In karst geology, estavelle or inversac is a ground orifice which, depending on weather conditions and season, can serve either as a sink or as a source of fresh water. It is a type of ponor or sinkhole. [1] [2]
Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. However, in regions where the dissolved bedrock is covered or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground.
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials.
A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are in locally also known as vrtače and shakeholes, and to openings where surface water enters into underground passages known as ponor, swallow hole or swallet. A cenote is a type of sinkhole that exposes groundwater underneath. A sink or stream sink are more general terms for sites that drain surface water, possibly by infiltration into sediment or crumbled rock.
The National Speleological Society (NSS) is an organization formed in 1941 to advance the exploration, conservation, study, and understanding of caves in the United States. Originally headquartered in Washington D.C., its current offices are in Huntsville, Alabama. The organization engages in the research and scientific study, restoration, exploration, and protection of caves. It has more than 10,000 members in more than 250 grottos.
Orjen is transboundary Dinaric Mediterranean limestone mountain range, located between southernmost Bosnia and Herzegovina and southwestern Montenegro.
A polje, also karst polje or karst field, is a large flat plain found in karstic geological regions of the world, with areas usually 5–400 km2 (2–154 sq mi). The name derives from the Slavic languages and literally means 'field', whereas in English polje specifically refers to a karst plain or karst field.
Ha Ha Tonka State Park is a public recreation area encompassing over 3,700 acres (1,500 ha) on the Niangua arm of the Lake of the Ozarks, about five miles south of Camdenton, Missouri, in the United States. The state park's most notable feature is the ruins of Ha Ha Tonka, an early 20th-century stone mansion that was modeled after European castles of the 16th century.
The Stone Forest or Shilin is a notable set of limestone formations about 500 km2 located in Shilin Yi Autonomous County, Yunnan Province, People's Republic of China, near Shilin approximately 90 km (56 mi) from the provincial capital Kunming.
Karst Underwater Research (KUR) is a registered 501(c)(3) non-profit organization that specializes in the research and documentation of karst aquifers and their corresponding surface features. KUR members perform a variety of scientific processes, including mapping and cartography, radio location, photography, videography, YSI water analysis and sampling.
The Trebižat is a river in the southern part of Bosnia and Herzegovina, and major right tributary of the Neretva River.
Lake Palčje is an intermittent lake in the Pivka basin north of the settlement Palčje in the Inner Carniola region of Slovenia. It fills an oval-shaped karst depression, crossed by Pivka, and approximately 1.5 km long and 0.5 km wide. Its bottom is relatively level at between 543 and 557 m above the sea, but the banks are steep. Lake Palčje is the largest among the Pivka Lakes with average maximum water area around 1 km2.
A karst spring or karstic spring is a spring that is part of a karst hydrological system.
The Hranice Abyss is the deepest flooded pit cave in the world. It is a karst sinkhole located near the town of Hranice, Czech Republic. The greatest confirmed depth is 473.5 m (1,553 ft), from which 404 m (1,325 ft) is under the water level. Moreover, the expected depth is 800–1200 m. In August 2020, a scientific campaign to the cave revealed that it is 1 kilometre deep.
Žabljak is a river near Livno in Western Bosnia, Bosnia and Herzegovina. It flows for roughly 6.6 kilometers westward through Livanjsko Polje before its confluence with the Bistrica, just upstream from beginning of its section with artificially created riverbed, from where river begins to turn southward toward Buško Blato.
The Municipality of Mirna Peč is a municipality in southeast Slovenia, located in the traditional region of Lower Carniola. The seat of the municipality, which was established in 1998, is Mirna Peč. With an estimated population of 2,800, the municipality is included in the Southeast Slovenia Statistical Region.
The Bločice Karst Field is a dry karst field in Inner Carniola.
The Račna Karst Field is a karst field in the northern edge of the Lower Carniolan karst area, south of Grosuplje, Slovenia. It has rich natural and cultural value. Because of its ecological significance, it is anticipated that a nature park will be established there and that it will be included in the Natura 2000 program.
The Šuica which is known as the Šujica (Шујица), is a sinking river flowing through Duvanjsko Polje and the wider region of Tropolje in Bosnia and Herzegovina. The river also runs through its subterranean section, which begins at the point where river goes underground within the main estavelle (ponor) at Kovači. This section of the Šuica is traversable for trained speleologists with proper equipment.
The Zalomka is a karstic river in the southern part of Bosnia and Herzegovina and one of the largest sinking rivers in the country and the world. It collects its waters from Gatačko Polje.
Trebišnjica wellspring-group is a system of two geographically and hydrologically distinct principal groupings of strong karstic springs, Trebišnjica and Čeplica, which together constitute source of the Trebišnjica river. Wellsprings are located just below town of Bileća in Bosnia and Herzegovina. The entire area where founts are situated is submerged under Bilećko Lake since 1967, formed after the construction of Trebinje-1 Hydroelectric Power Station and its large arch dam at Grnčarevo village.