Post-Seismic Deformation for the 1999 IZMIT/DUZCE Turkey Earthquake Sequence

研究人员建议监测和分析1999年8月17日土耳其伊兹米特(M=7.4)地震和1999年11月12日土耳其杜兹塞(M=7.1)地震的震后形变。这些地震共同导致北安纳托利亚断裂西段150公里处的地表连续破裂，右侧地表偏移量达到5米。这些地震对长期应变和同震断层滑动的严格约束，以及对震后运动早期阶段的详细监测，为发展约束后滑动和粘弹性松弛模型所需的观测提供了重要机会。区分这些机制的可能贡献对大陆岩层的流变学和断裂带的局部流变学具有重要意义--流变学特性目前受到观测的限制很差，对于模拟与板块相互作用相关的动态过程至关重要。此外，预计这项研究的结果将加强我们对这一构造区域和类似构造区域(如圣安德烈亚斯断层)地震循环机制的理解。虽然这项工作并不是对这一地区地震危险性的全面研究，但其结果将直接与估计马尔马拉地区NAF各分支上的滑动分区有关。此外，这项研究产生的同震和震后断层参数需要约束应力传递到相邻断层段的模型，为评估地震危险性提供更好的物理基础。

Robert E. ReilingerEAR-0001095The Investigators propose to monitor and analyze postseismic deformation for the 17 August 1999, Izmit (M=7.4) and the 12 November 1999, Duzce (M=7.1), Turkey earthquakes. Together, these earthquakes resulted in a continuous surface break along a 150-km segment of the western North Anatolian fault, with right-lateral surface offsets reaching 5 m. The tight constraints on secular strain and co-seismic fault slip for these events and the detailed monitoring of the early phase of post-seismic motions, provide an important opportunity to develop the observations needed to constrain models of after-slip and viscoelastic relaxation. Distinguishing the possible contributions of these mechanisms has implications for the rheology of the continental lithoshere and localized rheology in the fault zone - rheological properties that are currently poorly constrained by observations and that are critically important for modeling dynamic processes associated with plate interactions. In addition, it is anticipated that the results of this study will enhance our understanding of the mechanics of the earthquake cycle in this and similar tectonic regions (such as the San Andreas fault). While this work is not meant to be a comprehensive study of earthquake hazards in this area, the results will be directly relevant to estimating the partitioning of slip on the various branches of the NAF in the Marmara region. Furthermore, the co-seismic and post-seismic fault parameters resulting from the proposed research are needed to constrain models for stress transfer to adjacent fault segments, providing an improved physical basis for estimating earthquake hazards.