Technical note: A new online tool for δ¹⁸O–temperature conversions

The stable-oxygen-isotopic composition of marine carbonates (inline-formulaδ¹⁸Oinline-formula_c) is one of the oldest and most widely used paleothermometers. However, interpretation of these data is complicated by the necessity of knowing the inline-formulaδ¹⁸O of the source seawater (inline-formulaδ¹⁸Oinline-formula_w) from which CaCOinline-formula₃ is precipitated. The effect of local hydrography (the “salinity effect”) is particularly difficult to correct for and may lead to errors of inline-formula>10 inline-formula^∘C in sea-surface temperatures if neglected. A variety of methods for calculating inline-formulaδ¹⁸Oinline-formula_w have been developed in the literature, but not all are readily accessible to workers. Likewise, temperature estimates are sensitive to a range of other calibration choices (such as calibration species and the inclusion or exclusion of carbonate ion effects), which can require significant effort to intercompare. We present an online tool for inline-formulaδ¹⁸O–temperature conversions which provides convenient access to a wide range of calibrations and methods from the literature. Our tool provides a convenient way for workers to examine the effects of alternate calibration and correction procedures on their inline-formulaδ¹⁸O-based temperature estimates.