Variations of carbon dioxide in the air and dripwaters of Punkva Caves (Moravian Karst, Czech Republic)

Abstract

Carbon dioxide (CO 2 ) was studied in Punkva Caves in the Moravian Karst (Czech Republic) during a one-year period from February 2012 to March 2013. Partial pressures of the CO 2 corresponding to aqueous carbonates, P CO 2 ðWÞ (10 -2.91 -10 -2.35 , i.e., 0.12-0.45 vol%), and those participating in the initial dripwater formation, P CO 2 ðHÞ (10 -1.77 -10 -1.49 , i.e., 1.7-3.2 vol%), were calculated from dripwater hydrogeochemistry, and compared with the partial pressure in cave air, P CO 2 ðairÞ (10 -3.31 -10 -2.49 , i.e., 0.06-0.32 vol%). Both the P CO 2 ðairÞ and P CO 2 ðWÞ showed clear seasonal variations with maxima in summer and minima in winter. In contrast, the P CO 2 ðHÞ was very stable without any significant seasonality, which could indicate its independence on surface conditions. As an exception, one anomalous drip with significantly lower and varying P CO 2 ðWÞ , P CO 2 ðHÞ , and SI calcite was recognized as a result of prior calcite precipitation. Evolution of dripwater during CO 2 degassing and calcite precipitation is demonstrated in detail in a geochemical model. The study presents new data indicating that the CO 2 source might be deployed in deeper parts of karst profile (epikarst) in addition to karst soils.

The impact of door opening on CO2 levels: A case study from the Balcarka Cave (Moravian Karst, Czech Republic)

“…1A. Mean annual precipitation in the study area is about 700 mm; mean annual temperature of the external atmosphere is about 10°C (Pracný et al, 2016a). The cave has been formed in the Upper Devonian limestones of the Macocha Formation.…”

Anomalous drip in the Punkva caves (Moravian Karst): relevant implications for paleoclimatic proxies

“…They are situated approximately 20 km northwards from Brno in the Moravian Karst, the largest karst region in the country. The caves have developed in very pure Devonian limestone of the Macocha formation, specifically in the Lažánky and Vilémovice Limestones (Faimon et al ., ; Blecha and Faimon, ; Pracný et al ., ).…”

Low-Calcium Cave Dripwaters in a High CO2 Environment: Formation and Development of Corrosion Cups in Postojna Cave, Slovenia

“…In the vadose zone, this could be possible due to upward cave ventilation in the winter, which effectively flushes out some of the biogenic CO 2 . At the ceiling, it could be possible if drips do not fall directly on the stalagmite but flow along the outside of the stalactites or along the cave walls and even more so if the drip interval is long [27,30,58]. However, the ceiling of Pisani Passage is not overly occupied by stalactites, especially not the Red Hall, which limits the importance of PCP.…”