Active Deformation of the Central and Northern Dead Sea Fault

死海断裂系统是世界上最大的大陆走滑断裂之一。作为阿拉伯板块和非洲板块之间的转换板块边界，DFS代表了地中海东部地区的一个关键构造特征。尽管它具有构造意义，但对dsFS作为一种活跃的孕震构造的理解相对有限，特别是在叙利亚和黎巴嫩断层的中部和北段。通过对叙利亚和黎巴嫩的数字地震系统的跨学科研究，正在进行的研究正在解决几个重要问题，包括：(1)数字地震系统的北部变形是否完全解释了阿拉伯-非洲板块的运动，从而代表了今天的板块边界。(2)板块构造模型提出的向北滑动速率增加和断层-正态收敛的预测如何反映在数字地震系统运动学中。(3)地震在沿主要大陆转换(DFS)的板块边界变形中的作用，包括断层分段和无地震应变释放。(4)邻近阿拉伯板块的内部变形与沿数字地震系统的运动变化的关系，为了弥合新构造和大地/地震学应变评估之间通常存在的关键差距，这项新构造和大地测量工作的结果目前与跨越至少2000年的长时间、有充分记录的大地震(约6.5级)的历史记录相结合。为了解决上述问题，正在完成以下工作：(1)利用所有可用的遥感数据(包括航空照片和使用InSAR制作的高分辨率高程模型)绘制区域DFS活动分支图，以确定几何(和可能的孕震)段。(2)关键断层段的局部研究(详细绘图、测量与断层有关的地貌和古地震研究)，以划定：长期断层滑动速率和运动学(103-106年)；许多地震周期(全新世至今)的地震历史和重现性，以及过去的地震规模及其沿断层段的分布。(3)远场和近场的构造大地测量(主要是GPS)，以确定断层滑动和运动学的短期速率(几年)、可能的无震滑动和应变积累，以及可能的阿拉伯板块内部变形。综合和模拟新构造、大地测量和历史数据，为数字地震系统提供了关于数字地震系统运动学和动力学的新见解，总体上具有对活动走滑断层的更广泛的影响。此外，这项研究的结果对叙利亚和黎巴嫩以及邻国的地区性地震风险评估具有重要意义，在这些国家，人口迅速增长，迫切需要准确的地震风险评估。这项合作研究建立在康奈尔大学、麻省理工学院、斯特拉斯堡国际物理研究所以及叙利亚和黎巴嫩机构过去和正在进行的联合研究的基础上。(4)邻近阿拉伯板块的内部变形与dsFS沿线的运动学变化的关系，以及dsFS和阿拉伯-欧亚碰撞之间的联系。为了弥合新构造和大地测量/地震学应变评估之间通常存在的关键差距，这项新构造和大地测量工作的结果目前与至少过去2000年的长时间、有充分记录的大地震(约6.5级)的历史记录相结合。为了解决上述问题，正在完成以下工作：(1)利用所有可用的遥感数据(包括航空照片和使用InSAR制作的高分辨率高程模型)绘制区域DFS活动分支图，以确定几何(和可能的孕震)段。(2)关键断层段的局部研究(详细绘图、测量与断层有关的地貌和古地震研究)，以划定：长期断层滑动速率和运动学(103-106年)；许多地震周期(全新世至今)的地震历史和重现性，以及过去的地震规模及其沿断层段的分布。(3)远场和近场的构造大地测量(主要是GPS)，以确定断层滑动和运动学的短期速率(几年)、可能的无震滑动和应变积累，以及可能的阿拉伯板块内部变形。综合和模拟新构造、大地测量和历史数据，为数字地震系统提供了关于数字地震系统运动学和动力学的新见解，总体上具有对活动走滑断层的更广泛的影响。此外，这项研究的结果对叙利亚和黎巴嫩以及邻国的地区性地震风险评估具有重要意义，在这些国家，人口迅速增长，迫切需要准确的地震风险评估。这项合作研究建立在康奈尔大学、麻省理工学院、斯特拉斯堡IPG以及叙利亚和黎巴嫩机构过去和正在进行的联合研究的基础上。

0106238Muawia BarazangiThe Dead Sea Fault System (DSFS) is one of the largest continental strike-slip faults in the world. As the transform plate boundary between the Arabian and African plates, the DSFS represents a key tectonic feature in the eastern Mediterranean region. Despite its tectonic significance, the understanding of the DSFS as an active, seismogenic structure is relatively limited, particularly along the central and northern sections of the fault in Syria and Lebanon. Through an interdisciplinary study of DSFS in Syria and Lebanon, the ongoing research is addressing several important issues including:(1) Whether or not northern DSFS deformation fully accounts for Arabia-Africa plate motions and, hence, represents the present-day plate boundary.(2) How predictions of northward increase in slip rate and fault-normal convergence (suggested by plate tectonic models) are reflected in DSFS kinematics.(3) The role of earthquakes in plate boundary deformation along a major continental transform (the DSFS) including fault segmentation and aseismic strain release.(4) The relationship of internal deformation of the adjacent Arabian plate to kinematic variations along the DSFS, and the connection between the DSFS and the Arabian-Eurasian collision.In order to bridge the critical gap that typically exists between neotectonic and geodetic/seismological assessments of strain, results of this neotectonic and geodetic work are currently integrated with a lengthy, well-documented historical record of large earthquakes (approximately M 6.5) spanning at least the past 2,000 years. Such a lengthy historical record spanning multiple earthquake cycles is generally unavailable along almost any other major plate boundary.To address the issues outlined above, the following is being accomplished:(1) Regional mapping of the active branches of the DSFS using all available remote sensing data (including aerial photos and a high-resolution elevation models produced using InSAR) to determine geometric (and possible seismogenic) segments.(2) Local studies of key fault segments (detailed mapping, surveying fault-related landforms, and paleoseismic studies) in order to delimit: long-term fault slip rates and kinemetrics (103 - 106 years); earthquake histories and recurrence over many earthquake cycles (Holocene to present), and; past earthquake sizes and their distribution along fault segments. Historical earthquake data place further limits on earthquake size and recurrence during the past ~2,000 years.(3) Tectonic geodesy (primarily GPS) in the far-field and near-field to determine short-term rates of fault slip and kinematics (several years), possible aseismic slip vs. strain accumulation, and possible internal deformation of the northern Arabian plate.Integrating and modeling neotectonic, geodetic, and historical data for the DSFS provide new insight on the kinematics and dynamics of DSFS with broader implications for active strike-slip faults, in general. Furthermore, the results of this study have significance for regional earthquake hazard assessment in Syria and Lebanon, as well as neighboring countries, where large, rapidly expanding populations heighten the need for accurate earthquake hazard assessments. The collaborative study builds upon past and ongoing joint research involving Cornell, MIT, IPG Strasbourg, and Syrian and Lebanese institutions.(4) The relationship of internal deformation of the adjacent Arabian plate to kinematic variations along the DSFS, and the connection between the DSFS and the Arabian-Eurasian collision.In order to bridge the critical gap that typically exists between neotectonic and geodetic/seismological assessments of strain, results of this neotectonic and geodetic work are currently integrated with a lengthy, well-documented historical record of large earthquakes (approximately M 6.5) spanning at least the past 2,000 years. Such a lengthy historical record spanning multiple earthquake cycles is generally unavailable along almost any other major plate boundary.To address the issues outlined above, the following is being accomplished:(1) Regional mapping of the active branches of the DSFS using all available remote sensing data (including aerial photos and a high-resolution elevation models produced using InSAR) to determine geometric (and possible seismogenic) segments.(2) Local studies of key fault segments (detailed mapping, surveying fault-related landforms, and paleoseismic studies) in order to delimit: long-term fault slip rates and kinemetrics (103 - 106 years); earthquake histories and recurrence over many earthquake cycles (Holocene to present), and; past earthquake sizes and their distribution along fault segments. Historical earthquake data place further limits on earthquake size and recurrence during the past ~2,000 years.(3) Tectonic geodesy (primarily GPS) in the far-field and near-field to determine short-term rates of fault slip and kinematics (several years), possible aseismic slip vs. strain accumulation, and possible internal deformation of the northern Arabian plate.Integrating and modeling neotectonic, geodetic, and historical data for the DSFS provide new insight on the kinematics and dynamics of DSFS with broader implications for active strike-slip faults, in general. Furthermore, the results of this study have significance for regional earthquake hazard assessment in Syria and Lebanon, as well as neighboring countries, where large, rapidly expanding populations heighten the need for accurate earthquake hazard assessments. The collaborative study builds upon past and ongoing joint research involving Cornell, MIT, IPG Strasbourg, and Syrian and Lebanese institutions.