A Seismic Intensity Survey of the 16 April, 2016 Mw 7.8 Muisne, Ecuador Earthquake and a Comparison With Strong Motion Data

Date: 4/24/2019

Time: 06:00 PM

Room: Grand Ballroom

We conducted a regional seismic intensity field survey in Ecuador following the April 16, 2016 M7.8 Muisne earthquake to document the geographic distribution and level of damage caused by the earthquake. We observed several collapsed and partially collapsed structures which we infer is due to a combination of poorly constructed buildings, loose and unconsolidated soil, and the high frequency ground shaking experienced during this earthquake. This earthquake nucleated at a depth 20 km and produced extensive amounts of damage in the cities of Pedernales, Chone, Manta, and Portoviejo. The Modified Mercalli Intensities (MMIs) reached a maximum value of VIII, and the Peak Ground Velocities (PGVs) and Peak Ground Accelerations (PGAs) reached a maximum value of 82 cm/s and 1,410 cm/sec². Our highest observed MMI intensities correlate with PGA and PGV values. We determined empirical relationship between instrumental peak ground motions and observed intensities for this earthquake. Additionally, our observed MMI intensities strongly correlate with high frequency radiation determined by the seismic back projection technique. These results contribute to a growing database of field observations of seismic intensities and strong motion measurements for large subduction zone earthquakes.

Presenting Author: Ellen M. Smith

Authors