Finite-Fault Rupture Detector (Finder): Rapid Line-Source Models for Large Crustal Earthquakes in Sichuan, China

Date: 4/25/2019

Time: 06:00 PM

Room: Grand Ballroom

Sichuan province, China, has been hit hard in the last decade with the successive occurrence of the 2008 Mw7.9 Wenchuan, 2013 Mw6.6 Lushan, and 2017 Mw 6.5 Jiuzhaigou earthquakes, causing more than 87,000 fatalities and economic losses of about 1.5 trillion US dollars. Following the Wenchuan earthquake, the China Earthquake Administration (CEA) started building a nationwide earthquake early warning (EEW) system with about 3,200 strong-motion, ~2,000 broadband and ~10,200 low-cost MEMS sensors. Large earthquakes like the Mw7.9 Wenchuan mainshock are challenging for EEW, because traditional seismic network stations tend to saturate and source dimensions need to be known to predict seismic ground-motion at high accuracy. In this study, we run playbacks of local and regional on-scale strong-motion waveforms recorded by the China Strong Motion Networks Center (CSMNC) during the Mw7.9 Wenchuan, Mw6.6 Lushan, and Mw 6.5 Jiuzhaigou earthquakes to study the possible performance of the Finite-Fault Rupture Detector(FinDer) algorithm (Böse et al., 2018). We show that the FinDer line-source models agree well with the later observed spatial distribution of aftershocks and finite-fault models determined from waveform inversion. If the available set of strong motion data had been available in real-time, more than 70 percent of sites experiencing shaking intensities of MMI IV-VII could receive >=5 seconds of warning, and around 30 percent of sites experiencing MMI VII-IX could receive >=10 seconds of warning. FinDer finite-fault models could also help providing faster and more accurate loss estimates for rapid response in the aftermath of devastating earthquakes.

Presenting Author: John Clinton

Authors