Magnetic attraction: Institute for Rock Magnetism

For more than two decades, the IRM has studied everything from termites to Martian meteorites

“Old rocks and sediments contain secrets,” said Joshua Feinberg, professor of earth sciences and associate director of the University of Minnesota’s Institute for Rock Magnetism (IRM). “Going back more than a billion years, they contain a record of what was happening to Earth’s magnetic field when the rock was formed.”

For Feinberg, unlocking the clues held in rocks and sediments is what drives his passion for understanding the past to predict the future.

“From the direction and strength of Earth’s magnetic field held in a simple rock sample, we can learn how continents drifted across the planet, how climate has changed since the last glacial period, how often we can expect a flood to occur, and more,” he said. “They hold a very detailed record that can help scientists more accurately contrast ancient and modern patterns.”

For more than 27 years, the IRM has provided hundreds of University of Minnesota faculty and visiting researchers with access to state-of-the-art facilities and technical expertise for studying the magnetic properties of natural materials.

“Researchers from all over the world, representing an enormous range of disciplines, have come to the Institute for Rock Magnetism,” said Bruce Moskowitz, professor of earth sciences and IRM director.

“One week it may be to study meteorites,” he said. “Two weeks later, we might be onto archaeological sites. Then it can be tectonics and how the Earth’s plates are moving over time. It’s a really great place to work because new projects and challenges come in all the time.”

An important beginning

The IRM began as the brainchild of Subir Banerjee, professor emeritus of earth sciences. He envisioned an interdisciplinary workspace where scientists in earth science could come together to study magnetic materials. Through the National Science Foundation’s Science and Technology Centers program, Banerjee submitted a proposal for funding.

“This was 1988, and surprisingly, the proposal made it into the final round,” Moskowitz said. “When the review panel came for a site visit, which included Governor Rudy Perpich of Minnesota, he argued that ‘Minnesota must have more rock magnetism!’”

Unfortunately, the proposal was turned down, but thanks to the W. M. Keck Foundation and the NSF’s Earth Science Division, a proposal for a more modest facility was funded.

“So we opened in fall 1990, and we’ve been here ever since,” Moskowitz said.

There are other rock magnetism labs at other universities. But, what makes the University of Minnesota IRM distinctive is its unique and comprehensive array of instrumentation typically not found in earth science laboratories. It’s also designed as an open facility that draws visiting researchers from the earth sciences and other disciplines across the globe through various fellowship programs—from graduate students to senior faculty.

Visiting research fellows come to the IRM to use the facility for 10 days, solely to focus on a particular aspect of a project. Before being accepted, they must put together a short project proposal.

Preference is given to projects relating magnetism to geological or environmental studies, or to fundamental physical studies relevant to the magnetism of Earth materials. An external committee reviews each of the proposals and selects about 14 fellows each year.

Over the past 27 years, more than 400 fellowships have been awarded to students, post-docs, and senior researchers representing 157 institutions in the U.S. and 30 countries.

“The people who come to IRM have measured everything from termites to Martian meteorites,” said Moskowitz.

“A third of our visitors may not have much of a background in magnetism, but they see that a magnetic approach may be something that is useful for their studies,” he added. “Our goal is to teach and provide our visitors with the skills and data to advance their research. Everyone in the IRM strives to help our visitors conduct the best research possible. It’s also a wonderful networking opportunity for our graduate students and post-docs.”

From issues surrounding climate change to atmospheric dust, research at the IRM has been applied to a variety of problems.

Feinberg uses mineral magnetism to address questions in both archaeology and geoscience. His research on the magnetic properties of layered stalagmites in caves in central China could shed light on flood forecasting and climate modeling.

Moskowitz, whose recent work centers on environmental magnetism, focuses on understanding the flux of magnetic particles and dust in the atmosphere, which can accelerate rates of snowpack melting, fertilize marine phytoplankton, and impact public health. In Utah and Colorado, much of the ground and drinking water comes from melted snow.

“If there are more dust particles in the snowpack, which absorbs solar energy at a higher rate, the snow melts faster,” he said. “You end up losing more snowpack during certain times of the year than you would otherwise. It’s important to distinguish where the dust came from by measuring the magnetic mineralogy.”

New home for IRM

In August 2017, the IRM moved from its home in Shepherd Laboratories on the University’s East Bank to the newly renovated John T. Tate Hall, along with the Department of Earth Sciences, which was previously housed mostly in Pillsbury Hall. The space, which is located on the second floor, was designed by the IRM in collaboration with the architects.

Featuring an open-concept floor plan, the new space includes a magnetic shielded laboratory; two separate sound and vibration-proof rooms; and a fully equipped clean sample preparation room. Staff, faculty, and visiting fellow offices are located adjacent to the lab.

Additionally, a general-purpose room for rock cutting, drilling, and crushing—that's shared with the geology department—is located in the basement of John T. Tate Hall.

“The new IRM facility in Tate Hall allows us to be more collaborative,” said Moskowitz.

“There is opportunity for people to walk down the hall and say, ‘Hey, can I take a look at this?’ The cross-fertilization of ideas will be wonderful,” he said. “Even hanging out with the astronomers will be good if any of them are dealing with meteorites or planetary dust particles.”

Story by Silva Young 

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