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
ALE-II LH1-00 LH2-00 S 0001 2014.154 2015.224 358.0 87.5 445 60 x x x x x x -4 x x x x x x x x
ALE-II LH1-00 LH2-00 S 0003 2015.254 2016.245 358.0 87.5 393 38 x x x x x x -4 x x x x x x x x
ALE-II LH1-00 LH2-00 S 0004 2016.247 2018.275 358.0 87.5 795 112 x x x x x x -4 x x x x x x x x
ALE-II LH1-00 LH2-00 S 0005 2018.277 2018.365 358.0 87.5 125 19 x x x x x x -3 x x x x x x x x
ALE-II LH1-10 LH2-10 S 0001 2014.154 2015.224 358.3 88.6 459 91 x x x x x x -4 x x x x x x x x
ALE-II LH1-10 LH2-10 S 0003 2015.244 2016.245 358.3 88.6 408 55 x x x x x x -2 x x x x x x x x
ALE-II LH1-10 LH2-10 S 0004 2016.247 2018.365 358.3 88.6 937 179 x x x x x x -3 x x x x x x x x
ALE-II LHN-00 LHE-00 S 0005 2009.001 2012.176 0.0 90.0 1434 278 x x x x x x x -1 x x x x x x x
ALE-II LHN-10 LHE-10 S 0001 2009.001 2012.176 0.0 90.0 1374 228 x x x x x x x 0 x x x x x x x
BORG-II LH1-00 LH2-00 S 0002 2009.001 2011.274 225.2 316.8 1274 208 x x x x x x x 0 x x x x x x x
BORG-II LH1-00 LH2-00 S 0003 2011.280 2016.293 225.2 316.8 2075 270 x x x x x x x 0 x x x x x x x
BORG-II LH1-00 LH2-00 S 0004 2016.294 2017.273 225.2 316.8 365 66 x x x x x x x -1 x x x x x x x
BORG-II LH1-00 LH2-00 S 0006 2017.279 2018.204 170.4 260.0 295 10 x x x x x -5 x x x x x x x x x
BORG-II LH1-00 LH2-00 S 0007 2018.215 2018.365 249.9 339.6 218 6 x x x x x x x 1 x x x x x x x
BORG-II LH1-10 LH2-10 S 0001 2011.279 2012.108 358.8 89.4 207 7 x x x x x x x 0 x x x x x x x
BORG-II LH1-10 LH2-10 S 0002 2012.111 2012.171 359.9 89.9 76 0 x x x x x x x x x x x x x x x
BORG-II LH1-10 LH2-10 S 0003 2012.174 2016.289 358.1 88.3 1789 128 x x x x x x x 1 x x x x x x x
BORG-II LH1-10 LH2-10 S 0004 2016.291 2017.273 358.1 88.3 370 39 x x x x x x x 0 x x x x x x x
BORG-II LH1-10 LH2-10 S 0005 2017.276 2018.209 358.1 88.3 303 19 x x x x x -6 x x x x x x x x x
BORG-II LH1-10 LH2-10 S 0006 2018.215 2018.365 358.1 88.3 218 8 x x x x x x x 1 x x x x x x x
BORG-II LHN-10 LHE-10 S 0001 2009.001 2011.266 0.6 90.6 1271 21 x x x x x x x 0 x x x x x x x