Publication Date:
2017-04-04
Description:
A periodic sampling of the groundwaters and dissolved
and free gases in selected deep wells located in the area affected
by the May-June 2012 southern Po Valley seismic sequence
has provided insight into seismogenic-induced changes
of the local aquifer systems. The results obtained show progressive
changes in the fluid geochemistry, allowing it to be
established that deep-seated fluids were mobilized during the
seismic sequence and reached surface layers along faults and
fractures, which generated significant geochemical anomalies.
The May-June 2012 seismic swarm (mainshock on May
29, 2012, M 5.8; 7 shocks M 〉5, about 200 events 3 〉 M 〉 5)
induced several modifications in the circulating fluids. This
study reports the preliminary results obtained for the geochemical
features of the waters and gases collected over the
epicentral area from boreholes drilled at different depths,
thus intercepting water and gases with different origins and
circulation. The aim of the investigations was to improve our
knowledge of the fluids circulating over the seismic area (e.g.
origin, provenance, interactions, mixing of different components,
temporal changes). This was achieved by collecting
samples from both shallow and deep-drilled boreholes, and
then, after the selection of the relevant sites, we looked for
temporal changes with mid-to-long-term monitoring activity
following a constant sampling rate. This allowed us to gain
better insight into the relationships between the fluid circulation
and the faulting activity. The sampling sites are listed
in Table 1, along with the analytical results of the gas phase.
Description:
Published
Description:
815-821
Description:
3.2. Tettonica attiva
Description:
JCR Journal
Description:
open
Keywords:
Fluids
;
Geochemistry
;
Faults
;
Temporal changes.
;
04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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