česky english deutsch <<< >>>

ČGS Olomouc

Hranická propast (Hranická Abyss)

The Hranická Abyss is the deepest abyss in the central Europe. The greatest so far measured depth is 329.5 m, but is yet to be confirmed. The HYBALL probe has so far reached to the depth of 274.5 m. An expert estimate of the real depth is about 700 m. The abyss was not created as a result of cracks and cavities caused by underground water inhibation as in the majority of karst regions, but as a result of strong outbursts of thermal mineral springs coming out of the depths. The abyss also includes the Suchá Rotunda cave (Dry Rotunda) above the water level. Hart's-tongue fern (Asplenium scolopendrium), a rare alpine relic species of a fern, grows above the lake level. The rare wild service tree (Sorbus torminalis) also occurs around the abyss. The abyss was first noted in 1580 and later recorded in the map of Moravia by John Amos Comenius in 1627. The lake contains an acidulous spring water. The visibility in water ranges from 1 m to 60 m according to the current conditions, with an average visibility of 10 to 15 m. Diving at greater depths is only possible with a special gas mixture. The greatest depth of –170 m, recorded in the Czech Republic, was accomplished by the diver Pavel Říha on 23 November 2005.

GPS position

N 49° 31.908', E 17° 45.074'



Česká geografická společnost
Mgr. Petra Karvánková, Ph.D.
Katedra geografie PF JU v Českých Budějovicích, Jeronýmova 10, 371 15 České Budějovice
Tel.:+420 387 773 063