In this activity, students will use oxygen isotope values of two species of modern coral to reconstruct ambient water temperature over a four-year period. They use Microsoft Excel, or similar application, to create a spreadsheet of temperature values calculated from the isotope values of the corals by means of an algebraic equation. Students then use correlation and regression techniques to determine whether isotope records can be considered to be good proxies for records of past temperatures.

In this activity students work with data to analyze local and global temperature anomaly data to look for warming trends. The activity focuses on the Great Lakes area.