Scientists identified historic flood patterns in central China by measuring the magnetic properties of polished stalagmite growth layers. Photo by Becky Strauss/University of Minnesota
Jan. 19 (UPI) -- Scientists have found evidence of precipitation and flooding patterns in caves in central China, a discovery that should bolster flood forecasting and climate modeling.
"To predict how climate change will impact the future, it's important to know what has happened in the past," Joshua Feinberg, an associate professor of Earth sciences at the University of Minnesota, said in a news release.
By studying the magnetic properties of stalagmite layers, researchers were able to plot changes in precipitation rates over time. Iron-rich materials are deposited along with mineral calcite as water drips from the ceiling of the cave to the ground where stalagmites grow. More rain and flood carries more iron, which can be measured by magnetic sensors.
Magnetic analysis of the stalagmites yielded 8,000 years of precipitation data. Among the data, scientists discovered a unique 500-year pattern, a storm cycle.
The patterns discovered in the stalagmites of Heshang Cave -- a cave carved out by the waters of the Yangtze River system -- correspond with other well-studied climate cycles, like the El Nino Southern Oscillation pattern.
Researchers hope their findings -- detailed in the journal PNAS -- will help scientists improve storm prediction models in monsoon regions. The findings will also help scientists more accurately contrast ancient and modern patterns, in order to measure the impacts of climate change on weather patterns.
"As the variability and intensity of storms increase in the world, we need to reevaluate what the frequency of these major storms could be," Feinberg explained. "We didn't have the potential to develop these kinds of precipitation records for most of the world, until now."