URI researcher to drill African lake to assess climate history
Data will help predict future weather and impact of climate change
NARRAGANSETT, R.I. -- March 4, 2002 -- A University of Rhode Island researcher will map out millions of years of global climate changes by drilling deep into the sediment of Lake Malawi in equatorial East Africa, one of the largest, deepest and oldest lakes on Earth.
"The lake has restricted circulation and virtually no oxygen at the bottom, so each year seasonal deposition of sediment creates a pattern like tree rings," explained John King, professor of oceanography at the URI Graduate School of Oceanography. "Well be able to look at very old records of climate data simply by counting and analyzing the layers."
Joined by colleagues from three other universities, King will deploy a new drilling device that for the first time will enable researchers to collect lake sediment core samples up to 800 meters deep (shown in an NSF photo at right). Previous coring rigs could only sample tens of meters down into the sediment, which made the historic information in deeper, older sediments inaccessible.
"Were looking for records of climate in the tropics, because climate changes there appear to drive climate changes in higher latitudes," King said. "As we better understand past climate changes, we can then refine predictions of future climate."
Kings goal is to ultimately predict the impact of global warming. "By looking at intervals of time that were warmer than present conditions, we can assess the environmental impacts those warming events had and use them to predict whats going to happen over the next few centuries."
Drilling will take place for 70 days beginning in December, the time of year when conditions on the lake are usually calm. During the rest of the year, the lake can have high waves that would make drilling impossible. Upon completion of the drilling, the researchers will have hundreds of meters of core samples to analyze, enough to keep them busy for five or six years.
Once the core samples have been transported to the National Lake Core Repository in Minnesota, King will analyze them using a Geotek core analyzer to measure a range of physical properties down the cores that are indicators of climate changes. He will then use an automated cryogenic magnetometer to determine the age of the cores and to analyze changes in magnetic properties, another indicator of climate changes. URI is one of just two institutions in the country with the equipment needed to conduct these analyses.
Researchers from Syracuse University, the University of Minnesota-Duluth, and the University of Arizona will then study the cores for their biological, geochemical and geophysical properties. Funding for the project was provided by a $2 million grant from the National Science Foundations Earth System History program.
"Data sets generated by large interdisciplinary studies like the Malawi project are critical to documenting the potential magnitude of the impacts of global warming. I hope it will make it difficult for politicians to continue ignoring the science," said King.
For Information: John King 401-874-6594, Todd McLeish 401-874-7892