Glacier and lake-level variations in west-central Europe over the last 3500 years

Abstract

On the basis of glacier and lake-level records, this paper attempts, for the first time, a comparison between high-resolution palaeohydrological and palaeoglaciological data in west-central Europe over the past 3500 years. A data set of tree-ring width, radiocarbon and archaeological data, in addition to historical sources, were used to reconstruct fluctuations of the Great Aletsch, the Gorner and the Lower Grindelwald glaciers in the Swiss Alps. The three ice-streams experienced nearly synchronous advances at c. 1000-600 BC and AD 500-600, 800-900, 1100-1200 and 1300-1860. These glacier fluctuations show strong correspondence with lake-level variations reconstructed in eastern France (Jura mountains and Pre-Alps) and on the Swiss Plateau. This supports the hypothesis of climatically driven fluctuations. Historical data available for the period since AD 1550 reveal, in detail, various meteorological conditions behind the successive glacier advances. However, in agreement with the general trend shown by the historical data, the synchroneity between glacier advances and periods of higher lake level suggests the impact of general winter cooling and an increase in summer moisture as responsible for reinforced feeding of both glaciers and lakes in west-central Europe over the past 3500 years. Finally, a comparison between the Great Aletsch glacier and the residual 14C records supports the hypothesis that variations in solar activity were a major forcing factor of climatic oscillations in west-central Europe during the late Holocene.

Support for global climate reorganization during the “Medieval Climate Anomaly”

“…The model results do not reproduce the medieval summer warming in Europe indicated by proxy records (e.g., Lamb 1965;Holzhauser et al 2005;Büntgen et al 2006; see also Goosse et al 2006), at least not much beyond the global average temperature increase resulting from the artificially induced warmer tropical SSTs (about 0.5°C). The model results do, however, indicate 5-10% less summer rainfall over Britain, consistent with Lamb's (1965) reconstruction for medieval times (see also Proctor et al 2000;Charman et al 2006), this in association with a well developed ''summer NAO'' SLP pattern (Folland et al 2008; Fig.…”

Tree ring-dated fluctuation history of Midui glacier since the little ice age in the southeastern Tibetan plateau

“…The fluctuations of 1777, 1807-1818, 1874-1894 and 1912-1918 were also evidenced by tree rings in glaciers of Alaska. Both tree-ring evidence and historical documents about glaciers in mid-south Swiss Alps [49] show that there were at least two glacier fluctuations of 1778-1779 and 1855-1856. These glacier fluctuations are all in good agreement with activities of Midui glacier on decadal scale.…”

Quantifying and specifying the solar influence on terrestrial surface temperature

“…The lake level fluctuations closely correspond to the atmospheric 14 C fluctuations and therefore also to the history of solar activity. Holzhauser et al (2005) compared glacier and lake level fluctuations in westcentral Europe over the last 3500 years and demonstrated synchronicity between glacier advances, periods of higher lake levels and maxima of atmospheric radiocarbon. There are numerous other examples of sediment and lake level data that point to a solar link (Baker et al, 2005;Morrill et al, 2006;Patterson et al, 2004;Stager et al, 2005;Verschuren et al, 2000;Wu et al, 2006;Haltia-Hovi et al, 2007).…”