Coral Thermometers

MIT-WHOI Joint Program student Whitney Bernstein and her advisor, Konrad Hughen of the Marine Chemistry & Geochemistry Department, sort and measure cores taken from massive Porites corals  in November 2008. After splitting the cores, they used X-ray imagery to reveal annual density bands in the cores that are similar to growth rings in trees. Researchers then often use geochemical analyses to determine the temperature of the water during the time at which each annual band grew. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)