The July 2018 ML 4.5 sequence analysis, Sea of Galilee: geodynamic investigation using moment tensor and local earthquake tomography.
Abstract
From September 2017 to August 2018, we deployed a temporary seismological network around the Sea of Galilee composed of 12 short period stations to complete the Israel National Seismic Network (INSN) composed of broadband stations.
On July 4 2018, an earthquake of magnitude ML 4.5 occurred within the lake and was followed by aftershocks throughout the month. This earthquake was felt in the surrounding area where no major events have been recorded since 2013. Using manual picking of STA/LTA detections, we located 666 events corresponding to 14263 P- and 10862 S-waves. We derived a new 1D velocity model for the region using the Velest error minimization technique before relocating the events using the HypoDD package. We constrained the depths with the NonLinLoc software and calculated moment tensors of the main events using the ISOLA and FOCMEC packages. Results delineate a dense region of seismicity located in the northern part of the lake and deepening from 10 to 15 km from North to South. The main events seem to present a strike-slip motion in accordance with the Dead Sea fault system that spans NS across the lake. Additionally, the travel time data of 650 earthquakes was inverted for hypocentre parameters and a three-dimensional velocity model using the Simulps14 package. The P-wave and Vp/Vs velocities display a significantly high anomaly at 9 km depth where the sequence occurred. This structure is presumably related with the fluid movement in the area (salt diapirs / magmatic intrusions) and is critical to the understanding of the geodynamics of the area.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.S13B..08H
- Keywords:
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- 7230 Seismicity and tectonics;
- SEISMOLOGY