Please use this identifier to cite or link to this item:
Authors: Pischiutta, M.* 
Anselmi, M.* 
Cianfarra, P.* 
Rovelli, A.* 
Salvini, F.* 
Title: Directional site effects in a non-volcanic gas emission area (Mefite d’Ansanto, southern Italy): Evidence of a local transfer fault transversal to large NW–SE extensional faults?
Journal: Physics and Chemistry of the Earth 
Series/Report no.: /63 (2013) Elsevier Science Limited
Issue Date: 4-May-2013
DOI: 10.1016/j.pce.2013.03.008
Keywords: CO2 gas emission Directional resonance Fault damage zone Lineament analysis
Subject Classification04. Solid Earth::04.06. Seismology::04.06.04. Ground motion 
Abstract: The technique of the wavefield polarization is applied to ambient vibrations recorded in the Mefite d’Ansanto area, an important non-volcanic natural emission of low temperature CO2 enriched gases. Twentyfive measurements were performed in the study area, eleven near the emission site and the other fourteen in different sites within an area of 5 km. Polarization is assessed both in the frequency and time domain through the individual-station horizontal-to-vertical spectral ratio and covariance-matrix analysis, respectively. We find a significant tendency of ground motion in the gas emission area to be polarized in the horizontal plane, with a N115 predominant trend. This polarization tends to disappear while moving far from the site. According to previous papers in other study areas, such a directional effect is likely caused by fault-induced fractures and tends to be orthogonal to the fracture strike. The predominant NW–SE regional faulting does not fit the N115 polarization direction. To explain observations, we propose an interpretation in terms of a NE–SW oriented, local transfer fault as inferred from the lineament analysis. The intersection of the damage zone of this fault with the regional NW–SE normal fault system could easily be the responsible for the gas emissions since it favors a locally increased crustal weakness.
Appears in Collections:Article published / in press

Files in This Item:
File Description SizeFormat Existing users please Login
4_JPCE_Mefite.pdfMain article4.77 MBAdobe PDF
Show full item record

Page view(s) 50

Last Week
Last month
checked on Mar 28, 2020


checked on Mar 28, 2020

Google ScholarTM