Shallow structures of the marine Campi Flegrei Caldera and the volcanoclastic and sedimentary deposits in the Bay of Naples

坎皮·弗莱格雷火山区属于世界上最活跃的火山系统。该地区最显著的火山特征是半淹没的准圆形Campi Flegrei火山口，它是在一次重大火山喷发(所谓的那不勒斯黄色凝灰岩喷发)和随后发生的崩塌过程中形成的，公元前15000年。作为喷发的结果，侵位了厚厚的原始火山岩，覆盖了1000平方公里的区域。最近一次火山喷发发生在公元1538年，在3500年的平静之后，位于蒙特诺沃的火山喷发。在过去的几十年里，Campi Flegrei火山口的特点是短期的动乱，涉及相当大的地面变形(隆起和下沉几米)、地震活动和喷气孔温度上升。此外，在火山口中部可以观察到长期的形变(&lt；8ka)，几千年内的隆升速率可达几十米。长期和短期的隆起都可以解释为火山喷发的前兆，因此对未来的喷发高度关注，这将使生活在火山区周围的150多万人面临极端的火山风险。为了增进对这种动荡机制的了解和正确评估喷发危险，坎皮·弗莱格里火山区在ICDP和IODP计划中采用了联合两栖方法进行科学钻探。在DFG部分资助的2008年德国-意大利研究巡航期间，为了支持陆上和近海钻井计划，获得了高分辨率的多道地震数据。地震数据提供了自纽约时报喷发以来坎皮·弗莱格雷火山口演化的洞察，并在DFG？S ICDP优先方案正在进行的项目框架内进行了解释。尽管海底最下面300米处的数据质量很好，但信号穿透不足以达到ICDP/IODP钻探活动所需的深度(&gt；1000米)。在本提议的背景下，计划在2015年进行另一次地震调查，在此期间应部署低频地震系统，以便将信号穿透到拟议的ICDP/IODP钻探地点的目标深度。这一待获取的地震数据集可作为将最近完成的陆地ICDP钻探与波佐利湾和那不勒斯海湾拟议的IODP钻探地点进行对比的基础，以便绘制研究区域的大尺度图景。最终，这些数据将被用于准备最新的海洋钻探活动。此外，待采集的深穿透地震数据将对已有的高分辨率地震数据形成最佳补充。对这两个数据集的联合解释将提供对Campi Flegrei火山口发育的尚未存在的见解，包括那不勒斯黄色凝灰岩喷发之前的时间跨度。

The Campi Flegrei Volcanic District belongs to the world's most active volcanic systems. The most pronounced volcanic feature in that area is the half-submerged, quasi-circular Campi Flegrei caldera, which formed in the course of a major volcanic eruption (the so-called Neapolitan Yellow Tuff (NYT) eruption) and subsequent collapse that occurred 15000 years B.P. As consequence of the eruption, thick ignimbrites were emplaced, covering an area >1000 km². The last volcanic eruption occurred in 1538 AD at the Monte Nuovo after 3500 years of quiescence. In the last decades, the Campi Flegrei caldera has been characterized by short-term episodes of unrest involving considerable ground deformation (uplift and subsidence of several meters), seismicity and increased temperature at fumaroles. Furthermore, long-term deformation (<8 ka) can be observed in the central part of the caldera with uplift rates of several tens of meters within a few thousand years. Both long-term and short term uplift could be interpreted as eruption precursor, thereby posing high-concern for a future eruption, which would expose more than 1.5 million people living in the surroundings of the volcanic district to extreme volcanic risks.In order to improve the understanding of such unrest mechanisms and to correctly assess eruption hazards, the Campi Flegrei Volcanic District became subject to a joint amphibic approach for scientific drilling in the ICDP and IODP programmes. During a partially DFG funded, German-Italian research cruise in 2008, high-resolution multi-channel seismic data were acquired in order to support the onshore and offshore drilling programmes. The seismic data provide an insight into the evolution of the Campi Flegrei caldera since the NYT eruption and have been interpreted within the framework of an ongoing project in the DFG¿s ICDP Priority Programme. Despite outstanding data quality of the uppermost 300 m below the seafloor, the signal penetration is not sufficient to achieve the required depths (>1000 m) of the ICDP/IODP drilling campaigns.In the context of the present proposal another seismic survey is planned for 2015, during which a low-frequency seismic system shall be deployed in order to achieve signal penetration down to the target depth of the proposed ICDP/IODP drill sites. This to-be acquired seismic dataset may serve as a basis for the correlation of the recently completed onland ICDP drilling and proposed IODP drill sites in the Gulf of Pozzuoli and Naples Bay in order to develop a large scale picture of the study area. Eventually, the data shall be used to prepare an updated marine drilling campaign. Furthermore, the to-be acquired deep-penetrating seismic data would form an optimal complement to the already existing high-resolution seismic data. A joint interpretation of both datasets would provide not yet existing insights into the development of the Campi Flegrei caldera, including the time span before the Neapolitan Yellow Tuff eruption.