The tiny, pale surf clam about the size of a fingernail that most people have seen and collected on beaches around the world holds clues in its shell to Earth’s past. For the first time, researchers have been able to identify the monthly, and even weekly, ocean temperatures recorded in these smooth clam shells. Because ancient civilizations consumed these ubiquitous clams and left the shells at archeological sites, researchers now have a new way to reconstruct climate and its fluctuations from nearly 3,000 years ago.
“The equipment available now, compared to the past, is precise and powerful enough to be able to reveal the sea surface temperature and the overall climate at a specific location when the clam was building its shell. This gives us archaeologists and paleoclimatologists another tool in our proverbial toolbox to reconstruct past climate. As we know today, climate can influence all kinds of practices and behaviors, which may have been the case in ancient civilizations as well,” said LSU Department of Geography & Anthropology doctoral candidate Jacob Warner, who is the lead author on this new research published in Chemical Geology.
Warner will present this new research, Trace Element Ratios (Sr/Ca, Mg/Ca, and Ba/Ca) in the Short-Lived Bivalve Donax obesulus: Potential Environmental Proxies? at the American Geophysical Union, or AGU, Fall meeting on Tuesday, Dec. 14 from 4:00-6:00 p.m. Central. Members of the media can register to attend AGU for free.
Warner and colleagues are focused on tracking a climate phenomenon that affects a large part of the world called the El Niño Southern Oscillation, or ENSO, the warm phase of which is characterized by warmer than normal ocean temperatures, increased rainfall and more tropical storms and hurricanes in the southern U.S.
Read more at Louisiana State University
Image: Archaeologists have discovered a way to reconstruct past climates by analyzing the shells of this species of short-lived surf clams, Donax obesulus, which have been consumed by people since ancient times. (Credit: Jacob Warner, LSU)