Saturday, February 5, 2011

ACTIVE CALDERA

The Campi Flegrei volcanic field is the largest feature of the Phlegraean Volcanic District, which includes the islands of Procida and Ischia, as well as submarine vents in the northwestern Gulf of Naples.
The key issue for a highly explosive volcanic area like Campi Flegrei, an extremely populated region, is the accurate estimation of hazards from eruptions, and their impact on urban areas.
In particular, it is important to estimate the probability of occurrence, at each point of the area, of the two main eruption products which constitute the highest risk: pyroclastic currents and the fallout products (ash, pumice, etc.).
Campi Flegrei has been one of the world's most active calderas in the last 40 years, generating unrest phenomena not followed by eruptions, characterized by huge ground deformation and seismicity.
Studies of the Campi Flegrei substructure, involving gravimetric data, earthquake locations, active and passive seismic tomography and laboratory experiments on rock samples, allow us to make some inferences about the location of the brittle-ductile transition, shallow aquifers, and the thermal-rheological state of rocks down to 5 km depth. Clear evidence for magma
chambers only comes from petrological studies, indicating two main depth ranges for magma accumulation (5-8 and 11-15 km).
The complex dynamics evidenced at Campi Flegrei, characterized by strict magma-water interaction not only during eruptions, and the problems linked to location and rheology of magma chambers, all indicate the need fordetailed, direct studies of caldera substructure by deep drilling.
Detailed study of Campi Flegrei caldera, which represents a typical example of partially submerged super-volcano located in a densely populated urban area, thus gives a unique opportunity to deeply understand the dynamics of the most dangerous volcanoes on Earth, representing the most catastrophic natural hazards, after giant meteoritic impacts.

1 comment:

  1. [ G. De Natale, C. Troise, F. Pingue, G. Mastrolorenzo, L. Pappalardo, M. Battaglia & E. Boschi, The Campi Flegrei caldera: unrest mechanisms and hazards ]

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