2nd Amateur & Technical Diving Conference

SCIENCE AND CAVING

Dr. V. Giannopoulos

Speleology is the branch of geological science that deals with the study of caves as natural phenomena. The causes of their creation, their morphology, and the sediments contained within them are the most basic units studied by this branch of geology.

Cave research begins with geological studies. This allows one to form a general first picture in order to plan the exploration method and the materials that will be needed. In addition, geological studies are a great help and prerequisite for other studies that may follow, such as paleontological, biological, archaeological, etc. The morphology of a cave contributes to the creation of a peculiar and almost stable environment within it. Its sediments have recorded all the important events and changes that occurred, both inside the cave and in the wider external space. The preservation over time of all these elements can be little affected by any internal or external change (weather conditions, etc.). Thus, their study today by specialist scientists gives a complete picture of the evolution and geological changes. Quite rightly, therefore, some have called caves "a window into the past". Tectonic movements, but also eustatic changes in sea level are among the main reasons why many caves in Greece have been completely or partially flooded by water. The exploration and study of these caves until a few years ago was impossible. Today, however, the development of diving techniques and sports speleology laid the foundations for a new exploration technique, Cave Diving. Three of the main cave diving and study programs of the corresponding caves, although still in progress, have yielded significant results.

ΒΟΥΛΙΑΓΜΕΝΗ

Underwater cave entrance

The total length of the corridors explored to date is 3,123 m. The furthest point is located 788 m. from the entrance, in a straight line, north, below the building blocks of the homonymous city. The study of the morphology and hydrology of the cave leads to the conclusion that the main speleogenesis took place at an older level of the aquifer.

VOULIAGMENI - Section along the development of the cave

The result of the cave's morphology, tectonics, stratigraphy, type of limestone and, more generally, positive conditions for speleogenesis are the large, old and new, detachments and collapses observed in the cave. The mixing of fresh water with seawater, which penetrates through the fractures of the limestone, was observed to take place at a depth of -16 to -40 m. At approximately the same depths, small changes in water temperature are also observed, which stabilizes from -40 m. and below at 27° C. The identification, moreover, of decoration and travertine-like deposits provides evidence for the existence of a dry environment in earlier times and, more generally, for the paleomorphology of the area. Simultaneously with the exploration and study of the underwater cave, a surface reconnaissance of the morphology of the wider area was carried out. Taking into account previous data, in combination with the on-site research, the already known karst depressions, the cave abyss "German" and the underwater karst conduit, known as "Pigadi", were identified. The research also proceeded to identify many other small depressions, but mainly four sinkholes. Perhaps the most important element that emerged was that all these underground and surface karst depressions have been created along a straight line in a North-South direction and belong to the same karst system.

VOULIAGMENI - Exploration

The continuation of this program is considered extremely necessary, mainly due to the social problem that has arisen from the existence of the largest underwater hall in the world (approximately 2,000,000 m3) under the building blocks.

ΣΠΗΛΑΙΑ ΕΛΕΦΑΝΤΩΝ     

"Elephant" Cave, Vamos, Chania, Crete

Another cave diving was to be very important for the identification of paleontological findings and to contribute greatly to the promotion of science. In January 2000, television showed footage of G. Tzanakis from an underwater cave that M. Efthymakis had indicated. On March 31, 2000, the Ephorate of Paleoanthropology-Spelaeology, in collaboration with speleological associations and the Cretas Diving Center, organized the first expedition to explore the cave. The cave is located in the prefecture of Chania, outside the bay of Souda. It has been opened in Mesozoic limestone. Its entrance, 9 m wide and 6.5 m high, is currently underwater.

ELEPHANT CAVE - Entrance to the cave

The first part of the cave, approximately 40 m long, continues to be underwater. The remaining part, 125 m long and 2 m wide, which also constitutes the main chamber of the cave, has, due to its morphology, been partially flooded by water. The depth of the bottom in this chamber ranges from a few centimeters to 4 m, while the height of the ceiling above the water surface exceeds 10 m in some places. The lithic decoration is very rich throughout the cave, both above and below the water surface.

ELEPHANT CAVE - The great hall

The most important finding here, however, was the identification of paleontological material, which after an initial study, was found to consist mostly of elephant bones and a very small percentage of even-toed ungulates (Cervidae). This site is new for Crete and, compared to the other sites, is the only one under the sea. From the measurements carried out on the found parts of the elephant skeleton, it was possible to argue that this is a new species, which was named elephas chaniensis n.sp. Its size was larger than the current elephant and smaller than its ancestor, the antiquus.

ELEPHANT CAVE - Elephant molar

Η μελέτη των ιζημάτων (βιολογικών, κλαστικών και χημικών) καταδεικνύει με βεβαιότητα ότι το σπήλαιο σε παλαιότερες εποχές ήταν στεγνό.
Είναι γεγονός ότι και τα τρία μελετηθέντα σπήλαια βρίσκονται κατά μήκος της σημερινής ακτογραμμής και έχουν επηρεαστεί από τις ευστατικές κινήσεις του επιπέδου της θάλασσας, το οποίο έχει αποδειχθεί ότι, κατά τις παγετώδεις περιόδους, μετατοπίζεται έως και 150 μ. χαμηλότερα από το σημερινό. Συνεπώς, δεδομένου ότι, κατά μήκος των ακτογραμμών, πάντα παρατηρείται πιο έντονη παρουσία ανθρώπων και ζώων, είναι πολύ πιθανόν, ειδικά για τον ελλαδικό χώρο, να εντοπιστούν στο μέλλον και άλλα ανάλογα σπήλαια, που θα δώσουν νέα σημαντικά στοιχεία για τις διάφορες επιστήμες. 

Σπήλαιο «Γλυφάδα» Διρού Λακωνίας

Το σπήλαιο βρίσκεται στο νομό Λακωνίας, στη χερσόνησο της Μάνης και απέχει περίπου 2 χμ. από την κοινότητα Πύργου Διρού.
Το όνομά του οφείλεται στο υφάλμυρο νερό που εκβάλλει στη θάλασσα από τη φυσική του είσοδο. Από την είσοδο αυτή και με σκοπό την ανεύρεση πόσιμου ύδατος, το 1923, οι κάτοικοι της περιοχής ανακάλυψαν τυχαία τις πρώτες αίθουσες του σπηλαίου.
Από το 1949 άρχισαν οι συστηματικές εξερευνήσεις. Το 1961, τα σπήλαιο αξιοποιήθηκε τουριστικά και μέχρι το 1992 είχαν χαρτογραφηθεί 6.200 μ. διαδρόμων με συνολική έκταση 34.100 μ2 . Από το 1987 και συστηματικότερα από τα 1994, η Εφορεία Παλαιοανθρωπολογίας-Σπηλαιολογίας, στα πλαίσια ενός ευρύτερου προγράμματος εξερεύνησης και μελέτης των σπηλαίων της
Μάνης, αρχίζει συστηματικές έρευνες στο σπήλαιο «Γλυφάδα» . Σήμερα το συνολικό μήκος των χαρτογραφημένων διαδρόμων έχει ανέλθει στα 10.606 μ., από τα οποία τα 1833 είναι υποβρύχια (σε αυτά δεν έχει υπολογιστεί το χερσαίο τμήμα που οδηγεί στον «πάνθηρα» ).

GLYFADA OF DIROS - 3D visualization of the cave

The development of the cave is very labyrinthine. The causes of this morphology are mainly due to the creation of the stalagmite decoration. The original form of the cave was much simpler, with the main directions of the faults, SE-NW and E-W. It has been opened up in crystalline limestones and today is partially flooded by water. Both its geographical location and the general prevailing conditions are also the cause of its complex morphology. Thus, in order to study it, the cave was divided into six different sections, based on its morphological variations. As was natural in this case, the greatest scientific interest was presented in the underwater part of the cave, which had remained unexplored, and therefore relatively protected. It is a paleokarst with many stalactites, even at a depth of -71 m. A common feature throughout the surface, not only of the bottom, but also of the walls of the underwater corridors, is the existence of mud, from 1 to 20 cm thick, which, following tourist exploitation and the blocking of the natural outlets, has become trapped inside the cave.

GLYFADA, DIROS - Exploration

The study of the underwater morphology showed four points of intense caving, with the most frequent occurrence of widening in the interval between -15 and -25 m. The erosion of the underwater decoration and the rock is evident throughout the section, with more pronounced characteristics from -6 m. and below. From this depth, a reduction in the decoration was also observed, with stalactites and stalagmites fewer in number and larger in size. Although in general in the cave the caving has stopped and we are in the phase of filling it with chemical, mainly, sediments, it continues at a rapid pace in the underwater section. However, apart from the morphological observations, the study of the paleontological material stood out from the multitude of other studies: during cave diving and research of the underwater section, large vertebrate bones were identified in various parts of the cave, and mainly where there were sandstone sediments. This finding resulted in the development of a separate program and special studies for this particular cave.

First, all the sites with paleontological findings were identified and detailed mapping was carried out, both on land and underwater. The arduous and often dangerous task of photographing and removing the paleontological material from the seabed concluded the first phase of the work. The second phase, in the laboratory, included the preservation of the bones, their photography, their design and their identification. The results were very significant: more than 200 intact bones and 400 bone fragments were collected. The largest percentage belonged to a hippopotamus of the species Ippopotamus amphibius, while for the first time in such a southern geographical point, hyena bones were discovered. Also found were bones from a panther, a lion, a ferret, artiodactyls, small rodents, birds and seal teeth. The dating that was done gave an age of approximately 32,000 years.

ΓΛΥΦΑΔΑ ΔΙΡΟΥ - Οστά Ιπποπόταμου

Very important are also the indications of human presence along with the paleontological findings. The continuation of the study requires the conduct of an underwater paleontological excavation, which is expected to provide much more data in all areas.

GLYFADA OF DIROS

Σπήλαιο «Γλυφάδα» Διρού Λακωνίας

Το σπήλαιο βρίσκεται στο νομό Λακωνίας, στη χερσόνησο της Μάνης και απέχει περίπου 2 χμ. από την κοινότητα Πύργου Διρού.
Το όνομά του οφείλεται στο υφάλμυρο νερό που εκβάλλει στη θάλασσα από τη φυσική του είσοδο. Από την είσοδο αυτή και με σκοπό την ανεύρεση πόσιμου ύδατος, το 1923, οι κάτοικοι της περιοχής ανακάλυψαν τυχαία τις πρώτες αίθουσες του σπηλαίου.
Από το 1949 άρχισαν οι συστηματικές εξερευνήσεις. Το 1961, τα σπήλαιο αξιοποιήθηκε τουριστικά και μέχρι το 1992 είχαν χαρτογραφηθεί 6.200 μ. διαδρόμων με συνολική έκταση 34.100 μ2 . Από το 1987 και συστηματικότερα από τα 1994, η Εφορεία Παλαιοανθρωπολογίας-Σπηλαιολογίας, στα πλαίσια ενός ευρύτερου προγράμματος εξερεύνησης και μελέτης των σπηλαίων της
Μάνης, αρχίζει συστηματικές έρευνες στο σπήλαιο «Γλυφάδα» . Σήμερα το συνολικό μήκος των χαρτογραφημένων διαδρόμων έχει ανέλθει στα 10.606 μ., από τα οποία τα 1833 είναι υποβρύχια (σε αυτά δεν έχει υπολογιστεί το χερσαίο τμήμα που οδηγεί στον «πάνθηρα» ).

GLYFADA OF DIROS - 3D visualization of the cave

The development of the cave is very labyrinthine. The causes of this morphology are mainly due to the creation of the stalagmite decoration. The original form of the cave was much simpler, with the main directions of the faults, SE-NW and E-W. It has been opened up in crystalline limestones and today is partially flooded by water. Both its geographical location and the general prevailing conditions are also the cause of its complex morphology. Thus, in order to study it, the cave was divided into six different sections, based on its morphological variations. As was natural in this case, the greatest scientific interest was presented in the underwater part of the cave, which had remained unexplored, and therefore relatively protected. It is a paleokarst with many stalactites, even at a depth of -71 m. A common feature throughout the surface, not only of the bottom, but also of the walls of the underwater corridors, is the existence of mud, from 1 to 20 cm thick, which, following tourist exploitation and the blocking of the natural outlets, has become trapped inside the cave.

GLYFADA, DIROS - Exploration

The study of the underwater morphology showed four points of intense caving, with the most frequent occurrence of widening in the interval between -15 and -25 m. The erosion of the underwater decoration and the rock is evident throughout the section, with more pronounced characteristics from -6 m. and below. From this depth, a reduction in the decoration was also observed, with stalactites and stalagmites fewer in number and larger in size. Although in general in the cave the caving has stopped and we are in the phase of filling it with chemical, mainly, sediments, it continues at a rapid pace in the underwater section. However, apart from the morphological observations, the study of the paleontological material stood out from the multitude of other studies: during cave diving and research of the underwater section, large vertebrate bones were identified in various parts of the cave, and mainly where there were sandstone sediments. This finding resulted in the development of a separate program and special studies for this particular cave.

First, all the sites with paleontological findings were identified and detailed mapping was carried out, both on land and underwater. The arduous and often dangerous task of photographing and removing the paleontological material from the seabed concluded the first phase of the work. The second phase, in the laboratory, included the preservation of the bones, their photography, their design and their identification. The results were very significant: more than 200 intact bones and 400 bone fragments were collected. The largest percentage belonged to a hippopotamus of the species Ippopotamus amphibius, while for the first time in such a southern geographical point, hyena bones were discovered. Also found were bones from a panther, a lion, a ferret, artiodactyls, small rodents, birds and seal teeth. The dating that was done gave an age of approximately 32,000 years.

ΓΛΥΦΑΔΑ ΔΙΡΟΥ - Οστά Ιπποπόταμου

Very important are also the indications of human presence along with the paleontological findings. The continuation of the study requires the conduct of an underwater paleontological excavation, which is expected to provide much more data in all areas.