Glacial landscapes of the Alps

Abstract The European Alps are the highest mountain range between continental Europe and the Mediterranean region. The Alpine chain reaches the maximum elevation at 4809 m of Mont Blanc. The highest axial sector still hosts most of the 3500 Alpine glaciers that cover a total area of about 370 km2. In contrast, toward the surrounding plains, the relief gradually decreases in elevation, forming the Prealpine belt. The proximity to the Mediterranean Sea to the south and continental Europe to the northeast promotes sectors with markedly different climates and environments. The dominantly zonal circulation, mostly driven by Westerlies from the Atlantic and South Westerlies from the Western Mediterranean, contributes to making windward sectors humid and downwind areas drier. Precipitation rates vary from below 800 mm per annum in the trunk axial valleys (600–800 m) to above 2600 mm per annum in the Julian Alps and Bernese Alps. Mean annual temperature in the 20th century was 8°C, with mean temperature at 0°C for winter and 16.1°C for summer seasons. Present equilibrium-line altitudes show a marked orographic trend rising from 2400 m along the northern fringes to above 3000 m in the Pennine Alps. During Pleistocene glaciations, Alpine glaciers extended beyond the mountain fronts onto the forelands, spreading out as piedmont lobes to build terminal moraine systems. The study of Alpine glaciers began already at the end of the 18th century. The concepts of past mountain glaciations of much greater extent and that of multiple glaciations were developed in the Alps.