Sediment drilling on two local lakes is inspired by research in Antarctica
WILLMAR -- It was warmer on the day that she left McMurdo Station, Antarctica, than it was when she ventured out on Willmar and Eagle Lakes, but her mission was much the same.
Dr. Katherine Pound, a geologist in the Earth and Atmospheric Sciences Department at St. Cloud State University, drilled into the sediment below the two Kandiyohi County lakes to pull up cores for analysis in a laboratory. The sediment cores will offer information on the climactic and geological history of the two local lakes, and should give us an idea of how human habitation has affected them.
Pound ventured out on the two lakes on Sunday, Feb. 17, accompanied by science students from the Willmar and New London-Spicer High Schools. While Pound is keenly interested in what the sediment cores will tell her about our state's geology and the condition of our lakes, she is equally committed to introducing the science of geology to young people.
"They were great,'' said Pound of the dozen-plus students who accompanied her.
They were hardy, too. The weather was raw with sub-zero wind chills, but the students and Pound didn't let it deter them from their work. They collected two core samples from each of the lakes.
"They were visually very different,'' said Pound of the sediment cores from Willmar and Eagle Lakes.
The Willmar Lake samples were very dark in color, indicative of a high organic content.
In contrast, she described the core samples from Eagle Lake as being "pale, yellow-brown'' in appearance, with what appeared to be lots of "shelly material.''
She will be submitting the core samples to the University of Minnesota Limnology Research Center, where they will be sliced, analyzed and preserved as part of the National Lacustrine Core Repository.
A length of the cores will also be returned here, so that students can conduct their own analysis.
Pound is working with students from 11 different schools across Minnesota to collect lake sediment cores from lakes in the state. The Antarctic-like weather she and the students encountered here was only appropriate.
Her work with the students is an extension of her participation in Andrill: Project Iceberg.
It's an international project involving scientists and educators from Germany, Italy, New Zealand and the United States. It brought Pound to McMurdo Station, Antarctica, last October, November and December for sediment core drilling on the frozen continent's shoreline.
There, scientists were able to drill over a kilometer deep into the seabed and recover sediment cores from 20 million years of history.
The information should greatly increase our understanding of global climate change, according to Pound. Most of the sediment cores that we have drilled to understand our earth's climactic history have been taken from areas near the equator. We have only a very limited history of the changes that took place in Antarctica, even though the changes there have been profound, she explained.
Some 20 million years ago the continent had a mild climate and it was covered in plants and animals. We are not sure what brought about the changes that have transformed the continent into the ice-covered place we know today.
Pound doesn't expect to find changes quite so dramatic to be revealed in the sediment cores from Willmar and Eagle Lakes. But, it's possible they could tell the sediment history of the two waters bodies going back some 1,000 years. She won't know how many years of history are captured in the cores until the laboratory analysis is completed some weeks hence.
Like the ice drilling taking place in Antarctica, the drilling on the local lakes could also tell us something about how our west central Minnesota climate is changing. Pound noted that the drought of the 1930's is believed to have exposed much of the lake bed of Eagle Lake. The sediment core should reveal that abrupt change.
It's too early to guess what the local sediment cores may teach us, but that's only part of what matters, said Pound. She is just as excited about the opportunity it provided local students to discover what science in the field is like.
"That's what is really important,'' she said, "giving them the hands-on experience.''
Willmar High School instructors Robert Palmer and Margaret Schmitz joined the students on the ice-covered lakes. Palmer said the experience is one that will continue to engage the student's interest in science. A number of the students will be examining the sediment cores as part of a project through the remainder of the school year. Like their instructors, they are eager to learn what Willmar and Eagle Lakes can tell us about the natural world around us.