Dynamic site characterization of areas affected by the 2017 Puebla-Mexico city earthquake

Abstract

Dynamic site characterization was conducted using the microtremor and earthquake horizontal to vertical spectral ratio methods (MHVSR and EHVSR) and surface wave methods at locations affected by the 2017 Mw 7.1 Puebla-Mexico City Earthquake. These data were compared to published results to understand the accuracy of currently available dynamic site information including site period maps and Vs profiles. Results indicate the current Mexican design code site period map, NTC [9], provides superior estimates of microtremor site periods in Mexico City compared to maps published by Lermo and Chávez-García [7] and Arroyo et al. [11]. However, the NTC [9] map still had significant errors of 15–30% between the estimated and measured site periods, but only had an average bias of 5%. Moreover, the changes in site period within the Mexico basin due to groundwater withdrawal and consolidation of the lacustrine clay deposits were shown to be progressing faster than originally estimated by Arroyo et al. [11].