A new high-resolution reconstruction of the patterns and rates of Holocene climate change at the mid-latitudes is essential in order to test several recent hypotheses and models for sub-Milankovitch climate fluctuations. This proposal proposes to provide the first such reconstruction for the extreme western margin of the European landmass, through detailed geochemical, isotope and palaeoecological investigations of an exceptionally high-sedimentation, laminated lake core, which has already been recovered. Specific scientific objectives include:
(i) To reconstruct, at a decadal to annual
time-resolution, the climatic record for the entire Holocene. The emphasis will be on establishing well-dated quantitative records, based on pollen, macrofossils (plant and ostracod), stable isotope (delta-O-lB and delta-C-13 measured on single species ostracod shell (where possible) and also bulk carbonate), and trace metal ratios (also on single-species ostracod shell), in order to identify periods of rapid climate change and to quantify rates of change. Chronology will be based on sedimentological investigations (including lamination/verve analysis), and C14-AMS and U-series dating. Evidence for stepwise and oscillatory changes during the Holocene, a. proposed recently by glaciochemical studies on the Greenland ice cores, GRIP and GISP2, will be critically evaluated.
(ii) To establish whether climate-change events,
recorded in cores from this climate-sensitive region of western Europe, are synchronous with the atmosphere-driven events recorded in the high latitude, Greenland ice cores, changing sea-surface temperatures in the North Atlantic and/or North Atlantic Deep Water (NADW) formation.
(iii) To establish if the Little Ice Age (LIA) was characterised by increased N. Atlantic storminess.
The latter should provide a valuable test for suggestions that the LIA atmospheric circulation was more meridional than that of the present day.
(iv) To quantify the role of oceanic thermal inertia in controlling the amplitude and rate of climatic fluctuations in the Holocene by comparing our new high-resolution record with other well-dated records from similar latitudes in western and central Europe. Our investigations will provide a multi-proxy, well-dated quantitative climate record in oceanic Europe, at a resolution that was hitherto unattainable. It represents an unparalleled opportunity to test key aspects of current models for sub-Milankovitch climate change.
Funding SchemeCSC - Cost-sharing contracts
GL50 4AZ Cheltenham
KT1 2EE Kingston-upon-thames
9747 AG Groningen