The full programme book (PDF) - Royal Geographical Society

T8
Landscape response to abrupt climate events during the closest climatic analogue
to the Holocene
G.J. Tye 1 *, I. Candy 1 , A.P. Palmer 1 , P. Coxon 2 , M. Hardiman 1,3 , A. Scott 4 , D. Ryves 5 and K.
Loakes 5
1 Department of Geography, Royal Holloway, University of London, Egham, Surrey, TW20 0EX.
2 Department of Geography, Museum Building, Trinity College, Dublin 2
3 Department of Geography, Buckingham Building, Lion Terrace, Portsmouth, PO1 3HE
4 Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX
5 Department of Geography, Loughborough University, Leicester LE11 3TU
The British Isles offers a unique opportunity to study climates in the recent geological
record as it preserves one of the best resolved Quaternary stratigraphies in the world (e.g.
Bowen, 1999). Of the Interglacials preserved, Marine Isotope Stage 11 (MIS 11), ca
410,000 yrs BP, is the most complete and best represented (e.g. Thomas, 2001). Further
to this, MIS 11 is considered to be one of the most appropriate climatic analogues for the
Holocene, based on the similarity of orbital forcing patterns during both Interglacials
(Loutre and Berger, 2003).
Understanding the timing and dynamics of landscape response to abrupt climate change
during MIS 11 therefore has major implications for society. In this study we chose to focus
on MIS 11 because investigating the impacts of such events during the Holocene is
problematic, due to anthropogenic modification of the landscape potentially masking the
impact of climatic events. It has also been suggested that an 8.2 ka type-event occurs in
MIS 11 (Koutsodendris et al., 2012), identified through a short-lived, ca 300yr, period of
grassland expansion and woodland contraction (referred to as the Non-arboreal Pollen,
NAP phase; Turner, 1970). The spatial and temporal extent of this event can only be
deduced by high-resolution analysis of the sediments which is possible at the palaeolake
basin of Marks Tey, eastern England where an annually-laminated (varved) record of MIS
11 contains a very clear expression of the NAP phase.
We present a high-resolution, multi-proxy (oxygen isotopes, varve micro-facies, pollen,
charcoal and diatoms) reconstruction of the NAP phase at Marks Tey. The varve
chronology that is generated, when coupled with the range of proxies, allows us to
characterise the structure, magnitude and duration of this abrupt event. The varved record
also provides the opportunity to quantify any leads and lags in proxy response,
highlighting the potential problems of deriving comparable climatic data from different
archives. The forcing mechanism for this event is also discussed.
Keywords: Marine Isotope Stage 11, abrupt climate events, varve chronology, isotopes,
multi-proxy
Bowen, D.Q. (Ed.), 1999. A revised correlation of Quaternary deposits in the British Isles. Geological
Society of London Special Report No. 23.
Koutsodendris, A., Pross, J., Muller, U.C., Brauer, A., Fletcher, W.J., Kuhl, N., Kirilova, E., Verhagen,
T.M., Lucke, A. and Lotter, A.F., 2012. A short-term climate oscillation during the Holsteinian
interglacial (MIS 11c): an analogy to the 8.2 ka event? Global Planetary Change 92-93, 224-235.
Loutre, M.F. and Berger, A., 2003. Marine Isotope Stage 11 as an analogue for the present interglacial.
Global Planetary Change 762, 1-9.
Thomas, G.N., 2001. Late Middle Pleistocene pollen biostratigraphy in Britain: pitfalls and possibilities
in the separation of interglacial sequences. Quaternary Sciene Reviews 20, 1621-1630.
Turner, C., 1970. The Middle Pleistocene deposits at Marks Tey, Essex. Philosophical Transactions of
the Royal Society of London, B257, 373-440.