The last glacial cycle was characterized by substantial millennial-scale climate fluctuations, but the extent of any associated changes in global sea level (or, equivalently, ice volume) remains elusive. Highstands of sea level can be reconstructed from dated fossil coral reef terraces, and these data are complemented by a compilation of global sea-level estimates based on deep-sea oxygen isotope ratios at millennial-scale resolutions or higher. Records based on oxygen isotopes, however, contain uncertainties in the range of ±30 m, or ±1 °G in deep sea temperature. Here we analyse oxygen isotope records from Red Sea sediment cores to reconstruct the history of water residence times in the Red Sea. We then use a hydraulic model of the water exchange between the Red Sea and the world ocean to derive the sill depth - and hence global sea level-over the past 470,000 years (470 kyr). Our reconstruction is accurate to within ±12 m, and gives a centennial-scale resolution from 70 to 25 kyr before present. We find that sea-level changes of up to 35 m, at rates of up to 2 cm yr-1, occurred coincident with abrupt changes in climate.
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Acknowledgements We thank N. Shackleton for advice and permission to use the deep-sea d18O record of MD952042b, E. Bard for Tahiti sea-level estimates, and A. Hogg, J. F. McManus, P. M. Grootes and H. Erlenkeuser for help during the preparation of this Letter. M.S. has been funded by a NERC studentship.
Acknowledgements We thank N. Dempsey for critical reading of the manuscript, and D. Weller for discussions. This work was partly supported by the US National Science Foundation, Seagate Technology, the Catalan Direcció General de Recerca, and the Spanish Comisión Interministerial de Ciencia y Tecnología.