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Large Earthquakes Driven by Fluid Overpressure: The Apennines Normal Faulting System Case
Author(s) -
Chiarabba C.,
Buttinelli M.,
Cattaneo M.,
De Gori P.
Publication year - 2020
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/2019tc006014
Subject(s) - geology , overpressure , seismology , induced seismicity , fault plane , normal fault , fault (geology) , physics , thermodynamics
Abstract Fluid overpressure is a primary mechanism behind fault interaction and earthquakes triggering. The Apennines section within the young Alpine mobile belt is a key locus to investigate the interplay between fluids and faults. Here, seismicity develops along the extending mountain belt and the key role of fluids has been invoked in past large earthquake sequences. In this study, we use seismological data to get improved images of the Apennines normal faulting system, trying to catch evidences for the involvement of fluids in the preparatory phase of large earthquakes. We observe that extension preferentially reutilizes inherited fragments of faults which were assembled during the Mio‐Pliocene contraction, with steep segments that floor on a regional‐scale gently east dipping plane. We find evidences for wide volumes of overpressured fluids at the base of the seismogenic layer, which are connected to the activation of the recent large earthquakes. The recognition of fluids compartments with overpressuring and diffusion molding seismicity is a key to understand faulting processes and possibly develop forecasts scenarios.