Sr/Ca
 anomalies for the northernmost Red Sea. Bimonthly Porites coral d18O (red) and Sr/Ca (blue) time series and coral-based SST anomalies (respective mean was subtracted). a, Modern corals and in situ SST (dotted line), SST is from Genin et al., Nature (1995), b, late Holocene (2.9 kyr) and d, last interglacial coral (122 kyr). Modified from Felis et al., Increased seasonality in Middle East temperatures during the last interglacial period, Nature) |
| 164-168 (2004). |
Sr/Ca ratios in the aragonite skeleton of massive reef corals is one of the principle techniques used to derive past sea surface temperatures (SSTs) (e.g., Beck 1992; Guilderson et al., 1994; Hughen et al., 1999; McCulloch 2000; Correge et al., 2004). The technique is based on an inverse correlation between temperature and Sr/Ca in living corals that is applied to ancient specimens to reconstruct surface temperatures of past oceans. However, interpretation of paleoSST estimates obtained from coral Sr/Ca is confounded by vital effects, (Weber 1973; de Villiers et al., 1995; Cohen et al., 2001; 2002; Felis et al., 2004) which may be substantial relative to the small temperature dependence of Sr/Ca in experimentally produced aragonite crystals (Kinsman and Holland 1969; Dietzel et al., 2004). Because of the long residence times of Sr and Ca in the oceans [5.1 X 106 yr for Ca (Broecker and Peng, 1982)], it has generally been assumed that the Sr/Ca activity ratio has remained essentially constant over the past 100 000 years or so.
 anomalies for the northernmost Red Sea. Bimonthly Porites coral d18O (red) and Sr/Ca (blue) time series and coral-based SST anomalies (respective mean was subtracted). In situ SST (dotted line) is from Genin et al., Nature (1995). Modified from Felis et al., Increased seasonality in Middle East temperatures during the last interglacial period, Nature) |
| 164-168 (2004). |
