Publication Date:
2021-02-03
Description:
Abstract: The dynamic of groundwater systems feeding several springs
of the Sibillini Mountains was deeply affected by nine Mw 5.0÷6.5
seismic events occurred in central Italy starting from August 2016.
The strongest shock occurred on October 30th 2016 about 5 km NNE of
Norcia Town, 9 km below the surface, as a result of upper crust normal
faulting on the nearly 30 km-long Mt Vettore - Mt Bove fault system, a
NW-SE trending, SW-dipping fault system outcropping on the western
slope of Mt Vettore, the highest peak of Sibillini Mountains.
Soon after this event, a general increase of springs and rivers discharge
and groundwater levels was observed both in the Visso and Norcia areas,
west of the Sibillini Mountains. In the Visso area the hydrogeological
changes due to the seismic sequence exhausted in the 2019, while
nowadays both discharges and groundwater levels are still higher than
before in the Norcia area.
Discharge data of the main springs located east, south-east of the Sibillini
Mountains were analysed to verify whether the general increase
observed on the western side was associated to a decrease on the eastern
and southern-east area. The results show that the springs located on the
eastern side and southern-east side of Mt Vettore experienced a significant
long-term discharge decrease.
In this preliminary work, the analysis of the historical discharge series
of the Pescara di Arquata spring (SE of Mt Vettore), and its relationship
with the Standard Precipitation Index (SPI) shows that the
very low discharge values recorded during the post-seismic period are not
associated with SPI as low as documented in the past for similar discharges.
Moreover, the stable isotopic composition of Pescara di Arquata
water during the post-earthquake period is slightly different from that
measured before the seismic events; this suggests that a lower amount of
water having more enriched isotopic δ18O content reaches the spring after
the seismic sequence. These aspects seem to indicate that groundwater
circulation in the southern-east area of Sibillini Mountains has been
affected by the 2016-2017 seismic sequence
Description:
Published
Description:
19-25
Description:
4T. Sismicità dell'Italia
Description:
7T. Variazioni delle caratteristiche crostali e precursori sismici
Description:
2IT. Laboratori analitici e sperimentali
Description:
JCR Journal
Keywords:
earthquake, hydrogeology, spring discharge, SPI, Central Italy.
;
03.02. Hydrology
;
04.06. Seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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