Ocean sediment data - Ice Ages and Interglacials: Measurements, Interpretation, and Models - page 181

Figure 5.6. Isotope data from a stack of 57 records as derived by Lisiecki and Raymo (2005).
Furthermore, ice volume is an integral over relatively rapid variations in solar
intensity that lead to slower variations in ice volume. Therefore, one might expect
a priori that ocean sediment data would show less variation than ice core data and
significant time lags, particularly during the buildup of ice sheets. Figure 5.8 shows
a comparison of ocean sediment data with Antarctic ice core data. Ocean sediment
data are indeed smoother and show less high-frequency variation; however, some
of this is due to averaging a stack of data from different localities. But there is
no evidence at all of significant time lags between these datasets. This is a conun-
drum. If ice core data represent temperature and sediment data represent ice
volume, why are the two curves in Figure 5.8 so similar? It would seem that one
of the following possibilities must be true: (i) ocean sediment data respond more
to temperature than has been realized, (ii) ice core data respond more to ice
volume than has been realized, and (iii) the chronologies used in both cases have