Nisyros volcanic island, at the eastern end of the Aegean Volcanic Arc, was mainly constructed after the ultra-Plinian Kos Plateau Tuff (KPT) eruption at 161 ka. The surrounding submarine area consists mostly of marginal mass-transport deposits that commonly characterize insular stratovolcanoes. This study aims at providing insights into the deposition and volume of such deposits by elucidating the products of a mega-eruption and subsequent paroxysmal volcanicity, typical of subduction zone-island arc systems. Seismic reflection and multibeam bathymetry around Nisyros identify pyroclastic and debris flow deposits covering areas several orders of magnitude greater than the island. The entire seabed between the basins of East Kos and Tilos is underlain by a ~7 km³ volcaniclastic unit that defines a ubiquitous basal unconformity at an average depth of 30 m below the seafloor. Southwest of Nisyros, two groups of avalanche deposits from the same unit are bathymetrically identified on the slopes of the northernmost Karpathos basin apron. Seismic stratigraphic markers that trace the unit on the shelf of Tilos suggest it is concomitant with the KPT eruption. This formerly unknown submarine expansion of the KPT deposits into three neighboring basins, when added to the volume of this massive unit to the rest of the Nisyros surroundings, gives it an explosivity index (VEI) >6. As such, it represents the largest Quaternary subaqueous volcanogenic mass flow deposit of the eastern Mediterranean. From this dataset, it can be inferred that the submarine advance of the erupted material occurred mainly through erosive gravity flows, envisioned as the main dispersion mechanism of large-scale subaqueous pyroclastic deposits of Plinian eruptions. East of Nisyros, unique small-scale diapiric domes and seafloor mounds are attributed to loading by the KPT in combination with regional faulting. Subsequent Nisyros effusive activity produced pyroclastic units around the northeast as well as debris avalanche and lava flows south of the island. These have been correlated to known onshore formations. The present study documents the intensity and impacts of a volcanic island mega-eruption and paroxysmal epilogue over a cycle of 100 kyr.

尼西罗斯岛火山岛位于爱琴海火山弧的东端，主要是在161 ka的超普利期科斯高原凝灰岩（KPT）喷发之后建造的。周围的海底区域主要由边缘传质沉积物组成，这些特征通常是岛状平流火山的特征。这项研究旨在通过阐明大型俯冲带-岛弧系统典型的大喷发和随后的阵发性火山作用的产物，来提供有关此类沉积物的沉积和体积的见识。尼西罗斯岛周围的地震反射和多波束测深表明，火山碎屑和泥石流沉积物覆盖的区域比该岛大几个数量级。东科斯盆地和蒂洛斯盆地之间的整个海床下陷约7 km ³火山碎屑单元，在海底以下30 m的平均深度处定义了普遍存在的基底不整合面。在尼西罗斯（Nisyros）的西南部，在最北端的喀帕苏斯盆地停机坪的斜坡上，通过测深法确定了同一单元的两组雪崩沉积物。追踪Tilos架上单元的地震地层标记表明它与KPT喷发同时发生。KPT沉积物以前未知的海底扩张成三个相邻的盆地，再加上这个庞大的单位到尼西罗斯岛周围其他地区的体积，其爆炸性指数（VEI）> 6。因此，它代表了东地中海最大的第四纪水下火山成质流沉积物。从这个数据集中，可以推断，喷发物质的海底前进主要是通过侵蚀性重力流而发生的，这被认为是普林尼亚喷发的大规模水下水碎屑沉积的主要扩散机制。在尼西罗斯（Nisyros）以东，独特的小规模双底穹顶和海底丘陵归因于KPT与区域断层的结合。随后的Nisyros爆发性活动在该岛东北部形成了火山碎屑单元，并在该岛以南形成了碎片雪崩和熔岩流。这些已与已知的陆上岩层相关。本研究记录了一个火山岛的大规模喷发和阵发性尾声在100 kyr周期内的强度和影响。在尼西罗斯（Nisyros）以东，独特的小规模双底穹顶和海底丘陵归因于KPT与区域断层的结合。随后的Nisyros爆发性活动在该岛东北部形成了火山碎屑单元，并在该岛以南形成了碎片雪崩和熔岩流。这些已与已知的陆上岩层相关。本研究记录了一个火山岛的大规模喷发和阵发性尾声在100 kyr周期内的强度和影响。在尼西罗斯（Nisyros）以东，独特的小规模双底穹顶和海底丘陵归因于KPT与区域断层的结合。随后的Nisyros爆发性活动在该岛东北部形成了火山碎屑单元，并在该岛以南形成了碎片雪崩和熔岩流。这些已与已知的陆上岩层相关。本研究记录了一个火山岛的大规模喷发和阵发性尾声在100 kyr周期内的强度和影响。