Modeling the contemporary stress field and deformation pattern of eastern Mediterranean

Abstract

The contemporary stress field in the earth's crust is important and provides insights into mechanisms that drive plate motions. In this study, elastic plane stress finite element modeling incorporating realistic rock parameters was used to calculate the stress field, displacement field, and deformation of the plate interactions in the eastern Mediterranean. Modeled stress data for the AfricanArabian-Anatolian plate interactions with fixed European platform correlate well with observed contemporary stress indicator from the world stress map (WSM) and focal mechanism of earthquakes; while displacement field agrees qualitatively well with GPS vectors and sense of motion indicated by focal mechanisms for large crustal earthquakes (M s >6) and plate motion models. Modeling result shows the direction of maximum horizontal compressive stress (σ Hmax ) toward the direction of absolute motionof these plates. Large perturbations in σ Hmax orientations are shown to occur in and around tectonic boundaries between those plates. It is observed that, although the African plate acts mostly as indenter, which transmits the collisional motion from the Arabian plate to the Anatolian plate, in the current situation, the far-field stress, probably from the subduction in Aegean Arc, is needed to satisfy the contemporary stress field in Anatolia.

A challenge to the concept of slip-lines in extrusion tectonics

“…Another problem with extrusion-tectonic models is that the extruding rate is, in some cases, e.g., the Anatolian extruding plate, larger than the related Arabian plate indenting rate (McClusky et al, 2000;Dwivedi and Hayashi, 2010). In no case would such a situation have occurred if the extrusion operated along the conjugate slip-lines without any other driving force, because the indenting and extruding rates would be equal for a pure plane deformation without any obstacles to plate-movement (Fig.…”

“…1). This intriguing concept is termed escape-or extrusion tectonics and it has become one of the most popular models for over three decades to explain the tectonic pattern in the eastern Alps (Ratschbacher et al, 1991), the eastern Mediterranean (Seng€ or, 1979;Seng€ or and Kidd, 1979;Jackson and McKenzie, 1984;Taymaz et al, 1991;Westaway, 1994;Dhont et al, 2006;Dwivedi and Hayashi, 2010); eastern Afghanistan (Tapponnier et al, 1981;Brookfield and Hashmat, 2001); western Mongolia (Cuningham, 2005), Tibetmiddle Asia (Dewey et al, 1986(Dewey et al, , 1989England and Molnar, 1990;Yin and Harrison, 2000;Lee et al, 2003;Klinger et al, 2005), southwestern China (Sch€ arer et al, 1990;Ding and Zhong, 1992;Leloup and Kienast, 1993;Leloup et al, 1995;Chen and Wilson, 1995;Wang and Burchfiel, 1997;Zhang and Sch€ arer, 1999;Zhong et al, 2000;Searle, 2001Searle, , 2006Leloup et al, 2001;Burchfiel and Wang, 2003;Gilley et al, 2003;Zhang et al, 2004;Socquet and Pubellier, 2005;Wang et al, 2006;Zhang et al, 2006;Leloup et al, 2007;Searle et al, 2007;Burchfiel et al, 2008;Xu et al, 2008Xu et al, , 2009…”

Finite Element Models of Elastic Earthquake Deformation

“…Following the advanced numerical simulations, much work has been done recently on the deformation, stress distribution, faults, ruptures, dynamics, and wave propagation of tectonic plates by FEMs. An elastic plane stress FEM incorporating realistic rock parameters was used to calculate the stress field, displacement field, and deformation of the plate interactions in the eastern Mediterranean [40]. A 3D FE model of 3000 hexahedral elements and nodes is set up by Lu et al [41] for the surface topology, major active fault zones and the stress field of the Chinese continent to study the mechanism of the long-distance jumping migration over active seismogenic areas.…”