GPS constraints on Africa (Nubia) and Arabia plate motions
GPS constraints on Africa (Nubia) and Arabia plate motions
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DOI：
10.1046/j.1365-246x.2003.02023.x
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发表时间：
2003-10-01
影响因子：
2.8
通讯作者：
Tealeb, A
中科院分区：
文献类型：
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作者：
McClusky, S;Reilinger, R;Tealeb, A
我们使用连续记录 GPS (CGPS) 和勘测模式 GPS (SGPS) 观测来确定非洲（努比亚）、阿拉伯和欧亚板块相对运动的欧拉矢量。我们提出了一个约束良好的欧亚-努比亚欧拉矢量，源自欧洲的 23 个 IGS 站点以及努比亚板块上的 4 个 CGPS 和 3 个 SGPS 站点（-0.95 +/- 4.8 度北纬，-21.8 +/- 4.3 度东经，0.06 +/- 0.005 度 Myr(-1)）。我们没有看到努比亚板块有显着的（>1 mm yr(-1)）内部变形。 GPS 努比亚-欧亚欧拉矢量与 NUVEL-1A 显着不同（21.0 +/- 4.2 度北纬、20.6 +/- 0.6 度东经、0.12 +/- 0.015 度 Myr(-1)），这意味着非洲相对于欧亚大陆有更多的西移，而地中海东部的收敛速度较慢。阿拉伯-欧亚大陆和阿拉伯-努比亚 GPS 欧拉矢量的确定性较差，仅基于阿拉伯板块上的 1 个 CGPS 和 3 个 SGPS 站点。初步的阿拉伯-欧亚大陆和阿拉伯-努比亚欧拉矢量为 27.4 +/- 1.0 度北纬、18.4 +/- 2.5 度东经、0.40 +/- 0.04 度 Myr(-1) 和 30.5 +/- 1.0 度北纬、25.7 +/- 2.3 度东经、0.37 +/- 0.04 度 分别为Myr(-1)。 GPS 阿拉伯-努比亚欧拉矢量与 NUVEL-1A（北纬 24.1 +/- 1.7 度、东经 24.0 +/- 3.5 度、东经 0.40 +/- 0.05 度 Myr(-1)）有显着差异，但在统计上与 Chu 和 Gordon 报告的基于磁力重新评估的修正版欧拉矢量在 95% 置信度上是一致的。 红海异常（31.5 +/- 1.2 度北纬、23.0 +/- 2.7 度东经、0.40 +/- 0.05 度 Myr(-1)）。新的 GPS 努比亚-阿拉伯欧拉矢量（即忽略可能的西奈地块运动和可能的内部板块变形）在亚喀巴湾和死海断层（DSF）中暗示的运动从海湾和南部 DSF 的纯左旋走滑开始，中部和北部 DSF 的压缩不断增加，相对运动从 5.6 mm yr(-1) 增加到 7.5 mm yr(-1) (+/-1 mm yr(-1)) 从南到北。沿着 DSF 北部（即黎巴嫩约束弯曲以北），运动分为平行于断层迹线的 6 +/- 1 mm yr(-1) 左旋运动和 4 +/- 1 mm yr(-1) 断层正向压缩。从 GPS 欧拉矢量导出的其他板块边界（包括安纳托利亚和爱琴海微板块）上的相对运动在质量上与大地壳地震（M > 6）的震源机制所指示的运动感一致。如果有关于板块边界断层（北安纳托利亚断层、东安纳托利亚断层、死海断层、红海裂谷）的断层滑动速率的数据，它们通常低于完整的板块运动估计，但没有显着差异，表明大部分相对板块运动都在这些结构上进行。
We use continuously recording GPS (CGPS) and survey-mode GPS (SGPS) observations to determine Euler vectors for relative motion of the African (Nubian), Arabian and Eurasian plates. We present a well-constrained Eurasia-Nubia Euler vector derived from 23 IGS sites in Europe and four CGPS and three SGPS sites on the Nubian Plate (-0.95 +/- 4.8degreesN, -21.8 +/- 4.3degreesE, 0.06 +/- 0.005degrees Myr(-1)). We see no significant (>1 mm yr(-1)) internal deformation of the Nubian Plate. The GPS Nubian-Eurasian Euler vector differs significantly from NUVEL-1A (21.0 +/- 4.2degreesN, 20.6 +/- 0.6degreesE, 0.12 +/- 0.015degrees Myr(-1)), implying more westward motion of Africa relative to Eurasia and slower convergence in the eastern Mediterranean. The Arabia-Eurasia and Arabia-Nubia GPS Euler vectors are less well determined, based on only one CGPS and three SGPS sites on the Arabian Plate. The preliminary Arabia-Eurasia and Arabia-Nubia Euler vectors are 27.4 +/- 1.0degreesN, 18.4 +/- 2.5degreesE, 0.40 +/- 0.04degrees Myr(-1), and 30.5 +/- 1.0degreesN, 25.7 +/- 2.3degreesE, 0.37 +/- 0.04degrees Myr(-1), respectively. The GPS Arabia-Nubia Euler vector differs significantly from NUVEL-1A (24.1 +/- 1.7degreesN, 24.0 +/- 3.5degreesE, 0.40 +/- 0.05degrees Myr(-1)), but is statistically consistent at the 95 per cent confidence level with the revised Euler vector reported by Chu & Gordon based on a re-evaluation of magnetic anomalies in the Red Sea (31.5 +/- 1.2degreesN, 23.0 +/- 2.7degreesE, 0.40 +/- 0.05degrees Myr(-1)). The motion implied in the Gulf of Aqaba and on the Dead Sea fault (DSF) by the new GPS Nubia-Arabia Euler vector (i.e. ignoring possible Sinai block motion and possible internal plate deformation) grades from pure left lateral strike-slip in the Gulf and on the southern DSF with increasing compression on the central and northern DSF with relative motion increasing from 5.6 to 7.5 mm yr(-1) (+/-1 mm yr(-1)) from south to north. Along the northern DSF (i.e. north of the Lebanon restraining bend) motion is partitioned between 6 +/- 1 mm yr(-1) left-lateral motion parallel to the fault trace and 4 +/- 1 mm yr(-1) fault-normal compression. Relative motions on other plate boundaries (including the Anatolian and Aegean microplates) derived from the GPS Euler vectors agree qualitatively with the sense of motion indicated by focal mechanisms for large crustal earthquakes (M > 6). Where data are available on fault-slip rates on plate bounding faults (North Anatolian fault, East Anatolian fault, Dead Sea fault, Red Sea rift), they are generally lower than, but not significantly different from, the full plate motion estimates suggesting that the majority of relative plate motion is accommodated on these structures.