Holocene climate variability as reflected by mid-European lake-level fluctuations and its probable impact on prehistoric human settlements

Abstract

A data set of 180 radiocarbon, tree-ring and archaeological dates obtained from sediment sequences of 26 lakes in the Jura mountains, the northern French Pre-Alps and the Swiss Plateau was used to construct a Holocene mid-European lake-level record. The dates do not indicate a random distribution over the Holocene, but form clusters suggesting an alternation of lower and higher, climatically driven lake-level phases. They provide evidence of a rather unstable Holocene climate punctuated by 15 phases of higher lake-level: 11 250–11 050, 10 300–10 000, 9550–9150, 8300–8050, 7550–7250, 6350–5900, 5650–5200, 4850–4800, 4150–3950, 3500–3100, 2750–2350, 1800–1700, 1300–1100, 750–650 cal. BP and after 1394 AD. A comparison of this mid-European lake-level record with the GISP2-Polar Circulation Index (PCI) record, the North Atlantic ice-rafting debris (IRD) events and the 14C record suggests teleconnections in a complex cryosphere-ocean-atmosphere system. Correlations between the GISP2-PCI, the mid-European lake-level, the North Atlantic IRD, and the residual 14C records, suggest that changes in the solar activity played a major role in Holocene climate oscillations over the North Atlantic area.