A Texas‐specific VS30 map incorporating geology and VS30 observations
Meibai Li, Ellen M. Rathje, Brady R. Cox, Michael Yust
Abstract
A Texas‐specific map that uses geostatistical kriging integrated with a region‐specific geologic proxy, field measurements of , and P‐wave seismogram estimates of is developed. The region‐specific geologic proxy is used first to predict from the surface geologic conditions across the state, and then geostatistical kriging with an external drift is used to incorporate the local measurements/estimates into the map. Compared with the map of Texas developed from a topographic slope proxy, the Texas‐specific map predicts larger values across much of Texas, except for the Gulf Coast region where the values are similar. The utilization of kriging brings the Texas‐specific map into better agreement with the in situ measurements and estimates of . The sensitivity of predicted ground motions by ShakeMap to changes in values is evaluated with a scenario earthquake in the Dallas–Fort Worth area. The results suggest smaller predicted ground motions due to the generally larger values of in the Texas‐specific map as compared to the from the topographic proxy.