Links between Climate and Sea Level Change - Miami University.pdfVIP

insight review articles Links between climate and sea levels for the past three million years Kurt Lambeck*†, Tezer M. Esat* Emma-Kate Potter* *Research School of Earth Sciences, Australian National University, Canberra 0200, Australia †Swedish Research Council and Lund University, Tornavägen 13, S223 63, Sweden The oscillations between glacial and interglacial climate conditions over the past three million years have been characterized by a transfer of immense amounts of water between two of its largest reservoirs on Earth — the ice sheets and the oceans. Since the latest of these oscillations, the Last Glacial Maximum (between about 30,000 and 19,000 years ago), ~50 million cubic kilometres of ice has melted from the land-based ice sheets, raising global sea level by ~130 metres. Such rapid changes in sea level are part of a complex pattern of interactions between the atmosphere, oceans, ice sheets and solid earth, all of which have different response timescales. The trigger for the sea-level fluctuations most probably lies with changes in insolation, caused by astronomical forcing, but internal feedback cycles complicate the simple model of causes and effects. he onset of Pleistocene glaciations occurred ratio shifts to lesser values and is reflected in the isotopic sig- about three million years ago with formation of nature of high-latitude snow. At times of major glaciations, permanent ice sheets at high northern latitudes. the oceans become depleted in the lighter oxygen isotope. As the ice sheets waxed and waned, the The isotope ratio 18O {(18O/16O)sample/(18O/16O)standard Tconcomitant fall and rise of sea level left direct 1}, expressed as parts per thousand, is therefore believed evi