Do the Oxygen Isotopes of Foraminifera Record Temperature?
The objective of this project was to examine how well the temperatures inferred from the oxygen isotope ratios (d18O) in the skeletons of different species of planktonic foraminifera record the temperature of the water in which the forams grew. Scientists studying future climate change use d18O in forams from sea floor sediments to understand past climate change. But the isotopic temperature record and month of bloom of different planktonic species is not well understood. The study area is in the North Atlantic Ocean, near 40°N, 70°W. The samples were collected in 1981-82 and were stored in buffered solutions. I sieved the solutions and extractedcarbonate skeletons of several different species of planktonic foraminifera. d18O was measured on a mass spectrometer at Woods Hole Oceanographic Institution. Based on salinity, I estimated the d18O value of the water for this area and calculated temperatures using a published equilibrium equation. I compared the resulting temperatures to ocean
