Monitoring of the endoglacial caves position in Gorner glacier (Switzerland)

The importance of the exploration of endoglacial cavities in the glaciers has recently opened new challenge for scientific research due to a need for observational data to understand the effects of global warming on ice masses. As cryo-karstic phenomenon is directly related to the study of hydrology and physics of glaciers, intensive surface melt and ice movement together with the massive decrease in elevation since the 1980s could affect not only the ice mass balance but also the glacial deep drainage. In fact on glacier surface with relatively flat and compact, the meltwater feed epiglacial streams with a discharge of a few cubic meters per second that make up a complex network of surface drainage that after short distances disappear in pits (moulins) created by water falling in the mass of ice. In the last 15 years, the monitoring of the position of several endoglacial caves have been performed in the Gornergletscher, the most interesting glacier in the Alps (South West of Switzerland), with the aim to distinguish local factors from global processes in the annual evolution of its moulins. Since 1999 the study took place with multiple field campaigns for morphological and location data compilation, rendered by maps. All field items have been inventoried with corresponding spatial position and compared with the previously existing information. The preliminary data elaboration shows that, even though the Gorner glacier has not yet adapted its size to the new climate and are still far away from a steady-state, moulins still form at the same spot year after year, surviving at the surface ice movement toward the margins as observed during events triggered by intensive surface melt.