Abstract We present here for the first time a morpho-structural study of the submarine sector of the Ustica volcanic edifice, located in the south-western Tyrrhenian Sea, considered as an inactive volcanic system, middle Pleistocene in age. The main aim of this research study is to unravel the submarine dynamics along the slope sectors of the Ustica volcano, in order to provide new insights on one of the most tectonically active regions of the Central Mediterranean during the Quaternary. We analysed and interpreted an integrated seismo-acoustic data set consisting of multibeam swath-bathymetry, sub bottom profiles, single-channel seismic reflection records, all of them acquired during the last two decades. The seismostratigraphic analysis indicates that the Ustica volcano is composed by a sequence of lava flows and pyroclastic products, whose geometry can be interpreted as the consequence of combined upward growing and northward shifting of the volcanic centers. The mapped geomorphological elements distributed along the submerged slopes were classified based on their specific morphogenetic process. The achieved results reveal that volcanic, tectonic, oceanographic and gravity processes interacted in shaping the complex current physiography of the volcanic edifice, which is characterized by extremely uneven submarine flanks. The northern region is characterized by the widespread occurrence of well-preserved cones, probably linked to the last submarine volcanic activity of the area. Along the eastern sector, elongate gullies and linear furrows locally incise the shelf break and develop downward producing slope failures. Furrows and gullies represent the main conduits for flushing sediments through various types of flows and mass wasting, from the shallow sectors to the bathyal plain. Along the southern and eastern region slope failures processes carve almost totally of the shelf edge and mainly propagate through retrograding collapses. Further on, the southern region is mainly shaped by E-W and N-S trending fault escarpments that may have triggered the largest slope failures of the area. The main results of this study contribute to improve the understanding of the geological processes and geodynamic activity between the Northern Sicily Continental Margin and the Tyrrhenian Basin and represent a baseline for assessing the geo-hazard potential on the Ustica Island.

中文翻译：

---

非洲-欧洲板块边缘（第勒尼安海）乌斯蒂卡火山复合体的生长和地貌演化

摘要 我们在此首次介绍了位于第勒尼安海西南部的 Ustica 火山结构海底部分的形态结构研究，该火山被认为是一个不活动的火山系统，年龄为中更新世。这项研究的主要目的是解开乌斯蒂卡火山斜坡部分的海底动力学，以便为第四纪期间地中海中部构造最活跃的地区之一提供新的见解。我们分析和解释了一个综合地震声学数据集，包括多波束条带水深测量、海底剖面、单通道地震反射记录，所有这些数据都是在过去二十年中获得的。地震地层分析表明，乌斯蒂卡火山由一系列熔岩流和火山碎屑产物组成，其几何形状可以解释为火山中心向上生长和向北移动的结果。沿淹没斜坡分布的映射地貌要素根据其特定的形态发生过程进行分类。取得的结果表明，火山、构造、海洋和重力过程相互作用，形成了火山结构复杂的水流地貌，其特点是海底侧翼极不均匀。北部地区的特点是广泛存在保存完好的锥体，这可能与该地区最后一次海底火山活动有关。沿着东部地区，细长的沟渠和线性沟在局部切割了陆架断裂并形成向下的斜坡破坏。沟渠和沟壑是通过各种类型的水流和物质浪费冲洗沉积物的主要渠道，从浅部到深海平原。沿着南部和东部地区，斜坡破坏过程几乎完全切割了陆架边缘，并且主要通过倒积坍塌传播。此外，南部地区主要由 EW 和 NS 走向的断层悬崖形成，这些断崖可能引发了该地区最大的斜坡破坏。这项研究的主要结果有助于提高对北西西里大陆边缘和第勒尼安盆地之间地质过程和地球动力学活动的了解，并代表了评估乌斯蒂卡岛地质灾害潜力的基线。从浅层到深海平原。沿着南部和东部地区，斜坡破坏过程几乎完全切割了陆架边缘，并且主要通过倒退坍塌传播。此外，南部地区主要由 EW 和 NS 走向的断层悬崖形成，这些断崖可能引发了该地区最大的斜坡破坏。这项研究的主要结果有助于提高对北西西里大陆边缘和第勒尼安盆地之间地质过程和地球动力学活动的了解，并代表了评估乌斯蒂卡岛地质灾害潜力的基线。从浅层到深海平原。沿着南部和东部地区，斜坡破坏过程几乎完全切割了陆架边缘，并且主要通过倒退坍塌传播。此外，南部地区主要由 EW 和 NS 走向的断层悬崖形成，这些断崖可能引发了该地区最大的斜坡破坏。这项研究的主要结果有助于提高对北西西里大陆边缘和第勒尼安盆地之间地质过程和地球动力学活动的了解，并代表了评估乌斯蒂卡岛地质灾害潜力的基线。南部地区主要由 EW 和 NS 走向的断层悬崖形成，这些断崖可能引发了该地区最大的斜坡破坏。这项研究的主要结果有助于提高对北西西里大陆边缘和第勒尼安盆地之间地质过程和地球动力学活动的了解，并代表了评估乌斯蒂卡岛地质灾害潜力的基线。南部地区主要由 EW 和 NS 走向的断层悬崖形成，这可能引发了该地区最大的斜坡破坏。这项研究的主要结果有助于提高对北西西里大陆边缘和第勒尼安盆地之间地质过程和地球动力学活动的了解，并代表了评估乌斯蒂卡岛地质灾害潜力的基线。