Approaching the dog days, the heat wave is scorching. The Wuling Xiakou Ecological Tourism Zone in Yuan'an County, Hubei Province has recently launched the "Cave Four Seasons Ski Resort" project, which is very popular.
The site of the "Cave Four Seasons Ski Resort" in the Wuling Gorge Mouth Ecological Tourism Zone
Can you ski in the hot summer? What caves are so magical?
Recently, the Hubei Provincial Institute of Geological Sciences organized personnel to go to Yuan'an to carry out on-site verification and investigation of special tourism resources.
The ski resort is located in a huge cave hall 1 km inward from the "Yangshu Cave" in the Wuling Gorge Mouth Ecotourism Zone. At the site of the "Cave Four Seasons Ski Resort", investigators witnessed that the snow covered an area of more than 3,000 square meters, and the thickness of the snow reached more than 30 cm. The temperature in the entire hall has been measured to be around 3-5°C, which is like two worlds from the scorching heat outside the cave.
Karst cave stalactite landscape
Researchers found that although snowmaking facilities are used in the scenic area, they mainly rely on the low-temperature snow storage conditions of the cave itself.
Why is the temperature in the cave so low, and it can still open up thousands of square meters of snow field and create such a large ice and snow world?
Huge karst cave in Wuling Gorge Mouth Ecological Tourism Zone
Zou Yarui, an engineer at the Hubei Provincial Institute of Geological Sciences, said that the abnormal low temperature in summer in underground karst caves has been reported in a few locations in the world. For example United States the Caldesport Ice Cave in Pennsylvania, the Ningwu Ice Cave in Shanxi Province, China, and the Baiyi Rock "Summer Ice Cave" in Wufeng County, Hubei Province, not far from the mouth of Wuling Gorge...... These magical caves usually produce thick ice in the caverns during the hottest summer months, but in the really cold winters, the temperature in the caves "bounces" and the snow melts away.
Schematic diagram of karst landform structure in Wuling Gorge Estuary Ecotourism Area
Through the study of ice caves in many places, the academic community is currently inclined to believe that "cave breathing" may be the driving force behind this natural phenomenon. The well-known karst cave is actually a branch of the underground karst system in the whole region, the whole karst system is like a person who can breathe, the underground karst space is the viscera, the cave is the trachea, and the cave breathing is mainly controlled by the underground karst process. When the amount of groundwater is small and the minerals in the water are oversaturated, a large amount of carbon dioxide will be combined with the cave and precipitated to form thick stalactites; In the stage when there is a lot of external water, a large amount of groundwater, and the dissolution is the main effect, the rocks in the cave are "dissolved" in large quantities and carbon dioxide is released. In the former case, the cave is subjected to negative pressure, allowing hot air from outside the cave to penetrate into the cave, while in the latter case, the "cold wind" blowing from the ground blows outside.
Tiankengdong in Wuling Gorge Ecological Tourism Zone
Li Jiangli, a senior engineer of Hubei Provincial Institute of Geological Sciences, further explained that due to the northward advance of the East Asian monsoon in southern China in summer, there will be plum rain, precipitation will generally increase, and the amount of underground river water will become larger, which will also enhance the dissolution and erosion amplitude in many karst areas.
The entrance of the poplar cave in the Wuling Gorge Ecological Tourism Zone
However, not all karst caves have the potential to become "ice caves", and some unusually closed or too open caves cannot exchange gas inside and outside the caves, and the cave respiration will be relatively weak. The Yuan'an Wuling Gorge Mouth Ecotourism Area is located in the underground runoff area of Hongyan River, an important tributary of the left bank of the Fu River, and has formed a unique karst cave group with regional characteristics such as poplar cave, Tiankeng cave, terracotta cave and moon cave in the area through an underground river for a long time.