Naslov
Assessment of the hydrological behaviour in cave environments at varying altitudes on the eastern Adriatic coast (Croatia)

Autori
Surić, Maša ; Buzjak, Nenad ; Lončarić, Robert ; Lončar, Nina ; Bajo, Petra ; Drysdale, Russell N

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
7th International Conference Climate Change: The Karst Record. KR7 "Down Under" - Scientific Programme and Abstracts / - Melbourne : The University of Melbourne, 2014, 153-153

Skup
7th International Conference Climate Change: The Karst Record. KR7 "Down Under"

Mjesto i datum
Melbourne, Australija, 29.09.2014. - 03.10.2014

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Stable isotopes; hydrological behaviour; cave; altitude effect; Croatia

Sažetak
Croatian eastern Adriatic coast, with the Dinarides as orographic barrier, occupies a key position between eastern and western Mediterranean basins and delimits central European and the Mediterranean regions. This boundary region is influenced both by Atlantic and Mediterranean air masses, and during past climate changes it has probably been shifting, leaving the palaeoclimate signals records within the speleothems. In order to characterize cave environments eligible for the reconstruction of the palaeoenvironmental settings, we selected three caves at the different altitudes along the transection from Dalmatian islands to Velebit Mt peaks (Croatia): Strašna peć Cave on Dugi otok Island (70 m a.s.l.), Manita peć Cave in Velika Paklenica canyon (Velebit Mt, 570 m a.s.l.) and Spilja u Zubu Buljme Cave (Velebit Mt, 1305 m a.s.l.). We have conducted cave microclimate and dripwater monitoring to select representative site/speleothems for palaeoclimate reconstruction, and analyzed isotopic composition of precipitation and cave dripwater. The aim of the latter was to estimate contemporary regional and local influences of Atlantic and Mediterranean air masses and differences between coastal and continental, and between low- and high-altitude sites. As for the water isotopic imprints, altitude effect was noted both in precipitation and in dripwater isotopic composition. Two lower caves, in spite of the altitude difference of 500 m, have local meteoric water line (LMWL) of similar slope and intercept. Slopes lower than that of the global meteoric water line (GMWL) indicate enhanced evaporation during the warm season. As expected, the LMWL of the highest cave region resembles the GMWL by the slope, but obtained values of deuterium excess for all three caves (dZB = 16.0‰, dMP = 14.6‰ and dSP = 14.5‰) do not match neither Atlantic (10‰) nor Mediterranean (22‰) values, indicating both continental and maritime influences. According to the cave microclimate conditions, two lower caves showed potential for the studies to come with their stable cave environments (temperature amplitudes of 1.7 and 1.8 °C, and RH of 100%), and drip sites with corresponding speleothems which showed stable discharge mode with only weak response to the rain events. Unfortunately, the highest cave has too large air temperature amplitude (5.3 °C), so the isotopic signal in already sparse calcite precipitation is surely affected by kinetic fractionation.

Izvorni jezik
Engleski

Znanstvena područja
Geografija

Napomena
Projekt 60200 Sveučilišta u Zadru: Rekonstrukcija regionalnih paleoklimatskih promjena – zapisi iz siga sjeverne Dalmacije. Voditeljica: Maša Surić

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