Collaborative Research: Space-Based Measurements of Crustal Deformation along the Entire Dead Sea Fault System (Eastern Mediterranean)

合作研究：沿整个死海断层系统（东地中海）地壳变形的天基测量

• 批准号: 0947969
• 负责人: Robert Reilinger
• 金额: $ 9.69万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-15 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0947969&HistoricalAwards=false
• 关键词: Collaborative; Research; Space; Based; Measurements

This study assembles the first, comprehensive view of near-field strain along the entire Dead Sea fault system using Global Positioning System (GPS) measurements. The fault system, a prominent element of the eastern Mediterranean geodynamic framework, bounds the Arabian and Sinai plates and links proto-oceanic spreading in the Red Sea (Gulf of Aqaba) with the Arabian-Eurasian collision (southern Turkey). Spanning more than 800 km, the left-lateral Dead Sea fault system ranks among the large continental transform systems of the world. With mean recurrence intervals between 500 to 1,100 years for large earthquakes on different sections and a paucity of large (magnitude greater than 7) earthquakes during the past two centuries, the fault system is an excellent locale to understand the relationship between earthquake recurrence and crustal deformation along a slow moving (less than 10 mm/yr) transform fault. By the fourth year of this project, most GPS sites (survey and new continuous) will have 1-sigma uncertainties less than 0.5 mm/yr. The resulting GPS velocity field will provide a basis for kinematic and geodynamic modeling of the Dead Sea fault system that will elucidate fundamental aspects of transform tectonics, as well as broader issues pertaining to eastern Mediterranean tectonics (e.g., internal deformation of the Sinai and Arabian plates, nature of the Dead Sea fault-East Anatolian Fault-Cyprus arc triple junction, age and geological evolution of the Dead Sea fault). Key issues addressed by the research include: 1) variation of slip rates along the transform and the implications about existing plate tectonic models for the region; 2) comparison between present-day slip rates with geological estimates with implications for the timing of initiation of the main parts of the Dead Sea fault system and its relationship to the Arabia-Eurasia collision and Red Sea rifting; 3) slip transfer and strain partitioning at fault bends and step-overs (e.g., the Lebanese restraining bend and the Dead Sea Basin); 4) the influence of lithospheric rheology on strain partitioning along a transform.The Dead Sea fault system ranks among the major continental transform fault systems in the world. In addition to elucidating geodynamic aspects of the eastern Mediterranean region, focused studies on the fault system can yield insight into tectonic and geodynamic processes operating along continental transforms, in general. From a structural perspective, the Dead Sea fault system is relatively simple when compared with other transform fault systems. The structural simplicity permits relatively straightforward modeling of the earthquake cycle and crustal deformation processes, which can yield fundamental insight pertinent to more complicated fault systems, such as the San Andreas fault system. To this end, sufficient historical and palaeoseismic records of large earthquakes exist to facilitate such studies along most of the Dead Sea fault system. This study provides the critical constraints on present-day crustal deformation using high-precision GPS measurements. Additionally, results from this project will be directly applicable for an urgently needed improvement in the understanding of the earthquake hazard in a region that is potentially overdue for a large earthquake. Regional earthquake hazard is a concern for nearby megacities including Damascus, Beirut, Amman, Aleppo, and Jerusalem.

这项研究使用全球定位系统（GPS）测量沿整个死海断层系统组装了近场应变的第一个全面视图。断层系统是地中海东部地球动力学框架的突出元素，它界定了阿拉伯和西奈板，并将其在红海（Aqaba的墨西哥湾）与阿拉伯 - 欧拉西亚碰撞（土耳其南部）联系起来。左侧死海断层系统跨越了800多公里，在世界上大型大陆转型系统中排名。在过去的两个世纪中，大地震在不同部分的大地震中的平均复发时间间隔在500至1,100年之间，大地震的大地震很少（幅度大于7）地震，断层系统是理解地震复发和地震变形之间的关系的绝佳位置，沿缓慢移动（小于10 mm/yr）发生故障。到该项目的第四年，大多数GPS站点（调查和新连续）的不确定性小于0.5 mm/yr。由此产生的GPS速度领域将为死海断层系统的运动学和地球动力学建模提供基础，该系统将阐明转化构造学的基本方面，以及与东地中海构造有关的更广泛的问题死海断层的演变）。研究解决的关键问题包括：1）沿转换的滑移速率的变化以及该地区现有板块构造模型的含义； 2）当今的滑移速率与地质估计值之间的比较与对死海断层系统主要部分的启动的时间及其与阿拉伯 - 欧亚碰撞和红海裂缝的关系的影响； 3）在断层弯曲和渐进式上进行滑移和应变分配（例如，黎巴嫩约束弯曲和死海盆地）； 4）岩石圈流变学对沿变换的应变分配的影响。死海断层系统在世界上主要的大陆变换断层系统中排名。除了阐明东地中海地区的地球动力学方面外，对断层系统的重点研究总体上可以洞悉沿大陆变换运行的构造和地球动力学过程。从结构的角度来看，与其他变换断层系统相比，死海断层系统相对简单。结构简单允许地震周期和地壳变形过程相对直接的建模，这可以产生与更复杂的断层系统（例如San Andreas断层系统）有关的基本见解。为此，存在足够的大地震历史和古古记录记录，以促进大多数死海断层系统的研究。这项研究提供了使用高精度GPS测量值对当今地壳变形的关键限制。此外，该项目的结果将直接适用于在理解大地震可能逾期的地区的地震危险中急需改善。区域地震危险是大马士革，贝鲁特，安曼，阿勒颇和耶路撒冷等附近大城市的关注点。