Bathymetry and Shallow Seismic Imaging of the 2018 Flank Collapse of Anak Krakatau
Bathymetry and Shallow Seismic Imaging of the 2018 Flank Collapse of Anak Krakatau
复制标题
DOI：
10.3389/feart.2020.577448
复制
发表时间：
2021-01
期刊：
影响因子：
--
通讯作者：
W. Priyanto;J. Hunt;M. Hanif;D. Tappin;H. Permana;Susilohadi;M. Cassidy;E. Yulianto
中科院分区：
文献类型：
--
作者：
W. Priyanto;J. Hunt;M. Hanif;D. Tappin;H. Permana;Susilohadi;M. Cassidy;E. Yulianto
2018年12月22日，Anak Krakatau的侧翼失败和崩溃引发了毁灭性的海啸。火山的先前活动是否导致了这次崩溃，或者它是由另一种方式引发的，仍然是一个挑战。本研究旨在调查最近的火山海底滑坡体存款和就位过程，包括侧翼塌陷的海底形态和滑坡存款范围。在这项研究中使用了测深和火花地震数据。2019年8月收集的测深数据显示了流出区和海底滑坡存款形态。2017年5月获得的水深测量数据被用作塌陷的底限，以估计侧翼塌陷的体积。2017年和2019年采集的地震数据之间的比较提供了对滑坡就位过程、存款序列和海底以下结构的深入了解。从这些结果中，我们突出了两个地区的海底滑坡存款，一个近端Anak Krakatau岛（1.6公里）和一个远端（1.4公里）。结果分析表明，海底滑坡存款可能产生的正面挤压，断层，滑坡，触发的临界稳定性斜坡，并由于最近的火山活动。块状的海底特征明显位于Anak Krakatau的西南部，可能代表滑坡的崩塌块。对2019年8月采集的数据进行的地震分析显示，块状相在Anak Krakatau周围的宽度范围内延伸至1.62 km，块体厚度变化高达70.4 m。海洋数据提供了一个新的见解，滑坡运行和范围，以及滑坡存款形态和结构，无法从卫星图像或陆上调查。我们得出，滑坡跑出面积西南最近的崩溃，是17.02 ± 0.21 km2。
The flank failure and collapse of Anak Krakatau on December 22nd, 2018 triggered a destructive tsunami. Whether the prior activity of the volcano led to this collapse, or it was triggered by another means, remains a challenge to understand. This study seeks to investigate the recent volcano submarine mass-landslide deposit and emplacement processes, including the seafloor morphology of the flank collapse and the landslide deposit extent. Bathymetry and sparker seismic data were used during this study. Bathymetry data collected in August, 2019 shows the run-out area and the seafloor landslide deposit morphology. Bathymetry data acquired in May, 2017, is used as the base limit of the collapse to estimate the volume of the flank collapse. Comparisons between seismic data acquired in 2017 and 2019 provide an insight into the landslide emplacement processes, the deposit sequence, and structure below the seafloor. From these results we highlight two areas of the submarine-mass landslide deposit, one proximal to Anak Krakatau island (∼1.6 km) and one distal (∼1.4 km). The resulting analysis suggests that the submarine-mass landslide deposit might be produced by a frontally compressional, faulted, landslide, triggered by the critical stability slope, and due to the recent volcanic activity. Blocky seabed features clearly lie to the southwest of Anak Krakatau, and may represent the collapse blocks of the landslide. The seismic analysis of the data acquired in August, 2019 reveals that the blocky facies extends to ∼1.62 km in the width around Anak Krakatau, and the block thicknesses vary up to 70.4 m. The marine data provides a new insight into the landslide run out and extent, together with the landslide deposit morphology and structure that are not available from satellite imagery or subaerial surveys. We conclude that the landslide run out area southwest of the recent collapse, is ∼7.02 ± 0.21 km2.