A sinkhole, also known as a “sink”, “shake hole”, “swallow hole”, “swallet”, “doline” or “cenote”, is a natural depression or hole in the Earth’s surface caused by karst processes — the chemical dissolution of carbonate rocks or suffosion processes for example in sandstone.
Sinkholes may vary in size from 1 to 600 meters (3.3 to 2,000 ft) both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may be formed gradually or suddenly, and are found worldwide.
Guatemala Sinkhole, 2007-In 2007 a similar sinkhole had opened up in Guatemala City—not far from where the 2010 sinkhole appeared. Based on pictures, both sinkholes are thought to have been about 60 feet (18 meters) wide and about 300 feet (100 meters) deep immediately after collapsing.
Blue Hole, Belize- If the sinkhole is near the sea—or in the sea, as with the famous Blue Hole in Lighthouse Reef off the coast of Belize—seawater can quickly seep in after a collapse, forming a deep pool.
Picher, Oklahoma, Sinkhole 2008 – Years of mining for zinc and lead has left Picher, Oklahoma, near the border with Kansas literally full of holes. Some mines were dug too close to the surface, and the roofs were unable to support the weight of earth on top, leading to collapses.
Iceland Sinkhole – Adventure kayaker Mick Coyne lowers himself down the wall of a sinkhole toward the headwaters of the Jokulsa, Iceland’s second longest river.Though the river is fed by melt from a glacier, this 150-foot (45-meter), inverted funnel-shaped hole was blasted into being by rising steam from geothermal vents below.
Ik-Kil Cenote, Mexico – Swimmers float in the sapphire waters of the Ik-Kil cenote, near the Maya site of Chichén Itzá in Mexico’s Yucatán Peninsula. Cenote means “natural well” in Spanish.Sinkholes occurring at sea level will fill up as high as the water table, creating the famous clear blue pools, used by the Maya royalty for both relaxation and ritual sacrifices.
Lisbon, Portugal, Sinkhole, 2003 – A parked bus was the unfortunate “meal” of a sinkhole that opened up in the streets of Lisbon, Portugal. In many cities, utility infrastructure such as sewer lines and fiber optic cables are buried in troughs filled with loose material, which can wash away over time. In some cases, a stretch of road can essentially become a concrete bridge over mostly empty space.
Neversink Pit, Alabama- Neversink Pit, a wet limestone sinkhole in Alabama seen above in 1998, is about 50 feet (15 meters) deep and houses a rare species of fern. The sinkhole was bought in the 1990s by a group of cavers to preserve it for future generations.
Karst is the geologic term for landscapes formed mainly by the dissolving of limestone or dolomite bedrock. In the United States, karst underlies parts of Missouri, Arkansas, Kentucky, Tennessee, northern Alabama, Texas, and most of Florida. Such areas are marked by sinking streams, subterranean drainage, large springs, caves—and, of course, sinkholes.
Devil’s Hole, Hawthorne, Florida – This was the original site for a limestone dig near Hawthorne, Florida. The Devil’s Hole (sometimes referred to as the “Devil’s Toilet Bowl” by the locals) is a fun spot for an afternoon dip. There is a rope swing, and two stands to jump from.
(VIA National Geographic)