Microseismic monitoring in central Italy: evaluation of the background seismicity and its tectonic insights addressed to future potential geo-gas storage sites
Abstract
The topic of this work is the monitoring of the background seismicity of an on-shore region close to a future potential injection site, located off-shore in Central Italy. The study area is spanning also 8000 km2 and including both the outer North Apennines belt, NW-SE oriented, and the coastal area, roughly between the towns of Rimini and Ancona. The same area is also interested by a geochemical monitoring (soil gases and shallow aquifers) in order to evaluate the evolution of the diffuse degassing patterns before and after the eventual geo-gas storage (i.e. CO2 and CH4). For the one-year long monitoring (from March 2010 to March 2011), a suitable local seismic network was installed, in order to improve the detection capabilities of both the permanent National Seismic Network (R.S.N.) and the Marche network (Centro Nazionale Terremoti). The preliminary results gathered by the temporary seismic experiment (designed to monitor the background and fluids-related induced seismicity) are discussed A dataset of almost 620 local earthquakes was collected within the study area, showing a heterogeneous and sparse location of the seismicity. In the Northern part of the focus area seismicity is basically located both at the transition zone between the Apennines chain/piedmont plain and in an area close to the coast. In the central part there is a lack of seismicity, except the very low-magnitude seismicity located close to the Apennines chain. In the Southern part there is most of the detected seismicity. It seems to be placed in two main clusters and sparse seismicity, both on-shore and off-shore. In this area the earthquakes hypocenters alignments follow the geometries of the main thrust structures. This feature, although the seismic activity is poor in the off-shore, indicates that the thrust structures are active, as suggested also by seismic profiles and geological data. The discussed data delineate the future seismic monitoring area and the areas where the future seismological and geochemical studies will be carried out to better constrain the geo-gas storage site.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.S33A2305A
- Keywords:
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- 7230 SEISMOLOGY / Seismicity and tectonics;
- 7240 SEISMOLOGY / Subduction zones;
- 8108 TECTONOPHYSICS / Continental tectonics: compressional;
- 8123 TECTONOPHYSICS / Dynamics: seismotectonics