The distribution of sea surface and bottom water temperature and salinity is perhaps the best representation of the state of the climate system, as the ocean plays a fundamental role in the evolution of Earth’s climate. Therefore, determining the past temperature evolution of the ocean is key for understanding Earth’s history. This article discusses the four important paleotemperature proxies, namely Mg/Ca in planktonic foraminifera and Sr/Ca in corals as recorders of sea-surface temperatures and Mg/Ca in benthic foraminifera and ostracods as proxies of bottom-water temperatures. A clear advantage of these carbonate-based thermometers is that coupling δ18O and Mg/Ca measurements in foraminifera or Sr/Ca in corals, provides a novel way to adjust for the temperature-dependency of δ18O and isolate the record of δ18Owater, which can then be used to reconstruct local changes in evaporation-precipitation (and by inference salinity) and provide valuable information about changes in continental ice volume.
All Science Journal Classification (ASJC) codes
- Earth and Planetary Sciences(all)