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Titel |
Thermal anomalies and fluid geochemistry framework in occurrence of the 2000-2001 Nizza Monferrate seismic sequence (northern Italy): Episodic changes in the fault zone heat flow or chemical mixing phenomena? |
VerfasserIn |
F. Quattrocchi, R. Favara, G. Capasso, L. Pizzino, R. Bencini, D. Cinti, G. Galli, F. Grassa, S. Francofonte, G. Volpicielli |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 3, no. 3/4 ; Nr. 3, no. 3/4, S.269-277 |
Datensatznummer |
250000687
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Publikation (Nr.) |
copernicus.org/nhess-3-269-2003.pdf |
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Zusammenfassung |
The paper discusses
the correlation between the heating of shallow groundwater over a 10 × 20
km wide area close to the town of Nizza Monferrato (Piemonte Region,
Northern Italy) and the concomitant local seismic sequences during the
period August 2000 – July 2001. The first seismic sequence started on 21
August 2000 with a Ml = 5.2 earthquake. Within few hours, the
local authorities received calls alerting that the groundwater temperature
rose from 10 to 30°C in many shallow wells. Our geochemical experimental
data and the geological-seismotectonic framework do not allow the
hypothesis of simple fluid mixing between the thermal reservoir of Acqui
Terme and the Nizza-Monferrato shallow groundwater to explain the observed
thermal anomalies. On the other hand, we invoke more complex processes
such as frictional heating, mechano-chemistry, fault-valve mechanism,
adiabatic decompression and hydrogeologically driven heat flow i.e.,
thermal effects due to variations of basin-scale permeability field. All
these processes are able to transmit heat to the surface and to generate a
transient incremental heat flow better than the mass transfer occurring
typically when fluids from different reservoirs mix. |
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