For each and every of your own crossplots, more data to your Plio-Pleistocene get to incorporate a resource with the dating ranging from the relevant heat and you can sea-level to have cold climates
An only and you may a reduced and you may highest guess are offered with the Nj highstand study. The reduced and you will large guess is calculated as actually sixty% and you can 150% of the best guess, correspondingly. Hence, the best guess isn’t the midpoint of your own imagine range; new skewed mistakes try a result of having fun with foraminifera environment selections just like the a liquids depth indication, the mistakes at which raise with broadening water depth [ Kominz ainsi que al., 2008 ]. So you’re able to carry out the regression, we require a symmetrical error delivery. I determine a great midpoint regarding the asymmetrical (triangular) mistake shipping and construct a plastic studies lay who’s symmetrical errors (see Profile step one). Problems commonly delivered to the brand new abstract lowstand study [ Kominz mais aussi al., 2008 ], in the event lowstand mistakes could be bigger than the newest highstand errors; right here we use lowstand mistakes from ±fifty yards. The new Milligrams/California DST curve are calculated having fun with an excellent adjusted regional regression off new raw study [ Lear mais aussi al., 2000 ]. Right here we repeat this regression acquire an error estimate away from the fresh new intense study. Mistakes to your DST investigation are unevenly distributed, and again we carry out a plastic material studies place which have a symmetric shipments.
cuatro.dos. Sea-level In place of Heat Crossplots
Figure 6 includes DST and Red Sea sea level data [ Siddall et al., 2003 ] compiled by Siddall et al. [2010a] . This highlights that as DSTs approach the freezing point for seawater (also highlighted in Figure 6) they show very little variation [ Siddall et al., 2010a ]. Figure 7 includes Antarctic air temperature and sea level data for the last 500 ka [ Rohling et al., 2009 ]; again the sea level data come from the Red Sea record [ Siddall et al., 2003 ; Rohling et al., 2009 ]. The proxy Antarctic air temperatures come from deuterium isotope (?D) data from EPICA Dome C [ Jouzel et al., 2007 ] and are presented as an anomaly relative to average temperature over the past 1 ka [ Rohling et al., 2009 ]. Figure 8 uses temperature data from a low-latitude SST stack from five tropical sites in the major ocean basins using the U k? 37 proxy [ Herbert et al., 2010 ] and Mg/Ca of planktic foraminifera [ Medina-Elizalde and Lea, 2005 ]. We repeat the stacking method outlined by Herbert et al. [2010 , supplementary information] but calculate temperatures as an anomaly relative to the average of the past 3 ka. Again the Plio-Pleistocene sea level data come from the Red Sea record [ Siddall et al., 2003 ; Rohling et al., 2009 ].
All of the plots of sea level against temperature exhibit a positive correlation. There is an additional component to the sea level record that may not be directly related to temperature: the change in ocean basin volume. However, it is possible that there is a common driving mechanism: decreased chatiw seafloor spreading could cause a decline in atmospheric CO2, resulting in increased basin volume (i.e., lower sea level) and decreased temperature [ Larson, 1991 ; Miller et al., 2009a ]. The sea level record may contain regional tectonic influences, which are not related to temperature change (see section 2.1). The thermal expansion gradient assuming ice-free conditions (54 m above present at NJ ; Miller et al., 2005a ]) is shown on all of the plots (6, 7–8) as a guide to how much of the NJ sea level variability is likely due to thermal expansion and glacioeustasy.