An Updated Vs30 Map for California with Geologic and Topographic Constraints (ver. 2.0, July 2022)
Dates
Publication Date
2018-01-24
Time Period
2018-01-17
Revision
2022-07-12
Citation
Thompson, E.M., 2018, An Updated Vs30 Map for California with Geologic and Topographic Constraints (ver. 2.0, July 2022): U.S. Geological Survey data release, https://doi.org/10.5066/F7JQ108S.
Summary
This data release provides a map of the time-averaged shear-wave velocity in the upper 30 m (Vs30) for California using the method described by Thompson and others (2014). There are two adjustments to the algorithm described by Thompson and others (2014), which is built on the geology-based Vs30 map by Wills and Clahan (2006). In this data release, we use the Wills and others (2015) updated geology-based Vs30 map. The second change is that we have adjusted the kriging procedure so that measured Vs30 values do not affect the predictions across distinctly different geologic units. July 2022 Update (ver. 2.0) Resolution is now 3 arcseconds instead of 7.5 arcseconds Fixed a code error that prevented some of the Vs30 measurements from [...]
Summary
This data release provides a map of the time-averaged shear-wave velocity in the upper 30 m (Vs30) for California using the method described by Thompson and others (2014). There are two adjustments to the algorithm described by Thompson and others (2014), which is built on the geology-based Vs30 map by Wills and Clahan (2006). In this data release, we use the Wills and others (2015) updated geology-based Vs30 map. The second change is that we have adjusted the kriging procedure so that measured Vs30 values do not affect the predictions across distinctly different geologic units.
July 2022 Update (ver. 2.0)
Resolution is now 3 arcseconds instead of 7.5 arcseconds
Fixed a code error that prevented some of the Vs30 measurements from being used for kriging the Vs30 map.
Removed some outlier Vs30 measurements that were misclassified, either because of errors in the map units or because of uncertainty in the location of the measurement.
Data Description
Resolution: 3 arcseconds, ~90 m
Units: m/s
Values of zero indicate ocean cells.
Nan values indicate inland water cells.
References
Thompson, E. M., D. J. Wald, and C. B. Worden, 2014, A Vs30 map for California with geologic and topographic constraints: Bulletin of the Seismological Society of America, v. 104, p. 2313–2321, https://doi.org/10.1785/0120130312.
Wills, C. J. and Clahan, K. B., 2006, Developing a map of geologically defined site-condition categories for California: Bulletin of the Seismological Society of America, v. 96, p.1483-1501, https://doi.org/10.1785/0120050179.
Wills, C. J., Gutierrez, C. I., Perez, F. G. and Branum, D. M., 2015, A next generation Vs30 map for California based on geology and topography: Bulletin of the Seismological Society of America, v. 105, p. 3083-3091, https://doi.org/10.1785/0120150105.
Revisions
Version 1.0: 2018-01-24, files are archived in the "version_1.0.zip" file.
Version 2.0: 2022-07-11
