Holocene Spatial Correlation Dynamics of European Lakes.
by
Daniel J. Herron
Department of Geological Sciences, University College London, Gower Street, London WC1E 6BT, UK.
Coauthors: Peter D. Ditlevsen (University of Copenhagen, Denmark), Achim Bruaer (GFZ, Potsdam, Germany), Tomasz Goslar (Silesian Technical University, Poland), Josef Merkt (German Geological Survey, Hannover, Germany)

The study of thickness variations of annually laminated sediments can yield much information regarding palaeoclimatic conditions. In this study, thickness time series were generated from a network of several European Lakes, and analysed for spatial correlation. For the period 9000 to 7500 cal yrs BP correlation coefficients indicate weak correlation. However, ‘running’ correlation coefficients reveal the emergence of stronger correlation on decadal timescales. This relates to the capacity of lake systems to act as a type of low-pass filter. High frequency atmospheric variability or "noise" is simply absorbed into the lake system dynamics, unlike the longer timescale climatic variability, or "signal". As such, the emergence of correlation effectively represents the transition between signal and noise dynamics. This basic mechanism varies in each lake as evidenced by the varying timescale (5 to 25 yrs) over which the running correlation reaches a significant level. This represents the individual nature of each lake system, relating to morphometry, hydrological budget, as well as the local catchment properties. Although, the emergence of correlation primarily represents temporal dynamics, spatial dynamics play a vital role. Essentially, the transition from local scale, though, regional, continental, hemispheric to a global scale is characterised by a weakening of energy and matter feedback mechanisms. Thus the coherency between one or more lake systems increases, as the area of which they are correlated becomes larger. Therefore, much as today, lake systems in the early Holocene experienced symbiotic emergence of complex correlation as spatio-temporal scales increased.

Date received: April 27, 2001

Copyright © 2001 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cahi-42.