Combining satellite and seismic images to analyse the shallow structure of the Dead Sea Transform near the DESERT transect
Combining satellite and seismic images to analyse the shallow structure of the Dead Sea Transform near the DESERT transect
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结合卫星和地震图像分析沙漠横断面附近死海变换的浅层结构
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
The Desert Group
中科院分区：
文献类型：
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作者：
D. Kesten;M. Weber;C. Haberland;C. Janssen;A. Agnon;Y. Bartov;I. Rabba;The Desert Group
中东地区的左旋死海转换断层是世界上最大的大陆走滑断层之一。位于死海和红海之间的阿拉瓦/阿拉巴谷的DST南段，称为阿拉瓦/阿拉巴断层（AF），已在多学科沙漠（DEad SEa裂谷断面）项目中进行了详细研究。在此基础上，结合ASTER多光谱卫星图像解译和地震反射研究，对地质构造进行了分析。虽然卫星图像显示新构造活动在浅年轻的沉积物，反射地震图像深断层可能是目前不活跃。这两种方法的组合允许对单个故障链的活动施加一些年龄限制。虽然AF显然是主要的活动断层段的南部DST，我们建议，它只容纳了有限的（高达60公里）的一部分，整体105公里的左旋板块运动自中新世时代。根据包括卫星图像判读在内的地质研究，有证据表明其他断层沿着向左位移。此外，在两条东西走向的地震反射剖面上，在AF以西约40km处发现了一条地下断层。虽然这些地震数据显示了典型的走滑断层的花状结构，但在卫星图像上，该断层在中新世后的沉积物中没有表现出来，这意味着它在过去的几百万年里一直不活跃。在AF以东约1公里处，另一个现在被掩埋的断层在沙漠的地震、大地电磁和重力研究中被发现。综合各种证据，我们认为，在转换运动开始时，变形发生在一个相当宽的带内，可能伴随着古老的南北走向构造的复活。后来，变形集中在今天的阿拉瓦山谷地区。直到1500万年前，在现今的AF附近可能还有其他现在不活跃的断层痕迹，它们发生了横向运动。再加上0.5Ma前板块的重组，主断裂轨迹移动到今天的AF位置。
The left-lateral Dead Sea Transform (DST) in the Middle East is one of the largest continental strike-slip faults of the world. The southern segment of the DST in the Arava/Araba Valley between the Dead Sea and the Red Sea, called Arava/Araba Fault (AF), has been studied in detail in the multidisciplinary DESERT (DEad SEa Rift Transect) project. Based on these results, here, the interpretations of multi-spectral (ASTER) satellite images and seismic reflection studies have been combined to analyse geologic structures. Whereas satellite images reveal neotectonic activity in shallow young sediments, reflection seismic image deep faults that are possibly inactive at present. The combination of the two methods allows putting some age constraint on the activity of individual fault strands. Although the AF is clearly the main active fault segment of the southern DST, we propose that it has accommodated only a limited (up to 60 km) part of the overall 105 km of sinistral plate motion since Miocene times. There is evidence for sinistral displacement along other faults, based on geological studies, including satellite image interpretation. Furthermore, a subsurface fault is revealed ≈4 km west of the AF on two ≈E–W running seismic reflection profiles. Whereas these seismic data show a flower structure typical for strike-slip faults, on the satellite image this fault is not expressed in the post-Miocene sediments, implying that it has been inactive for the last few million years. About 1 km to the east of the AF another, now buried fault, was detected in seismic, magnetotelluric and gravity studies of DESERT. Taking together various evidences, we suggest that at the beginning of transform motion deformation occurred in a rather wide belt, possibly with the reactivation of older ≈N–S striking structures. Later, deformation became concentrated in the region of today’s Arava Valley. Till ≈5 Ma ago there might have been other, now inactive fault traces in the vicinity of the present day AF that took up lateral motion. Together with a rearrangement of plates ≈5 Ma ago, the main fault trace shifted then to the position of today’s AF.