Tiefe seismische Erkundung des marinen Sektors der Campi Flegrei Caldera zur Unterstützung einer amphibischen ICDP/IODP Bohrinitiative
Physik des Erdkörpers
Zusammenfassung der Projektergebnisse
Caldera-forming eruptions are among the most catastrophic natural events to affect the Earth's surface. The partly-submerged Campi Flegrei caldera (CFc) (southern Italy) represents a prime example of an active, resurgent caldera and, thus, an ideal natural laboratory to study fundamental caldera processes. The CFc was associated with at least two large-scale caldera-forming eruptions, namely the Campanian Ignimbrite (CI) and the Neapolitan Yellow Tuff (NYT) eruptions at 39 and 15 ka, respectively. In the last decades, the caldera centre has undergone short-term episodes of unrest involving considerable ground deformation, seismicity and increased fumarolic activity. Furthermore, long-term deformation occurs with uplift rates of several tens of meters within a few thousand years. Both phenomena could be interpreted as eruption precursor, thereby posing high-concern for a future eruption, which would expose more several million people to extreme volcanic hazards. In order to improve our understanding of the nature of caldera-forming volcanic as well as to correctly assess eruption hazards, the CFc has become subject to a joint approach for scientific drilling in the ICDP and IODP programmes. Within the framework of this project, 3D low-frequency (20-300 Hz) multichannel seismic data from the marine portion of the CFc were acquired to serve as site-survey database for the amphibian drilling initiative. This deep-penetrating (~2 km subsurface depth) dataset provides novel information on the deep caldera architecture, reaching ICDP/IODP target depth. Therefore, the dataset has proven to be suitable to guide the planned diverted ICDP drilling as well as to precisely position IODP drill sites and develop an updated IODP proposal complementary and directly linked to an active ICDP campaign (Campi Flegrei Deep Drilling, CFDDP). Scientifically, preliminary results have shown that the low-frequency data will provide key information on the characteristics and location of hydrothermally- and magmaticallyinfluenced zones as well as their deep-seated pathways (e.g. faults). Such knowledge is crucial to reliably assess the risk of a future eruption. Also, the dataset will image the maximum vertical extent of the caldera fill, representing a unique and high-resolution sedimentary archive of regional volcanic activity and earlier large-scale eruptions. The postcruise data processing and interpretation is currently carried out in a follow-up PostDoc project.
Projektbezogene Publikationen (Auswahl)
-
2016. Deep seismic imaging of the offshore sector of the CFc: preliminary IODP site survey results from a low-frequency multichannel seismic investigation. IODP/ICDP colloquium, 14-16 March 2016, Heidelberg, Germany
Steinmann, L., Spiess, V., Sacchi, M.
-
2016. Reconstruction of volcano-tectonic processes in interplay with sedimentary deposition in the Gulf of Naples (Italy) using a seismoacoustic dataset. Dissertation, University of Bremen
Steinmann, L.
-
2016. The Evolution of the CFc (Italy): High- and lowfrequency multichannel 2.5D seismic surveying for an amphibian IODP/ICDP drilling approach. EGU, 17-22 April 2016, Vienna, Austria
Steinmann, L., Spiess, V., Sacchi, M.
