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 M 0001 2014.165 2015.224 358.0 87.5 53 13 x x x x x x -2 x x x x x x x x
ALE-II LH1-00 LH2-00 M 0003 2015.256 2016.245 358.0 87.5 51 5 x x x x x -6 x x x x x x x x x
ALE-II LH1-00 LH2-00 M 0004 2016.268 2018.273 358.0 87.5 89 16 x x x x x x -2 x x x x x x x x
ALE-II LH1-00 LH2-00 M 0005 2018.283 2018.363 358.0 87.5 17 4 x x x x x x x -1 x x x x x x x
ALE-II LH1-10 LH2-10 M 0001 2014.165 2015.222 358.3 88.6 53 20 x x x x x x -2 x x x x x x x x
ALE-II LH1-10 LH2-10 M 0003 2015.256 2016.245 358.3 88.6 51 10 x x x x x x -3 x x x x x x x x
ALE-II LH1-10 LH2-10 M 0004 2016.268 2018.363 358.3 88.6 106 29 x x x x x x -2 x x x x x x x x
ALE-II LHN-00 LHE-00 M 0005 2009.003 2012.119 0.0 90.0 163 59 x x x x x x x -1 x x x x x x x
ALE-II LHN-10 LHE-10 M 0001 2009.003 2012.119 0.0 90.0 159 31 x x x x x x x -1 x x x x x x x
BORG-II LH1-00 LH2-00 M 0002 2009.003 2011.261 225.2 316.8 150 65 x x x x x x x 0 x x x x x x x
BORG-II LH1-00 LH2-00 M 0003 2011.287 2016.293 225.2 316.8 244 99 x x x x x x x 0 x x x x x x x
BORG-II LH1-00 LH2-00 M 0004 2016.304 2017.262 225.2 316.8 41 23 x x x x x x x 1 x x x x x x x
BORG-II LH1-00 LH2-00 M 0006 2017.281 2018.124 170.4 260.0 27 4 x x x x x x x -1 x x x x x x x
BORG-II LH1-00 LH2-00 M 0007 2018.217 2018.363 249.9 339.6 34 6 x x x x x x -2 x x x x x x x x
BORG-II LH1-10 LH2-10 M 0001 2011.287 2012.108 358.8 89.4 27 0 x x x x x x x x x x x x x x x
BORG-II LH1-10 LH2-10 M 0002 2012.112 2012.149 359.9 89.9 3 0 x x x x x x x x x x x x x x x
BORG-II LH1-10 LH2-10 M 0003 2012.208 2016.268 358.1 88.3 212 51 x x x x x x x 0 x x x x x x x
BORG-II LH1-10 LH2-10 M 0004 2016.291 2017.262 358.1 88.3 43 8 x x x x x x x 1 x x x x x x x
BORG-II LH1-10 LH2-10 M 0005 2017.281 2018.209 358.1 88.3 28 7 x x x x x x x 1 x x x x x x x
BORG-II LH1-10 LH2-10 M 0006 2018.217 2018.363 358.1 88.3 34 4 x x x x x x -2 x x x x x x x x
BORG-II LHN-10 LHE-10 M 0001 2009.003 2011.261 0.6 90.6 150 6 x x x x x x x x x 6 x x x x x