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
CTAO-AS LHN LHE M 0001 1976.307 1987.250 0.0 90.0 376 91 x x x x x x -3 x x x x x x x x
CTAO-AS LHN LHE M 0002 1987.271 1991.150 0.0 90.0 126 52 x x x x x x x -1 x x x x x x x
KAAO-AS LHN LHE M 0001 1977.133 1981.019 0.0 90.0 133 18 x x x x x x -3 x x x x x x x x
KAAO-AS LHN LHZ M 0002 1981.023 1981.260 0.0 90.0 16 0 x x x x x x x x x x x x x x x
KONO-AS LHN LHE M 0001 1978.249 1980.284 0.0 90.0 76 22 x x x x x x x 0 x x x x x x x
KONO-AS LHN LHE M 0002 1980.298 1991.150 0.0 90.0 347 117 x x x x x x x 0 x x x x x x x
MAJO-AS LHN LHE M 0001 1977.202 1978.083 0.0 90.0 26 1 x x x x x -6 x x x x x x x x x
MAJO-AS LHN LHE M 0002 1978.100 1978.163 180.0 90.0 8 1 x x x x x -6 x x x x x x x x x
MAJO-AS LHN LHE M 0003 1978.165 1988.233 0.0 90.0 351 31 x x x x x -5 x x x x x x x x x
MAJO-AS LHN LHE M 0004 1988.251 1990.208 353.0 83.0 58 13 x x x x x x -2 x x x x x x x x
ZOBO-AS LHN LHE M 0001 1976.274 1978.040 0.0 90.0 43 13 x x x x x x -2 x x x x x x x x
ZOBO-AS LHN LHE M 0003 1978.051 1987.009 0.0 90.0 269 36 x x x x x x x 0 x x x x x x x
ZOBO-AS LHN LHE M 0004 1987.030 1988.170 180.0 270.0 52 0 x x x x x x x x x x x x x x x
ZOBO-AS LHN LHE M 0005 1988.185 1993.270 0.0 90.0 166 3 x x x x x x x 1 x x x x x x x