Image

Putting History on Ice

WHOI paleoceanographer Konrad Hughen (left) and WHOI research associate Daniel Montlucon pour liquid nitrogen into sediments retrieved from the seafloor to freeze and preserve them. Sediments accumulate over time in layers on the seafloor, and they contain fossil shells of surface-dwelling microscopic marine animals. The shells incorporate radiocarbon and other isotopes from seawater that existed when the animals lived, and hence provide a chronological record of past ocean conditions. (Photo by Tim Eglinton, Woods Hole Oceanographic Institution)