Significance of earthquake-related anomalies in fluids of Val D’Agri (southern Italy)
✍ Scribed by F. Italiano; M. Martelli; G. Martinelli; P. M. Nuccio; M. Paternoster
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 257 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0954-4879
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✦ Synopsis
Geochemical investigations carried out at the Campano–Lucano Apennine (Southern Italy) revealed the presence of fluids composed of a mixing between components of shallow and deep origin, where mantle‐derived helium is also detectable. For the gas phase, the deep component is represented by both CH~4~ and CO~2~‐rich gases, while the shallow one is N~2~‐dominated. Coinciding with the 3 April 1996 M~L~=4.9 earthquake, the CH~4~‐rich component mixed with the shallow, N~2~‐dominated one at the Tramutola well (Val d’Agri), displaying wide variations in mixing proportions. In contrast, no significant modifications occurred in relation to the 1998 M~L~=5.5 event. According to the collected data, an earthquake‐related transient modification of local crustal permeability is suggested for the 1996 event. The different crustal response to the two events may be related to different stress distributions around the epicentres or may suggest a different tectonic connection between the Val d’Agri and the two earthquake locations.