Slip Rates and Seismic Potential Along Main Faults in the Eastern Mediterranean and Caucasus from dense GPS Observations and Seismic Data

摘要

The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming continental regions. Monitoring and studies of the extensive deformation processes in this comparatively limited region enhance our understanding of the continental collision in the region. In this paper, we built a new elastic block model to constrain present-day plate motions and regional deformation in the intraplate zone and estimate fault slip rates from a dense global positioning system (GPS) velocity field. We additionally considered differences in moment accumulation rate per unit fault length using seismogenic and geodetic depth along the main faults. The right-lateral slip rates were estimated at between 24.33 +/- 0.47 and 28 +/- 0.5 mm/year along the North Anatolian Fault Zone (NAFZ) and the left-lateral slip at 10.6 +/- 0.9 to 12 +/- 1 mm/year on the East Anatolian Fault Zone (EAFZ). The Dead Sea Transform Fault (DSTF) slip rate ranges between 4.1 +/- 0.95 and 6 +/- 1 mm/year. The slip rate for the Main Caucasus Thrust Fault (MCTF) is 6.5 +/- 0.2 to 14.3 +/- 0.7 mm/year from west to the east. A shallow locking depth of 9 +/- 3.2 km was found in the Marmara region. The locking depth along the DSTF is 10.9 +/- 5.5 km in the northern segment, 9 +/- 6.7 km in the central section and 11.8 +/- 4 km in the southern section. The locking depth of the EAFZ is 16.7 +/- 4.4 km in the northern segment, 19.8 +/- 7.4 km in the middle segment and 12.5 +/- 4.2 km in the southern segment. The locking depths along the MCTF range between 12.7 +/- 5.8 and 17.8 +/- 4.9 km from west to east. Our new block model has the best fit to the observed velocities. The results provide an overall understanding of fault activity and have implications for the earthquake hazard along the main faults in the region.