The full programme book (PDF) - Royal Geographical Society

T6
Postglacial relative sea-level change and the deglaciation of northwest Iceland
M. D. Brader 1 *, J. M. Lloyd 1 , M. J. Bentley 1 , A. J. Newton 2 and N. L. M. Barlow 1
1 Department of Geography, Durham University, South Road, Durham, DH13LE
2 Institute of Geography, University of Edinburgh, Drummond Street, Edinburgh, EH8 9XP
Until recently, comparatively little scientific investigation had been undertaken to establish
postglacial relative sea level (RSL) changes in Iceland, particularly in the northwest. This
project aims to employ new and existing RSL data to resolve the current debates
regarding the Last Glacial Maximum (LGM) ice extent of the Icelandic Ice Sheet (IIS). An
accurate understanding of the LGM ice extent in Iceland is important, as the two
contrasting LGM ice loading scenarios would have very different implications for global
thermohaline circulation and therefore climate. Previous studies of glacial geomorphology
and sedimentology have failed to unequivocally distinguish between the two scenarios.
However, RSL study has the potential to address this issue when undertaken in specific
locations that are likely to yield contrasting histories under the two glaciation hypotheses.
Northwest Iceland has this potential, whilst also proving sensitive to current ice and Earth
models. As a result, this study will provide a critical test of these models for Iceland,
through the employment of RSL data and subsequent glacio-isostatic adjustment (GIA)
modelling. A number of isolation basin and coastal lowland sites have been sampled and
analysed for microfossils along two transects of research in northwest Iceland, with
tephrochronological analyses identifying useful isochrones for the study. Mapping of the
marine limit has also provided an insight into the pattern and timing of deglaciation. New
RSL records have therefore been generated for a number of the proposed research
locations, allowing the testing of a series of crustal characteristics and ice loading
scenarios for Iceland. Further modelling of GIA will allow the two contrasting hypotheses
of the LGM glaciation of Iceland to be tested and evaluated.
Keywords: sea-level; Iceland; deglaciation; glacio-isostatic adjustment