Active rock glaciers

Elevation: A: 2430-2600m, B: 2450-2580m - Massif: Western Tessin Alps (Gotthard) - Commune: Airolo (Ti)

The Monte Prosa site is located about one kilometer north of the Gotthard Pass at the foot the homonymous summit. There are two active rock glaciers named A and B (in some publications North and South respectively). In situ kinematic (DGNSS) and thermal (GST) monitoring started in summer 2009. The primarily goal was to get information on the specificities of the behavior of rock glaciers in this part of the Alps, where the rain/snow conditions may be very contrasted in comparison to the surrounding alpine regions.

Monte Prosa A is the fastest rock glacier, which is monitored in the Tessin Alps and the Gotthard region with velocities that can be faster than 50 cm/year. Monte Prosa B is a smaller rock glacier, which moves slower at a rate of about 10-15 cm/year. Monte Prosa A is integrated since 2010 as a “kinematics” site within the PERMOS (PERmafrost MOnitoring Switerland) network.


  • Measurements and observations

    Thermal (ground surface temperature : GST)
    Geodetic (GNSS)

  • Figures

    Rock glacier Monte Prosa A (MP-A): the main body consists of two fronts superimposed on a cutting plane. There are also several ridges that testify to the activity.



    Rock glacier Monte Prosa B (MP-B) seen from the valley : the front can be clearly distinguished.



    Measured horizontal flow field.



    Annual horizontal surface velocity. Mean of a set of points selected in the most active part of both rock glaciers.



    Velocities derived from a permanent GNSS (GPS) station located in the central part of Monte Prosa A rock glacier.



    Daily ground surface temperature (GST) at two locations on the Monte Prosa A rock glacier.



    Mean annual ground surface temperature (MAGST) at two locations on the Monte Prosa A rock glacier.



    Contribution of the annual Ground Freezing (sum of all daily mean values < 0°C) and Ground Thawing (>0°C) Indexes to the mean annual ground surface temperature (MAGST) on a set of selected locations (n) on the site with indication of the respective trend since the beginning of the time series. Or : how cold was the winter and how warm was the summer at the surface of the ground ?



    Annual dates of the start and end of the snowmelt period (zero curtain phase). Mean of n sensors placed on permafrost terrain. The dotted lines show the mean dates since the beginning of the time series.



  • Collaboration

    Gruppo Permafrost Ticino (GPT) (Dr. Cristian Scapozza, Istituto scienze della Terra (IST), Scuola universitaria professionale della Svizzera italiana (SUPSI); Stefano Mari, Liceo 2 Lugano)

    Geosat SA

  • Publications

    PERMOS 2019. Permafrost in Switzerland 2014/2015 to 2017/2018. Noetzli, J., Pellet, C., and Staub, B. (eds.), Glaciological Report (Permafrost) No. 16-19 of the Cryospheric Commission of the Swiss Academy of Sciences, 104 pp, DOI:10.13093/permos-rep-2019-16-19.  

    PERMOS (2016). Permafrost in Switzerland 2010/2011 to 2013/2014. Noetzli, J., Luethi, R., and Staub, B. (eds.), Glaciological Report (Permafrost) No. 12-15 of the Cryospheric Commission of the Swiss Academy of Sciences, 85 pp.  (pdf)  

    Mari, S. (2014). Studio e insegnamento dei movimenti di versante in ambiente periglaciale in Ticino e nella Regione Gottardo. Tesi di dottorato, Università di Friborgo, 375 pp.

    Mari, S., Scapozza, C., Delaloye, R., Lambiel, C. (2012). Il permafrost nelle Alpi Ticinesi (2006–2011). Rapporto no. 1 del Gruppo Permafrost Ticino. Bollettino della Società ticinese di scienze naturali, 100, 2012, pp. 135 - 139 (ISSN 0379-1254). (pdf)

    Mari, S., Delaloye, R., Scapozza, C. and Strozzi, T. (2011). Inventario dei movimenti di terreno per analisi dei segnali InSAR nelle Alpi meridionali svizzere (periodo 1994-2007). In Lambiel C., Reynard E. & Scapozza C. (eds.). La géomorphologie alpine: entre patrimoine et contrainte. Actes du colloque de la Société Suisse de Géomorphologie, 3-5 septembre 2009, Olivone. Lausanne: Université, Institut de géographie, Géovisions 36: 145-159. (pdf)

    Scapozza, C. & Mari, S. (2010). Catasto, caratteristiche e dinamica dei rock glaciers delle Alpi Ticinesi. Bollettino della Società ticinese di Scienze naturali, 98: 15-29.