Network Outage


Starting around 2017-02-17 16:20 UTC (11:20 EDT / 8:20 PDT) IRIS Data Services experienced a network outage. We are still looking into the cause of the outage and hope to be back online as soon as possible. We apologize for the inconvenience to your workflow.

Data Services Products: SWS-DB-MST: Data: Repository


The shear-wave splitting measurements for western and central United States is a teleseismic shear-wave splitting (SWS) database based on all the data from all the broadband seismic stations in North America that contains over 16,000 pairs of well-defined (and manually checked) SWS measurements for the western and central United States (west of 90°W).

Table below shows the content of this database. The columns in the database are as follows (columns in bold are shown in table below) :

  1. Station_network name. The station name is padded with "x"s if it has less than 6 characters, and the network name is padded with a "y" if it has only one character
  2. Phase name (SKS, PKS, SKK which is SKKS)
  3. Event name (EQ + yr + ddd + hh + mm)
  4. Station latitude in degrees
  5. Station longitude in degrees
  6. phi, fast polarization direction in degree, measured clockwise from the North
  7. Standard deviation of the fast direction in degree
  8. dt, splitting time in second
  9. Standard deviation of the splitting time in second
  10. Back azimuth, measured clockwise from the North
  11. Modulo-90 degree back-azimuth
  12. Event latitude
  13. Event longitude
  14. Event depth
  15. Rank, measurement quality
  16. Longitude of XKS raypiercing point at 200 km depth
  17. Latitude of XKS raypiercing point at 200 km depth



If you use these data in publications please cite:

  • Liu, K.H., A. Elsheikh, A. Lemnifi, U. Purevsuren, M. Ray, H. Refayee, B. Yang, Y. Yu, and S.S. Gao (2014), A uniform database of teleseismic shear wave splitting measurements for the western and central United States, Geochemistry Geophysics Geosystems , doi: 10.1002/2014GC005267
  • Yang, B.B., S.S. Gao, K.H. Liu, A.A. Elsheikh, A.A. Lemnifi, H.A. Refayee, and Y. Yu (2014), Seismic anisotropy and mantle flow beneath the northern Great Plains of North America, Journal of Geophysical Research, , volume 119, doi: 10.1002/2013JB010561
  • Trabant, C., A. R. Hutko, M. Bahavar, R. Karstens, T. Ahern and R. Aster (2012), Data products at the IRIS DMC: stepping-stones for research and other application, Seismological Research Letters, 83(6), 846:854. doi: 10.1785/0220120032


  1. click links under Station column for a station summary plot
  2. click links under Plot column for the corresponding Shear-wave splitting measurement plot

NOTE: The following table contains over 15,000 rows and as a result, depending on the browser, the vertical scrollbar on its right edge may not be visible. Hover over the right edge of the table to see the scrollbar or use your mouse scroll wheel to scroll the table

[Click the column headings to sort in ascending and descending order]