Source parameters and moment tensor of the ML 4.6 earthquake of November 19, 2011, southwest Sharm El-Sheikh, Egypt

Abstract

The southern part of the Gulf of Suez is one of the most seismically active areas in Egypt. On Saturday November 19, 2011 at 07:12:15 (GMT) an earthquake of ML 4.6 occurred in southwest Sharm El-Sheikh, Egypt. The quake has been felt at Sharm El-Sheikh city while no casualties were reported. The instrumental epicenter is located at 27.69°N and 34.06°E. Seismic moment is 1.47 E+22dynecm, corresponding to a moment magnitude Mw 4.1. Following a Brune model, the source radius is 101.36m with an average dislocation of 0.015cm and a 0.06MPa stress drop. The source mechanism from a fault plane solution shows a normal fault, the actual fault plane is strike 358, dip 34 and rake -60, the computer code ISOLA is used.Twenty seven small and micro earthquakes (1.5⩽ML⩽4.2) were also recorded by the Egyptian National Seismological Network (ENSN) from the same region. We estimate the source parameters for these earthquakes using displacement spectra. The obtained source parameters include seismic moments of 2.77E+16–1.47E+22dynecm, stress drops of 0.0005–0.0617MPa and relative displacement of 0.0001–0.0152cm.