Modelled atmospheric temperatures and global sea levels over the past million years

Abstract

Marine records of sediment oxygen isotope compositions show that the Earth's climate has gone through a succession of glacial and interglacial periods during the past million years. But the interpretation of the oxygen isotope records is complicated because both isotope storage in ice sheets and deep-water temperature affect the recorded isotopic composition. Separating these two effects would require long records of either sea level or deep-ocean temperature, which are currently not available. Here we use a coupled model of the Northern Hemisphere ice sheets and ocean temperatures, forced to match an oxygen isotope record for the past million years compiled from 57 globally distributed sediment cores, to quantify both contributions simultaneously. We find that the ice-sheet contribution to the variability in oxygen isotope composition varied from ten per cent in the beginning of glacial periods to sixty per cent at glacial maxima, suggesting that strong ocean cooling preceded slow ice-sheet build-up. The model yields mutually consistent time series of continental mean surface temperatures between 40 and 80 degrees N, ice volume and global sea level. We find that during extreme glacial stages, air temperatures were 17 +/- 1.8 degrees C lower than present, with a 120 +/- 10 m sea level equivalent of continental ice present.

Stratigraphic units of the Apulian Tavoliere plain (Southern Italy): Chronology, correlation with marine isotope stages and implications regarding vertical movements

“…However, some perplexities arise from their potentially subjective use, exposed as well in Caputo (2007). Nevertheless, for this work, the Waelbroeck et al (2002) and Bintanja et al (2005) curves have been followed because they are among the most recent. Moreover, the Bintanja curve covers the whole time range of the identified stratigraphic units.…”

“…-110 m (Waelbroeck et al, 2002) or ca. -90 m (Bintanja et al, 2005), exposing wide áreas to subaerial erosión.…”

“…-125±12m; Bintanja et al, 2005), a generalised emersión occurred, also in the central parts ofthe Manfredonia paleogulf.…”

“…The latter accumulated in a shallow marine environment during a period (MIS 17-16) characterised by a sea level lower than the present (Imbrie et al, 1984;Bintanja et al, 2005;Fig. 4).…”

Speciation dynamics in the SE Asian tropics: Putting a time perspective on the phylogeny and biogeography of Sundaland tree squirrels, Sundasciurus

“…During the Pleistocene (2 million years ago-10,000 years ago), sea level fluctuations exposed large regions of the shelf thereby connecting these islands to each other and to the mainland (Bintanja et al, 2005;Bird et al, 2005;Hall, 1998;Heaney, 1991) and then isolating them again multiple times. These connections lasted for tens of thousands of years, and the islands last became isolated only 10,000-12,000 years ago when sea level rose to less than 50 m below present levels (Voris, 2000;Hanebuth et al, 2000).…”