eprintid: 1808 rev_number: 12 eprint_status: archive userid: 6 dir: disk0/00/00/18/08 datestamp: 2017-01-03 12:48:05 lastmod: 2017-02-08 12:21:43 status_changed: 2017-01-03 12:48:05 type: article metadata_visibility: show creators_name: Ventura, Guido creators_name: Di Giovambattista, Rita corp_creators: Istituto Nazionale di Geofisica e Vulcanologia, Italy corp_creators: Istituto Nazionale di Geofisica e Vulcanologia, Italy title: Fluid pressure, stress field and propagation style of coalescing thrusts from the analysis of the 20 May 2012 ML5.9 Emilia earthquake (Northern Apennines, Italy) subjects: MP2 subjects: MP6 subjects: RIt1 subjects: SHC divisions: IP8 full_text_status: none abstract: Two major earthquakes of ML 5.9 and 5.8 and hundreds of aftershocks affected the Emilia region (Po Plain, Italy) between 20 May and June 2012. The events concentrate in the uppermost 10 km of the crust with few events up to 30 km. Two buried, sub-parallel N100°E striking thrusts of the Northern Apennines belt are reactivated. These thrusts coalesce at the interface between the metamorphic basement of the belt and the overlying, about 10-km thick, sedimentary succession. Focal mechanisms indicate a compressive stress field with a sub-horizontal, roughly N-S striking σ1. This stress field is consistent with active shortening in Northern Apennines. Suprahydrostatic pore pressure and σ1 ∼ σ2≠σ3 are required to reactivate the thrusts. The involved fluids could be gas and brines hosted in the folded sedimentary successions. The time and spatial evolution of the seismicity indicates a foreland to hinterland propagation of the ruptures and a thin-skinned deformation of Northern Apennines. date: 2012 date_type: published publication: Terra Nova volume: 25 number: 1 publisher: Wiley pagerange: 72-78 id_number: doi:10.1111/ter.12007 issn: 0954-4879 official_url: http://doi.org/10.1111/ter.12007 access_IS-EPOS: limited owner: Publisher citation: Ventura, Guido and Di Giovambattista, Rita (2012) Fluid pressure, stress field and propagation style of coalescing thrusts from the analysis of the 20 May 2012 ML5.9 Emilia earthquake (Northern Apennines, Italy). Terra Nova, 25 (1). pp. 72-78. DOI: https://doi.org/10.1111/ter.12007