Thermal Stress Weathering in the Inner Solar System
by Jamie Molaro, PhD candidate at the University of Arizona’s Lunar and Planetary Laboratory
Abstract: Thermomechanical processes such as fatigue and shock have been suggested to cause or contribute to rock breakdown on Earth, particularly in arid environments where other weathering processes are slow. The formation and propagation of microfractures in rocks can occur due to expansion and contraction caused by changes in temperature, and by mismatches in thermal expansion behavior of adjacent mineral grains. Debate over the efficacy of this process began nearly a century ago, and has recently become an area of renewed interest, particularly in the planetary science community. Airless bodies may provide an environment uniquely suited to this process, as they may experience larger diurnal temperature ranges and/or rapid rotation rates. Understanding where in the solar system thermomechanical breakdown may occur has important implications for regolith production rates, surface ages and crater degradation rates, and landscape evolution over time. It may also provide invaluable information for future human exploration endeavors. I will present research exploring thermoelastic behavior of rock surfaces throughout the inner solar system (particularly the Moon, Mercury, and near earth asteroids), and discuss the implications for rock breakdown and landscape evolution on these bodies.
Bio: Jamie Molaro was raised in Grass Valley, California, located in the foothills of the Sierra Nevada Range. She did her undergraduate studies at San Francisco State University in Physics from 2004 until 2009. Before moving on to graduate school, she worked as a research assistant at the NASA Ames Research Center.
Jamie Molaro is presently a PhD candidate at the University of Arizona’s Lunar and Planetary Laboratory. In addition to research, she organizes the department’s annual Art of Planetary Science art show, and is teaching a course called Intro to Planetary Science for Teachers. Her research interests include thermomechanical surface processes, weathering in desert environments, and fluvial erosion processes on Earth and Titan. Tonight’s talk is the subject of her thesis research.