Subaerial-submarine morphological changes at Stromboli volcano (Italy) induced by the 2019-2020 eruptive activity
Subaerial-submarine morphological changes at Stromboli volcano (Italy) induced by the 2019-2020 eruptive activity
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2019-2020 年喷发活动引起的斯特龙博利火山（意大利）的水下形态变化
DOI：
10.1016/j.geomorph.2021.108093
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发表时间：
2022
期刊：
影响因子：
3.9
通讯作者：
Di Traglia F
中科院分区：
文献类型：
--
作者：
Di Traglia F
本研究分析了2019年7 - 8月意大利斯特隆博利火山喷发期间和之后的形态变化。这一时期的特点是强烈的喷发活动（两次阵发性爆炸，长达两个月的熔岩喷发，以及更强烈和频繁的“普通”爆炸活动），在位于火山最不稳定的西北侧的Sciara del Fuoco地区产生了重大变化。自2019年9月以来，火山喷发活动减弱，但仍然很强烈，侵蚀现象继续导致火山火山的重新塑造。这里描述的形态变化是通过整合地形（PLÉIADES卫星三立体数字高程模型）和多波束测深数据记录的，这些数据是在突发事件发生之前、期间和之后获得的。这样就可以研究不同过程的累积效应，并描述火山碎屑物质的堆积/就位、侵蚀、再活化和再沉积的不同阶段。在2018年9月至2020年4月之间的几个时期获得的数据可以比较2019年事件的地面和海底影响。我们发现了2019年7月3日爆发引发的两次火山碎屑密度流之后局部显著侵蚀的证据。我们认为这种侵蚀是由火山碎屑密度流沿火山山斜坡向下传播而引发的海底和陆上滑坡引起的。爆炸发生后，持续了大约两个月的喷发活动产生了一个熔岩场，积聚在地面斜坡上。随后，新形成的熔岩，特别是角砾岩，被侵蚀，物质转移到海底斜坡上。这项工作证明了反复的地形测深测量如何能够识别由于火山喷发活动引起的快速地貌变化而引发的斜坡过程。这些调查还可以区分估计的体积损失是单一质量流动的结果还是逐渐侵蚀过程的结果，从而对有关的地质灾害产生影响。此外，这项工作强调了海底斜坡的破坏是如何由火山碎屑密度流进入水中触发的，即使是中等规模的。这些结果对于开发和改进由大量流动引起的海啸预警系统非常重要，无论是在Stromboli，还是在其他地方的岛基火山和沿海火山，在这些地方，山体滑坡和火山碎屑密度流都可能引发严重的、潜在破坏性的海啸波。
This study analyses the morphological changes induced by eruptive activity at Stromboli volcano (Italy) during and after events occurring during July–August 2019. This period was characterized by intense eruptive activity (two paroxysmal explosions, a two-month-long lava emission, and more intense and frequent “ordinary” explosive activity) that produced significant changes within the region known as Sciara del Fuoco, located on the most unstable, north-western flank of the volcano. Since September 2019, the eruptive activity waned but remained intense, and erosive phenomena continued to contribute to the re-shaping of the Sciara del Fuoco. The morphological changes described here were documented by integrating topographic (PLÉIADES satellite tri-stereo Digital Elevation Models) and multibeam bathymetric data, acquired before, during, and after the paroxysmal events. This allowed the study of the cumulative effect of the different processes and the characterization of the different phases of accumulation/emplacement, erosion, remobilization and re-sedimentation of the volcaniclastic materials.Data acquired at several periods between September 2018 and April 2020, allowed a comparison of the subaerial and submarine effects of the 2019 events. We find evidence of localized, significant erosion following the two pyroclastic density currents triggered by the paroxysmal explosion of the 3 July 2019. We interpret this erosion as being caused by submarine and subaerial landslides triggered by the propagation of pyroclastic density currents down the Sciara del Fuoco slope. Immediately after the explosion, a lava field accumulated on the sub-aerial slope, produced by effusive activity which lasted about two months. Subsequently, the newly emplaced lava, and in particular its breccia, was eroded, with the transfer of material onto the submarine slope. This work demonstrates how repeated topo-bathymetric surveys allowed identification of the slope processes that were triggered in response to the rapid geomorphological variations due to the eruptive activity. The surveys also allowed distinction of whether estimated volumetric losses were the result of single mass-flows or gradual erosive processes, with implications on the related geohazard. Furthermore, this work highlights how submarine slope failures can be triggered by the entry into the water of pyroclastic density currents, even of modest size. These results are important for the development and improvement of an early warning system for tsunami-induced by mass flows, both in Stromboli and for island-based and coastal volcanoes elsewhere, where landslides and pyroclastic density currents can trigger significant, potentially destructive, tsunami waves.