x x x x 21 x
TGUH-CU LHN LHE S 0001 2006.264 2008.063 4.0 94.0 267 13 x x x x x x x x 3 x x x x x x
TGUH-CU LHN LHE S 0002 2008.072 2010.152 0.0 90.0 331 40 x x x x x x x 0 x x x x x x x