An up-to-date Mapping for the Movement and the Deformation of the Sinai Micro-plate from a Combined GPS Velocity Field

Abstract

<p>We use combined GPS velocities covering Sinai peninsula to estimate the current rates across the Sinai micro-plate boundaries. New GPS velocities were estimated for 67 sites located within and around Sinai (Arabia, Eurasia and Nubia plates) covering the time span 1999-2018 using GAMIT/GLOBK 10.6 (Herring et al., 2015). We have combined our velocity field with two other recent solutions of GPS sites located around Sinai area. We used the VELROT tool from GAMIT/GLOBK package to combine all solutions resulting in a velocity field of 265 GPS sites in ITRF2018. Then, we selected 61 sites that represent the Sinai plate interior to estimate the Euler pole of Sinai micro-plate. Our computed the Euler pole parameters, latitude, longitude, and angular velocity for Sinai are 53.3±1.8°, -7.8±2.2°, and 0.451±0.014°/Ma, respectively, which are comparable to previous estimates, but with better uncertainties. The relative block motions at the Sinai plate boundaries are estimated using the DEFNODE code (McCaffrey, 2002) by minimizing the GPS residual motions within the blocks in a least squares sense. Our block motion model for Sinai sub-plate shows a fault-parallel velocity at the Gulf of Aqaba of 4.7-4.5 mm/yr, associated with negligible fault-normal component, which decreased toward the north direction along the Dead Sea Transform Fault. On the other hand, an opening rate of 3 mm/yr is estimated at the southern part of the Gulf of Suez with negligible fault-parallel component. At central and northern parts of the Gulf of Suez, the opening rate decreases until it vanished at the northern part of the Suez Canal while the fault-parallel component increases.</p>