Hydrography of the subpolar North Atlantic during the Last Interglacial

Lead Research Organisation: University of St Andrews
Department Name: Geography and Sustainable Development


We intend to reconstruct detailed information on the past variability of climate from the subpolar region of the North Atlantic in order to obtain a better understanding of the factors controlling oceanic circulation and the modes of variability that have existed in the recent past. We plan to recover quantitative palaeoclimatic information about sea surface temperatures, the geographical distribution of drift ice and current patterns as well as information about the temperature and ventilation of the deep ocean. The main time period of interest is the last interglacial period, a warm phase some 125,000 years ago when climate was comparable to the present day but global average temperatures and sea levels were slightly elevated with respect to modern values. Our overall aim is to produce new palaeoclimatic data at four key North Atlantic localities which will characterize the temporal and spatial evolution of the surface and deep ocean circulation from the end of the extremely cold conditions of the penultimate glacial period, through full interglacial conditions, to the inception of glaciation and the re-expansion of terrestrial ice sheets. This corresponds to the time interval between 135,000 and 100,000 years ago. This investigation intends to address deficiencies in our knowledge by focusing on high resolution analyses of palaeoceanographic and palaeoclimatic parameters using deep-sea sediment core material collected from high accumulation rate sites that offers the possibility of reconstructing North Atlantic surface and deep hydrography on centennial timescales. The climatic information we recover will inform us, not only about the way climate has varied in the past and the relative influence of the various climatic mechanisms, but also give us important clues about possible future changes.


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Description Our results have shown how tephra can be used to link palaeoclimate records during the last interglacial, when the Earth last experienced warm climates and high sea-levels. At this time, it is difficult to obtain reliable age data, so the tephra (volcanic ash) provide very useful marker horizons. We have provided a test for the subdivision of the last interglacial, showing how ocean circulation state continued to change during the transition into the interglacial.
Exploitation Route The results will largely be used by the scientific community working on palaeoclimate research.
Sectors Environment