A group of Chinese scientists have discovered a new giant sinkhole with a forest at the bottom.
According to the Xinhua news agency, the sinkhole is 630 feet (192 meters) deep and deep enough to easily swallow an arch in St. Louis (USA). A group of cavers descended into this amazing sinkhole on Friday (May 6), discovering that the abyss has three cave entrances, as well as ancient trees 131 feet (40 m) high, stretching their branches to the sunlight, which hardly penetrates through them. , sometimes illuminating the bottom of the formation.
“This is great news,” said George Veni, executive director of the National Cave and Karst Research Institute (NCKRI) in the US and an international cave expert. Weni was not involved in the exploration of the cave, but the organization that was present, the Karst Geology of the China Geological Survey, is an affiliate of the NCKRI.
Place for sinkholes
The discovery is not surprising, Weni told Live Science, because southern China is home to karst topography — the local landscape is able to produce dramatic sinkholes and out-of-this-world caves. According to Venya, karst landscapes are formed mainly as a result of the dissolution of bedrock. The slightly acidic rainwater in this region absorbs carbon dioxide and becomes more acidic as it passes through the soil. Finding different ways and roads for itself, it flows through cracks in the rocks, slowly expanding them into tunnels and voids. Over time, if the chamber of the cave becomes large enough, its vault can gradually collapse, revealing huge sinkholes.
“Due to local differences in geology, climate, and a number of other factors, karst can appear differently on the surface,” he explained. “In China, there is this incredibly impressive karst with huge sinkholes, giant cave entrances and so on. In other parts of the world, you walk around the karst and don’t really notice anything. Funnels can be quite shallow, only a meter or two in diameter. Cave entrances can be very small, such that you just have to squeeze through them.
En fait, 25% des États-Unis sont en fait du karst, ou pseudokarst, dans lequel des grottes ont été formées par des facteurs autres que la dissolution, comme l’activité volcanique ou le vent, dit Veni. Environ 20% de la masse continentale du monde se compose de l’un de ces deux paysages riches en grottes.
La nouvelle découverte a été faite dans la région autonome Zhuang du Guangxi, près du village de Ping’e dans le comté de Leie, rapporte Xinhua. Le Guangxi est connu pour ses fabuleuses formations karstiques, qui vont des gouffres aux piliers de pierre et aux ponts naturels, et ce sont ces bizarreries naturelles qui ont valu à la région un site du patrimoine mondial de l’UNESCO.
Pourquoi les entonnoirs sont importants
L’intérieur du gouffre mesure 1 004 pieds (306 m) de long et 492 pieds (150 m) de large, a déclaré à Xinhua Zhang Yuanhai, ingénieur principal à l’Institut de géologie du karst. Le mot chinois pour ces énormes entonnoirs est “tiankeng”, ou “fosse céleste”, et si vous regardez le corbeau lui-même, alors en effet son fond semble être un autre monde. Chen Lixin, un expert de ces formations, qui a mené une expédition dans la grotte, a déclaré à l’agence de presse Xinhua que l’épais sous-bois au fond de l’entonnoir atteint la hauteur des épaules d’une personne. Selon Venya, les grottes karstiques et les gouffres peuvent souvent devenir une oasis pour la vie.
“Je ne serais pas surpris d’apprendre que des espèces seront trouvées dans ces grottes que la science n’a pas encore rapportées ou décrites”, a déclaré Lixin.
Par exemple, dans une grotte de l’ouest du Texas, a déclaré Veni, les fougères tropicales abondent : les spores de fougères semblent avoir été introduites dans une zone abritée par des chauves-souris migrant vers l’Amérique du Sud et centrale.
Sinks and caves not only provide shelter for life, they are also conduits to aquifers or deep groundwater reservoirs. According to Weni, karst aquifers are the sole or main source of water for 700 million people worldwide. But they are easy to access, which is why they are often either drained or simply polluted.
“Karst aquifers are the only types of aquifers that can be polluted by solid waste,” Veni said. “I have had occasion to pull out car batteries, bodies, barrels and bottles of God knows what with from an active cave stream.”
The new discovery has increased the number of sinkholes in Leie County to 30, Xinhua reports. The same researchers previously found dozens of sinkholes in northwest China’s Shaanxi province and a group of interconnected sinkholes in Guangxi, according to China Daily.