Hranice Abyss

Flooded sinkhole near the town of Hranice, Czech Republic

Hranice Abyss

Hranice Abyss (Czech: Hranická propast) is the deepest flooded pit cave in the world. It is a karst sinkhole near the town of Hranice, Czech Republic. The greatest confirmed depth is 519.5 m (1,704 ft), of which 450 m (1,476 ft) is underwater.[1][2] In 2020, a scientific expedition to the cave revealed that part of the system apparently reaches 1 kilometre deep, albeit with the lowest reaches sediment-filled. Analysis of the water found carbon and helium isotopes which implied that the cave has been formed by acidic waters, heated by the mantle, welling up from below.[3]

## Description

[edit]

It is located near the Zbrašov Aragonite Caves, which are open to the public. The total depth of the abyss (at least 473.5 m) is unknown, as the lower part of the abyss is flooded by the Hranice Lake. The abyss has an elliptical shape and is situated in the SE-SW direction. It is approximately 110 metres long at its longest point and 50 metres wide at its widest point. For most visitors the most interesting figure is the depth of the abyss including the flooded part, but in reality it is a rather rugged karst system. Karst phenomena (e.g. sinkholes) can also be observed in the immediate vicinity of the abyss.

At a depth of 48 metres below the surface of the lake, after crossing the siphon called Zubatice (after its jagged shape), it is possible to ascend to the dry caves (Rotunda Dry, Heaven I-III, Monika). These are continuously monitored, including water and air temperature measurements. In addition, the Dry Rotunda is known as a roosting site for bats, which enter it through a very narrow passage from the Jezírka area. They have to cross about 7 metres of rock mass. The occurrence of bats is monitored and studied by experts from the Institute of Biology of the Academy of Sciences of the Czech Republic.

Below the Zubatice is narrow neck opening to the deep underwater cave called Lift. The bottom of the Lift in the depth of 219 m is covered by sunken trees and branches making every further movement complicated and dangerous. The area is therefore called Mikado (a reference to the popular game). Behind this obstacle is the neck leading to another deep cave whose depth remains still uncertain.

## Depth

[edit]

The dry part of the abyss is 69.5 metres (228 ft) deep. There is a small lake at the bottom. Below the surface, the abyss was mapped to a depth of −170 metres (−560 ft) (Pavel Říha, 2005), followed by a dive to a depth of −181 metres (−594 ft) (Starnawski, 2000) and a 21 June 2012 dive to a depth of −217 metres (−712 ft) (Starnawski with a team of six Czech and Polish divers). Robot (R.O.V.) Hyball was at a depth of -205 m (1995). The bottom was not reached because further investigations revealed a configuration of topography preventing further progress of the robot.

Map of the cave

The measurement of the depth of the abyss was made on 1 October 2012, when Krzysztof Starnawski launched a probe from a depth of 217 metres (712 ft) to a depth of 373 metres (1,224 ft) during a caving action from the organization ZO ČSS 7-02 Hranický kras Olomouc. He then briefly descended to a depth of 225 metres (738 ft) himself, which is the deepest depth reached by a diver in this location.

On 12 October 2014, Krzysztof Starnawski again measured the new maximum depth of the submerged part of the Hranice Abyss – 384 metres (1,260 ft). On 27 September 2016, the ROV made by GRALmarine reached a depth of 404 metres (1,325 ft) without reaching the bottom.[4] This surpassed the depth of Italy's Pozzo del Merro, which until then had been considered the deepest submerged chasm in the world with a maximum measured depth of 392 metres (1,286 ft). In 2022 the UNEXMIN Georobotics Ltd reached 450 metres (1,480 ft) water depth with the UX1-Neo robot[5] and set the new word record.

The total confirmed depth in 2022 was 519.5 metres (1,704 ft) – 69.5 metres (228 ft) above water, and 450 metres (1,480 ft) below. It is estimated that the depth of the abyss could be between 800–1,200 metres (2,600–3,900 ft), as indicated by the temperature and chemical composition of the water. This is confirmed by other studies published in the scientific press in 2022.

The report of Jiří Pogoda states that he launched a specially designed probe (glider) from Zubatice to a total depth of 260 metres (850 ft) on 13 April 1980, during a solitary dive, without reaching the bottom. However, his measurements are incomplete and considered unreliable, as they have not been further verified. In terms of current knowledge, Pogoda's measurements are true, but due to the constriction at −205 metres (−673 ft) metres, it would have to be a huge coincidence for his probe to sink lower and, more importantly, to be able to pull it back through a tangle of logs, branches and other obstacles at that level.

## References

[edit]

1. ^ "Exclusive: Deepest Underwater Cave Discovered". National Geographic Society. Archived from the original on 1 October 2016.
2. ^ "Hranice Abyss is believed to be 1200 m. deep (in Czech)".
3. ^ "SCIENCEMAG: The world's deepest freshwater cave just got a whole lot deeper".
4. ^ "Hranická propast je nejhlubší na světě, robot se ponořil do 404 metrů". iDNES.cz (in Czech). 30 September 2016. Retrieved 9 August 2021.
5. ^ "The Robot and the Abyss (Screener)". Retrieved 8 May 2023 - via www.youtube.com.

## External links

[edit]

Wikimedia Commons has media related to Hranická propast.

* Propast 373m depth of new pit

49°31′55″N 17°45′03″E﻿ / ﻿49.532°N 17.750778°E﻿ / 49.532; 17.750778

* v
* t
* e

Recreational dive sites

Reef diving regions

* Akumal
* Aliwal Shoal Marine Protected Area
* Aliwal Shoal
* Amed (Bali)
* Anilao
* Apo Island
* Apo Reef
* Arrecifes de Cozumel National Park
* Bay of Pigs
* Belize Barrier Reef
* Biscayne National Park
* Bohol Sea
* Bowie Seamount
* Bunaken
* Bunaken National Park
* Cahuita National Park
* Calve Island
* Capurganá
* Ċirkewwa
* Cliff Villa Peninsula
* Cozumel
* Dhilba Guuranda-Innes National Park
* Edmonds Underwater Park
* El Ikhwa Islands
* False Bay
* Għar Qawqla
* Gili Islands
* Great Barrier Reef
* Great Southern Reef
* Guadalupe Island Biosphere Reserve
* Haql
* Hol Chan Marine Reserve
* iSimangaliso Marine Protected Area
* Sodwana Bay
* John Pennekamp Coral Reef State Park
* Kadmat Island
* Ko Tao
* Lighthouse Reef
* Mantanani Islands
* Malapascua
* Martin's Haven
* Marsa Alam
* Molasses Reef
* Molokini
* Neptune Islands
* Osprey Reef
* Palancar Reef
* Panglao, Bohol
* Pescador Island
* Petit Saint Vincent
* Poor Knights Islands
* Porteau Cove Provincial Park
* Puerto Galera
* Punta Cana
* Ras Muhammad National Park
* Rondo Island
* Rottnest Island
* San Andrés (island)
* San Pedro Nolasco Island
* Shaʽb Abu Nuħas
* Shadwan Island
* Similan Islands
* Sipadan
* Socorro Island
* Sound of Mull
* St. Crispin's Reef
* Table Mountain National Park Marine Protected Area
* Taganga
* Tsitsikamma Marine Protected Area
* Tubbataha Reef
* Utila
* Wakatobi Regency
* Weh Island

Reef dive sites

* Azure Window
* Cod Hole
* Daedalus Reef
* Darwin's Arch
* Devil's Throat at Punta Sur
* Elphinstone Reef
* Eyemouth
* Fanadir
* Frederiksted Pier
* French Reef
* Fowey Rocks Light
* Gamul Kebir
* Hillsea Point Rock
* Inland Sea, Gozo
* Kennack Sands
* The Manacles
* Magic Point
* Octopus Hole
* Pope's Eye
* Portsea Hole
* Second Valley
* Sund Rock
* St Abbs
* Stingray City, Grand Cayman
* Wolf Rock

| Artificial reefs|

* Edithburgh jetty
* Gibraltar Artificial Reef
* Merkanti Reef
* Port Hughes jetty
* Port Noarlunga jetty
* Rapid Bay jetty
* Shark River Reef
* South Channel Fort
* Osborne Reef

|

Underwater artworks|

* Cancún Underwater Museum
* Christ of the Abyss
* Circle of Heroes
* Kristu tal-Baħħara
* Molinere Underwater Sculpture Park

Snorkelling sites|

* Fungus Rock

Wreck diving regions

* Bullhead Point Historical and Archeological District
* Calve Island
* Chuuk Lagoon
* Coron Bay
* Edmonds Underwater Park
* Shipwrecks of Isle Royale
* Loch Long
* Maritime Heritage Trail – Battle of Saipan
* Michigan Underwater Preserves
* Pearl and Hermes Atoll
* Porteau Cove Provincial Park
* Robben Island Marine Protected Area
* Scapa Flow
* Table Mountain National Park Marine Protected Area
* Tulagi
* Tulamben
* Thunder Bay National Marine Sanctuary
* List of shipwrecks in the Thunder Bay National Marine Sanctuary
* Ve Skerries
* Wardang Island
* Western Rocks, Isles of Scilly
* Whitefish Point Underwater Preserve
* Wreck Alley, San Diego

Wreck dive sites

* 115 (barge)

| A|

* HMS A1
* HMS A3
* USS Aaron Ward
* Abessinia
* USS Accokeek
* HMAS Adelaide
* SS Admiral Sampson
* MV Adolphus Busch
* Aeolian Sky
* USS Aeolus
* Agat World War II Amtrac
* SS Ajax
* Albert C. Field
* USS Algol
* SS Algoma
* Al Munassir
* Amaryllis
* SS America
* USS Anderson
* Andrea Doria
* Antilla
* Antilles
* USS Apogon
* SS Appomattox
* Aquila
* Aratama Maru
* Arctic
* USS Arkansas
* SS Arratoon Apcar
* USS Arthur W. Radford
* SS Atlanta
* USS Atlanta (CL-51)
* SS Australasia

|

* HMAS Bayonet
* SS Ben Doran
* SS Benwood
* Bianca C.
* USCGC Bibb
* SS Binnendijk
* USS Blenny
* HMS Boadicea
* Booya
* HMSAS Bloemfontein
* Breda
* Brian Davis
* HMAS Brisbane
* HMHS Britannic
* Bud Bar
* Bungsberg
* Byron

* HMAS Canberra
* HMCS Cape Breton
* USCGC Cape Henlopen
* Captain Keith Tibbetts
* Carl D. Bradley
* USS Carlisle
* Carnatic
* Carthaginian II
* SS Cayuga
* SS Cedarville
* Christina Nilsson
* City of Bangor
* SS City of Everett
* SS City of Launceston
* HMCS Chaudière
* ROCS Chen Hai
* Chester A. Congdon
* SS Clan Ranald
* SS Clifton
* USCGC Comanche
* SS Comet
* Constandis
* HMAS Coogee
* Cormoran
* Cornelia B. Windiate
* HMS Coronation
* Crusader
* PS Cumberland
* USS Curb
* USCGC Cuyahoga

* MV Dania
* Daniel Lyons
* David Tucker
* SMS Dresden
* SS D.R. Hanna
* USCGC Duane
* Dunraven
* SS Dwight L. Moody

* Eagle
* Eastfield
* SS Eber Ward
* SS Edgar E. Clark
* HMT Elk
* Ellengowan
* USS Emmons
* SS Emperor
* RMS Empress of Ireland
* SS Erie L. Hackley
* SS Espagne
* SS Etruria

* HMS Falmouth
* Fifi
* Fleetwing
* SS Francisco Morazan
* SS Francis Hinton
* SS Frank O'Connor
* F.T. Barney
* Fujikawa Maru
* Fumizuki

* Gallinipper
* SATS General Botha
* USNS General Hoyt S. Vandenberg
* George A. Marsh
* SS George Dewey
* George M. Cox
* Georg Thiele
* HMS Ghurka
* USS Gilliam
* SS Glenlyon
* Glen Strathallan
* SAS Good Hope
* HMAS Goorangai
* Gothenburg
* Grace A. Channon
* SS Grecian
* Green Bay
* MV Gregory Poole
* Gunilda

* MT Haven
* SS Henry Chisholm
* MT Hephaestus
* Hermann Künne
* HMS Hermes
* Herzogin Cecilie
* SS Hesper
* Hilma Hooker
* Hispania
* Home
* HMS Hood
* HMAS Hobart

* Igara
* USS Indra
* SS Ironsides
* SS Isaac M. Scott
* Island City

* HMAS J1
* HMAS J2
* HMAS J4
* HMAS J5
* James Eagan Layne
* J.S. Seaverns
* SS John B. Cowle
* John M. Osborn
* SS John Mitchell
* Jura

* SS Kamloops
* Kashi Maru
* PS Keystone State
* King Cruiser
* USS Kittiwake
* Kizugawa Maru
* SMS Kronprinz
* Kyarra
* Kyle Spangler

* PS Lady Elgin
* Lady Thetis
* HMS Laforey
* SS Lakeland
* USS Lamson
* USAT Liberty
* SS Louisiana
* Louis Sheid
* SS L.R. Doty
* USS LST-507
* Lumberman

* HMS M2
* HMCS Mackenzie
* Madeira
* SMS Markgraf
* SS Marquette
* Mayflower (scow)
* Mikhail Lermontov
* Maine
* Maloja
* HMS Maori
* SS Maori
* SS Margaret Olwill
* Marguerite
* SS Mauna Loa
* USAT Meigs
* Mendi
* MV Mercedes I
* USCGC Mesquite
* Metamora
* SS Midland City
* USS Mindanao
* Minnedosa
* SS Miowera
* SS Milwaukee
* USS Mizpah
* Miztec
* USCGC Mohawk
* Mohegan
* RMS Moldavia
* SS Monarch
* SS Monrovia
* HMS Montagu
* SS M.M. Drake
* MV RMS Mulheim
* USS Muliphen
* SS Myron

* Nagato
* Niagara
* Niagara (tug)
* HMCS Nipigon
* SS Norman
* Northerner

* Oceana
* SS Onoko
* USS Oriskany
* Oslofjord
* Ozone

* P29
* P31
* SS Panay
* SS Papoose
* Pedernales
* Persier
* HMAS Perth
* SS Pewabic
* SAS Pietermaritzburg
* USS Pilotfish
* Piłsudski
* SS Pioneer
* USCGC Point Swift
* Pool Fisher
* SS Port Kembla
* HMS Port Napier
* Preußen
* President Coolidge
* HMS Prince of Wales

* PS Queen Victoria

* SS R.P. Resor
* Radaas
* USS Rankin
* Rainbow Warrior
* SS Regina
* HMS Repulse
* RMS Rhone
* Riva Palacio
* Robert C. Pringle
* SS Robert Wallace
* USS Rochester
* Rondo
* Rosehill
* Rosinco
* Rotorua
* Rouse Simmons
* Royal Adelaide
* Royal Charter
* Rozi
* SS Russia

* HMS Safari
* Sagamore
* HMCS Saguenay
* Sakawa
* Salem Express
* SS Samuel Mather
* Samuel P. Ely
* Sanko Harvest
* USS Saratoga
* HMCS Saskatchewan
* SS S.C. Baldwin
* USS Schurz
* USS Scuffle
* USS Scrimmage
* HMS Scylla
* SS Selah Chamberlain
* HMS Sidon
* USCGC Spar
* South Australian
* USS Spiegel Grove
* Sport
* Stanegarth
* Stanwood
* Stella
* SS Stepas Darius
* HMS St Lawrence
* SS Superior City
* HMAS Swan
* Sweepstakes

* SS Tahoe
* USCGC Tamaroa
* USS Tarpon
* Thesis
* Thistlegorm
* Thomas Friant
* Thomas Wilson
* Thunderbolt Wreck
* Toa Maru
* HMAS Tobruk
* Tokai Maru
* Torrey Canyon
* SAS Transvaal
* MV Treasure
* HMNZS Tui

* U-40
* U-352
* U-1195
* Um El Faroud

* Varvassi
* USS Vermilion
* SS Vernon
* SS Vienna

* HMNZS Waikato
* Walter L M Russ
* Washingtonian (1913)
* PS Waubuno
* HMNZS Wellington
* SS Wexford
* SS William C. Moreland
* SS Wisconsin
* USS Wilkes-Barre

* USS Yancey
* YO-257
* Yongala
* HMCS Yukon

* Zenobia
* Zealandia
* Zingara

Cave dive sites

Cave diving regions of the world

Cave dive sites:

* Blauhöhle
* Blue hole
* Blue Hole (Red Sea)
* Great Blue Hole
* Blue Hole (Guam)
* Boesmansgat
* Cenote
* Dzibilchaltun
* Chinhoyi Caves
* Cocklebiddy, Western Australia
* Devil's Throat at Punta Sur
* Engelbrecht Cave
* Fossil Cave
* Hranice Abyss
* Jordbrugrotta
* Kilsby sinkhole
* Molnár János Cave
* Nereo Cave
* Piccaninnie Ponds
* Pluragrotta
* Pollatoomary
* Ricks Spring
* The Shaft
* Sistema Dos Ojos
* Sistema Huautla
* Sistema Nohoch Nah Chich
* Sistema Ox Bel Ha
* Sistema Sac Actun
* Uamh an Claonaite
* Vortex Spring
* Wakulla Springs
* Wondergat
* Zacatón

Freshwater dive sites

* Blue Hole (New Mexico)
* Blue Lake (Utah)
* Dinorwic quarry
* Dorothea quarry
* Dutch Springs
* Ewens Ponds
* Homestead caldera
* Little Blue Lake
* Logue Brook Dam
* Ponce de Leon Spring
* Rum Jungle
* Silfra
* Vortex Spring
* Wast Water
* Wazee Lake

Training sites

* Blue Abyss
* Capernwray Dive Centre
* Deep Dive Dubai
* Deepspot
* Eccleston Quarry
* Hotel Terme Millepini
* National Diving and Activity Centre
* Nemo 33
* Seacrest Cove 2
* Slickstones Quarry, Cromhall
* Stoney Cove
* Swanage Pier

Related topics

* Black-water diving
* Blue-water diving
* Low impact diving
* Recreational diving
* Scuba diving
* Scuba diving tourism
* Underwater archaeology
* Underwater diving
* Wall diving

* Outline of recreational dive sites
* Category: Underwater diving sites
* Commons: Category:Recreational dive sites
* Index of recreational dive sites
* Portal:Underwater diving

Authority control databases: National |

* Czech Republic

|

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template