Xiaozhai Tiankeng Heavenly Pit, China

Sentinel-1 CSAR IW acquired on 17 June 2020 at 10:44:09 UTC
Sentinel-1 CSAR IW acquired on 11 July 2020 at 10:44:11 UTC
Sentinel-2 MSI acquired on 04 June 2021 at 03:15:39 UTC
Sentinel-2 MSI acquired on 06 December 2021 at 03:21:21 UTC
Author(s): Sentinel Vision team, VisioTerra, France - svp@visioterra.fr
Keyword(s): Land, geology, erosion, UNESCO World Heritage, biodiversity, China
Fig. 1 - COP-DEM - Formed within a karst formation, Xiaozhai Pit in China is the biggest sinkhole on Earth.
The Xiaozhai Tiankeng or Heavenly Pit is both the deepest and largest sinkhole in the world with 626 m length, 537 m width, 511-662 m depth with vertical walls. Its volume is 120 million m³. The sinkhole is a doubly nested structure—the upper bowl is 320 m deep, the lower bowl is 342 m deep, and the two bowls are 257-268 m across.
Fig. 2 - S1 (2023.06.17-2020.07.11) / S2 (06.12.2021) / COP-DEM - It has become known to the outside World only recently.
Known only by locals, it was only "discovered" by the outside world in 1994. The region was added to the UNESCO World Heritage list in 2007. It is home to a thriving ecosystem of some 1285 plant and animal species – including the rare gingko and clouded leopard.
Fig. 3 - S2 (04.06.2021 / 15.04.2023 / 11.11.2020) / COP-DEM - The shadows show its double-nested structure.
Despite attempting to map the underground river five times in a 10-year period, speleologists found the gushing torrent too difficult to navigate and the team never succeeded.