40 Fun Facts About Sinkholes

Eight rare cars of which American sports model fell into a sinkhole beneath a Bowling Green, Kentucky museum?

The National Corvette Museum turned its disaster into an exhibit about the collapse. Five of the eight cars were hauled out within a month, some of them badly damaged.

Off the coast of which Central American country does the Great Blue Hole, a 318-metre-wide marine sinkhole, lie?

Belize protects the Great Blue Hole as part of its barrier reef reserve, a UNESCO World Heritage Site. The pit sits near the middle of Lighthouse Reef, about 70 km from the mainland.

Which rock, built largely from the remains of sea creatures, most often dissolves to form sinkholes and caves?

Limestone gives way slowly: water seeping through its cracks carves hidden voids until the surface loses its support. The land above often stays intact until the moment it drops.

Which country's capital saw a three-story building vanish into a 20-metre-wide hole after Tropical Storm Agatha?

Guatemala City stands on loose volcanic debris, so geologists say the 2010 hole was no true sinkhole: escaping water had washed out a cavity from below. A similar pit had opened nearby in 2007.

Which US state, where over 110 sinkholes opened around Dover during a 2010 freeze, is famous for frequent collapses?

Florida rests on a thick platform of soluble rock, and its collapses cluster in the centre of the state. On the fringes, where the rock is far younger, sinkholes are rare.

Which explorer made the Great Blue Hole famous after sailing his ship Calypso there to chart its depths?

Jacques Cousteau brought the Calypso to the reef in 1971 and declared the site one of the world's best places to scuba dive. His expedition measured the pit at about 125 metres deep.

A sinkhole that opened in Daisetta, Texas in spring 2008 earned a local nickname punning on which holiday?

Cinco de Mayo became the Sinkhole de Mayo for locals as the pit spread to about 183 by 160 metres. The town had already seen the ground open in 1969 and 1981.

Which country holds the world's deepest sinkhole, a 662-metre pit whose local name translates as Heavenly Pit?

China calls such giants tiankengs, and Xiaozhai Tiankeng in Chongqing is the deepest of all. Visitors descend a 2,800-step staircase, and a waterfall pours over the rim in the rainy season.

Which household change, along with fresh cracks and sagging ground, can be an early warning of a sinkhole?

Doors that jam can mean the ground under a building has started to move. Some collapses give such hints first, along with cracking noises; others arrive with no warning at all.

Which NBC drama opens with a giant sinkhole in Los Angeles that drops survivors into a dangerous primeval land?

La Brea takes its name from the tar pits where the fictional hole opens, swallowing people, vehicles and a whole car museum. The pit turns out to be a portal to 10,000 BC.

What name, from a Yucatec Maya word, is given to the water-filled sinkholes of Mexico's Yucatán Peninsula?

Cenote comes from a Maya word for any place with reachable water underground, and the peninsula has thousands of them. Each formed when a cave roof fell in and exposed the water table.

Rainwater dissolves bedrock into sinkholes because, after absorbing carbon dioxide from the air, it is slightly what?

Acidic, though only mildly: the dissolved gas makes a weak carbonic acid that reacts with calcium carbonate. Over many years that is enough to hollow out whole caverns.

City holes reported as sinkholes are most often collapses caused by the failure of which buried infrastructure?

Old pipes give way, and a burst water main or broken sewer washes the soil out from under a street. Strictly speaking, such man-made holes are not true sinkholes.

A Texaco oil rig emptied Louisiana's Lake Peigneur into a vast sinkhole in 1980 by piercing which kind of mine?

Salt was being dug beneath the lake when the water poured in, yet all 55 miners escaped. The whirlpool swallowed the rig and eleven barges, and the lake refilled from the sea as brackish water.

Sinkhole pools were vital to Maya cities such as Chichen Itza because the Yucatán Peninsula has almost no what?

Rivers barely exist on the peninsula because rain sinks straight into the porous rock. Major Maya settlements were therefore built around natural wells that reached the water below.

Up to three million of which animals swirl out of the Devil's Sinkhole cavern in Texas on summer evenings?

Mexican free-tailed bats roost in the cavern from April to October, and visitors book evening tours to watch them leave. In the 1920s workers mined their guano there for fertiliser.

Which famous US highway passes the Blue Hole of Santa Rosa, a clear sinkhole pool popular with scuba divers?

Route 66 brought motorists right past the pool from the 1920s, and it remains a New Mexico tourist stop. Its water stays at 62°F all year, fed by 3,000 gallons a minute.

Which shrinking Middle Eastern lake has lost most of its western beach resorts to sinkholes opening along its shore?

The Dead Sea has been dropping for decades, and fresh water seeping in behind the retreating shoreline dissolves buried mineral layers. The cavities left behind then cave in.

Heavy pumping from which source, for farms and city supplies, can trigger new sinkholes in prone areas?

Groundwater helps hold up the soil above buried cavities, so lowering its level removes that support. Changing natural drainage with ponds, ditches and paving can have the same effect.

What term, named after a plateau shared by Slovenia and Italy, describes landscapes riddled with sinkholes and caves?

Karst is the German form of Kras, the Slovene name for the stony plateau behind Trieste, and geologists adopted it in the 1890s. It now covers any terrain of caves, springs and disappearing streams.

A ring of sinkhole pools in Yucatán traces the rim of which buried crater, left by a dinosaur-killing asteroid?

Chicxulub lies buried beneath the peninsula, and the arc of pools helped scientists confirm where it sits. Water probably moves more easily through the fractured rock along its rim.

NASA tested a diving robot in Mexico's Zacatón sinkhole as practice for exploring which ice-covered moon of Jupiter?

Europa was the goal: NASA's autonomous DEPTHX robot used Zacatón to learn to explore deep water unaided. The flooded pit is 339 metres deep and fed by volcanically heated water.

To which Maya rain god were valuables and human victims thrown into the sacred sinkhole well at Chichen Itza?

Chaac was believed to live in such wells, so offerings went into the water in times of drought. Dredging that began in 1904 brought up gold, jade and human bones.

Which island nation has Dean's Blue Hole, a 202-metre marine sinkhole that hosts an elite freediving contest?

The Bahamas holds Dean's Blue Hole in a bay on Long Island, where the Vertical Blue contest is held. A freediver there has passed 90 metres on one breath without even wearing fins.

In which country is the Blue Hole of Dahab, a Red Sea sinkhole reputed to have the most diver deaths anywhere?

Egypt's Sinai coast holds the site, where the danger is the Arch, a tunnel to the open sea whose roof lies 55 metres down. The pool itself is no riskier than other local dives.

In which modern country did German troops dump cannons into the sinkhole lake Otjikoto before surrendering in 1915?

Namibia has only two permanent natural lakes, and Otjikoto is the smaller. The retreating troops sank their weapons so the enemy could not use them, and two cannons still lie there.

Which country's Sarisariñama plateau holds Sima Humboldt, a 314-metre-deep sinkhole with its own forest on the floor?

Venezuela's flat-topped tepui mountains are sandstone, making Sima Humboldt the largest sinkhole known in that rock. A pilot spotted it from the air in 1961; nobody climbed down until 1974.

The Czech sinkhole Macocha, more than 138 metres deep, is named after which wicked relative in a local folk tale?

Stepmother is what the name means in Czech, and the folk tale explains why: she threw her stepson into the abyss. He survived, and in one telling the villagers threw her in instead.

What did divers find deep inside the Great Blue Hole that proved the flooded pit formed as a dry cave?

Stalactites grow only where water drips through air, so the cave stood above the sea when levels were far lower. Some hang five degrees off vertical, showing the land later tilted.

Five sports cars of which make, parked at a repair shop, sank into the Winter Park sinkhole of 1981?

Porsche owners were not the only losers: the hole also took a house, a camper truck and the deep end of the city swimming pool. The water-filled pit is now called Lake Rose.

Which soft rock dissolves beneath the English cathedral city of Ripon, leaving it prone to sinkholes?

Gypsum lies in pockets beneath Ripon's soil, where water steadily eats it away. Evaporite rocks like it underlie over a third of the United States too, though often at great depth.

Which European space probe found active pits on comet 67P in 2015 that scientists linked to sinkhole collapses?

Rosetta was the first spacecraft to orbit a comet, and its pictures showed pits that seem to form when the surface caves in over a void. The collapses may be tied to the comet's outbursts.

Which extreme sport draws thrill-seekers to Mexico's Cave of Swallows, a pit with a sheer drop of over 330 metres?

BASE jumping suits the shaft because a fall from its mouth to the floor lasts almost ten seconds, time enough to open a parachute. The birds nesting in its walls are mostly swifts, not swallows.

The ancient Maya saw sinkhole pools as gateways to which underworld, whose name roughly means place of fright?

Xibalba was ruled by the Maya death gods, and caves and flooded pits were seen as ways down to it. That belief helps explain why offerings were dropped into so many of the pools.

Which US state has Montezuma Well, a sinkhole fed by 1.5 million gallons of spring water a day?

Arizona's early farmers diverted the outflow into a canal more than a thousand years ago, and parts still carry water. At least five species, including a leech and a water scorpion, live nowhere else.

What do divers call the blurry layer in Yucatán sinkhole pools where fresh water floats above denser seawater?

Halocline marks a sharp change in salinity over a small change in depth. Swimming through it blurs a diver's vision until the water evens out again, and it lies deeper the farther inland you go.

Which word, from a Slavic term for a valley, do geologists use worldwide as the technical name for a sinkhole?

Doline appears in Jovan Cvijić's 1893 study of the Balkans, a founding text of cave-country science. Another name for the same hollow is a shakehole.

Folklore says Yemen's Well of Barhout, a sinkhole nicknamed the Well of Hell, was made as a prison for what?

Jinn were said to be locked inside, and some locals think it unlucky even to talk about the hole. Cavers from Oman who reached the floor in 2021 found waterfalls, snakes and cave pearls.

Giant sinkholes, one dubbed The Grandfather, opened in the Russian city of Berezniki above mines of which mineral?

Potash mining built Berezniki, a city placed directly over the workings. Water flooding in dissolved the mine's supporting pillars, and the largest hole grew to nearly 400 metres long.

Which US state is home to the Golly Hole, a giant 1972 sinkhole also known as the December Giant?

Alabama's hole opened near Montevallo after a nearby quarry lowered the water table, a man-made trigger for a natural-looking collapse. Its other name records the month it appeared.