This article is about cracks that open on a planetary surface. For other types of geological cracks, see Fracture (geology). For other uses, see Fissure (disambiguation).
A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word fissura, which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes.
Ground cracks at an east–west segment of Kamoamoa after its 2011 fissure eruption. The geologist is about 180 cm (5.9 ft) tall.[1]
Aerial view of the Almannagja fissure in Thingvellir National Park, Iceland
A ground fissure, also called an earth fissure, is a long, narrow crack or linear opening in the Earth's crust. Ground fissures can form naturally, such as from tectonic faulting and earthquakes, or as a consequence of human activity, such as oil mining and groundwater pumping.[2][3] Once formed, ground fissures can be extended and eroded by torrential rain.[4] They can be hazardous to people and livestock living on the affected surfaces and damaging to property and infrastructure, such as roads, underground pipes, canals, and dams.[2][5][6][7]
In circumstances where there is the extensive withdrawal of groundwater, the earth above the water table can subside causing fissures to form at the surface.[8][9] This typically occurs at the floor of arid valleys having rock formations and compacted soils with a high percentage of fine-grained material.[7][5]
A crevasse, also called an ice fissure, is a deep linear crack in an ice sheet or glacier resulting from the opposing force produced by their movement at different rates of speed. The force builds until their associated shear stress is sufficient to break the ice along the faces. The breakage often forms vertical or near-vertical walls, which can melt and create seracs, arches, and other ice formations.[10] A crevasse may be as deep as 45 metres (148 ft) and as wide as 20 metres (66 ft).[11] A crevasse may be covered, but not necessarily filled, by a snow bridge made of the previous years' accumulation and snow drifts. The result is that crevasses are rendered invisible, and extremely dangerous to anyone attempting to traverse a glacier.[12]
Karst terrain or simply karst are vast regions of barren land with rocky ground and generally consisting of nearby caves, fissured ground, and sinkholes. Although these regions normally have moderate to heavy rainfall, they are noticeably devoid of vegetation and characteristically have no lakes, rivers, or streams on their surface. They form when large to massive veins of soluble aggregate like limestone, gypsum, or dolomite are excavated by underground torrents of flowing water.[16][17]
Karst aquifers
Map of major US aquifers by rock type
In the United States, about 40% of the groundwater used for drinking comes from karst aquifers.[18] Some of these areas are well known vacation destinations like Carlsbad Caverns and Mammoth Cave. Karst aquifers are a vital resource in the US; about 20 percent of the land surface in the US is classified as karst. Other parts of the world with large areas of karst include the Caribbean, China, and Australia.
Typical karst hydrogeology consists of a network of interconnected fissures, fractures, and conduits emplaced within permeable rock. Most of the groundwater flow occurs through a network of openings, while groundwater is held in storage within the geological structures themselves.
List of karst aquifers in North America
Arbuckle-Simpson aquifer
Basin and Range and Bear River range carbonate aquifers
Colorado Plateau karst
Edwards Balcones Fault Zone aquifer
Edwards-Trinity Plateau aquifer
Upper Floridan and Biscayne aquifers
Madison aquifer
Midwest Paleozoic Carbonate aquifers
New England karst aquifers
Ozark Plateau karst aquifers
Roswell Basin aquifer
Pacific Northwest basalt aquifers
Valley and Ridge, Piedmont, and Blue Ridge aquifers
^"Volcano Watch — A recap of the Kamoamoa fissure eruption on its third anniversary". www.usgs.gov. Retrieved 25 September 2021.
^ abYang, Chengshen; Lu, Zhong; Zhang, Qin; Zhao, Chaoying; Peng, Jianbing; Ji, Lingyun (May 2018), "Deformation at longyao ground fissure and its surroundings, north China plain, revealed by ALOS PALSAR PS-InSAR" (PDF), International Journal of Applied Earth Observation and Geoinformation, 67: 1, Bibcode:2018IJAEO..67....1Y, doi:10.1016/j.jag.2017.12.010
^Berkeley, UC. "The Mystery about Earthquake Fissures". seismo.berkeley.edu.
^Carlson, Grace; Carnes, Lorraine K.; Cook, Joseph P. (4 September 2019). "Exploring Arizona earth fissures: An anthropogenic geologic hazard". Geologic Excursions in Southwestern North America. doi:10.1130/2019.0055(04). ISBN978-0-8137-5655-4. Retrieved 24 September 2021.
^ ab"Earth Fissures, Subsidence & Karst in Arizona". AZGS. 12 July 2017. Retrieved 21 September 2021.
^"USGS: Volcano Hazards Program Glossary - Fissure". volcanoes.usgs.gov. Retrieved 21 September 2021.
^ abStar, Tony Davis Arizona Daily. "Record Pinal County fissure shows Arizona is still prone to shifting earth levels". Arizona Daily Star. Retrieved 22 September 2021.
^Lund, W.R.; DuRoss, C.B.; Kirby, S.M.; McDonald, G.N.; Hunt, G.; Vice, G.S. (2005). The Origin and Extent of Earth Fissures in Escalante Valley, Southern Escalante Desert, Iron County, Utah. Special Study. Utah Geological Survey. ISBN978-1-55791-730-0. Retrieved 21 September 2021.[page needed]
^Inkenbrandt, P.; Lund, W.; Lowe, M.; Knudsen, T.; Bowman, S. (2014). Investigation of land subsidence and earth fissures in Cedar Valley, Iron County, Utah. Special Study. Utah Geological Survey. ISBN978-1-55791-891-8. Retrieved 21 September 2021.[page needed]
^van der Veen, C (1990). "Crevasses on Glaciers". Polar Geography. 23 (3): 213–245. doi:10.1080/10889379909377677.
^Dodds, Klaus. "Fissure". Society for Cultural Anthropology. Retrieved 26 September 2021.
^ abHoldsworth, G (October 1956). "Primary Transverse Crevasses". Journal of Glaciology. 8 (52): 107–129. doi:10.1017/S0022143000020797.
^"Geology glossary". www.volcanodiscovery.com. Retrieved 25 September 2001.
^"How Volcanoes Work". sci.sdsu.edu. Retrieved 26 September 2021.
^"Karst | geology". Encyclopedia Britannica. Retrieved 26 September 2021.
^"Karst Aquifers: Colorado Plateau Karst". www.usgs.gov. Retrieved 26 September 2021.
^"Karst Aquifers". www.usgs.gov. Retrieved 27 September 2021.
External links
External images of Almannagja fissures
February 25, 2023
fissure, this, article, about, cracks, that, open, planetary, surface, other, types, geological, cracks, fracture, geology, other, uses, disambiguation, fissure, long, narrow, crack, opening, along, surface, earth, term, derived, from, latin, word, fissura, wh. This article is about cracks that open on a planetary surface For other types of geological cracks see Fracture geology For other uses see Fissure disambiguation A fissure is a long narrow crack opening along the surface of Earth The term is derived from the Latin word fissura which means cleft or crack Fissures emerge in Earth s crust on ice sheets and glaciers and on volcanoes Ground cracks at an east west segment of Kamoamoa after its 2011 fissure eruption The geologist is about 180 cm 5 9 ft tall 1 Contents 1 Ground fissure 2 Crevasse 2 1 Types of crevasses 3 Fissure vent 4 Karst terrain 4 1 Karst aquifers 4 2 List of karst aquifers in North America 5 See also 6 References 7 External linksGround fissure Edit Aerial view of the Almannagja fissure in Thingvellir National Park Iceland A ground fissure also called an earth fissure is a long narrow crack or linear opening in the Earth s crust Ground fissures can form naturally such as from tectonic faulting and earthquakes or as a consequence of human activity such as oil mining and groundwater pumping 2 3 Once formed ground fissures can be extended and eroded by torrential rain 4 They can be hazardous to people and livestock living on the affected surfaces and damaging to property and infrastructure such as roads underground pipes canals and dams 2 5 6 7 In circumstances where there is the extensive withdrawal of groundwater the earth above the water table can subside causing fissures to form at the surface 8 9 This typically occurs at the floor of arid valleys having rock formations and compacted soils with a high percentage of fine grained material 7 5 Crevasse EditMain article Crevasse A crevasse in the Tangra Mountains Antarctica A crevasse also called an ice fissure is a deep linear crack in an ice sheet or glacier resulting from the opposing force produced by their movement at different rates of speed The force builds until their associated shear stress is sufficient to break the ice along the faces The breakage often forms vertical or near vertical walls which can melt and create seracs arches and other ice formations 10 A crevasse may be as deep as 45 metres 148 ft and as wide as 20 metres 66 ft 11 A crevasse may be covered but not necessarily filled by a snow bridge made of the previous years accumulation and snow drifts The result is that crevasses are rendered invisible and extremely dangerous to anyone attempting to traverse a glacier 12 Types of crevasses Edit Transverse crevasses in Chugach State Park Alaska Longitudinal crevasses form parallel to the ice flow where the glacier width is expanding 13 Splaying crevasses appear along the edges of a glacier Transverse crevasses form in a zone of longitudinal extension where the principal stresses are parallel to the direction of glacier flow 13 Fissure vent EditMain article Fissure vent A volcanic fissure and lava channel A fissure vent also known as a volcanic fissure or eruption fissure is a long volcanic vent through which lava erupts Fissure vents are connected to deep magma reservoirs and are typically found in and along rifts and rift zones 14 They are commonly associated with shield volcanoes Over time fissure vents form spatter cones and can feed lava channels and lava tubes 15 Karst terrain EditMain article Karst Doline in the causse de Sauveterre Lozere France Karst terrain or simply karst are vast regions of barren land with rocky ground and generally consisting of nearby caves fissured ground and sinkholes Although these regions normally have moderate to heavy rainfall they are noticeably devoid of vegetation and characteristically have no lakes rivers or streams on their surface They form when large to massive veins of soluble aggregate like limestone gypsum or dolomite are excavated by underground torrents of flowing water 16 17 Karst aquifers Edit Map of major US aquifers by rock type In the United States about 40 of the groundwater used for drinking comes from karst aquifers 18 Some of these areas are well known vacation destinations like Carlsbad Caverns and Mammoth Cave Karst aquifers are a vital resource in the US about 20 percent of the land surface in the US is classified as karst Other parts of the world with large areas of karst include the Caribbean China and Australia Typical karst hydrogeology consists of a network of interconnected fissures fractures and conduits emplaced within permeable rock Most of the groundwater flow occurs through a network of openings while groundwater is held in storage within the geological structures themselves List of karst aquifers in North America Edit Arbuckle Simpson aquifer Basin and Range and Bear River range carbonate aquifers Colorado Plateau karst Edwards Balcones Fault Zone aquifer Edwards Trinity Plateau aquifer Upper Floridan and Biscayne aquifers Madison aquifer Midwest Paleozoic Carbonate aquifers New England karst aquifers Ozark Plateau karst aquifers Roswell Basin aquifer Pacific Northwest basalt aquifers Valley and Ridge Piedmont and Blue Ridge aquifersSee also EditFabric geology Fissure vein Thermokarst TopographyReferences Edit Volcano Watch A recap of the Kamoamoa fissure eruption on its third anniversary www usgs gov Retrieved 25 September 2021 a b Yang Chengshen Lu Zhong Zhang Qin Zhao Chaoying Peng Jianbing Ji Lingyun May 2018 Deformation at longyao ground fissure and its surroundings north China plain revealed by ALOS PALSAR PS InSAR PDF International Journal of Applied Earth Observation and Geoinformation 67 1 Bibcode 2018IJAEO 67 1Y doi 10 1016 j jag 2017 12 010 Berkeley UC The Mystery about Earthquake Fissures seismo berkeley edu Carlson Grace Carnes Lorraine K Cook Joseph P 4 September 2019 Exploring Arizona earth fissures An anthropogenic geologic hazard Geologic Excursions in Southwestern North America doi 10 1130 2019 0055 04 ISBN 978 0 8137 5655 4 Retrieved 24 September 2021 a b Earth Fissures Subsidence amp Karst in Arizona AZGS 12 July 2017 Retrieved 21 September 2021 USGS Volcano Hazards Program Glossary Fissure volcanoes usgs gov Retrieved 21 September 2021 a b Star Tony Davis Arizona Daily Record Pinal County fissure shows Arizona is still prone to shifting earth levels Arizona Daily Star Retrieved 22 September 2021 Lund W R DuRoss C B Kirby S M McDonald G N Hunt G Vice G S 2005 The Origin and Extent of Earth Fissures in Escalante Valley Southern Escalante Desert Iron County Utah Special Study Utah Geological Survey ISBN 978 1 55791 730 0 Retrieved 21 September 2021 page needed Inkenbrandt P Lund W Lowe M Knudsen T Bowman S 2014 Investigation of land subsidence and earth fissures in Cedar Valley Iron County Utah Special Study Utah Geological Survey ISBN 978 1 55791 891 8 Retrieved 21 September 2021 page needed van der Veen C 1990 Crevasses on Glaciers Polar Geography 23 3 213 245 doi 10 1080 10889379909377677 Crevasse by National Geographic Dodds Klaus Fissure Society for Cultural Anthropology Retrieved 26 September 2021 a b Holdsworth G October 1956 Primary Transverse Crevasses Journal of Glaciology 8 52 107 129 doi 10 1017 S0022143000020797 Geology glossary www volcanodiscovery com Retrieved 25 September 2001 How Volcanoes Work sci sdsu edu Retrieved 26 September 2021 Karst geology Encyclopedia Britannica Retrieved 26 September 2021 Karst Aquifers Colorado Plateau Karst www usgs gov Retrieved 26 September 2021 Karst Aquifers www usgs gov Retrieved 27 September 2021 External links EditExternal images of Almannagja fissures Retrieved from https en wikipedia org w index php title Fissure amp oldid 1137585267, wikipedia, wiki, book, books, library,
