Deep within the bowels of the University of Minnesota, a plastic tube filled with mud from an Indonesian lake bed inches its way through a machine.
By the time the sediment completes its pass through the "core logger," scientists will have a clear picture of what a faraway lake looked like centuries ago, as well as insight into what the lake might look like in the near future.
The university's civil engineering building basement houses the largest collection of core samples in the United States. Each year, hundreds of scientists send their mud, sediment and rock to the university's Limnological Research Center, seeking answers to vexing problems.
"A lot of the research we see focuses on climate change," said Anders Noren, director of the center's Continental Scientific Drilling Coordination Office (CSDCO). "Climate change is nothing new. The difference now is that the changes are much faster and more extreme. With core samples, we can see how temperatures changed in the past, so we have context for understanding how temperatures are changing right now."
Core samples contain fossil remains of pollen, algae and small organisms, as well as ash, storm debris and different types of rock. By analyzing them, scientists can reconstruct historical ecosystems to determine how climate has changed over time. They also can understand seismic and volcanic processes, and show how living things have adapted to their ever-changing environment. In fact, core samples can be used to answer big questions, like how humans left Africa. Was it out of a spirit of adventure, or to flee a changing climate?
That's what Prof. Alan Deino from the University of California, Berkeley is here to find out. Sitting at a 30-inch screen in the coordination office's unique laboratory, the National Lacustrine Core Facility (LacCore), Deino zooms in on cross-sections of core samples taken from the Rift Valley in East Africa. He is involved with the Hominin Sites and Paleolakes Drilling Project, an effort to understand climatic changes in Africa millions of years ago.
Closer to home, the laboratory is at the center of a heated debate over wild rice.
Core samples are helping the Minnesota Pollution Control Agency (MPCA) determine sulfate levels in Minnesota's waterways. Sulfate can be toxic to wild rice when it is converted to sulfide in the sediments, and is released into the state's lakes and rivers via wastewater or mining operations. LacCore data can help pinpoint exactly when sulfide levels became toxic. Using other data, it can paint a picture of what was going on in the ecosystem at that time.