Tomasz Bytomski

Abstract The Wywierzysko Goryczkowe karst system has been the subject of numerous studies, and it was this extensive literature dating back to the 1960s, the 1980s and the end of the 20th and beginning of the 21st century that gave rise to a question regarding the role played in the development of the Wywierzysko Goryczkowe karst system by the last (Würm) Glaciation. The answer to this and other questions was sought via a reconstruction of glacial dynamic that, built on a previously agreed reconstruction of the geometry of the Sucha Woda glacier. The key here was an estimation of the amount of meltwater following the maximum extent of the glacier noted some 21–19 ka BP. The maximum coincided with the most marked Würm Glaciation cooling, this period usually being associated with deteriorating weather conditions, i.e. a decline in air temperature, lower rainfall (not exceeding 500 mm a–1 at the time) and consequently more limited ablation). During the period of maximum coverage to the likely speed of movement was of c. 14 ma–1. The movement at an altitude of 1600 m a.s.l. was thus of a little over 2 million m3a–1 of snow and ice. Taking into account the volume of snow and ice, rainfall, and the speed of the glacier, the volume of meltwater is deemed to have exceeded 105 k m3d–1. As the total volume of the glacier is an estimated 1.4 billion m3, this volume of meltwater seems relatively small. To better illustrate theissue, the author compared contemporary outflow with that during the glaciation. The outflow of water from the Sucha Woda Valley is currently 66.9 k m3d–1, though it needs to be noted that only 37% of rainwater leaves the basin at the outlet of the Tatra Mountains, the vast majority feeding the Wywierzysko Goryczkowe and Olczyskie karst system. The volume of the Wywierzysko Goryczkowe karst systemis 2.1 million m3 according to the Mangin method, making this the largest local aquifer in the Tatra Mountains. During the period of maximum glaciation prevailing climatic conditions did not facilitate the free flow of water in the glacier, which represented a natural barrier to the flow of meltwater, while a major role in the circulation of water was played by the varied relief of the Stawy Gąsienicowe Valley. In tension areas especially, deep crevices allow water to penetrate into the interior, and then to supply the ground. However, most meltwater would have flowed on the surface of the glacier. It would therefore appear that the reconstructed volume of meltwater might have had a limited role in shaping the environment in the Wywierzysko Goryczkowe karst system during the time of the valley-glaciation maximum. The author assumes that the subsequent period of glacier recession, and above all the unveiling of the sinkholes area at Hala Gąsienicowa, allowed for more free penetration of water into the karst system, probably during the early stage of permafrost formation.

Tomasz Bytomski

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