A Regional Vs30 Map for Texas and Its Effect on Ground Shaking Estimates from ShakeMap

Session: Near-Surface Effects: Advances in Site Response Estimation and Its Applications [Poster]
Type: Poster
Date: 4/28/2020
Time: 08:00 AM
Room: Ballroom
Description: 

An integrated Vs30 map for Texas is developed that uses a regional geologic proxy, field measurements and P-wave seismogram estimates of Vs30 and geostatistical kriging. The regionally-based geologic proxy is used first to predict the Vs30 from the surface geologic conditions, and geostatistical kriging with an external drift is used to incorporate the local Vs30 measurements into the map. Compared with the default global scale Vs30 map of Texas developed based on topographic slope, the integrated Vs30 map predicts larger Vs30 across much of Texas, except for the Gulf Coast region where the values are similar. The utilization of kriging brings the integrated Vs30 map into better agreement with the in-situ measurements and estimates of Vs30. The sensitivity of predicted ground motions by ShakeMap to changes in Vs30 values is evaluated with a scenario earthquake in Dallas area. The results suggest smaller predicted ground motions due to the general increase in Vs30 in the study area.

Presenting Author: Meibai Li

Authors