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Monitoraggio delle acque di fondo del Bus de la Genziana (Pian Cansiglio, Nord-Est Italia)
Full text linkIn this paper we present the results of groundwater monitoring of the Bus de la Genziana (Cansiglio,
North-Eastern Italy). It is a cave 587 m deep and about 7 km long with a siphon hanging in the bottom. For the
fi rst time a diver instrument was installed here from March 2013 to December 2014 to discover the underground
hydrodynamics.
The level has been raised with a pattern of impulsive average of 4-5 meters with a few millimeters of rain: it
has reached 27 meters in one event and twice it has exceeded 50 meters with heavy rainfall lasting for several
days. A direct relationship is between tiltmeters recording (installed here at 25 m deep) and water level
in the siphon.
Observing the conductivity and the temperature, before the events of fl ood, the conductivity values (EC,
at 25°C) were an average of 215 and 260 μS/cm, while the parameter fell between 150 μS/cm and 190 μS/cm
when the karstic system fi lls. On the contrary the temperature changes a little bit: the variations are sometimes
near the error measurement of the instrument with 0.04 to 0.3° C, minimum values 7.48° C and maximum value
8.34° C. These parameters show that the place can be affected by mixing of new infi ltration water, which is however very fast as a trigger, as less outfl ow. This type of dynamic helps us to understand that the underground
water circuits are highly conductive, as confi rmed by tiltmeters signal, and enrich the knowledge of the Cansiglio
complex hydrogeology.
Prospects for the future are to continue monitoring by installing a diver instrument also in the Abisso del Col
della Rizza, a cave near Genziana, 800 m deep, in order to understand better the underground hydrodynamics,
which are much more complex than they look
I clinometri del Bus de La Genziana (1000VTV)
No full textVengono mostrate e discusse alcune osservazioni clinometriche della stazione geofisico-geodetica ipogea nel Bus de la Genziana (1000VTV), installata nella Riserva Naturale Ipogea del Cansiglio (Veneto Orientale). La localizzazione di questa cavita', situata in una zona sismica nel Pian Cansiglio sotto il comune di Fregona (Treviso), completa verso Ovest la rete di stazioni clinometriche del Dipartimento di Geoscienze dell'Universita' di Trieste gia' esistenti in Friuli Venezia Giulia (Grotta Gigante in Trieste e Grotta Nuova di Villanova in Tarcento di Udine). Tutte le stazioni sono poste in cavita' facenti parte di interessanti aree carsiche di particolare rilievo idrogeologico. Nel caso specifico del Cansiglio alle pendici friulane del massiccio carsico nasce il fiume Livenza. Mediante un confronto del segnale clinometrico registrato nella stazione Genziana con la serie pluviometrica del Cansiglio e idrometrica del Livenza, sono stati osservati gli effetti idrologici locali. Le deformazioni lente registrate si accompagnano a lungo periodo alle curve di deflusso della falda carsica. Gli strumenti sono inoltre molto sensibili agli eventi piovosi. Lo scopo della ricerca e', oltre al monitoraggio dei movimenti crostali lenti, quello di aprire una nuova frontiera multidisciplinare tra gli studi geodetici e quelli dei sistemi carsici per ottenere informazioni indirette sull'idrodinamica sotterranea
The study of karstic aquifers by geodetic measurements
No full textWe propose to study a karstic aquifer by using tiltmeter observations from the underground geodetic station of Bus de la Genziana (1000VTV) located in the Natural Hypogeum Reserve in Cansiglio (Eastern Veneto, Italy). The location of this cavity, situated in a known seismic zone on the Cansiglio Plateau in Fregona (Treviso), completes the network of tiltmeters stations of the Department of Earth Sciences (DST), University of Trieste. The network includes two further stations in Friuli Venezia Giulia (Grotta Gigante in Trieste and Grotta Nuova of Villanova in Tarcento, Udine). All the stations are set in a natural cavity that is part of an area of particular hydro-geologic importance. In the specific case of the Cansiglio-massif, the River Livenza springs at its foot-slopes. By means of comparison of the observed tilt-signal recorded in the Genziana station with the pluviometrical records provided by ARPA Veneto, local hydrologic effects have been recognised and interpretations have been proposed. The purpose of this talk is to open a new multidisciplinary frontier between the geodetic studies and the karstic system to obtain a more complete geodetic description
Vertical crustal movements in Italy from tidal gauge and satellite altimetry data
No full textGeophysical Research Abstracts
Vol. 12, EGU2010-12894-3,2010
EGU General Assembly 2010
Vienna, 2-7 /05/201
The Spinel Peridotite Mantle xenoliths of Waw-En Namus volcano, southern Libia
No full textalkaline) since Jurassic times (Guiraud et al. 2005). Moreover, paleomagnetic data, suggest that the drifting of the
African plate during the last 100 Ma has been very limited, thus allowing for the keeping the contact with the
deeper mantle. Starting from these premises, the peridotite xenoliths, hosted in nephelinitic basalts from the Waw
En-Namus volcano and investigated in comparison with those from Gharyan area (Beccaluva et al., 2007), could
shed a light on the evolution of the Libyan sub-continental lithospheric mantle and on the geodynamic events that
affected it over time. The mineral phases of such xenoliths, as well as few glassy veins, were studied in order to
determine major and trace elements compositions.
Three types of olivines, orthopyroxenes, clinopyroxenes, and spinels were recognized (magmatic, peridotitic and
related to melt-peridotite reactions), as well as the presence of Na, K and ultra-potassic (UK) glasses.
The investigated glasses, selected among those which apparently have been not (or scarcely) modified in their
composition by peridotite-melt reactions, show higher La/Yb and Zr/Hf ratios with respect to Waw En-Namus
lavas implying the involvements of slightly different mantle sources. Moreover, the presence of UK glasses (characterized
by a strong Pb positive anomaly) suggest the involvement, as source, of a lithospheric or sub-lithospheric
component.
The mantle phases indicate a moment of basaltic extraction starting from a depleted (DMM-like) condition
followed by a recent metasomatism. In the apparently not metasomatized ones, Th/Yb and Ta/Yb ratios suggest
that ancient metasomatic events, which probably occurred during the Pan-African cycle, played a role in their
history. In comparison, the metasomatized mineral phases, according with the recent geophysical data (Begg et
al., 2009), mainly suggest relationships with the continuous asthenospheric upwelling.
Beccaluva, L., Bianchini G., Ellam, R.M., Marzola, M., Oun, K.M., Siena, F., Stuart, F.M. (2008). 253–
277 in: Coltorti, M., & Grégoire, M., (eds.). Geol. Soc. Lond. Spec. Publ. 293.
Begg, G.C., Griffin,W.L., Natapov, L.M., O’Reilly S.Y., Grand, S.P., Hronsky, J.M.A., Djomani, Y.P., Swain, C.J.,
Deen, T., Bowden, P. (2009). Geosphere, 5, 23-50.
Guiraud, R., Bosworth, W., Thierry, J., Delplanque, A. (2005). Journal of African Earth Sciences, 43, 83-14
The study of karstic aquifers by geodetic measurements in Bus de la Genziana station – Cansiglio Plateau (Northeastern Italy)
Full text linkWe propose an interdisciplinary study of karstic aquifers using titlmeters and GPS observations. The study region is located in northeastern Italy, in the seismic area of the Cansiglio Playeau. The Zollner type Marussi tiltmeters are installed in a natural cavity (Bus del la Genziana) that is part of an interesting karstic area of particular hydrogeologic importance. The Livenza river forms from a number of springs at the foothills of the karstic massif and flows through the Friuli-Veneto plain into the Adriatic Sea. Comparing the tiltmeter signal recorded at the Genziana station with the local pluviometrical series and the hydrometric series of the Livenza river, a clear correlation is recognized. Moreover, the data of a permanent GPS station located on the southern slopes of the Cansiglio Massif (CANV) show also a clear correspondence with the water runoff. Here we present the hydrologic induced deformations as observed by tiltmeter and GPS. After heavy rain events we record rapid deformations both by tiltmeters and GPS corresponding to the rainfall duration. In the following days a slow geodetic motion recovers the accumulated deformation with a distinctive pattern both in tilt and GPS data, which correlates with the runoff of the karstic aquifer. The purpose of this research is to open a new multidisciplinary frontier between geodetic and karstic system studies to improve the knowledge of the underground fluid flow circulation in karstic areas. Furthermore a better characterization of the hydrologic effects on GPS and tilt observations will have the benefit that these signals can be corrected when the focus of the study is to recover the tectonic deformation
I primi 10 mesi di registrazione della stazione geofisica ipogea del Bus de la Genziana (1000VTV) - Pian Cansiglio
No full textTilting tra il Friuli-Venezia Giulia ed il Veneto dal 2006 al 2008
No full textVengono descritti i risultati dei primi tre anni di registrazione (da dicembre 2005 a dicembre 2008) della stazione geofisico-geodetica ipogea nel Bus de la Genziana (1000VTV), installata nella Riserva Naturale Ipogea del Cansiglio (Veneto Orientale). La localizzazione di questa cavita', situata in una nota zona sismica nella parte veneta del Pian Cansiglio sotto il comune di Fregona (Treviso), completa verso Ovest la rete di stazioni clinometriche del DST dell'Universita' di Trieste gia' esistenti in Friuli (grotta Gigante in Trieste e Grotta Nuova di Villanova in Tarcento di Udine). Per appurare se la sua forte deriva verso sud sia un effetto locale oppure regionale, si e' provveduto ad installare in giugno 2008 una seconda coppia di clinometri presso il Comando Forestale del Pian Cansiglio a qualche centinaia di metri dalla Grotta Genziana. Facciamo un esame critico, tenendo conto delle osservaioni del segnale di marea terrestre e di effetti idrologici e tettonici
Vertical crustal movements from comperative analyses of spaceborn and local sea level change observations
No full text3rd Coastal Altimetry Workshop, 17-18 September 2009, Frascati (Rome), Italy, Abstract Lis
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