Vietnam Hosts Largest Cave

This cave is huge and it sets a record that may even stand up. 

We are presently living through a golden age for cave discovery.  There are plenty of participants and almostall prospective country is open for cavers. They are thus been discovered.  The only thing needed to finish the job is remotesensing technology able to pick up deep hidden caves without access.

I find the cavern size amazing in terms of unsupported spans that haveheld up.  A simple fracture will quicklypropagate to bring down a roof.  It doesnot take any sort of a tremor to get one going.

World's Biggest Cave Found in Vietnam

A British caver wades through Vietnam's Son Doong cave, Earth'slargest known cave passage, according to a survey team.

Photograph by Barcroft/FamePictures

James Owen

for National Geographic News

Updated January 3, 2011 (Published July 24,2009)

http://news.nationalgeographic.com/news/2009/07/090724-biggest-cave-vietnam/

A massive cave recently uncovered in a remote Vietnamese jungle is the largest singlecave passage yet found, a new survey shows.

At 262-by-262 feet (80-by-80 meters) in mostplaces, the Son Doong cave beats out the previous world-record holder, Deer Cave inthe Malaysian section of the island of Borneo.

Deer Cave is no less than 300-by-300 feet (91-by-91meters), but it's only about a mile (1.6 kilometers) long.

By contrast, explorers walked 2.8 miles (4.5kilometers) into Son Doong, in Phong Nha-Ke Bang National Park, beforebeing blocked by seasonal floodwaters—and they think that the passage is evenlonger.

In addition, for a couple of miles Son Doongreaches more than 460-by-460 feet (140-by-140 meters), said Adam Spillane, amember of the British Cave Research Associationexpedition that explored the massive cavern.

Spillane was in the first of two groups toenter the cave. His team followed the passage as far as a 46-foot-high(14-meter-high) wall.

"The second team that went in got floodedout," he said. "We're going back next year to climb that wall andexplore the cave further."

Laser Precision

A local farmer, who had found the entrance tothe Son Doong cave several years ago, led the joint British-Vietnameseexpedition team to the cavern in April.

The team found an underground river runningthrough the first 1.6 miles (2.5 kilometers) of the limestone cavern, as wellas giant stalagmites more than 230 feet (70 meters) high.

The explorers surveyed Son Doong's size usinglaser-based measuring devices.

Such modern technology allows caves to bemeasured to the nearest millimeter, said Andy Eavis, president of theInternational Union of Speleology, the world caving authority, based in France.

"With these laser-measuring devices, thecave sizes are dead accurate," he said. "It tends to make the cavessmaller, because years ago we were estimating, and we tended tooverestimate."

Eavis, who wasn't involved in the survey,agreed that the new findings confirm Son Doong's record status—despite the factthat he had discovered Borneo's now demoted Deer Cave.

"This one in Vietnam is bigger," Eavisconceded.

However the British caver can still claim thediscovery of the world's largest cave chamber, Sarawak Chamber, also in Borneo.

"That is so large it may not actually bebeaten," he said. "It's three times the size of Wembley Stadium"in London.

Noisy and Intimidating

Son Doong had somehow escaped detection duringprevious British caving expeditions to the region, which is rich in limestonegrottos.

"The terrain in that area of Vietnam is verydifficult," said expedition team member Spillane.

"The cave is very far out of the way.It's totally covered in jungle, and you can't see anything on GoogleEarth," he added, referring to the free 3-D globe software.

"You've got to be very close to the caveto find it," Spillane said. "Certainly, on previous expeditions,people have passed within a few hundred meters of the entrance without findingit."

The team was told that local people had knownof the cave but were too scared to delve inside.

"It has a very loud draft and you canhear the river from the cave entrance, so it is very noisy andintimidating," Spillane said.

Bigger Caves Waiting?

Of more concern to the caving team were thepoisonous centipedes that live in Son Doong.

The explorers also spotted monkeys enteringthrough the roof of the cave to feed on snails, according to Spillane.

"There are a couple of skylights about300 meters [985 feet] above," he said. "The monkeys are obviouslyable to climb in and out."

A biologist will accompany the team on itsreturn visit next year to survey the cave's subterranean wildlife.

Eavis, of the International Union ofSpeleology, added that there are almost certainly bigger cave passages awaitingdiscovery around the world.

"That's the fantastic thing aboutcaving," he said.

Satellite images hint, for example, that caveseven larger than Son Doong lie deep in the Amazon rain forest, he said.