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
ANMO-SR LHN LHE M 0002 1976.001 1980.211 0.0 90.0 182 59 x x x x x x -4 x x x x x x x x
ANMO-SR LHN LHE M 0003 1980.222 1983.135 0.0 90.0 107 35 x x x x x x -4 x x x x x x x x
ANMO-SR LHN LHE M 0004 1983.146 1985.332 0.0 90.0 87 32 x x x x x x -4 x x x x x x x x
ANMO-SR LHN LHE M 0005 1985.350 1985.361 0.0 270.0 5 3 x x x x x -5 x x x x x x x x x
ANMO-SR LHN LHE M 0006 1986.015 1986.015 0.0 90.0 1 0 x x x x x x x x x x x x x x x
ANMO-SR LHN LHE M 0008 1986.065 1989.233 0.0 90.0 127 52 x x x x x x -4 x x x x x x x x
ANTO-SR LHN LHE M 0001 1978.204 1979.047 0.0 90.0 20 3 x x x x x x x x x 5 x x x x x
ANTO-SR LHN LHE M 0002 1979.059 1979.272 0.0 90.0 21 8 x x x x x x -3 x x x x x x x x
ANTO-SR LHN LHE M 0003 1979.285 1980.222 0.0 90.0 40 18 x x x x x x -3 x x x x x x x x
ANTO-SR LHN LHE M 0004 1980.313 1992.109 0.0 90.0 265 50 x x x x x x -4 x x x x x x x x
BCAO-SR LHN LHE M 0001 1979.173 1980.104 180.0 270.0 34 11 x x x x x x x -1 x x x x x x x
BCAO-SR LHN LHE M 0002 1980.125 1980.222 0.0 90.0 16 1 x x x x x x -4 x x x x x x x x
BCAO-SR LHN LHE M 0003 1980.270 1984.038 0.0 90.0 88 13 x x x x x x x -1 x x x x x x x
BCAO-SR LHN LHE M 0004 1984.254 1990.310 0.0 90.0 171 19 x x x x x x -2 x x x x x x x x
BGIO-SR LHN LHE M 0001 1986.197 1988.164 0.0 90.0 26 2 x x x -11 x x x x x x x x x x x
BOCO-SR LHN LHE M 0001 1978.051 1979.047 0.0 90.0 42 7 x x x x x x x x 3 x x x x x x
BOCO-SR LHN LHE M 0002 1979.082 1987.302 0.0 90.0 163 28 x x x x x x -3 x x x x x x x x
CHTO-SR LHN LHE M 0001 1977.202 1979.121 0.0 90.0 66 17 x x x x x x -3 x x x x x x x x
CHTO-SR LHN LHE M 0002 1979.217 1980.328 0.0 90.0 52 18 x x x x x x -3 x x x x x x x x
CHTO-SR LHN LHE M 0003 1981.002 1982.127 0.0 90.0 22 9 x x x x x x -2 x x x x x x x x
CHTO-SR LHN LHE M 0005 1984.038 1984.115 0.0 90.0 8 0 x x x x x x x x x x x x x x x
CHTO-SR LHN LHE M 0006 1984.147 1992.220 0.0 90.0 234 85 x x x x x x -4 x x x x x x x x
GRFO-SR LHN LHE M 0001 1978.227 1978.305 0.0 90.0 4 0 x x x x x x x x x x x x x x x
GRFO-SR LHN LHE M 0003 1978.346 1989.143 0.0 90.0 353 98 x x x x x x -4 x x x x x x x x
GUMO-SR LHN LHE M 0001 1976.001 1979.320 0.0 90.0 126 12 x x x x x x x -1 x x x x x x x
GUMO-SR LHN LHE M 0002 1980.001 1984.365 0.0 90.0 167 22 x x x x x x -3 x x x x x x x x
GUMO-SR LHN LHE M 0003 1985.103 1988.282 0.0 90.0 123 0 x x x x x x x x x x x x x x x
GUMO-SR LHN LHE M 0004 1988.342 1990.319 0.0 90.0 61 0 x x x x x x x x x x x x x x x
MAIO-SR LHN LHE M 0001 1976.001 1978.266 0.0 90.0 99 32 x x x x x x x x 4 x x x x x x
NWAO-SR LHN LHE M 0001 1976.064 1978.359 0.0 90.0 112 21 x x x x x x -3 x x x x x x x x
NWAO-SR LHN LHE M 0002 1979.016 1991.309 0.0 90.0 443 108 x x x x x -5 x x x x x x x x x
SHIO-SR LHN LHE M 0001 1978.133 1978.204 0.0 90.0 11 1 x x x x x x x x x x x x x x x
SHIO-SR LHN LHE M 0002 1978.215 1978.266 180.0 270.0 6 1 x x x x x -5 x x x x x x x x x
SHIO-SR LHN LHE M 0003 1978.305 1980.104 0.0 90.0 55 15 x x x x x -6 x x x x x x x x x
SHIO-SR LHN LHE M 0004 1980.352 1981.065 0.0 90.0 12 6 x x x x x -6 x x x x x x x x x
SHIO-SR LHN LHE M 0005 1985.235 1985.282 0.0 90.0 3 1 x x x x x x -2 x x x x x x x x
SNZO-SR LHN LHE M 0001 1976.064 1978.305 0.0 90.0 92 11 x x x x x -7 x x x x x x x x x
SNZO-SR LHN LHE M 0002 1978.308 1981.002 0.0 90.0 87 16 x x x x x -5 x x x x x x x x x
SNZO-SR LHN LHE M 0003 1981.018 1991.123 0.0 90.0 300 34 x x x x x x -4 x x x x x x x x
TATO-SR LHN LHE M 0001 1976.099 1979.016 0.0 90.0 77 10 x x x x x -6 x x x x x x x x x
TATO-SR LHN LHE M 0002 1979.026 1979.176 0.0 90.0 16 1 x x x x x x x x x x 9 x x x x
TATO-SR LHN LHE M 0003 1979.272 1980.222 180.0 270.0 34 7 x x x x x -5 x x x x x x x x x
TATO-SR LHN LHE M 0005 1980.270 1992.180 0.0 90.0 364 65 x x x x x x x x x x x 15 x x x