Misurazioni di gravita' e relativa analisi dati della "Grotta Impossibile" - Carso Triestino

In this study we focus on the “Grotta Impossibile” cave, near Basovizza (Trieste). It was discovered in November 2004 thanks to a highway tunnel construction. We report the results of the gravimetric survey made over the part of the cave free of tree vegetation and demonstrate that the gravity minimum over the cave is well defi ned. Additionally, we ran simulations of the anomaly based on the available reliefs of the cave provided by speleological explorations. The good agreement of the data with simulations disproves the existence of any branch yet to discover of size comparable to the main hall of the cave, at least in the studied area. Furthermore, we detect a gravimetric gradient equal to 0.00184·10−5 m/s2 per meter with a northward positive change, which is due to subsurface density and structure inhomogeneities.