A Geostatistical and Bioclimatological Comparison of the Central Great Caucasus and the Central Alps

Abstract

Although almost 3000 km apart, the Great Caucasus at the eastern edge of Europe and the Alps in central Europe share a common young geological age, an approximative W-E orientation, they both belong to the Eurasian mountain chain that formed and is still forming as a result of southern continents pushing northwards. Using a 1000 m elevation minimum, the Great Caucasus is stretching from 41° 15′ N to 43° 45′ N (central part at 43°N) and the Alps from 44° 10′ N to 47° 40′ N (central part at 46° 30′N), with both chains belonging to the temperate zone (Fig. 1.1). In their central part, the Alps experience a stronger maritime and the Great Caucasus or more continental influence. Both ranges divide the weather systems into northern and southern climates, and both show strong precipitation gradients. In the Great Caucasus this is a NW-SE gradient, in the Alps (with some exceptions) a N-S gradient, ranging from around 2000 mm per year to less than 500 mm at places. Both mountain systems show a mass elevation effect (‘massenerhebungseffekt’), with a higher elevation of isotherms in the interior parts compared to front ranges, and a dry, step-type climate in parts of their deep central valleys. Yet, the Caucasus forms a single main divide with a series of side valleys on either side, whereas the Alps have several chains in parallel, permitting a more pronounced mass elevation effect to occur in its interior valleys. The maximum elevation is similar, with the highest peak of the Great Caucasus, Mount Elbrus 5642 m, and that of the Alps, Mont Blanc 4809 m. Yet, some of the highest peaks in the Caucasus are former volcanoes (Mount Kasbek with 5047 m, is one of them, in the core study region of this volume), whereas in the Alps, all summits are tectonic summits.