Credit: UM News Service
MISSOULA – A University of Montana geosciences professor who studies the structure and evolution of the Earth has received a prestigious grant from NASA’s Earth Surface and Interior Division.
Hilary Martens, assistant professor in the Department of Geosciences, housed in UM’s College of Humanities and Sciences, recently was awarded a $443,000 three-year grant to investigate the structure of the Earth’s interior using GPS observations of ocean tides.
Martens will serve as the grant’s principal investigator, and the award includes funding to the California Institute of Technology as a collaborating institution, in addition to providing support for one full-time doctoral student at UM.
Martens will examine the relationship between the ocean tides and changes in the shape of the Earth. The project will use GPS to measure how the Earth flexes and deforms under the shifting weight of the ocean water, which will provide new knowledge on the materials that make up the layers of the Earth, according to Martens.
“Imagine pressing your finger into a Nerf ball or a bowling ball,” Martens said. “Objects respond differently to the same force because they are made of different stuff. The structure and rigidity of the Earth have implications for how the Earth deforms under pressure. By gaining insight into the elasticity and density structure of the Earth from studying its dynamic response to loading by ocean tides, we can improve our understanding of what drives plate tectonics and surface hazards, such as earthquakes and volcanoes.”
Using GPS, the project will measure the response of the Earth’s crust and mantle to the weight of ocean tides, from which material properties of the Earth can be inferred.
Martens said GPS is able to monitor the changing shape of the Earth over time. That information can be used as a model to predict future changes, as well as to develop hypotheses about the Earth’s physical evolution.
“Water and air move around on Earth’s surface and the pressure changes cause the Earth to respond,” Martens said. “The Earth is not perfectly rigid. It flexes under the weight of the water moving around on the surface, so it’s constantly changing. We can learn about the material properties of the Earth’s interior, which control how deformable the Earth is.”
Martens said a better understanding of the structural model of the Earth can be used to improve the precision of locating earthquakes, in addition to having a deeper understanding of the Earth’s history and the stability of continents. She said her research as a geoscientist includes a variety of scientific disciplines and methods, including data collection and analysis, analytical and numerical modeling, and ground and space-based observations.
Martens’ research also provides a wider lens on water storage on the planet – including snowpack, groundwater, and water in lakes, soils, and the atmosphere – which is especially important for water resource management in a warming climate. Last year, Martens received $1.4 million in funding from the National Science Foundation as part of a multi-disciplinary team to track changes in the shape of the Earth from the storage and flow of water in mountain watersheds.
At UM, Martens manages the Martens Lab, a geophysics research group that studies earthquakes in Montana and the interactions between the Earth and its water surface, or fluid envelopes. Martens possesses a robust background in space science, planetary science and geophysics. She founded a seismic network for UM that engages students in local science and hazard monitoring, including measuring the aftershocks of Montana earthquakes.
Martens received undergraduate degrees in music and physics from UM as a Presidential Leadership Scholar in UM’s Davidson Honors College. As a UM undergraduate, she also earned Marshall and Goldwater Scholarships.
She received master’s degrees in geophysics from the University of Cambridge, University College London and the California Institute of Technology. She earned her doctorate in geophysics from the California Institute of Technology.