The volcano-seismic crisis in Afar, Ethiopia, starting September 2005
The volcano-seismic crisis in Afar, Ethiopia, starting September 2005
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DOI：
10.1016/j.epsl.2006.12.014
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发表时间：
2007-03-15
影响因子：
5.3
通讯作者：
King, Geoffrey
中科院分区：
文献类型：
--
作者：
Ayele, Atalay;Jacques, Eric;King, Geoffrey
我们描述了2005年底发生在阿法尔北方的地震火山危机，其中包括15次大于M5的地震和一次来自一个名为Da'Ure的喷口的小型爆炸性火山喷发（在北纬12.651度，北纬40.519度）靠近达巴胡火山。其目的是将不同的信息来源整合到一起，对所发生的事情做出连贯的初步解释。主要的地球物理数据是最大地震的位置，以及质量异常高的雷达干涉图，显示了一个60公里长的堤坝的注入，表面变形表现为正常断层。在达巴鲁火山建筑周围发生了沉降。大部分的堤坝可能是玄武质的，而不是玄武岩，尽管喷发是缓慢的。下沉的体积最多占注入岩墙的岩浆的25%。玄武质岩浆与浅部储集层的相互作用可能是玄武质岩浆喷发的触发因素。大约在喷发和筑堤的同时，在喷发地点以北约150公里处的埃尔塔阿莱火山的熔岩湖似乎也发生了一些活动。我们评估的可能性，可能有一些联系，通过计算应力与裂缝的开口，并期待在熔岩湖的活动所揭示的热异常所看到的气象卫星。(c)2006 Elsevier B.V.保留所有权利。
We describe the seismo-volcanic crisis that occurred in northern Afar in late 2005, which involved 15 earthquakes greater than M5 and a small explosive silicic eruption from a vent called Da'Ure (at 12.651 degrees N., 40.519 degrees N) close to Dabbahu volcano. The purpose is to pull together the different sources of information into a coherent preliminary interpretation of what happened. The main geophysical data are the locations of the largest earthquakes, and a radar interferogram of unusually high quality that reveals injection of a 60 km long dyke with surface deformation expressed as normal faulting. Subsidence occurred around the Dabbalru volcanic edifice. Most of the dyke is likely to have been basaltic rather than silicic although the eruption was silicic. The volume of the subsidence represents at most 25% of the magma injected into the dyke. The silicic eruption was possibly triggered by interaction of basaltic magma with a shallow silicic reservoir. At about the same time as the eruption and dyking episode, some activity appears also to have taken place at the lava lake at Erta Ale volcano, some 150 km to the north of the eruption site. We evaluate the possibility that there may be some link by calculating stresses associated with opening of the fissure and looking at the activity of the lava lake as revealed by the thermal anomaly seen by weather satellites. (c) 2006 Elsevier B.V. All rights reserved.