World's biggest cave found in Vietnam
Son Doong cave beats out the previous world-record
holder, Deer Cave
*********------
The explorers surveyed Son Doong's
size using laser-based measuring devices.
******------
A massive cave recently uncovered in a remote Vietnamese jungle is
the largest single cave passage yet found, a new survey shows. At
262-by-262 feet (80-by-80 meters) in most places, the Son Doong cave
beats out the previous world-record holder, Deer Cave in the Malaysian
section of the island of Borneo.
A British caver wades through an underground river in Vietnam’s
Son Doong cave, the largest single cave passage yet found, a
survey team reported in July 2009. |
Deer Cave is no less than 300-by-300 feet (91-by-91 meters), but it's
only about a mile (1.6 kilometers) long.
By contrast, explorers walked 2.8 miles (4.5 kilometers) into Son
Doong, in Phong Nha-Ke Bang National Park, before being blocked by
seasonal floodwaters, and they think that the passage is even longer.
In addition, for a couple of miles Son Doong reaches more than
460-by-460 feet (140-by-140 meters), said Adam Spillane, a member of the
British Cave Research Association expedition that explored the massive
cavern.
Spillane was in the first of two groups to enter 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 flooded out," he said.
"We're going back next year to climb that wall and explore the cave
further."
Laser precision
A local farmer, who had found the entrance to the Son Doong cave
several years ago, led the joint British-Vietnamese expedition team to
the cavern in April. The team found an underground river running through
the first 1.6 miles (2.5 kilometers) of the limestone cavern, as well as
giant stalagmites more than 230 feet (70 meters) high.
The explorers surveyed Son Doong's size using laser-based measuring
devices. Such modern technology allows caves to be measured to the
nearest millimeter, said Andy Eavis, president of the International
Union of Speleology, the world caving authority, based in France.
First explored in April, the cave has since been measured using high-tech
lasers that give “dead accurate” sizes, according to an expert
with the International Union of Speleology. Photograph from BARM/Fame
Pictures |
"With these laser-measuring devices, the cave sizes are dead
accurate," he said. "It tends to make the caves smaller, because years
ago we were estimating, and we tended to over estimate.
"Eavis, who wasn't involved in the survey, agreed that the new
findings confirm Son Doong's record status, despite the fact that he had
discovered Borneo's now demoted Deer Cave.
"This one in Vietnam is bigger," Eavis conceded. However the British
caver can still claim the discovery of the world's largest cave chamber,
Sarawak Chamber, also in Borneo. "That is so large it may not actually
be beaten," he said. "It's three times the size of Wembley Stadium" in
London.
Noisy and intimidating
Son Doong had somehow escaped detection during previous British
caving expeditions to the region, which is rich in limestone grottos.
"The terrain in that area of Vietnam is very difficult," 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 Google Earth," he added, referring to the
free 3-D globe software. "You've got to be very close to the cave to
find it," Spillane said. "Certainly, on previous expeditions, people
have passed within a few hundred meters of the entrance without finding
it."
The team was told that local people had known of the cave but were
too scared to delve inside.
"It has a very loud draft and you can hear the river from the cave
entrance, so it is very noisy and intimidating," Spillane said.
Bigger caves waiting?
Of more concern to the caving team were the poisonous centipedes that
live in Son Doong.
The explorers also spotted monkeys entering through the roof of the
cave to feed on snails, according to Spillane. "There are a couple of
skylights about 300 meters [985 feet] above," he said. "The monkeys are
obviously able to climb in and out."
A biologist will accompany the team on its return visit next year to
survey the cave's subterranean wildlife. Eavis, of the International
Union of Speleology, added that there are almost certainly bigger cave
passages awaiting discovery around the world.
"That's the fantastic thing about caving," he said. Satellite images
hint, for example, that caves even larger than Son Doong lie deep in the
Amazon rain forest, he said. |