Rapid changes of the ice mass configuration in the dynamic Diablotins ice cave – Fribourg Prealps, Switzerland

Abstract. The Gouffre des Diablotins is a deep cave system located in the Swiss Prealps. In 1991, the lower entrance zone of the cave was almost free of ice. Nevertheless the ice volume sharply increased in 1994, plugging almost totally the gallery from the lower entrance. The ice cave has also experienced a flood period between 1996 and 2007 and very heterogeneous ice surface morphologies and textures have formed. Continuous cave climate measurements initiated in 2009 showed the predominant role of winter atmospheric air conditions to drive both the efficiency of chimney-effect air circulation and seasonal modifications of the ice mass. The main part of the ice loss is currently due to sublimation in wintertime.