MEXICO CITY (Reuters) - A group of divers has connected two underwater caverns in eastern Mexico to reveal what is believed to be the biggest flooded cave on the planet, a discovery that could help shed new light on the ancient Maya civilization.

The Gran Acuifero Maya (GAM), a project dedicated to the study and preservation of the subterranean waters of the Yucatan peninsula, said the 347-km (216-mile) cave was identified after months of exploring a maze of underwater channels.

Near the beach resort of Tulum, the group found that the cave system known as Sac Actun, once measured at 263 km, communicated with the 83-km Dos Ojos system, the GAM said in a statement. For that reason, Sac Actun now absorbs Dos Ojos.

Click here for a short movie about the cave.

6b. Israel

cave. A hollow extending beneath the surface of the earth. Caves have been used throughout human history for habitation (Gen. 19:30), refuge (Josh. 10:16), and burial (Jn. 11:38), and many legends and superstitions are attached to them. Some caves have been cut by wave action (sea caves), others scoured by wind action, particularly in desert regions (eolian caves), and still others result from glacial melt-water (glacial caves).

The largest and most common types of caves, both worldwide and in the Holy Land in particular, are solution caves that result from the action of underground water. Most of these caves are in limestone because no other rock equally abundant at the earth’s surface is so readily dissolved (see LIME). Calcite (calcium carbonate), which is the chief constituent of limestone, including the Judean limestone that crops out over large areas of Israel and Jordan, is dissolved by ground water containing carbon dioxide. Some of this carbon dioxide is taken up by rain water falling through the air, but much comes from the air in soil containing decaying humus, which holds 300 times more carbon dioxide than the air of the atmosphere. As dissolved carbon dioxide reacts with water to form carbonic acid, water passing through soil rich in humus may become strongly acidic. It is by the action of this water that most caves in limestone have been formed. Particularly in dense, jointed limestone, water is concentrated along restricted planes rather than being disseminated throughout the rock. In this way much solution takes place along joints and bedding planes by the reaction of the carbonic acid in the ground water with the calcium carbonate to give a solution of calcium bicarbonate.

Caves are formed just below the water table in regions where the water table remained stable for a long time. They have a characteristic pattern of passages that are usually horizontal, even where the limestone beds are steeply inclined, except in regions where the originally horizontal attitude of the cavern network has been tilted during later mountain building deformation. The development of most caves just below the water table—in rocks saturated with water rather than at random depths within the water-saturated part of the earth’s crust—is probably the result of a nonlinear relation between calcium carbonate solution and the partial pressure of carbon dioxide. The result is that the mixing of water percolating down from the surface with slowly moving ground water below the water table constantly produces an undersatu-rated solution capable of dissolving more calcium carbonate.

Most caverns are composed essentially of horizontal and some vertical passageways. Passage width and height varies from upwards of 30 meters to the smallest penetrable dimensions. Where not modified by collapse, the cave cross-sections are tubular or rectangular in shape, but others are irregular in cross-section. The pattern of their ground plan varies. A grid of intersecting passageways is referred to as a network cave: a dentritic branching pattern of increasingly smaller passages make up a branching cave and one tube, with numerous twists and turns is an angulate cave. The vertical passageways are the active recharge points of ground water into the limestone. Often these are roughly cylindrical vertical shafts with smooth walls and heights of 100 meters or more.

Collapse of the roof of a cavern or the downward solution of limestone or other soluble materials (e. g., dolomite [calcium magnesium carbonate] or gypsum [hydrated calcium sulphate]), results in the development of depressions at the surface commonly referred to as sinkholes. Typically they are circular and 11–20 meters deep and often of the order of 100 meters in diameter. Coalescence of sinkholes is common, particularly the coalescence of a linear series. In this way access from the surface to some caverns is provided.

Lowering of the water table makes the caverns accessible, and in many the process of deposition of calcite dominates over solution. As water drips from the cavern ceilings, it evaporates, loses carbon dioxide, and calcium carbonate (calcite) is precipitated. Progressively icicle-like forms, known as stalactites, develop hanging down from the ceiling. Calcite precipitated when water drips to the floor is built up as stalagmites. Continued precipitation of calcite may result in the meeting of stalactites and stalagmites to form columns.

The abundance of limestone cropping out in Israel and Jordan—the Judean limestone made up mainly of massive hard beds of limestone and dolomite with some softer chalky marls, shales, and gypsiferous strata—and the semiarid climate, resulted in an abundance of caves throughout the region. With the successive downward movement of the JORDAN Rift Valley, the base level of the streams draining into this tectonic depression has been lowered, as has the water table (see EARTHQUAKES; PALESTINE IV). The resultant cutting down of valleys exposed caves on valley sides, such as the cave of ADULLAM in which DAVID took refuge (1 Sam. 22:1), and insured that the caves were relatively dry so that they could be used for habitation (Gen. 19:30) or for burial (23:19).

The branching pattern of some caves made them suitable for places of BURIAL, particularly if the entrance was small and could easily be sealed (Jn. 11:31–39). The network pattern of many cave systems together with the columns and stalagmites make them ideal places of refuge (1 Sam. 13:6), even for large numbers (22:2) and for surprise (1 Sam. 24), with small entrances easy to hide or defend and other exits available for escape (see DEAD SEA SCROLLS). The figurative use of caves and caverns as places of refuge is given in Isa. 2:11–21; Rev. 6:15. (See further R. W. Fairbridge, ed., The Encyclopedia of Geomorphology [1968], 652–53, 1031–39; D. J. Easterbrook, Principles of Geomorphology [1969], 251–65; C. Bonsall and C. Tolan-Smith, eds., The Human Use of Caves [1997]; M. E. Taylor, Exploring Hidden Realms [2001]; A. S. Goudie, ed., Encyclopedia of Geomorphology [2004]; J. Gunn, ed., Encyclopedia of Caves and Karst Science [2004].) D. R. BOWES
The Zondervan Encyclopedia Of The Bible - Entry: caves

6c. Saraswati river in India

Satellite images, supported by a four-year drilling exercise, which was guided by ancient literature, have established that the river saraswati is not a myth. It was a huge river that died a premature death about 5,000 years ago, and is now buried 60 metres [approximately 197 feet] below the ground. A map of all the channels discovered so far leads one to conclude that it was probably 1,500 km [approximately 932 miles] long, three to fifteen kms [approximately 1.9 to 9.3 miles] wide, and about five meters [approximately 16.4 feet] deep. The river probably crisscrossed the present-day states of  Himachal Pradesh, Haryana, Punjab and Rajasthan. S C Sharma, regional director, cgwb [Central Ground Water Board], says it continues to flow to the sea at a rate of 20 meters [65.6 feet] a year.

The prospect of rediscovering the Saraswati was triggered off by digital photographs sent by the American satellite Landsat. To the surprise of many scientists, the photographs showed the presence of underground water in a definitive pattern in the Jaisalmer area. It was during this time that scientists started speaking of a large palaeo[ancient]-channel in Rajasthan that could well belong to a big river.

REMOTE SENSING IMAGES of the isro [Indian Space Research Organization] and the Geological Survey of India (gsi) also found the existence of palaeo-channels of a mighty river in seven to eight places, all lying on the west of the Aravalli ranges. The images pointed to the possibility that the river started at the foothills of the Aravallis and shifted westward in stages. The river seems to enter Rajasthan in Ganganagar district, with its tail ends in Bikaner and Jaisalmer districts, a few kilometres from the Rann of Kutchh.

Further, a geopysical survey undertaken by the rgwd [Rajasthan Groundwater Department] in the Tanot and Longewala areas indicated the existence of course sediments in the depth range of 30 [approximately 98.4 feet] to 60 [approximately 196.9 feet] meters pointing to the possibility of the existence of a river in the region. …S. Kalyan Raman, member of the new project committee, is clear that he is working on the Saraswati. “The Harappan civilization existed on the banks of the Saraswati. Nearly 2,000 of the 2,600 Harappan sites that have been discovered are situated on the old palaeo-channels of Saraswati.” K K Srivastava, divisional chief of rgwd’s research, design and development division, puts it differently, “It is a cooperative exercise involving both history and science.” The first evidence of the ancient underground channels came in the 1930s, when scientists Haren and B C Gupta from the gsi spoke of the channels. They claimed that they might belong to the river Saraswati.

Bimal Ghose, former scientist at Central Arid Zone Research Institute (cazri), Jodpur, also made a reading based on the topography map of Rajasthan. He confirmed that The ancient channels were a dead river that could well be the saraswati. It may be mentioned here that ancient literature and texts and the geographical history of the region were constant bases of reference in these studies.

The Rigveda, for example, mentions a mighty river that originates in the Himalaya and flows south-westwards. The Mahabharata speaks of a river that disappeared underground near the present-day town of Sirsa in Haryana. Besides, the geographical history of the now arid western rajasthan points to the fact that the region used to be green and did not lack water resources. Barely 10,000 years ago, the whole region was host to a big river system, which attracted civilizations like the Mohenjodaro and Harappa.

Archaeological findings also indicate that a major river originating primarily from the same source as the present Sutlej flowed through northern Rajasthan, Bahawalpur and Sindh. The course of the river was southeast of the Sutlej’s present course. Some scholars working on ancient literature also suggest that the Saraswati flowed along the present course of Luni river in Rajasthan, and shifted westwards progressively. Baldeo Sahai, one of the members of the new research project says, “Latest research indicates that the Saraswati was a perennial [continuously-flowing] river connected to the Bander Poonch glacier in the Himalayas.”

rgwd scientists say that the desertification of western Rajasthan started only 5,000-6,000 years ago. After the Ice Age, it is believed that the area had some massive glaciers, which flushed it with fresh water for thousands of years. Due to marine tectonic activity, the area from the Rann of Kutchh to Bikaner was submerged by seawater. This was the beginning of the desertification process.

The tectonic activity is also said to be the reason behind saraswati’s delinking from its source of water. Consequently, it is believed, the river dried up and was buried under desertification sands and alluvium.

In the early 1980s, rgwd scientists were amazed by the fact that fresh water was available in many places of the Jaisaimer district, and some wells never dried up. This aroused considerable interest, for Jaisaimer’s water is known to be saline. Investigations revealed that about 100 meters [approximately 328 feet] away from the site of the fresh water, the groundwater was saline. Some of the cgwb’s observation stations for monitoring groundwater have fresh water in the depth range of 30-40 meters [approximately 98.5-131 feet]. “These are located in a linear pattern in the northeast-southeast direction, and never go dry”, says S C Sharma, “During drilling operations, alluvial sediments were found at a depth of 78-100 meters [approximately 256-328 feet], pointing to the existence of a flow channel. It also points towards the existence of a fresh water source along the inferred palaeo-channel”, says K K Srivastava.

Extensive surveys showed that there was a big water channel 60-70 meters [approximately 197-300 feet] underground, and the water was moving very slowly towards the sea. Drilling work to trace these channels were started in Jaisaimer. The second stage of the operations is in the Bikaner-Kolait region, upward of Jaisaimer. There are palaeo-channels in all 10 districts of western Rajasthan, and these have been mapped to prepare the river’s ancient course.

The course of the river is yet to be traced completely, though. Besides, it is believed that, like any other major river, the Saraswati also changed its course frequently. This would explain the very large number of channels buried underground.

Once the fact that the channels do exist was established, rgwd commissioned the Physical Research Laboratory, Ahmedabad and barc [Bhabha Atomic Research Centre], Bombay to determine the age of the water and soil. A team of scientists led by S M Rao of barc’s isotope division studied the samples collected from different depths. barc’s dating suggests that the samples are as old as 20,000- 40,000 years. The youngest samples date back to 2,500 years. These findings place the samples in the ‘marine transgression’ age, when the desertification of Rajasthan started. The groundwater today contains more tritium, a radioactive material, due to atmospheric nuclear tests conducted in the 1960s and 1970s by the us and the erstwhile ussr.

rgwd, in a proposal to the rgnmdw [Rajiv Gandhi National Mission for Drinking Water], outlined the utility of the project. This report suggests that once the channels are demarcated, and their course traced, they could contribute substantially towards solving the water crisis in arid western Rajasthan. “Transporting water through palaeo-channels would reduce the cost of water transportation drastically, because we do not need to build a canal. It would also reduce wastage due to evaporation”, says S C Sharma. The channels could also double up as storage facility for surplus monsoon water.

Officials say that the defense ministry has also shown interest in the project, as it could mean adequate water supply to its soldiers stationed on the India-Pakistan border. Whether the large amounts of data available with the army is utilized or not, the findings of the two projects on Saraswati are worth waiting for.

6d. New Train Points to Underground River in Jerusalem

Posted on June 13, 2011 by Arieh O'Sullivan - The Media Line in Cities, Transportation underground river

Jerusalem will get a new railway line, and in the process, geologists find large underground river.

Excavators digging for a new railway station deep under the surface of central Jerusalem have discovered what geologists say is the largest underground river ever found in Israel. And while its deep canyons and waterfalls may be an impressive find for scientists, it doesn’t contain a significant amount of the precious fluids to affect the water balance in this traditionally parched city.

“We found a nice but small underground river,” Professor Amos Frumkin, head of the Cave Research Unit of the Hebrew University’s Department of Geography, told The Media Line.

“In terms of Israel, it’s the longest underground stream that we have ever seen. It is a kind of a canyon that has been cut by the stream of the water over a long period of time, maybe millions of years,” Frumkin said.

Frumkin and his team were called upon by Israel Railways after its engineers chanced upon the cave while excavating an 80-meter (260-foot) shaft close to the city’s main convention centre and central bus station that is being drilled for a huge, underground station that will serve the high-speed Jerusalem-Tel Aviv railway.

“When they reached the depth of 75 meters they cut into this cave accidentally. The water started flowing into this shaft and they had some problems until they found some engineering solution and called us,” Frumkin said.

“We were the first humans ever to set foot inside this cave. However, it wasn’t very easy. It meant crawling in mud and some rappelling on ropes was required. So you needed some spelunking techniques,” he said. “It was beautiful. One canyon was over 200 meters long and we never reached its end. We found some waterfalls inside, which was nice for our arid country.”

Jerusalem is not known for its water sources and there is only one major spring in the city, the biblical Gihon, which has been gurgling since before King David’s time. With a population of some 700,000, Jerusalem gets its water pumped up from the coastal aquifer.

Frumkin said the cave appears to have developed after water seeped in from the surface and dissolved the underlying limestone. While other major caves have been discovered in Israel, this was the only one with running water.

“This is the longest one with an active stream flowing through it. All the other stalactite caves in Israel are without any stream of water today. They are just dripping water from the ceiling and the stream that formed the cave have long vanished because of geological and hydrological changes in the mountains,” he said.

“This one is still active in terms that the stream which was forming the cave is still active and this is not very common in Israel. It is much more common in other countries that are wetter like Europe and America and tropical countries,” Frumkin said.

Frumkin said the cave was at some points a few dozen meters high and speculated that the water originated from the surface and it was likely rainwater and possibly leakage from pipes and even sewage. Unlike a cave discovered a few years ago in central Israel that contained previously unknown crustaceans, the Jerusalem cavern has been found to host some microbes but no other major forms of life in this cave.

“The study of the cave can help us understand the precise mechanism by which water flows through the aquifer in the Jerusalem area,” he added.

He said that efforts were underway to reseal the cave entrance so that the water channel could be preserved without compromising the railway project.

“The train station will be built, but I believe that we can also preserve the cave by building some doorway to seal the cave but to allow the entry to anyone who needs to get into it for one reason or another. So the cave won’t be lost,” he said.