Istituto Nazionale di Geofisica e Vulcanologia, via di Vigna Murata 605, 00143 Roma, Italy.
Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Piazza Roma 2, 95125 Catania, Italy.
Sci Rep. 2014 Jun 13;4:5293. doi: 10.1038/srep05293.
The flanks of volcanoes may slide in response to the loading of the edifice on a weak basement, magma push, and/or to tectonic stress. However, examples of stratovolcanoes emplaced on active landslides are lacking and the possible effects on the volcano dynamics unknown. Here, we use aeromagnetic data to construct a three-dimensional model of the clay-rich basement of Etna volcano (Italy). We provide evidence for a large stratovolcano growing on a pre-existing basement landslide and show that the eastern Etna flank, which slides toward the sea irrespective of volcanic activity, moves coherently with the underlying landslide. The filling of the landslide depression by lava flows through time allows the formation of a stiffness barrier, which is responsible for the long-term migration of the magma pathways from the coast to the present-day Etna summit. These unexpected results provide a new interpretation clue on the causes of the volcanic instability processes and of the mechanisms of deflection and migration of volcanic conduits.
火山的侧翼可能会因山体对软弱基底的加载、岩浆的推动和/或构造应力而发生滑动。然而，缺乏安放在活动滑坡上的层状火山的例子，其对火山动力学的可能影响也不得而知。在这里，我们使用航空磁力数据构建了意大利埃特纳火山富粘土基底的三维模型。我们提供了在预先存在的基底滑坡上生长的大型层状火山的证据，并表明无论火山活动如何，朝向大海的埃特纳火山东侧都与下面的滑坡一致地移动。随着时间的推移，熔岩流填充滑坡洼地，形成了一个刚度屏障，这是导致岩浆通道从海岸迁移到现在的埃特纳火山山顶的长期原因。这些意外的结果为火山不稳定性过程的原因以及火山管道的偏斜和迁移机制提供了新的解释线索。
