Seismic hazard assessment

Herein, a combined analysis of Global Navigation Satellite System-derived strain rate maps, in accordance with recent seismicity, was presented to reveal that the N-S extension is accommodated primarily by strike-slip faulting of the İzmir-Balıkesir Transfer Zone (İBTZ), where a counter clockwise rotation (~25–100°/Myr) along the vertical axis is dominant. The results indicated that strike-slip segments within the İBTZ show variable transport sense and amount of slip along them, and they connect by hard linkage relay ramps with the dip to oblique slip normal faults.

18p tanmocphong 29-01-2022 19 1   Download

The southern part of the Western Anatolia Extensional Province is governed by E-W-trending horst-graben systems and NW-SE-oriented active faults. The NW-striking Yatağan Fault is characterised by an almost pure normal sense of motion with a minor dextral strike slip component. Although the settlements within the area have been affected by several earthquake events since ancient times (~2000 BCE), the earthquake potential and history of the Yatağan Fault has remained unknown until a few years ago.

21p tanmocphong 29-01-2022 14 1   Download

A geological interpretation of the faulting mechanism is also proposed. The existence of a new unknown source in an intermontane area is problematic. The role of inherited alpine structures seems more important today than in the past. The strike of the two new seismogenic sources, responsible for the two strongest events of the 2021 earthquake succession, differs from the previously known active faults. This forces us to reconsider older views on the direction of development of active faults and the orientation of the stress field.

11p tanmocphong 29-01-2022 21 0   Download