Bosworth W, Montagna P, Pons-Branchu E, Rasul N, Taviani M
Apache Egypt Companies, 11 Street 281, New Maadi, Cairo, Egypt.
Istituto di Scienze Marine (ISMAR), CNR, Via Gobetti 101, 40129, Bologna, Italy.
Sci Rep. 2017 Feb 24;7(1):38. doi: 10.1038/s41598-017-00074-2.
The Gulf of Aqaba transform plate boundary is a source of destructive teleseismic earthquakes. Seismicity is concentrated in the central sub-basin and decreases to both the north and south. Although principally a strike-slip plate boundary, the faulted margins of the Gulf display largely dip-slip extensional movement and accompanying footwall uplift. We have constrained rates of this uplift by measurements of elevated Pleistocene coral terraces. In particular the terrace that formed during the last interglacial (~125 ka) is found discontinuously along the length of the Gulf at elevations of 3 to 26 m. Global sea level was ~7 m higher than today at 125 ka indicating net maximum tectonic uplift of ~19 m with an average rate of ~0.015 cm/yr. Uplift has been greatest adjacent to the central sub-basin and like the seismicity decreases to the north and south. We suggest that the present pattern of a seismically active central region linked to more aseismic areas in the north and south has therefore persisted for at least the past 125 kyr. Consequently the potential for future destructive earthquakes in the central Gulf is greater than in the sub-basins to the north and south.
亚喀巴湾转换板块边界是破坏性远震的一个震源。地震活动集中在中央子盆地，向北和向南都有所减少。尽管主要是一个走滑板块边界，但海湾的断层边缘主要表现为倾滑伸展运动以及伴随的下盘隆升。我们通过对更新世珊瑚阶地高程的测量来确定这种隆升的速率。特别是在末次间冰期（约12.5万年）形成的阶地，在海湾沿岸断断续续地出露，海拔高度在3至26米之间。在12.5万年前，全球海平面比现在高约7米，这表明构造净最大隆升约为19米，平均速率约为0.015厘米/年。隆升在中央子盆地附近最为显著，并且与地震活动一样，向北和向南都有所减少。我们认为，因此，目前中央地震活跃地区与北部和南部地震活动较少地区相联系的格局至少在过去12.5万年中一直持续存在。因此，未来海湾中部发生破坏性地震的可能性大于北部和南部的子盆地。
