Abstract by Ian Bell
Comparing MASW measurements with previous earthquake data in Lombok Indonesia
This study will explain the investigation on the island of Lombok, Indonesia. Indonesia has had a host of natural disasters plague Densley populated country. We visited the island a year before the earthquake and collected data indicating an earthquake was overdue. Three strong earthquakes occurred a year after our study causing 563 deaths, thousands of injuries, and displacing over 400,000 residents.
In 2019 we conducted MASW (multichannel analysis of surface waves) measurements to help us understand differences in Vs30 (shear-wave velocity to a depth of 30 meters). These measurements are used as a proxy for likely earthquake shaking intensity or MMI. Processing these data revealed a close correlation between actual MMI from the earthquake and those predicted from our measurements.The next step is to construct a shaking susceptibility map to guide reconstruction efforts. Our field investigation of the damage helped us identify a place where the thrust earthquake ruptured the surface, which is consistent with the onshore epicenter. This discovery indicates the earthquake occurred on an unmapped, out of sequence thrust and not the Flores Thrust as reported.