Earth and Planetary Science
EPS Near-Surface Geochemistry and Geobiology

Berkeley Researcher Finds Source Characteristics of the 2015 Mw6.5 Lefkada, Greece Earthquake

Wednesday, March 15, 2017

Diego Melgar Moctezuma, Ph.D., assistant geodetic researcher in the Berkeley Seismology Lab, Earth and Planetary Science Department, is first author of “Source characteristics of the 2015 Mw6.5 Lefkada, Greece, strike-slip earthquake.” The article came out in the Journal of Geophysical Research: Solid Earth.

Dr. Melgar and his co-authors present a kinematic slip model from the inversion of 1Hz GPS, strong motion and InSAR data for the 2015 Mw6.5 Lefkada, Greece earthquake. They show that most of the slip during this event is up-dip of the hypocenter (10.7 km depth) with substantial slip (>0.5 m) between 5 km depth and the surface. The peak slip is ~1.6 m and the inverted rake angles show predominantly strike-slip motion. Slip concentrates mostly to the south of the hypocenter and the source time function indicates a total duration of ~17 s with peak moment rate at ~6 s. They also show that a 65° dipping geometry is the most plausible due to a lack of polarity reversals in the InSAR data and good agreement with Coulomb stress modeling, aftershock locations, and regional moment tensors. Finally, they note that there was a ~20 cm peak to peak tsunami observed at one tide gauge station 300 km away from the earthquake. In conclusion, they discuss tsunami modeling results and study the possible source of the amplitude discrepancy between the modeled and the observed data at far-field tide gauges.

Dr. Melgar received his undergraduate degree at the National Autonomous University of Mexico (UNAM); his doctoral degree at the Scripps Institution of Oceanography, UC San Diego; and most recently completed a postdoc at UC Berkeley. Already, Dr. Melgar has made significant contributions to the research areas of earthquake rupture, earthquake early warning, and tsunami modeling. Taking a keen interest in public outreach Dr. Melgar has also spoken on the significance and science of seismology to audiences in La Jolla, Berkeley and Marin County, California.

For the full-length article please click here.