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{{Short description|Natural opening where surface water enters caves}}
{{other uses|Ponor (disambiguation)}}
{{other uses|Ponor (disambiguation)}}
[[File:Djulin ponor jama.jpg|thumb|upright|The [[Dobra (Kupa)|Dobra River]] enters a 17 km long cave system at {{ill|Đulin ponor|hr}} in [[Ogulin]], [[Croatia]].]]
{{Refimprove|date=January 2011}}
A '''ponor''' is a natural opening where surface water enters into underground passages; they may be found in [[Karst topography|karst]] landscapes where the geology and the geomorphology is typically dominated by porous [[limestone]] rock. Ponors can drain stream or lake water continuously or can at times work as [[Spring (hydrology)|springs]], similar to [[estavelle]]s.<ref name=":0">{{Cite book|last=Bonacci|first=Ognjen|url=https://books.google.com/books?id=bhiJ10Xx9VwC|title=Encyclopedia of Caves and Karst Science|date=2004|publisher=Taylor & Francis|isbn=978-1-57958-399-6|editor-last=Gunn|editor-first=John|pages=1282–1284|language=en|chapter=Ponor}}</ref> Morphologically, ponors come in forms of large pits and [[cave]]s, large [[fissure]]s and caverns, networks of smaller cracks, and sedimentary, [[Alluvium|alluvial]] drains.<ref name=":0" />
[[File:RakovSkocjan3.jpg|thumb|right|One of several ponors of the [[Rak (river)|Rak River]], Slovenia]]
A '''ponor''' is a natural surface opening that may be found in landscapes where the geology and the geomorphology is characterized by some kind of [[Karst topography|karst]].


==Etymology==
==Etymology==
{{wiktionary|ponor}}
The term "ponor" has become the international geological term for larger karst-induced surface water inlets. The word derives from the [[proto-Slavic language|proto-Slavic]] ''nora'' (pit, hole, abyss). The word "ponor" itself comes from [[Slovene language|Slovene]] in which word ''ponor'' has the same meaning.<ref>{{cite journal |last1=Dicken |first1=Samuel N. |date=November 1935 |title=Kentucky Karst Landscapes |journal=The Journal of Geology |volume=43 |issue=7 |pages=708–728 |doi=10.1086/624363 |jstor=30057941 |quote = Since local terms such as "sink," "sink hole", "kettle", "bottom", etc., are vague and confusing the Slovene terminology ("ponor", "doline", etc.) is used for the karst forms.}}</ref>
The name for the karst formation ponor comes from [[Croatian language|Croatian]] and [[Slovene language|Slovene]].<ref>{{cite journal|last1=Dicken|first1=Samuel N.|date=November 1935|title=Kentucky Karst Landscapes|journal=The Journal of Geology|volume=43|issue=7|pages=708–728|doi=10.1086/624363|jstor=30057941|s2cid=140553389|quote=Since local terms such as "sink," "sink hole", "kettle", "bottom", etc., are vague and confusing the Slovene terminology ("ponor", "doline", etc.) is used for the karst forms.}}</ref> It derives from the [[proto-Slavic language|proto-Slavic]] word ''*nora'', meaning ''pit'', ''hole''.<ref>{{Cite web|title=Ponor/ponirati|url=https://hjp.znanje.hr/index.php?show=search_by_id&id=eVpnXRE=&keyword=ponirati|access-date=2021-11-03|website=Hrvatski jezični portal}}</ref>

Several places in southeast Europe (Bulgaria, Croatia, Czech Republic, Hungary, Romania, Montenegro, Slovenia) [[Ponor (disambiguation)|bear the name ''Ponor'']] due to associated karst openings.


==Description==
==Description==
Whereas a [[sinkhole]] is a depression ([[Sinkhole|doline]]) of surface topography with a pit or cavity directly underneath, a ponor is kind of a portal where a surface stream or lake flows either partially or completely underground into a karst [[groundwater]] system. Steady water erosion may have formed or enlarged the portal in (mainly [[limestone]]) rock, in a [[Conglomerate (geology)|conglomerate]], or in looser materials.
Whereas a [[sinkhole]] (doline) is a depression of surface topography with a pit or cavity directly underneath, a ponor is kind of a portal where a surface stream or lake flows either partially or completely underground into a karst [[groundwater]] system.<ref name=":0" /> Steady water erosion may have formed or enlarged the portal in (mainly [[limestone]]) rock, in a [[Conglomerate (geology)|conglomerate]], or in looser materials. Karst terrains are known for surface water losses through small ponors and its resurgence after having traveled through vast underground systems.<ref name=":0" />


==Prevalence==
==Prevalence==
Ponors are found worldwide, but only in karst regions. The entire [[Adriatic Basin|Adriatic watershed]] within [[Bosnia and Herzegovina]] sits on Dinaric karst, with numerous explored and probably many more unexplored ponors and underground flows.<ref name="Bosnia-Devon">{{cite web|title=The Karstography of the Dinaric Karst in Bosnia and Hercegovina|url=http://www.devonkarst.org.uk/Karstography%20of%20DINARIC%20KARST%20in%20BiH.html|website=devonkarst.org.uk|publisher=Devon Karst|accessdate=4 September 2016|language=English|format=.html}}</ref><ref name="home-Devon">{{cite web|title=The Devon Karst Research Society|url=http://www.devonkarst.org.uk/INDEX.html|website=www.devonkarst.org.uk|publisher=Devon Karst|accessdate=4 September 2016|language=English|format=.html}}</ref><br/> There are also several places in southeast Europe (Bulgaria, Croatia, Czech Republic, Hungary, Romania, Montenegro, Slovenia) with the name "Ponor" due to associated karst openings. There are significant geological ponors in the [[Carpathian Mountains]], the [[Dinaric Alps]], Greece, Turkey, and parts of the southern United States.{{citation needed|date=September 2016}}
Ponors are found worldwide, but only in karst regions. The entire [[Adriatic Basin|Adriatic watershed]] within [[Bosnia and Herzegovina]] sits on Dinaric karst, with numerous explored and probably many more unexplored ponors and underground flows.<ref name="Bosnia-Devon">{{cite web|title=The Karstography of the Dinaric Karst in Bosnia and Hercegovina|url=http://www.devonkarst.org.uk/Karstography%20of%20DINARIC%20KARST%20in%20BiH.html|access-date=4 September 2016|publisher=The Devon Karst Research Society|language=en}}</ref><ref name="home-Devon">{{cite web|title=The Devon Karst Research Society|url=http://www.devonkarst.org.uk/INDEX.html|website=www.devonkarst.org.uk|publisher=Devon Karst|access-date=4 September 2016|language=en|format=.html}}</ref> There are significant geological ponors in the [[Carpathian Mountains]], the [[Dinaric Alps]], Greece, Turkey, and parts of the southern United States.{{citation needed|date=September 2016}}


<gallery>
<gallery>
File:Katavothra-Feneos ponor karst-depression Peloponnese Feneos mit katavothre.jpg|Polje of [[Feneos]], [[Greece]], lake until late 19. Century. Rain showers flood large parts even today
File:Skocjanske-Ponor3.jpg|A ponor where the [[Reka River]] disappears into [[Škocjan Caves]], Slovenia
File:Katavothra Peloponnese.jpg|Collecting basin, stone rake, ponor (behind viewer), Peloponnese
File:Ponor, Stubaier Alpen.jpg|A [[Stubai Alps]] stream terminates in a ponor
File:Kraski Poziralnik.jpg|A fenced-in ponor south of [[Grosuplje]], Slovenia
File:Avenul campeneasca.jpg|Closeup of ponor in Câmpeneasca cave near [[Izbuc]] village, Romania
File:Avenul campeneasca.jpg|Closeup of ponor in Câmpeneasca cave near [[Izbuc]] village, Romania
File:Skocjanske-Ponor3.jpg|A ponor where the [[Reka River]] disappears into [[Škocjan Caves]], Slovenia
File:Risle ponor.jpg|The [[Risle]] River disappears into a ponor between [[Ajou]] and [[La Houssaye]] ([[Eure]], France)
File:Risle ponor.jpg|The [[Risle]] River disappears into a ponor between [[Ajou]] and [[La Houssaye]] ([[Eure]], France)
File:Jakovica, Logatec - požiralnik Pod stenami na Planinskem polju.jpg|A man-made ponor in [[Logatec]], [[Slovenia]]
File:Katavothra ponor Nestani-Polje Peloponnes Greece.jpg|In [[Polje]] "[[Argon Pedion]]" (untilled plain). Plain and ponor documented since 2nd century AD by [[Pausanias (geographer)|Pausanias]]
</gallery>
</gallery>

== Dams and reservoirs in karst ==
[[Reservoir]]s in karst are prone to losses due to leakage through ponors. The construction of [[dam]]s to capture water in karst terrains may pose a great [[financial risk]] despite initial investigations and thorough sealing treatments.<ref name=":1">{{Cite book|last=Milanović|first=Petar|url=https://books.google.com/books?id=bhiJ10Xx9VwC|title=Encyclopedia of Caves and Karst Science|date=2004|publisher=Taylor & Francis|isbn=978-1-57958-399-6|editor-last=Gunn|editor-first=John|pages=571–575|language=en|chapter=Dams and reservoirs on karst}}</ref> It wasn't until the twentieth century that the first dams in karst were built, some of which famously failed.<ref name=":1" />


== See also ==
== See also ==
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==References==
==References==
{{Reflist}}
{{Reflist|colwidth=30em}}

{{Caves}}
{{Rivers, streams and springs}}


[[Category:Karst caves|.]]
[[Category:Karst caves|.]]
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[[Category:Dinaric Alps]]
[[Category:Dinaric Alps]]
[[Category:Dinaric karst formations]]
[[Category:Dinaric karst formations]]
[[Category:Sinkholes]]

Latest revision as of 09:05, 3 August 2024

The Dobra River enters a 17 km long cave system at Đulin ponor [hr] in Ogulin, Croatia.

A ponor is a natural opening where surface water enters into underground passages; they may be found in karst landscapes where the geology and the geomorphology is typically dominated by porous limestone rock. Ponors can drain stream or lake water continuously or can at times work as springs, similar to estavelles.[1] Morphologically, ponors come in forms of large pits and caves, large fissures and caverns, networks of smaller cracks, and sedimentary, alluvial drains.[1]

Etymology

[edit]

The name for the karst formation ponor comes from Croatian and Slovene.[2] It derives from the proto-Slavic word *nora, meaning pit, hole.[3]

Several places in southeast Europe (Bulgaria, Croatia, Czech Republic, Hungary, Romania, Montenegro, Slovenia) bear the name Ponor due to associated karst openings.

Description

[edit]

Whereas a sinkhole (doline) is a depression of surface topography with a pit or cavity directly underneath, a ponor is kind of a portal where a surface stream or lake flows either partially or completely underground into a karst groundwater system.[1] Steady water erosion may have formed or enlarged the portal in (mainly limestone) rock, in a conglomerate, or in looser materials. Karst terrains are known for surface water losses through small ponors and its resurgence after having traveled through vast underground systems.[1]

Prevalence

[edit]

Ponors are found worldwide, but only in karst regions. The entire Adriatic watershed within Bosnia and Herzegovina sits on Dinaric karst, with numerous explored and probably many more unexplored ponors and underground flows.[4][5] There are significant geological ponors in the Carpathian Mountains, the Dinaric Alps, Greece, Turkey, and parts of the southern United States.[citation needed]

Dams and reservoirs in karst

[edit]

Reservoirs in karst are prone to losses due to leakage through ponors. The construction of dams to capture water in karst terrains may pose a great financial risk despite initial investigations and thorough sealing treatments.[6] It wasn't until the twentieth century that the first dams in karst were built, some of which famously failed.[6]

See also

[edit]

References

[edit]
  1. ^ a b c d Bonacci, Ognjen (2004). "Ponor". In Gunn, John (ed.). Encyclopedia of Caves and Karst Science. Taylor & Francis. pp. 1282–1284. ISBN 978-1-57958-399-6.
  2. ^ Dicken, Samuel N. (November 1935). "Kentucky Karst Landscapes". The Journal of Geology. 43 (7): 708–728. doi:10.1086/624363. JSTOR 30057941. S2CID 140553389. Since local terms such as "sink," "sink hole", "kettle", "bottom", etc., are vague and confusing the Slovene terminology ("ponor", "doline", etc.) is used for the karst forms.
  3. ^ "Ponor/ponirati". Hrvatski jezični portal. Retrieved 2021-11-03.
  4. ^ "The Karstography of the Dinaric Karst in Bosnia and Hercegovina". The Devon Karst Research Society. Retrieved 4 September 2016.
  5. ^ "The Devon Karst Research Society" (.html). www.devonkarst.org.uk. Devon Karst. Retrieved 4 September 2016.
  6. ^ a b Milanović, Petar (2004). "Dams and reservoirs on karst". In Gunn, John (ed.). Encyclopedia of Caves and Karst Science. Taylor & Francis. pp. 571–575. ISBN 978-1-57958-399-6.