Located in West Cairo, Egypt the Qattara Depression is the largest natural sinkhole in the world measuring 50 miles long by 75 miles wide. It is a 100% natural by-product of fierce which tear into the slimy salt beds right down to the water table. Due to its sheer size, scientists are attempting to develop a massive hydroelectric project that would harness the sinkhole’s hydroelectric energy potential. The plan for this project would require digging a ditch from the sinkhole’s edge to the Mediterranean and allowing the channeled water to fall into the sinkhole while passing through a series of hydro-electric penstocks thus creating energy.
Located between Adelaide and Melbourne in South East Australia, Mount Gambier is known for its geographical features such as water channels, caves, volcanic rocks, and the famous Blue Lake. Nicknamed “The city of craters”, its volcanic craters are actually naturally-occurring sinkholes that are filled with water thus creating gorgeous scenery.
The sinkhole in Berezniki, Soviet Russia began in 1986 as a result of a flooding event in a potash mine and has gradually worsened each passing year. At over 200m deep, 80m long and 40m wide, it is expected to swallow up the only rail line that leads to and from the potash mines, where 10% of the world’s potash used in fertilizer come from.
Due to the weakening of the karst (a type of bedrock) in an urbanized area of South Florida, the ground gave way to a sizable sinkhole. The 20 feet wide by 10 feet deep sinkhole opened up near the University of South Florida in Tampa, swallowing a car and threatening a nearby condo. Eleven people were evacuated from the condo but thankfully no one was hurt (except for the car).
Guatemala City 2007
In late February 2007, residents of Guatemala City heard some rumbling underneath them but were not sure what was happening until instantly a near-perfect circle of earth dropped some 30 stories. The sink hole killed two and forced the evacuation of over 1,000 people. Authorities believed that the sinkhole was the result of a corroded sewage system deep beneath the surface.
Guatemala City 2010
Another giant sinkhole in Guatemala City swallowed a three-story building on May 2010. This 60 ft. wide by 200 ft. deep sinkhole could have been developing for weeks or even years, however the flood waters from the tropical storm Agatha accelerated the sinkhole’s growth and caused it to finally collapse.
Undertaking a major development in Bowling Green, Kentucky can be a very risky business since the city is dotted with naturally-occurring sinks that could open up at any time. One of these sinks halted the plans for the construction of the Trimodal Transpark after the 200ft wide sinkhole gave way near the construction site.
The Sinai Blue Hole (Dahab)
A popular (and dangerous) diving site on east Sinai on the coast of the Red Sea a few miles north of the small town of Dahab, The Sinai Blue Hole is a submarine sinkhole which is around 130m deep. The sink hole is renowned for scuba attempts and free-diving, while the surrounding area has an abundance of corals and reef fish. However, it is also renowned for its danger and has been labeled “the World’s most dangerous dive site”.
The Devil’s Sinkhole
The Devil’s Sinkhole in Edward’s County Texas is a limestone wonder that has a 40 ft. x 60 ft. opening and a total drop of 400 ft. The sink is famous for being a vertical natural bat habitat for the Mexican Free Tailed Bat which houses an estimated 3 million bats.
The Boesmansgat, also known as the “Bushman’s Hole,” is believed to be the third-deepest freshwater sinkhole in the world. Approximately 270m (886 ft.) deep, the Boesmansgat in the Northern Cape province of South Africa was first explored by amateur diver Mike Rathbourne in 1977 and is home to the Guinness Woman’s World Record for the deepest dive (a 221m dive by Verna van Schaik on November 24, 2004).
The most beautiful and most mysterious sinkholes of Venezuela are natural wonders which include four types of round basins containing their own unique ecosystem found nowhere else on earth. Scientists are clueless on the origin of the stunning sink holes.
The combination of underground pipe problems and extremely bad weather produced a three-meter wide sinkhole that opened up in Idylwyld Drive in Saskatoon, Sasketchewan on March 12, 2012. The constant freezing and thawing; and an unseasonably warm winter put pressure on the underground pipes causing a 20-centimeter pipe under the roadway to break spewing water and compromising the road’s integrity.
One of nature’s great oddities has been turned into a virtual tourist trap. Residents of Bimmah Oman have turned a spectacular looking natural-occurring sinkhole into a swim park. Located about 6km from Dibab along the coast graded road from Muscat to Sur the Oman sink hole boasts of clear blue picturesque waters.
Even the biggest city in Canada is not immune to sinkholes two of which appeared in the city of Toronto within the space of a few weeks: the 10m long, 3m wide fissure that ruptured from the street watermain at Woodbine Avenue and John Street on September 28, 2011 and the 30m long 1.5m deep sinkhole on Bayview Avenue on November 4th of the same year. Thankfully there were no casualties when these sinkholes happened.
Agrico Gypsum Stack
The most devastating sinkhole erosion in Florida occurred in 1994 when a 15-story sinkhole tore open right beneath an 80-million-ton pile of gypsum stack. The cave-in dumped 4 million to 6 million cubic feet of toxic and radioactive gypsum and waste water into the Floridian aquifer, which provides 90 percent of the state’s drinking water.
Winnipeg Highway Sinkhole
The most dramatic example of all the Canadian sinkholes happened on the highway of Manitoba where parts of the highway simply disappeared. After days of heavy rains with up to 12 inches of precipitation, 200 meters of highway 83 near Inglis was literally washed away with some points of the highway dropping to as low as 8m below its original surface point.
The Macungie sinkhole which formed in June 1986 is a man-made sink hole attributed to aging water infrastructure. At 75 feet wide and 35 feet deep, it caused major disruption of traffic and utility services causing around $450,000 in stabilization and repair costs.
Dead Sea Holes
Several large sink holes have been appearing near Ein Gedi, Israel. The phenomenon stems from a dire water shortage, compounded in recent years by tourism and chemical industries as well as a growing population. There are over 3,000 open sinkholes along the coast and likely just as many that haven’t burst open yet.
What started out as a small 20-foot sinkhole in a residential neighborhood in Daisetta, Texas spread to over 900 ft. with a depth of 260 ft. within a day and consumed everything in its path. This former oil town sits on the Hull Salt Dome which is a four-mile-in-diameter geologic formation of compacted salt. Consequently, geologists speculate that years of storing saltwater waste -a byproduct of oil production- caused the massive pit.
Also known as the Heavenly Pit, this double-nested sinkhole has 662m deep vertical walls. Located in the Chongqing District, this sinkhole is arguably the ‘world’s largest sinkhole’ at 626m long, 537m wide and between 511 to 662m deep. It is a double-nested structure with an upper bowl of 320m deep, while its lower bowl is 342m deep, and both of them are on average 257 to 268m across. It’s said that the sinkhole formed over the last 128,000 years.
Dean’s Blue Hole
Located in Long Island, Bahamas Dean’s Blue Hole is the deepest known sinkhole under the sea at the depth of 203 meters. This is a popular location for world’s championship of free diving and it’s the location where William Trubridge broke a free diving record reaching a depth of 92 meters (302 ft.).
Located in Abel Tasman National Park in New Zealand, Harwood Hole is one of several important cave systems in Takaka Hill, between the Tasman Bay and the Golden Bay. From the surface is a 50m round sinkhole entrance that descends into 183m. For adventurers, the long rope descent is considered to be one of the most spectacular caving experiences at Hardwood’s, which has an overall depth of 357m.
The largest sinkhole in sandstone, Sima Humboldt is located on the summit of the plateau in Bolivar State, Venezuela. At 314m deep with vertical walls it is very unusual sink hole for several reasons: Its location is on top of the only forested tepui; it’s enormous in size and depth; and it has a patch of forest on its base due to the weathering process that formed the sinkhole.
Great Blue Hole
Part of the larger Belize Barrier Reef Reserve System, which was declared a World Heritage Site by UNESCO; the Great Blue Hole is a spectacular sinkhole at 124m deep with stilted stalactites as its most unusual features. The largest submarine sinkhole off the coast of Belize, it lies in the center of Lighthouse Reef. It is circular in shape, over 300m across and 124m deep and was formed during several episodes of Quaternary glaciations when sea levels were much lower.