date: Sun, 15 Jan 2006 16:12:45 -0500 from: "W.R Peltier" subject: [Wg1-ar4-ch06] Emailing: IPCCsealevelgraphic.eps to: Wg1-ar4-ch06@joss.ucar.edu Dear Colleagues, Attached is the next draft of the graphic describing the variation of sea level through the most recent ice age cycle. I have modified it in the way suggested during our meeting in Christchurch. This has involved incorporating the data assembled in the paper by Waelbroeck et al (2002) into an inset for the entire last glacial interglacial cycle. Claire very kindly sent me the original data plotted in this paper. For the last 30,000 years, however, I've shown the complete set of data that is now available from the Barbados location at a sufficiently high resolution that one can appreciate the importance of the new samples that have become available . In particular, the complete set of U/Th dated coral samples enables us to refine our understanding of the period extending from pre- to post-LGM in an important way. the new data have also provided better resolution of the post-Younger Dryas event called meltwater pulse 1b. Suggestions for further improvements of this Figure will be welcome. The caption for this revised version of the Figure is as follows: Figure 6.4. In (a) the range of allowed variations of eustatic sea level that have occurred over the last glacial-interglacial cycle is depicted according to the data assembled by Waelbroeck et al.(2002). These data included both dated coral assemblages from the tropics as well as oxygen isotope records from deep sea sedimentary cores that have been corrected in order to optimally remove the influence of temperature variations in the abyssal ocean that contaminate what is otherwise an excellent proxy for the volume of continental ice on the continents and therefor eustatic sea level. Superimposed upon the Waelbroeck et al. record is the eustatic sea level record corresponding to the ICE-5G model of this cycle ( shown in red) of Peltier (2004) for which the global distribution of time dependent ice thickness is available from http://www.sbl.statkart.no/projects/pgs/ice_models/. The black curve on the insert is the SPECMAP oxygen isotope record of Imbrie et al. (1984) scaled so as to deliver the same sea level as that observed at Barbados at 30 ka. In (b) is shown the complete set of U/Th dated coral derived sea level index points now available from the Barbados location (Fairbanks 1989, Peltier and Fairbanks 2006). The acropora palmata samples, which provide the tightest constraint on sea level, are shown with an error bar of 5m extending upwards from the depth at which they were sampled as is appropriate given that this is the greatest depth below sea level at which this species is found in the modern ecology. The data with the 20m intermediate length error bars attached are samples of the species monastrea annularis. Although they do not provide a tight constraint on sea level they are nevertheless useful as they provide a upper bound upon the sea level depression where such samples are available. The other samples for which the data are also shown provide similar information. The red curve superimposed upon the data, as in (a), is the theoretical prediction for the sea level history at this site based upon the ICE-4G(VM2) model of Peltier (2004). As noted directly on the Figure, the net eustatic sea level depression at the conventional age of the LGM ( 21 ka) according to the ICE-5G(VM2) model, which accurately fits the observations, is 118.7m. This is very close to the conventional oxygen isotope derived estimate of Shackleton (eg. 2000) and to the temperature corrected oxygen isotope records shown in Waelbroeck et al.(2002). Cheers Dick PS. The font employed for the lettering on this Figure will be reduced in size in the next edition of the graphic. IPCCsealevelgraphic.eps Note: To protect against computer viruses, e-mail programs may prevent sending or receiving certain types of file attachments. Check your e-mail security settings to determine how attachments are handled. Prof W.R Peltier Dept of Physics, University of Toronto 60 St. George Street, Toronto, Ontario, CANADA, M5S 1A7 Tel (416)-978-2938 Fax (416)-978-8905 email peltier@atmosp.physics.utoronto.ca Attachment Converted: "c:\eudora\attach\IPCCsealevelgraphic.eps" _______________________________________________ Wg1-ar4-ch06 mailing list Wg1-ar4-ch06@joss.ucar.edu http://www.joss.ucar.edu/mailman/listinfo/wg1-ar4-ch06