Stress coupling between earthquakes in northwest Turkey and the north Aegean Sea

Abstract

Abstract. We have investigated the Coulomb stress interactions of 29 earthquakes (Ms > 6.0) that have occurred in the region of northwest Turkey and north Aegean Sea since 1912. Of these events, 23 may be related to earlier events, and 16 are clearly related to earlier events. All events at•er 1967 are related to previous events. Events in the early part of our time interval that show no correlation could be related to historical events as yet unidentified. In some cases, faults that have received a stress reduction fxom earlier events are prepared for an event by an earthquake occurring a few years before that creates a local Coulomb stress rise. Thus regions of Coulomb stress shadow can become regions where a damaging earthquake may occur. The relation between smaller events and the Coulomb stress distribution is less clear, but may be related to poor data quality and practical limitations of our modeling technique. Nonetheless, there are 4 times as many events per unit area in regions of enhanced stress than where stress is reduced. We discuss the contemporary distribution of Coulomb stress and argue that it is possible to identify the likely locations of future damaging earthquakes including identifying the most likely candidate faults.

Distributed power-law seismicity changes and crustal deformation in the SW Hellenic ARC

“…There is now evidence that static stress changes may advance (retard) the time of large earthquakes and although the consensus from hitherto large scale observational studies is that both near and far field earthquake triggering is identified by periods of increased seismicity rates, there's no definitive information as to the rise and decay modes of such changes (for instance see Reasenberg and Simpson, 1992;Dieterich, 1994;Stein et al, 1997;Toda et al, 1998;Nalbant et al, 1998). The situation is aggravated in the case of far field triggering, where limited observational data exists, with contradictory (e.g.…”

Estimates of Seismic Potential in the Marmara Sea Region from Block Models of Secular Deformation Constrained by Global Positioning System Measurements

“…These two earthquakes were the latest in a series of 11 M w Ͼ6.7 shocks during the last century that broke most of the NAFZ from the Karliova triple junction to the Aegean Sea, a distance of more than 1000 km (Ambraseys, 1970;Barka, 1999). The progression of earthquake activity to the east of the Marmara Sea has been modeled in terms of stress transfer and release (Stein et al, 1997;Nalbant et al, 1998). In these models the static stress field induced by each large coseismic shock is oriented such that nearby fault segments are promoted toward failure by an increase in their Coulomb failure stress.…”

Seismicity Rate Changes in Association With Time Dependent Stress Transfer in the Region of Northern Aegean Sea, Greece

“…Calculations were performed for the whole area, although coseismic slip alters the stress state in a limited area, depending upon the magnitude of the modeled event. ΔCFF is calculated from (5) with μ΄ set to 0.4 (Stein et al, 1997;Nalbant et al, 1998). Shear modulus G, is assumed to be 33GPa and Poisson ratio 0.25 (Papadimitriou & Sykes, 2001).…”