Zacatón: Difference between revisions
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'''Zacatón''' (El Zacatón sinkhole) is thermal water filled [[sinkhole]] belonging to Zacatón system - group of unusual [[karst]] features located in the northeastern state of [[Tamaulipas]], [[Mexico]]. It is the deepest known water-filled sinkhole in the world with a total depth of {{convert|339|m|ft}}.<ref> |
'''Zacatón''' (El Zacatón sinkhole) is thermal water filled [[sinkhole]] belonging to Zacatón system - group of unusual [[karst]] features located in the northeastern state of [[Tamaulipas]], [[Mexico]]. It is the deepest known water-filled sinkhole in the world with a total depth of {{convert|339|m|ft}}.<ref name=GaryDEPTHX>{{cite journal |author=Gary, Marcus; Fairfield, Nathaniel; [[William Stone (caver)|Stone, William C]]; Wettergreen, David; Kantor, George A.; Sharp Jr, John M. |title=3D Mapping and Characterization of Sistema Zacatón from DEPTHX (DEep Phreatic THermal eXplorer) |journal=Proceedings of KARST08: 11th Sinkhole Conference ASCE |year=2008 |url=http://www.ri.cmu.edu/publication_view.html?pub_id=6144 |accessdate=2011-01-07}}</ref> The {{convert|392|m|ft}} deep Pozzo Merro (Italy) is deeper but is rather a near-vertical cave and not sinkhole. |
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[[DEPTHX]], a [[NASA]] funded project<ref> |
[[DEPTHX]], a [[NASA]] funded project<ref>{{cite web |url=http://www.stoneaerospace.com/news-/news-depthx-flight.php |publisher=Stone Aerospace |title=News: DEPTHX Takes Flight |accessdate=2011-01-07}}</ref> using an autonomous robot has measured the underwater portion of Zacatón to be {{convert|319|m|ft}} deep (a {{convert|adj=on|20|m|ft}} difference between the rim of cliff and surface of water adds to the total depth).<ref>[http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=2352&mode=thread&order=0&thold=0 Demystifying El Zacatón (Astrobiology, June 2007)]</ref> Zacatón is the only sinkhole of the five located in Rancho La Azufrosa to have any noticeable water flow.<ref name=Gary2000>{{cite journal |author=Gary, Marcus |title=Speleogenesis of Zacatón and cenotes of Rancho la Azufrosa. |journal=In: Hallock and French (eds). Diving for Science...2000. Proceedings of the 20th Annual Scientific Diving Symposium |publisher=[[American Academy of Underwater Sciences]] |year=2000 |url=http://archive.rubicon-foundation.org/8991 |accessdate=2011-01-07}}</ref> |
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The name Zacatón comes from the free-floating islands of zacate grass which move around on the surface with the wind.<ref>[http://www.mexicodesconocido.com.mx/english/naturaleza/bellezas_naturales/detalle.cfm?idsec=6&idsub=0&idpag=2146 The Unusual Cenotes]</ref> |
The name Zacatón comes from the free-floating islands of zacate grass which move around on the surface with the wind.<ref>[http://www.mexicodesconocido.com.mx/english/naturaleza/bellezas_naturales/detalle.cfm?idsec=6&idsub=0&idpag=2146 The Unusual Cenotes]</ref> |
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According to Gary, these sinkholes began to form during the Pleistocene as a result of volcanic activity from below.<ref>[http://www.geo.utexas.edu/zacaton/DEPTHX/Mission2-Blogs/2007-03-08/articles_and_papers/Gary_and_Sharp2006.pdf Volcanic karstification of Sistema Zacaton, Mexico (Gary, Sharp, 2006)]</ref> This view differs from the classical theory of cave formation and also hypotheses about the formation of other large caves in this part of Mexico. |
According to Gary, these sinkholes began to form during the Pleistocene as a result of volcanic activity from below.<ref>[http://www.geo.utexas.edu/zacaton/DEPTHX/Mission2-Blogs/2007-03-08/articles_and_papers/Gary_and_Sharp2006.pdf Volcanic karstification of Sistema Zacaton, Mexico (Gary, Sharp, 2006)]</ref> This view differs from the classical theory of cave formation and also hypotheses about the formation of other large caves in this part of Mexico. |
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In this view, volcanism turned deep water slightly acidic by adding dissolved carbon dioxide and hydrogen sulfide. This water slowly dissolved the limestone above, creating porous karst. This is referred to as “hypogenic karstification.” From time to time, overlying rock collapsed into hollow chambers below, creating deep shafts. If his interpretation is correct, Sistema Zacatón has more in common with [[Mammoth Hot Springs]] in [[Yellowstone]] than with other deep sinkholes in this same region of Mexico. |
In this view, volcanism turned deep water slightly acidic by adding dissolved carbon dioxide and hydrogen sulfide. This water slowly dissolved the limestone above, creating porous karst.<ref name=Gary2000/> This is referred to as “hypogenic karstification.” From time to time, overlying rock collapsed into hollow chambers below, creating deep shafts. If his interpretation is correct, Sistema Zacatón has more in common with [[Mammoth Hot Springs]] in [[Yellowstone]] than with other deep sinkholes in this same region of Mexico. |
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Another interesting hydrogeologic feature is that some of the sinkholes appear to be in the process of closing up at the top as crusts of [[travertine]] (a form of calcium carbonate) form at their surfaces. Marc Airhart, a science writer at the Jackson School of Geosciences wrote: |
Another interesting hydrogeologic feature is that some of the sinkholes appear to be in the process of closing up at the top as crusts of [[travertine]] (a form of calcium carbonate) form at their surfaces. Marc Airhart, a science writer at the Jackson School of Geosciences wrote: |
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It’s a bit like the skin on a can of paint that has been left open in the sun. For the paint, it might take a day or two. In this case, the process probably takes thousands of years. It is basically the sinkhole’s way of taking a bunch of dissolved rock floating in the water and recycling it to form new rock at the surface. At least one sinkhole ([[Poza Seca]]) appears to have closed up entirely, sealing off an underwater lake, possibly with unusual life forms. If such life forms exist, they’re likely to be bacteria that can live without oxygen and sunlight. And assuming the lake has been sealed off from the outside world for thousands and thousands of years, they might have evolved to be different from anything scientists have ever discovered and characterized before.<ref> |
It’s a bit like the skin on a can of paint that has been left open in the sun. For the paint, it might take a day or two. In this case, the process probably takes thousands of years. It is basically the sinkhole’s way of taking a bunch of dissolved rock floating in the water and recycling it to form new rock at the surface. At least one sinkhole ([[Poza Seca]]) appears to have closed up entirely, sealing off an underwater lake, possibly with unusual life forms. If such life forms exist, they’re likely to be bacteria that can live without oxygen and sunlight. And assuming the lake has been sealed off from the outside world for thousands and thousands of years, they might have evolved to be different from anything scientists have ever discovered and characterized before.<ref>{{ cite web |author=Airhart, Marc |date=2007-05-19 |url=http://geology.com/zacaton/#5-19 |title=Put a Lid On It |accessdate=2011-01-07}}</ref> |
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Revision as of 20:21, 7 January 2011
Zacatón (El Zacatón sinkhole) is thermal water filled sinkhole belonging to Zacatón system - group of unusual karst features located in the northeastern state of Tamaulipas, Mexico. It is the deepest known water-filled sinkhole in the world with a total depth of 339 metres (1,112 ft).[1] The 392 metres (1,286 ft) deep Pozzo Merro (Italy) is deeper but is rather a near-vertical cave and not sinkhole.
DEPTHX, a NASA funded project[2] using an autonomous robot has measured the underwater portion of Zacatón to be 319 metres (1,047 ft) deep (a 20-metre (66 ft) difference between the rim of cliff and surface of water adds to the total depth).[3] Zacatón is the only sinkhole of the five located in Rancho La Azufrosa to have any noticeable water flow.[4]
The name Zacatón comes from the free-floating islands of zacate grass which move around on the surface with the wind.[5]
Scrapings from the rock walls beneath the surface yielded at least 6 new phyla of bacteria.
Diving
El Zacatón's depth has made it an important dive site:
- Dr. Ann Kristovich set the women's world depth record of 554 feet (169 m) during a 1993 dive into the sinkhole.[6]
- On April 6, 1994, explorer diver Jim Bowden and cave diving pioneer Sheck Exley plunged into El Zacatón with the intent of reaching bottom. Bowden dove to a men's world record depth of 925 feet (282 m),[7] but Exley died, probably from high pressure nervous syndrome (HPNS) at a depth of 879 to 906 feet (268 to 276 m).[8][9]
- The NASA Deep Phreatic Thermal Explorer (DEPTHX) project used the sinkhole as a testbed for robotic hardware being developed to explore the Jovian moon of Europa.[10][11] DEPTHX was designed and integrated by NASA Principal Investigator Stone Aerospace. Additional co-investigators on the Deep Phreatic Thermal Explorer (DEPTHX) team included Carnegie Mellon University, Southwest Research Institute, Colorado School of Mines, The University of Arizona, and the University of Texas at Austin's Jackson School of Geosciences.[12][13][14]
Hydrogeology
Zacatón is just one of the numerous sinkholes and other karst features in the region. Here are located more than 15 sinkholes, several cave systems and karst springs with caves.[15] Several of these karst features have unusual characteristics like travertine lids over several of the sinkholes with isolated waterbodies below.
Since the late 1990s, Marcus Gary, a hydrogeology graduate student at the Jackson School of Geosciences at the University of Texas at Austin has studied Sistema Zacatón to better understand how the sinkholes formed and how they evolve over time.[16] During these studies, Gary made extensive use of high-end water quality monitoring instrumentation provided free of charge by (the now defunct) Hydrolab Corporation. Gary was a primary member on the DEPTHX mission, which used an autonomous underwater robot to explore the deepest parts of Zacatón for the first time.
According to Gary, these sinkholes began to form during the Pleistocene as a result of volcanic activity from below.[17] This view differs from the classical theory of cave formation and also hypotheses about the formation of other large caves in this part of Mexico.
In this view, volcanism turned deep water slightly acidic by adding dissolved carbon dioxide and hydrogen sulfide. This water slowly dissolved the limestone above, creating porous karst.[4] This is referred to as “hypogenic karstification.” From time to time, overlying rock collapsed into hollow chambers below, creating deep shafts. If his interpretation is correct, Sistema Zacatón has more in common with Mammoth Hot Springs in Yellowstone than with other deep sinkholes in this same region of Mexico.
Another interesting hydrogeologic feature is that some of the sinkholes appear to be in the process of closing up at the top as crusts of travertine (a form of calcium carbonate) form at their surfaces. Marc Airhart, a science writer at the Jackson School of Geosciences wrote:
It’s a bit like the skin on a can of paint that has been left open in the sun. For the paint, it might take a day or two. In this case, the process probably takes thousands of years. It is basically the sinkhole’s way of taking a bunch of dissolved rock floating in the water and recycling it to form new rock at the surface. At least one sinkhole (Poza Seca) appears to have closed up entirely, sealing off an underwater lake, possibly with unusual life forms. If such life forms exist, they’re likely to be bacteria that can live without oxygen and sunlight. And assuming the lake has been sealed off from the outside world for thousands and thousands of years, they might have evolved to be different from anything scientists have ever discovered and characterized before.[18]
References
- ^ Gary, Marcus; Fairfield, Nathaniel; Stone, William C; Wettergreen, David; Kantor, George A.; Sharp Jr, John M. (2008). "3D Mapping and Characterization of Sistema Zacatón from DEPTHX (DEep Phreatic THermal eXplorer)". Proceedings of KARST08: 11th Sinkhole Conference ASCE. Retrieved 2011-01-07.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ "News: DEPTHX Takes Flight". Stone Aerospace. Retrieved 2011-01-07.
- ^ Demystifying El Zacatón (Astrobiology, June 2007)
- ^ a b Gary, Marcus (2000). "Speleogenesis of Zacatón and cenotes of Rancho la Azufrosa". In: Hallock and French (eds). Diving for Science...2000. Proceedings of the 20th Annual Scientific Diving Symposium. American Academy of Underwater Sciences. Retrieved 2011-01-07.
- ^ The Unusual Cenotes
- ^ Proyecto de Buceo Espeleologico México y América Central Bio: Ann Kristovich
- ^ Zacaton. A History by Dr. by Ann Kristovich
- ^ A/C N10 Incident Reports
- ^ Eulogy for an Explorer
- ^ Robotic Mission to Zacaton
- ^ Mexican Sinkhole May Lead NASA to Jupiter
- ^ The Advance DEPTHX Team Missions
- ^ PDF: DepthX Goes To Mexico
- ^ Robotic submarine reaches new depths
- ^ Sistema Zacatón | Wondermondo
- ^ Sistema Zacatón
- ^ Volcanic karstification of Sistema Zacaton, Mexico (Gary, Sharp, 2006)
- ^ Airhart, Marc (2007-05-19). "Put a Lid On It". Retrieved 2011-01-07.
Further reading
- Sistema Zacatón
- Dispatches from Zacatón JSG Online, March/May 2007
- NASA-funded Robotic Sub Makes Final Dive To Reach Bottom of Earth’s Deepest Sinkhole JSG Online, May 14, 2007
- Sistema Zacatón by Wondermondo. Separate descriptions of 17 features in system.