thumb|Cenote at Hubiku, Yucatan

A cenote ( <small>or</small> ; ) is a natural pit, or sinkhole, resulting when a collapse of limestone bedrock exposes groundwater. The term originated on the Yucatán Peninsula of Mexico, where the ancient Maya commonly used cenotes for water supplies, and occasionally for sacrificial offerings. The name derives from a word used by the lowland Yucatec Maya—<!--⟨ʼ⟩ not ⟨'⟩-->—to refer to any location with accessible groundwater.

Cenotes are common geological forms in low-altitude regions, particularly on islands (such as Cefalonia, Greece), coastlines, and platforms with young post-Paleozoic limestone with little soil development. The term cenote, initially applying only to the features in Yucatán, has since been used by researchers to refer to similar karst features in other places, such as in Cuba, Australia, Europe, and the United States.

Definition and description

thumb|upright=1.45|The [[Sacred Cenote at Chichen Itza, Mexico]]

Cenotes are surface connections to subterranean water bodies. Cenote water is often apparent, as the water comes from rain water filtering slowly through the ground, and therefore contains very little suspended particulate matter. The groundwater flow rate within a cenote may be very slow. In many cases, cenotes are areas where sections of the cave roof have collapsed, revealing an underlying cave system, and the water flow rates may be much faster: up to per day.

Geology and hydrology

thumb|upright|The [[Samulá Cenote in Valladolid, Yucatán, Mexico]]

Cenotes are formed by the dissolution of rock and the resulting subsurface void, which may or may not be linked to an active cave system, and the subsequent structural collapse. The rock that falls into the water below continues to dissolve, creating space for more blocks to collapse. Likely, the rate of collapse increases during periods when the water table is below the ceiling of the void since the rock ceiling is no longer buoyantly supported by the water in the void.

Cenotes may be fully collapsed, forming an open-water pool, or partially collapsed, with a portion of a rock overhanging the water. The stereotypical cenotes often resemble small circular ponds, measuring some tens of meters in diameter with sheer rock walls. Most cenotes, however, require some stooping or crawling to reach the water.

Penetration and extent

thumb|upright|Cenote at [[Bolonchén, Campeche|Bolonchén, Mexico, used as a source of water, painting of 1842 by Frederick Catherwood]]

In the north and northwest of the Yucatán Peninsula in Mexico, cenotes generally overlie vertical voids that penetrate below the modern water table. However, very few of these cenotes appear to be connected with horizontally extensive underground river systems, with water flow through them being more likely dominated by aquifer matrix and fracture flows.

Chicxulub crater

thumb|Radar topography reveals the ring of the crater; clustered around the crater's trough are numerous [[sinkholes, suggesting a prehistoric oceanic basin in the depression left by the impact (Image courtesy NASA/JPL-Caltech).]]

Although cenotes are found widely throughout much of the Yucatán Peninsula, a higher-density circular alignment of cenotes overlies the measured rim of the Chicxulub crater. This crater structure, identified from the alignment of cenotes, The Maya often deposited human remains as well as ceremonial artifacts in these cenotes.

The discovery of golden sacrificial artifacts in some cenotes led to the archaeological exploration of most cenotes in the first part of the 20th century. Edward Herbert Thompson (1857–1935), an American diplomat who had bought the Chichen Itza site, began dredging the Sacred Cenote there in 1904. He discovered human skeletons and sacrificial objects confirming a local legend, the Cult of the Cenote, involving human sacrifice to the rain god Chaac by the ritual casting of victims and objects into the cenote.

The remains of this cultural heritage are protected by the UNESCO Convention on the Protection of the Underwater Cultural Heritage.

Contrary to cenote cavern diving, cenote cave diving requires special equipment and training (certification for cave diving). However, both cavern and cave diving require detailed briefings, diving experience, and weight adjustment to freshwater buoyancy. The cenotes are usually filled with rather cool fresh water. Cenote divers must be wary of possible halocline; this produces blurred vision until they reach a more homogeneous area.

Notable cenotes

Australia

  • Ewens Ponds, near Mount Gambier, South Australia
  • Kilsby sinkhole, near Mount Gambier, South Australia
  • Little Blue Lake, near Mount Schank, South Australia

Bahamas

  • Thunderball Grotto, on Staniel Cay

Belize

  • Great Blue Hole

Canada

  • Devil's Bath is the largest cenote in Canada at a size of 1178&nbsp;ft (359m) in diameter and 144&nbsp;ft (44m) in depth. It is located near the village of Port Alice, British Columbia on the northwest coastline of Vancouver Island. Devil's Bath is continuously fed by an underground spring and is connected by an underwater tunnel to the Benson River Cave.

Dominican Republic

  • Hoyo Azul (Punta Cana)
  • Los Tres Ojos
  • Ojos Indigenas (Punta Cana)

Greece

  • Melissani Cave, Kefalonia

Jamaica

  • Blue Hole (Ocho Rios)

Mexico

Yucatán Peninsula

  • Dos Ojos, Municipality of Tulum
  • Dzibilchaltun, Yucatán
  • Ik Kil, Yucatan
  • Gran Cenote, Municipality of Tulum
  • Hubiku, Yucatan
  • Sacred Cenote, Chichen Itza
  • Xtacunbilxunan, Bolonchén
  • Cenote Azul, Playa del Carmen
  • Jardin Del Eden, Bacalar
  • Choo-Ha, Coba
  • Zaci, Valladolid
  • El Zapote, the site of the Hells Bells bell-like rock formation

United States

  • Blue Hole, Santa Rosa, New Mexico
  • Blue Hole, Castalia, Ohio
  • Bottomless Lakes, near Roswell, New Mexico
  • Montezuma Well, Verde Valley, Arizona
  • Hamilton Pool, Austin, Texas

Zimbabwe

  • Chinhoyi Caves in Zimbabwe

See also

References

</references>

Other sources

  • Cenotes of Chichén Itzá
  • Doline, Sinkhole, Cenote
  • Sistema Zacatón
  • Stages in the Formation of a Cenote
  • Volcanic karstification of Sistema Zacaton, Mexico (Gary, Sharp, 2006)
  • Year 1999 Cenotes Conference in Perugia, Italy