Modelling Long Term Ground Deformation by a Submerged Archaeological Site: the Case of Basiluzzo Island (Aeolian Island, Italy)
Abstract
By means of a roman-age submerged wharf, dated 2000 +/- 50 a BP, we modelled the volcanic source which produced the long term vertical deformation of Basiluzzo island, located in the volcanic arc of the Aeolian island (Italy). This is the first attempt to model crustal deformation through a submerged archaeological structure. Nowa-days the top of the wharf, which can be considered as a non conventional levelling benchmark, is located near Punta Levante, at an average depth of 3.20 +/- 0.10 m be-low a.s.l., and it is still in good conservation. Its present location is due to combined effect of sea level uprising, volcanic and tectonic activity occurred since its building. Taking into account the architectural features of the wharf and that the mean sea level uprising for the Mediterranean sea has been estimated in 0.45 m during the last 2000 years, was estimated a total subsidence of 3.75 +/- 0.10 m, at a rate of 1.87 +/- 0.05 mm/a. Our model, considering the Earth's crust as a Maxwell body, aims to propose a possible mechanism to explain the long term subsidence on scale of time of thousand years, of a volcanic area, such observed in Basiluzzo island. We can suppose that the observed crustal deformation is mainly due to the slow cooling of a magmatic source located under Basiluzzo dome which underwent to a progressive solidification and a subsequent volume reduction, during the last 50000 years.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.V21A1179T
- Keywords:
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- 8439 Physics and chemistry of magma bodies;
- 8499 General or miscellaneous