|
The name of the subterranean river Moraig has its origin in
the age of the Moors. The Arabs who came from North Africa occupied the south-eastern
part of the Iberian Peninsula until 1492. The expressions "El Morach"
in contemporary Spanish and "El Moraig" in Catalan derived from "Fuente
del Moro"(source of the Moor). Catalan is still spoken by the older people
who live in the area of the river Moraig, located in the region of Cabo de la
Nao (the eastern promontory on the Mediterranean coast of Southern Spain).
Presumably the entrance to the cave was known by the Phoenicians
as early as 1000 years B.C.. It was them who founded the towns Denia, situated
16 kilometers northwards and Calpe 12 kilometers southwards in a coastal area,
which is in general very poor in drinking water. According to old legends they
drew their water supplies with the aid of earthenware jugs from the shaft of
Moraig's mouth. STRABO (a Greek geographer who lived from 63 B.C. to 20 A.C.)
reported that the Phoenician sailors applied - compared to the knowledge of
today's engineers - sophisticated techniques in order to draw drinking water
from the underwater sources. We may presume that at that time the salinity of
the water at the river mouth was lower than today, because of fluctuations of
the sea level during the last 3000 years. Nowadays the river's proportion of
sea-water is too high to be directly used as drinking water.
In the course of history the place where Moraig flows into
the sea was forgotten, not least because of its nearly inaccessible location
on the foot of a steep coast. However, numerous legends exist on the underground
course of the river and its hidden shaft at the mouth. In the villages you often
hear the explanation Moraig rises from a lake in the cave somewhere under the
mountains of Costa Blanca, or from an underground waterfall which never dries
up. Farmers from Benitachell say it runs through a flooded Phoenician harbour
...
As late as in 1950, the population started searching systematically
for the course of the river. In the same year the agricultural structure of
many fields was fundamentally changed (this affected an area near the Moraig
river of approximately 4000 hectares/15 square miles): Instead of growing wine,
olive and almond trees the farmers started planting orange and lemon trees which
need much more water. However, the few existing fountains and wells were not
sufficient to cover the increased irrigation. Fishermen frequently told about
a current coming out of the steep coast and drifting their boats out on the
sea. Gradually the farmers became aware of the huge amounts of freshwater flowing
beneath the land into the sea and which are for ever lost for the population.
In 1956, the villages Benitachell, Teulada, Javea, and Gata de Gorgos joined
together in order to finance a test drill hoping to meet the subterranean river.
Savador Conzales de Haro, a deviner, was asked to find an appropriate place
for the drilling. He chose a spot on the western side of Montaña Llorensa
at an altitude of 200 meters, from the technical point of view a very disadvantageous
place. Nevertheless they drilled a 75 meters deep shaft and discovered a cavity
filled with air. In order to prove there is a connection between the river Moraig
and the shaft, a red liquid was poured in. According to the daily newspaper
'Información' the whole village of Benitachell came to the steep coast
to watch the red colour that flowed out of the river's mouth into the sea. This
is said to have been the most important day in the history of the village. After
that, the farmers and their helpers, 700 people altogether, digged, with the
aid of picks and shovels, a larger shaft which gradually became 110 meters deep.
This means that there were still 90 meters missing to the ground-water level.
The works had to be stopped for lack of government support.
In 1967, speleologists from Alicante took interest in this
unsuccessful adventure. They explored the entrance to the cave, and drew up
its topography. This enabled them to confirm to the mayor of Benitachell the
existence of huge amounts of water (1.500 to 10.000 liters per second, depending
on the season) flowing out of Moraig. At the same time, the speleologists Eloy
Parra and Jaime Carbonell realized that the high salinity makes the drawing
of drinking water directly from the river's mouth impossible. They hypothesised
there would be pure drinking water deeper in the cave-system.
In 1974, Eloy Parra for the first time dared to dive into the
depths of the cave, and this with very simple equipment. According to his memoirs,
after the first few meters under water, he only saw a tunnel which dropped vertically.
As late as 1978, he managed to venture as far as 200 meters. He brought back
survey-drawings and water samples. Since the analyses showed a too high proportion
of salt, even at a distance of 200 meters to the exit of the cave, he stopped
his investigations.
In 1982, the speleologists Juan José Palmero and Vicente
Alegre attempted to continue Parra's works. On July 11th, 1982, they crossed
the 200 meters frontier reached by Parra, and went as far as 260 meters. With
more sophisticated equipment, they started another attempt on July 18th, which
they did not survive. After having waited an agreed time, one of the security
divers, who was waiting at the exit, followed the guide line into the interior
of the cave. He found Palmero at 160 meters from the exit entangled in the rope
without his bearings and his compressed air bottles being empty. Alegre's body
was found and recovered at a distance of 470 meters on July 20th, thanks to
the cooperation of 9 rescue teams. The exact cause of their death remained unknown.
In October of the same year, the speleologists of the 'Grupo
Standard de Madrid' started an expedition in order to enter even further into
the cave-system and to find freshwater. All attempts had to be stopped at a
distance of 550 meters from the exit, for defiles and the increasing depth of
the water making any advancing impossible.
In 1985 and 1986, because of heavy rains, the river's current
was too strong to enter the cave.
In 1987, the speleologists Mateo Gonzales and José Cortes
of the 'Grupo Espeleologico Alicante' suggested to several governmental authorities
a research project for Moraig: A topography should be drawn up of the subterranean
course of the river and its geological origin should be analysed. However, the
project could not be realized for lack of governmental aid.
The Course of the Moraig Project:
At the end of 1987, I ventured for the first time into Moraig following the
former guide-line of Eloy Parra. I was absolutely fascinated by the huge dimensions
of this cave, but also aware of the great dangers. For serious investigations,
I soon realized the necessity of appropriate cave diving equipment and experience.
A long time of preparations was lying ahead ...On the other hand, the importance
of Moraig's exploration was obvious: The course of the subterranean river is
situated near to the most arid region of the Mediterranean Europe. Owing to
annual precipitations of less than 200 millimeters in places, the farmers have
not enough water for their terrains and even the well's drinking-water supply
is not sufficient for the population. The river Moraig could prove to be the
solution to this great problem that has existed for generations.
In 1988, I was preparing adequate cave diving equipment that
had to be adjusted to the difficult conditions inside the cave. With the help
of the Norwegian design engineer Louis Nielson and the German technician Gunther
Kopp, an underwater vehicle was constructed taking up months of labour in the
workshop. This vessel enabled us to reach greater depths in Moraig, and transport
extensive parts of the equipment such as illumination-systems, supplementary
air tanks and cameras for documentation purposes. All material was meticulously
tested in swamps and water filled caverns in Germany. Deep tests were made in
the fjords of Norway.
Jochen Hasenmayer, a worldwide known cave diving pioneer, gave
final advice to our project. For safety reasons, he emphatically recommended
to go on cave dives alone, even if this is not usual for open-water diving.
In extrem dangerous situations, the diver can only take responsibility for his
own life. Trying to save his companion in the risky circumstances of the cave
will endanger himself inevitably.
In the beginning of 1989 we received all necessary permits
from the various Spanish ministries affected by our forthcoming project. After
final tests of the vessel in the open sea, the first dives were made in collaboration
with local speleologists. The transportation of expedition material from our
base camp to the harbour and from there on a dinghy along the coast to the cave-entrance
cost almost 6 hours of time respectively. Then, inside the cave, we prepared
a deposit of air tanks at a water depth of -9 meters. They contained 10.000
liters of compressed air as security for my return in case of decompression.
During the dive I carried 4 back-mounted tanks with an air supply of 6800 liters
calculated for an average diving time of up to 4 hours.
The expedition aim consisted in the drawing up of a detailed
topographical map. This one should enable a precise drilling to a localized
freshwater occurrence inside the cave system. In the longest dives, I could
reach an extended labyrinth lying beyond the 650 meter point. After months of
intensive cooperation of meanwhile 15 team members, we have not yet achieved
any positive result. All of the water samples, taken up from different distances,
still showed a too high content of salty sea-water. At the end of march 1989
we had to break off the expedition, because of unexpected storms. Furthermore
the dinghy was destroyed and an essential part of our equipment was stolen.
Before recommencing the project in July 1989, we took occasion
to repair and improve our equipment in Germany. In Spain again, I tried to continue
the exploration in Moraig. But I didn't manage to find the main passageway of
the river, because of the complexity of the labyrinth with its numerous crater-like
holes. Although the recent water samples again didn't contain any freshwater,
we could observe that the salinity in all of them is not varying at all. (The
water's conductivity amounts to approximately 17.900 µS/centimeter at
all examined places in Moraig.) This means that the sea is definitively not
intruding by the entrance, but somewhere beyond the up to now explored sector
of the cave system. Quite by chance, I discovered an example to this assumption
at the end of an unusual sediment funnel: A source of saltwater. At this point
the sea, due to the higher density of its salt containing water, flows into
the river. In order to explain the formation of the river's percentage of 10
g/liter, the existence of several other such sources has to be suspected. Thus,
the occurrence of drinking water in the Moraig-system can only be found at greater
distances... In September 1989, the project was interrupted because of the annual
autumn storms.
Continuing in October, I could detect the river's main course
diving at 710 meters into the hugest crater-like hole of the labyrinth. This
vertical shaft drops to a depth of -40 meters leading to a passageway that descends
gradually to further depths of -50 meters and finally to -62 meters. There,
the increased water pressure means the coming on of nitrogen narcosis which
affects the concentration on the dive and the complicated steering of the underwater
vehicle. To elevate the security, a second stage of air tanks was prepared at
700 meters. Furthermore two additional tanks were connected to the vessel extending
the autonomy of the diver considerably. Till the end of the year, 1085 meters
were reached, but the analyses of the water samples remained negative.
As a small aside-result, a crustacean was discovered in one
of the passageways, propably belonging to an undescribed species. We are still
working on its zoological classification.
A change of mood in the expedition-crew came unfortunately
with the unexpected death of our team member Mateo Gonzales in a cave diving
accident. A long period rethinking the diving mission and research activities
followed this mishap ...
In January 1990, our project went through another setback:
In the base camp the stored equipment was flooded and damaged by infiltrating
rainfalls.
Early in May, provided with new material, we set the wheels
of our investigation turning once more. Equiped with an extended air supply
of 16.000 liters and a dry-suit with better isolation qualities, I was able
to shift the borderline of exploration deeper into the cave. The prolonged diving
times of 7 to 8 hours required on account of a higher nitrogen absorption, additional
attention to the decompression. At the entrance, we completed the air tank deposit
up to 18.400 liters for safety reasons. After nearly 100 dives, 1160 meters
were reached and the total length of the explored passages in Moraig covered
2075 meters. Nevertheless, all of the water samples still resulted in a too
high proportion of saltwater. It was soon obvious to me, that deeper dives were
not reasonable anymore. We found ourselves at the limit of our technical possibilities.
The Moraig project seemed to come to an early end.
But there was still one phenomenon I couldn't understand: How
was it possible for the Phoenicians to draw drinking water out of Moraig's mouth
at that time? In the library of my home-university, I met with a solution to
this mystery looking at a diagram of the U.S. geologist Rhodes W. Fairbridge.
According to him, in 1000 B.C., just in the time when the Phoenicians landed
in Southern Spain, the world sea levels were about 3 meters lower than today.
Perhaps this may explain the former drinkability of Moraig's water. Perhaps
this also could lead to a solution of our main problem: We have to recreate
artifically the hydrostatic situation that existed once in Phoenician times
by means of a construction of a wall in front of Moraig's mouth. The river-water
could then rise behind this wall to a certain height where it forms a counterpoise
against the sea-water which is heavier due to its salt content. Thus, the wall
will effect a higher water pressure inside the cave system and consequently
stop the intrusion of the sea through the saltwater sources.
So far a theoretical solution. But which altitude the wall
must have? For its calculation we have to count with sources of saltwater appearing
at depths of down to -100 meters beneath today's sea level. They date from the
most recent Ice Ages functioning as off-leading channels for the river down
to ancient sea levels that were situated about 100 meters lower than nowadays.
(During the Ice Ages, voluminous amounts of the water in the world's oceans
were frozen into solid glacial ice at the Poles.)
The necessary altitude of the planed wall is directly dependent
on the deepest possible intrusion point of the sea into the Moraig system, that
means at approximately -100 meters. There, the pressure of the river-water must
be equalized to that of the denser sea-water by raising the river's surface
up to the height of 2,75 meters above the sea. This is calculable as follows:
The pressure represents the product of the water's density and altitude. A 102,75
meters high column of freshwater (possessing a density of 1,0005 g/cubic centimeter)
develops the same pressure as a 100 meters high column of saltwater (density
of 1,028 g/cubic centimeter). Consequently the construction of an at least 2,75
meters high wall at Moraig's mouth will be necessary to dry up our deepest presumed
saltwater sources.
In the course of 1991 - 92 the governmental authorities of
the district of Alicante gave all necessary permits for the planed construction
at the coast. In order to conserve the original aspect of the coastal landscape,
the dam is scheduled for the inside of the cave's entrance-hall. The building-plans
have been already calculated by engineers of the university of Alicante and
Valencia, the construction itself is proposed to be realized by local architects
in the coming years.
Bernhard Pack, March 5th, 1992
Bitte beachtet das Copyright:
© Bernhard Pack, Weiterverwendung nicht gestattet!
*Contenido extraido de la Web http://www.weber-joerg.de/moraig.htm
|
página inicio
mapa web
contactar
añadir a favoritos
recomiéndanos
