Researchers from University of Minnesota Duluth (UMD), Syracuse University, University of Rhode Island and the University of Arizona will study past climates through analyses of sediment from the bottom of one of the oldest and deepest lakes on Earth.
Researchers from four universities have been awarded a $2 million grant through the National Science Foundation's Earth System History (ESH) program to take the scientific drilling of large lakes for paleoclimate research to the next level. The Global Lake 800 Drilling System (GLAD800) will be deployed to Lake Malawi at the southern end of the East African Rift Valley in a project involving researchers from the University of Minnesota Duluth (UMD), Syracuse University, the University of Rhode Island and the University of Arizona. This recently acquired drilling rig is dedicated to recovering undisturbed scientific cores samples from the bottom of large lakes.
At more than 700 meters in depth and more than 7 million years old, Lake Malawi is one of the largest, deepest and oldest lakes on Earth. The archives of paleoclimatic information preserved in its quiet depths, inaccessible until now, hold the promise of revealing important new clues concerning the evolution of Earth's climate.
"We believe that Lake Malawi will provide a unique, continuous and high resolution (annual to decadal) record of past climates in the continental tropics over the last 800,000 years," says Christopher Scholz, associate professor of earth sciences in Syracuse University's College of Arts and Sciences and principal investigator on the project. SU is receiving $1.5 million of the grant and will be responsible for oversight of the drill core acquisition portion of the project and other analyses.
Through their research, Scholz and colleagues Thomas Johnson of the University of Minnesota Duluth (UMD); Andrew Cohen of the University of Arizona; and John King of the University of Rhode Island, will attempt to understand the links between low-latitude solar insolation and high-latitude ice volume and their effect on tropical terrestrial climates.
"Understanding how inter-annual African climate variability may be influenced by longer-term climate variations such as glacial-interglacial wet and dry climate cycles is important to understanding global climate," notes Johnson.
Furthermore, the researchers will use the sediments recovered from Lake Malawi to explore the biological evolution of aquatic organisms in the region over time. "This research will complement ongoing research and educational activities at Lake Tanganyika, where NSF has supported an international science field station for several years," says Cohen, co-investigator and director of the Lake Tanganyika field station.
Drilling operations will be facilitated by the NSF-supported consortium of academic, federal and state partners in the Drilling, Observation and Sampling of the Earth"s Continental Crust (DOSECC) Program and the International Continental Drilling Program (ICDP), an international scientific drilling organization.
Preparation for the project will begin in October, and actual drilling is expected to begin in December or January 2003, Scholz says. A team comprised of a dozen faculty level researchers and graduate students will work in the field for 70 days, obtaining the samples and performing preliminary, noninvasive analysis. Core recovered during the expedition will be returned to the United States and stored at the NSF supported National Lacustrine Core Curation Facility at the University of Minnesota in Minneapolis, to be used as a resource for the wider scientific community. This research will be enhanced through collaboration with scientific colleagues from Europe and Africa, as both intellectual and financial partners.
"The GLAD800 is a tremendous tool for international paleoclimate research," says King of the University of Rhode Island. "With this innovative and flexible drilling system, the science community will demonstrate a whole new range of capability for fundamental research in paleoclimatology while stretching the boundaries of exploration for maximum public benefit."
Normally, the GLAD800 would be set up on a barge anchored over the drill site. On Lake Malawi, however, the water is too deep for anchoring so the drill rig and barge will be floating free on the lake with its position controlled by thrusters linked to a Global Positioning System (GPS) that will continually adjust the barge"s position above the drill hole. This poses some technical challenges.
"This is a risky scientific expedition, to be sure," says ESH program director David Verardo. "We are moving a new drilling system into a technologically-challenging environment. Lake Malawi is deep and the weather window for drilling operations is short and unforgiving. What spurs us on, however, is the potential scientific payoff in recovering critical baseline data on Earth"s climate system that will help us understand the range of natural climate variability. Betting on future climates without such baseline data is like investing in a company"s stock without assessing its past performance. It just isn"t prudent."
The ESH program supports coordinated projects that focus on the past behavior of the coupled Earth-Ocean-Atmosphere-Biosphere system which are conducted to provide insight into the factors that govern environmental variability, rates of climate change, and large-scale responses to climate forcing.