Impaginato PPUR ok_La Venta 22/05/20 11:58 Pagina 76
within the stratigraphic column and therefore its age is still unknown ranging from 25 to 10 million years BP. Until now the presence of sirenians in the Far East fossil record is rare and proved only as far east as Java. Therefore the fossil of the Underground River is extremely important because it pushes the limit of diffusion of these animals some 1500 km eastward. At the moment, by using only the photos of the outcropping bones it is impossible to state if the sirenian of the Underground River belongs to a known fossil family or to a new genus yet to be defined. It would surely be possible to exactly define the genus of this fossil but to perform these studies it would be necessary to extract as much as possible of the bones from the rock, thus completely destroying the location. Therefore we strongly discourage making these studies because, in the near future, new techniques could allow us to study this fossil preserving it. Underground meteorology G. B. Io venni in loco d’ogne luce muto, che mugghia come fa mar per tempesta, se da contrari venti è combattuto. Inferno, Canto V I arrived in a place where all light was mute, which bellowed like a sea in storm, when battled by contrary winds. Dante, Inferno Canto V One of the many reasons that make this cave, carved by the Underground River, so exceptional, is that the underground meteorological phenomena are at their most intense level. We could even say that there is a permanent invisible ‘underground storm’, stirred up by the shape of its deep galleries. The Underground River cave is a type of tunnel into which an external river flows and which transports all the meteorological events from the outside deep into 76
Recording meteorological data is the best way to study the energy balance of a cave
the rocks: precipitation peaks, large biological load and temperature jumps. This in itself is not exceptional: around the world there are many caves of this type, some having much more impressive rivers. The peculiarity which makes this cave so unique is that it reaches the sea level already within the mountain, in the core of Mount St. Paul. This gives the cave several extraordinary characteristics. Not only can you enter directly from the sea, not only it is navigable for kilometres, but in this way the sea carries its dynamics through tidal currents - tied to the positions of the Sun and the Moon - which penetrate up to over 6 km from the entrance. So, part of the meteorology inside Mount St. Paul depends on the Sun and the Moon; therefore the Underground River environmental conditions have a clear astral origin. The flows of fresh water from upstream and salt water from downstream are not connected to each other and, on the contrary, for long distances they don't mix, the former flowing on top of the latter. This creates pockets of cooler air in contact with the water and, seasonally, generates flows of relatively warm and humid air which fills the galleries. Micro-meteorological niches and extremely complicated ecosystems are thus created,