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)
Does solar activity or ocean circulation—or both—drive changes in the atmosphere?
By Konrad Hughen, Associate Scientist
Marine Chemistry and Geochemistry Department
Woods Hole Oceanographic Institution
Source: Oceanus Magazine
Natural materials such as shells, ice, corals, and tree rings contain clues to help scientists piece together how our oceans, atmosphere, and land have changed in the past. The history of the Earth is recorded in many different chemical codes and languages, however, so we geochemists and paleoceanographers create tools that help us translate what the planet is telling us.
My research focuses on developing tools to trace environmental changes that occurred over millennia and centuries, and even over decades and years—long before humans were recording them. The trouble is that sometimes these paleo-science tools give us conflicting information; we construct or interpret a story of the past, and then new observations upset that story.
Recently, my colleagues and I encountered such a problem. While some environmental clues tell us that the sun had a crucial role in ancient atmospheric changes on Earth, we found other clues suggesting that the oceans also play a central part. My research group is looking closely at the environmental tracers themselves to see if our current history of the Holocene Epoch (the past 10,000 years or so) is a work of fiction or nonfiction. Article posted here
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