Glacial sea level lowstands of the last 500,000 years

• Published in: Nature
• Main Authors: Rohling, E.J., Fenton, M., Jorissen, F.J., Bertrand, P., Ganssen, G.M., Caulet, J.P
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1998
• Subjects: /dk/atira/pure/sustainabledevelopmentgoals/life_below_water; name=SDG 14 - Life Below Water; Antarc*; Antarctic; Greenland
• Online Access: https://research.vu.nl/en/publications/0b301c13-f4c0-4d6a-8322-7ee7ef9fc314; https://doi.org/10.1038/28134

Existing techniques for estimating natural fluctuations of sea level and global ice-volume from the recent geological past exploit fossil coral-reef terraces or oxygen-isotope records from benthic foraminifera. Fossil reefs reveal the magnitude of sea-level peaks (highstands) of the past million years, but fail to produce significant values for minima (lowstands) before the Last Glacial Maximum (LGM) about 20,000 years ago, a time at which sea level was about 120 m lower than it is today. The isotope method provides a continuous sea-level record for the past 140,000 years (ref. 5) (calibrated with fossil-reef data), but the realistic uncertainty in the sea-level estimates is around ±20 m. Here we present improved lowstand estimates- extending the record back to 500,000 years before present-using an independent method based on combining evidence of extreme high-salinity conditions in the glacial Red Sea with a simple hydraulic control model of water flow through the Strait of Bab-el-Mandab, which links the Red Sea to the open ocean. We find that the world can glaciate more intensely than during the LGM by up to an additional 20-m lowering of global sea-level. Such a 20-m difference is equivalent to a change in global ice-volume of the order of today's Greenland and West Antarctic ice-sheets.