In places around the world, there are enormous holes in the ground that have seemingly appeared out of nowhere – they can appear suddenly, and are big enough to swallow whole buildings.
Click start to play today’s Spell It, where we spot sinkholes that look like they’ve taken a big ‘scoop’ out of the ground.
Sinkholes form when the rock beneath the surface can naturally be dissolved by groundwater. As the rock dissolves, it leaves gaping caverns that grow and grow until the land above can no longer support it, causing the surface to collapse. Some sinkholes even have their own specialised ecosystems. In 2022, for instance, scientists in southern China found a 192m-deep sinkhole containing an ancient forest, dense overgrowth, and the possibility of new species unknown to science.
Here are some of the biggest known sinkholes on Earth:
1. Xiaozhai Tiankeng, China
Measuring 660m deep, with a volume of 130 million cubic metres, the Xiaozhai Tiankeng is the deepest and largest sinkhole in the world. Its name translates to ‘The Divine Pit’, and the sinkhole is home to a thriving ecosystem of over 1,285 plant and animal species, including the rare gingko and clouded leopard. In the monsoon season, waterfalls cascade from the mouth of the pit, and feed a subterranean river and cave network at the bottom of the sinkhole. While speleologists have attempted to map the underground river five times, they haven’t succeeded because of difficulty navigating along the powerful torrents. It’s why the deep, dark world still remains one of China’s biggest geological mysteries.
2. Crveno Jezero, Croatia
Crveno Jezero or the Red Lake is a sinkhole comprising a karst lake, a body of water that formed as a result of the collapse of surrounding caves. Even though the lake is a beautiful blue in colour, it’s named for the reddish-brown cliffs around it, which are stained by iron oxide. The sinkhole is about 530m deep, and contains several species of fish, some of them endangered, like the spotted minnow and the Imotski spined loach.
3. Sima Humboldt, Venezuela
Viewed from above, you’ll find a dark abyss surrounded by a forest, sitting on top of a mountain. Sima Humboldt is an enormous sinkhole, located right on the summit of Cerro Sarisarinama, a flat-topped mountain in Bolivar State, Venezuela. With a depth of 314m, and a forest area at its base, this sinkhole isn’t the only strange sight in the vicinity. There’s another sinkhole called the Sima Martel, about 700m from the rim of Sima Humboldt.
What do you think of these natural wonders? Play today’s Spell It and tell us at games@gulfnews.com.
