Melodie French, winner of the 2022 AGU Mineral and Rock Physics Early Career Award, is primarily an experimentalist with interests in brittle faulting and crustal fluid-rock interactions. What distinguishes her experimental work is interpreting mechanical measurements using extensive, meticulously analyzed microstructures. While she is technically the best brittle experimentalist of her generation, it is the microstructures that invariably provide the physical explanations and the key to developing or applying theory. She is as adept at recognizing the limitations of existing theories of Earth deformation and designing studies to collect new data that reveal the physics, as she is at developing theory to explain complex experimental and natural observations. Melodie is fundamentally a physicist and is truly worthy of this award. She has made significant contributions to mineral and rock physics in virtually all of her published studies. As a Ph.D. student, Melodie studied the mechanics of San Andreas’s creeping section (CS), focusing on deformation mechanisms during dynamic slip and shear at the plate rate. In the process she explains the significance and origin of fluidized layers found (and misinterpreted) in natural shear zones. She also discovered the proper CS plate rate deformation mechanism, missed by other researchers. As a postdoc, Melodie shifted toward studies of subduction zone faulting and also eventually into leadership in the SZ4D initiative. As in the two early studies, Melodie’s primary experimental targets are saturated fault rheologies, spanning shallow splay faulting in accretionary sediments to deep nonvolcanic tremor. She first studied slow-slip events (SSEs), demonstrating that elevated fluid pressure (not reduced effective stress) decreases both fault slip speed during stress drop and degree of localization, producing much more dissipated energy than is assumed in standard models. More recent are unique experiments to determine wave speeds and attenuation in subduction settings; these target key geophysically determined deep crustal properties (tomography inferred wave speed, Vp/Vs ratios, frequency content of deep seismicity). As faculty, Melodie has built a lab for subduction conditions and was awarded a National Science Foundation CAREER Award to study the effects of loading history on the shallow extent of subduction megathrusts. Last is Melodie’s recent field collaboration that combines thickness from exhumed terranes and laboratory-determined rheology to establish the lithologies and strain rates that accommodate slow slip. This is a road map both for field geologists to find evidence of SSEs in microstructures, if such evidence is preserved, and for modelers to produce credible simulations of slow faulting in the deep crust. —Award Nominator

I am very grateful to the colleagues and mentors who thought of me and took the time to nominate me for this award, and to the many people who make my career a joyful and rewarding endeavor. I have benefited from formal mentors who taught me a great deal of science and challenged me to grow professionally and personally. At Oberlin, Steve Wojtal taught me to use simple, geology-inspired models to think across scales. At the University of Wisconsin–Madison, Laurel Goodwin instilled the importance of careful, unbiased observations. At Texas A&M, Fred Chester and Judi Chester taught me how to design research that precisely tests existing theories or develops new ones. And at the University of Maryland, Wenlu Zhu helped me combine all of these perspectives into the workings of a productive scientific career. A number of informal mentors have welcomed me into their labs and field seasons. I probably owe more of my success than I will ever know to their support from the sidelines. I am particularly lucky to have the best colleagues and friends in both the rock deformation community and the Earth, Environmental and Planetary Sciences Department at Rice University. At Rice I found a group of colleagues whom I genuinely enjoy and who have introduced me to new scientific problems and ways of thinking. In the latest stage of my career, I am most influenced by the students and postdocs at Rice. Starting an experimental research program comes with countless challenges, and I am in awe of the students (Celine, Ben, and Stewart) who joined our group early, took on these challenges with me, and made the science happen. I am also grateful to the students (Emory and Edgar) who actually saw what they were getting into and joined us anyway. Collaboration with my first postdoc at Rice (Cailey) has taken my research to unexpected places and resulted in the dearest of friendships. Finally, my greatest intellectual stimulation and growth come at the end of the day when I go home to the most interesting people I know. —Melodie French, Rice University, Houston, Texas