Collaborative Research: Crustal Deformation and Earthquake Behavior in the Lebanese Restraining Bend of the Dead Sea Fault System (Lebanon and SW Syria)

来自密苏里州大学和马萨诸塞州理工学院的科学家与来自黎巴嫩和叙利亚的科学家合作，正在调查黎巴嫩和叙利亚西南部死海断层系统沿着200公里长的抑制弯曲的活动构造和地震行为。死海断裂系统是世界上大型的大陆转换系统之一，是东地中海地区板块构造框架的关键要素。因此，除了阐明区域构造和地球动力学过程外，这项研究还涉及与世界各地其他大陆转变有关的科学问题。该小组正在调查：（1）沿着大型走滑断层的地震周期，包括相邻结构之间的地震相互作用（例如，应力加载），以及这与地壳流变学的关系;（2）在一个大的约束弯曲内的应变分配和隆起，以及它与阿拉伯板块内部变形的关系;（3）倾斜板块运动和预测的死海中部和北方断层系统沿走向滑动速率的变化。为了解决这些问题，该团队正在进行：（1）新构造野外研究，以评估约束弯曲内的详细运动学和断层滑动率;（2）古地震调查，以评估可能的断层分段并构建可靠的地震历史，（3）构造大地测量，使用GPS和干涉合成孔径雷达，在远场和近场确定断层滑动的短期速率和三维运动学，（4）根据大地测量和地质数据建立断层力学的地球物理模型，利用地质/大地测量数据和古地震学建立地震周期，以及西奈和阿拉伯板块的大板块运动。这些研究利用了一个漫长的，有据可查的，相对完整的大地震（约6.5级）的历史记录，跨越两千多年。世界上几乎所有其他板块边界都没有这样的历史记录，这有助于弥补该区域地质和大地测量应变评估之间的关键差距。

Scientists from the University of Missouri and Massachusetts Institute of Technology in collaboration with scientists from Lebanon and Syria are investigating the active tectonics and earthquake behavior of a 200-km-long restraining bend along the Dead Sea fault system in Lebanon and southwestern Syria. The Dead Sea fault system ranks among the large, continental transform systems of the world and comprises a key element in the plate tectonic framework of the eastern Mediterranean region. Thus, in addition to elucidating the regional tectonic and geodynamic processes, this research is addressing scientific questions relevant to other continental transforms worldwide. The team is investigating the: (1) earthquake cycle along a large strike-slip fault, including earthquake interactions between adjacent structures (e.g., stress loading), and how this relates to crustal rheology; (2) strain partitioning and uplift within a large restraining bend, and its relationship to internal deformation of the Arabian plate; and (3) oblique plate motions and predicted along-strike variations in slip rate of the central and northern Dead Sea fault system. To address these problems, the team is conducting: (1) neotectonic field studies to assess detailed kinematics and fault slip rates within the restraining bend; (2) paleoseismic investigations to assess possible fault segmentation and to construct robust earthquake histories, (3) tectonic geodesy, using GPS and InSAR, in the far-field and near-field to determine short term rates of fault slip and kinematics in three-dimensions, and (4) geophysical modeling of fault mechanics from geodetic and geological data, the earthquake cycle using geological/geodetic data and paleoseismology, and large plate motions of the Sinai and Arabia plates. These studies are taking advantage of a lengthy, well documented, and relatively complete historical record of large earthquakes (approximately magnitude 6.5) that spans more than two millennia. Such historical records are unavailable for nearly all other plate boundaries in the world and are helping to bridge the critical gap between geologic and geodetic assessments of strain in the region.