Jessica “JC” Creveling’s work reflects the power of interdisciplinary research practiced through a triptych of geology, geophysics and geochemistry. She has fundamentally deepened our understanding of critical events in Earth history through a creative combination of meticulous fieldwork, computational modeling and laboratory measurements. Moreover, JC is recognized as a gifted teacher and patient mentor, building a more inclusive community by attracting underrepresented minorities and first-generation and disadvantaged college students into geoscience research. As an undergraduate at Colorado College, JC learned that elucidating processes in sedimentary geology requires facies-level interrogation of strata, and this ignited her interest in sedimentary sequences. Her Ph.D. at Harvard combined fieldwork in Australia with geochemistry to explore environmental conditions that led to dramatic phosphate preservation across the Ediacaran to Cambrian transition. Moreover, she jumped into geophysical modeling by exploring conditions on Earth’s shape necessary to drive rapid, high-amplitude oscillations in Earth’s rotation pole inferred for the Neoproterozoic. JC’s interest in the Neoproterozoic continued at the California Institute of Technology, where her field-based investigation of the Noonday cap carbonate in Death Valley uncovered significantly more complex sea level histories than expected from eustasy. She also began intense study of sea level physics to complement this work. JC’s epiphany was to realize that physical processes that drive geographic variability in sea level during the Pleistocene ice age would be active in ancient events, where eustasy has been the prevailing assumption, and she is the first to bring the full machinery of sea level physics to bear on deep time glacial events. A series of seminal papers followed, including modeling studies of the “sea level fingerprint” of snowball Earth deglaciation and Late Ordovician glaciation that reconciled enigmatic field data; comparison of coral records and modeling results to constrain sea level high stands during marine isotope stages 5a and 5c; reanalysis of karstification-driven uplift of scarps along the Atlantic coastal plain that revised the age of the features; and a study, with graduate student Meghan King, of the unique imprint of ice age dynamics on stratigraphy along the U.S. west coast during the last glacial cycle. These studies have motivated a reassessment of correlation methods used in sequence stratigraphy and significantly expanded our understanding of the complex connection between local and global mean sea level. — Jerry X. Mitrovica Harvard University Cambridge, Massachusetts

Thank you, Jerry Mitrovica, for your generous remarks and Maureen Raymo, David Evans, Victoria Orphan, the James B. Macelwane Medal Committee, and the Union for the honor and the opportunity to publicly convey gratitude to many generous mentors. It’s not lost on me that the good fortune to receive such an award emerges from the greater fortune of the company that I keep. Sam Bowring mentored me to become a geoscientist deeply familiar with the questions and methods of a secondary discipline, and his words direct my career. I thank Paul Myrow, Andy Knoll, John Grotzinger and Sam for laying my geological bedrock. I thank Jerry Mitrovica and Daniel Muhs for orienting me toward the confluence of stratigraphy and geophysics. And I thank Mike Gurnis for asking me a few questions—that he likely won’t remember—that really made me think. Without geophysical collaborators Carling Hay, Jacky Austermann, Tamara Pico and Harriet Lau, my world would be much narrower and much less quantitative. Thank you all. I am indebted to Oregon State graduate students Meghan King, Schmitty Thompson, Cedric Hagen, Paige Reynolds and Harvard student Linda Pan for propelling our research forward. I thank my Oregon State colleagues for innumerable generosities, especially Andrew Meigs, Ed Brook and Peter Clark; I thank my dean, Tuba Özkan-Haller, for saying yes even when I say no; I thank my National Science Foundation program officers for taking a chance on me and my college’s exceptional administrative staff for keeping me solvent. Most importantly, I thank my dad, Brad, for reviewing the entirety of my high school physics homeworks; my mother, Linda, for sharing the joys of creative writing and staunch organization; and I thank Frank Sousa, undoubtedly the better geologist in our union, for making each day together bright. — Jessica Creveling Oregon State University Corvallis, Oregon