A model-estimation of gas overpressure in gas saturated layers in a volcanic setting: a case study from the Banco della Montagna (Naples Bay, Italy) |
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| Ventura G., Passaro S., Tamburrino S., Vallefuoco M., Sacchi M. |
- Abstract:
- The 5 km wide Banco della Montagna (BdM) morphological high is located on the seafloor of Naples Bay (Tyrrhenian Sea, Italy) and is characterized by a hummocky surface. Oceanographic surveys revealed active fluid vents at BdM. High-resolution mono-channel seismic and multibeam bathymetry allow us to define the detailed morphology and the inner geometry of BdM, which consists of a complex set of dome-like structures (pagodas) affecting the present-day seabed. We suggest that a gas-water-sand sediment mixture upraises from a gas saturated layer pushing up the overlying marine deposits and forming mounds, folds, and faults. According to a thin-plate elastic model, we estimate the fluid (gas) pressure Pdef required to form BdM and obtain Pdef = 0.3 Pa, a value consistent with that for doming processes in gas-hydrate settings. At BdM, the pressure ΔP required to break the seabed is in the order of 2-3 MPa, while the gas column height is about 240 m.
- Keywords:
- Marine Geology, Volcanology, Geophysics, Gas Geochemistry, Uplift, Unrest
- Download:
- IMEKO-TC4-GEO-2016-52.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC4
- Event name:
- TC4 International Workshop on Metrology for Geotechnics 2016
- Title:
1st IMEKO TC4 International Workshop on Metrology for Geotechnics
- Place:
- Benevento, ITALY
- Time:
- 17 March 2016 - 18 March 2016