Liz Johnson, a professor of geology and environmental science at James Madison University, was among the researchers who made a groundbreaking discovery of how volcanoes formed in the area of Bermuda.
A paper on the research, funded by the National Science Foundation, was published May 15 in Nature. Johnson was one of the paper’s eight authors.
During the project, which began in the 2015-16 academic year, the researchers discovered the first direct evidence that material from Earth’s mantle transition zone can percolate to the surface to form volcanoes. Before this discovery, researchers knew volcanoes formed when tectonic plates converged or diverged, or as a result of mantle plumes that rise from the core-mantle boundary to make hotspots at Earth’s crust.
“At JMU, we measured the amount of water stored in crystals of a mineral called pyroxene that grew within the molten rock, or magma,” Johnson said. Using a Fourier-transform infrared spectrometer, Johnson and her students were able to estimate a range for water content of the magma from 1.9 wt% to 5.7 wt%, much higher than typical hotspot or within-plate volcanoes, which range from 0.03 wt% to 1 wt%.
Those findings, according to the paper, support “a more volatile-rich source for Bermuda than has been recorded in any other oceanic intraplate volcanoes.”
About Liz Johnson
Liz Johnson is an associate professor of geology and environmental science who earned her doctorate at the California Institute of Technology. Her research includes investigating why volcanic eruptions happened in western Virginia during the Eocene. What can these volcanic rocks and their xenoliths tell us about the crust and mantle underneath the Shenandoah Valley and the passive margin of the eastern U.S.?
Johnson also has been involved in researching large felsic eruptions at Yellowstone, Long Valley, and Taupo.
Courses she teaches include geology of Skyline Drive; physical geology; Earth systems, cycles, and human impacts; and introduction to petrology.
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