With support from the National Science Foundation, civil & environmental engineering and materials science & engineering professor Rosa Espinosa Marzal will study the impact hydrothermal conditions have on fault friction at the nanoscale of the involved materials, a key factor governing when and where earthquakes will occur. By advancing understanding of these processes, her work aims to improve prediction, safety and resiliency in earthquake hazard management.
Friction between rocks creates stress along faults in the Earth’s crust, and the repeated buildup and release of this stress causes earthquakes. The way that frictional strength recovers after an earthquake determines when future fault slips will initiate, how ruptures spread and how frequently seismic events recur, making it an extremely important phenomenon to study for earthquake science.
The significance of hydrothermal effects on seismic activity has long been recognized, but the complexity of natural fault systems makes individual mechanisms difficult to study. This project addresses that critical knowledge gap by analyzing how characteristics like temperature, fluid chemistry and surface roughness influence frictional strength in a simplified, laboratory setting at the nanoscale.
Espinosa Marzal will examine the physical and chemical processes that occur at small points of contact between rocks by isolating calcite, a common material found in many tectonically active regions. Performing the experiments on single calcite crystals, she will observe the mechanisms that dictate how contact between calcite surfaces evolve over time and determine how fault surfaces are either made stronger or weaker under the influence of different hydrothermal conditions.
This research will improve interpretation of the geophysical observations used in earthquake modeling and support the design of future models that are better equipped to account for hydrothermal conditions. The end result will be more reliable prediction of seismic events, which will help cultivate security, safety and resilience on a national scale.
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Rosa Espinosa Marzal is the Ivan Racheff Professor of Environmental Engineering in the Department of Civil and Environmental Engineering at the University of Illinois Grainger College of Engineering. She has a joint position with the Grainger Engineering Department of Materials Science and Engineering and is affiliated with the Carl R. Woese Institute for Genomic Biology.