National Oceanography Centre, Southampton, UK.
British Geological Survey (BGS), Nottingham, UK.
Nat Commun. 2021 May 14;12(1):2827. doi: 10.1038/s41467-021-22610-5.
As demonstrated at Anak Krakatau on December 22, 2018, tsunamis generated by volcanic flank collapse are incompletely understood and can be devastating. Here, we present the first high-resolution characterisation of both subaerial and submarine components of the collapse. Combined Synthetic Aperture Radar data and aerial photographs reveal an extensive subaerial failure that bounds pre-event deformation and volcanic products. To the southwest of the volcano, bathymetric and seismic reflection data reveal a blocky landslide deposit (0.214 ± 0.036 km) emplaced over 1.5 km into the adjacent basin. Our findings are consistent with en-masse lateral collapse with a volume ≥0.175 km, resolving several ambiguities in previous reconstructions. Post-collapse eruptions produced an additional ~0.3 km of tephra, burying the scar and landslide deposit. The event provides a model for lateral collapse scenarios at other arc-volcanic islands showing that rapid island growth can lead to large-scale failure and that even faster rebuilding can obscure pre-existing collapse.
如 2018 年 12 月 22 日在喀拉喀托之子火山所展示的那样，由火山侧翼崩塌产生的海啸尚未被充分了解，但其具有毁灭性。在此，我们首次对崩塌的陆上和水下部分进行了高分辨率的特征描述。合成孔径雷达数据和航空照片的组合揭示了广泛的陆上崩塌，其限制了火山喷发前的变形和火山产物。在火山的西南方向，水深和地震反射数据揭示了一个块状的滑坡堆积物（0.214±0.036 公里），被安置在毗邻的盆地中超过 1.5 公里处。我们的发现与整体侧向崩塌一致，其体积≥0.175 公里，解决了先前重建中的几个问题。崩塌后的喷发产生了额外的约 0.3 公里的火山灰，掩埋了火山口和滑坡堆积物。该事件为其他弧形火山岛的侧向崩塌情景提供了模型，表明快速的岛屿生长可能导致大规模的崩塌，而更快的重建可能会掩盖原有的崩塌。
