A group of Chinese scientists discovered a giant sinkhole or hole. What's interesting, unlike other sinkholes, this one has a forest at the bottom.
Quoted from Xinhua, the hole has a depth of 192 meters. A team of speleologists and spelunkers slid into this hole on Friday (6/5), and found that there are three entrances to the cave, as well as ancient trees as high as 40 m stretching their branches towards the sun.
"This is a cool find," said George Veni, executive director of the National Cave and Karst Research Institute (NCKRI) in the US, and an international cave expert. Veni was not involved in exploring this cave, but the organization, which was formerly the Institute of Karst Geology of the China Geological Survey, is a sister institution to NCKRI.
"This finding is not surprising, as southern China is home to karst topography, a landscape prone to dramatic sinkhole formations and caves that harbor 'other worlds'," said Veni.
Karst landforms are formed mainly by the dissolution of bedrock. Slightly acidic rainwater, taking up carbon dioxide as it flows through the soil, becomes more acidic. Then, the water drips, rushes and flows through the cracks in the bedrock.
Slowly, the pool of water widens it into tunnels and cavities. Over time, if the cavernous space becomes large enough, the ceiling may gradually collapse and open a large hole.
"Due to local differences in geology, climate and other factors, the way karst appears on the surface can be very different," he said.
"So, in China we can find visually spectacular karst with very large sinkholes and giant cave entrances and so on," he continued.
The new discovery took place in the Guangxi Zhuang Autonomous Region, near the village of Ping'e in the Leye county. Guangxi is famous for its stunning karst formations, which range from sinkholes to stone pillars to natural bridges and has earned the region a UNESCO world heritage site designation.
The inside of the drain hole is 306 m long and 150 m wide. Chen Lixin, who led the cave expedition team, said the thicket grew thickly at the bottom of the hole to the height of an average adult's shoulder.
"I would not be surprised to learn that there are species found in these caves that have not been reported or described by science until now," Lixin said.
Sinkholes and caves not only offer protection for life, they are also conduits to aquifers, or deep underground stores of water.
Karst aquifers provide the only major source of water for 700 million people worldwide. However, karst aquifers are easily accessible and drained or polluted. Therefore, the discovery of a giant hole with a forest in it is very important for scientific research.
