Citation by Seth Stein and Randy Keller
It is a pleasure to honor Mian Liu for pioneering studies of geodynamic processes in active tectonics, mountain building, and mantle dynamics.
He gets to the heart of complex issues in an elegant and insightful way. Combining data, elegant simple modeling, and sophisticated numerical analysis yields insights that leave us wondering "why didn't I think of that?"
To Mian, models are ways to explore questions. He recognizes the famous adage that “all models are wrong – but some models are useful.” When asked to model a system, he asks "what's the question you're trying to answer?" His models allow him to explore the most crucial aspects of complicated systems, bring important new insights, and test these with diverse data.
A few of his many important results show his style. One involved the Tangshan region in China where a 1976 earthquake destroyed the city. The question is whether recent earthquakes are precursors of new major seismicity, or aftershocks of the 1976 earthquake. Mian used his results that aftershocks in continental interiors can go on for many years to show that these are likely continuing aftershocks.
Another involved analysis of the 2000-year record from North China, showing that no large earthquakes ruptured the same fault segment twice. The paper proposed a model for intracontinental earthquakes, in which slow tectonic loading is accommodated collectively by a system of interacting faults, each of which can be active for a short period after long dormancy. The resulting earthquakes are episodic and spatially migrating, in contrast to the more regular patterns of interplate earthquakes. Naturally, this view has major implications for earthquake hazard assessment.
Mian has also been doing imaginative work on mountain building, faulting, and other aspects of the evolution of North America, Asia, and South America.
He is a superb choice for the Woollard award.
Response by Mian Liu
Thank you, Seth, for your kind words. I am deeply grateful to you and Randy Keller for nominating me. I thank the GSA and everyone who helped to bring this distinction to me. The Georgy P. Woollard Award recognizes outstanding contributions to the studies of geology by applying the principles and techniques of geophysics. While I cannot say that I deserve this honor, I take some comfort in believing that I am in the right pool. Throughout my career, I have consciously or unconsciously blended geology and geophysics.
I grew up in China during the so called “cultural revolution,” when all universities were shut down. After high school, I got a job in a geological survey team. One year later, the cultural revolution ended, and universities reopened. I applied for physics but was assigned by the government to study geology, presumably because where I was working at that time. I wish I could say that I enjoyed geology in college, but my interest was in physics. Upon graduation I received a scholarship to study at McGill University in Canada. My supervisor there was Andrew Hynes, a brilliant petrologist who also published papers in gravity and geodynamics. My master’s thesis was about the petrochemical evolution of a greenstone belt in northern Quebec, where I spent my first summer camping and mapping in the bush. Several close encounters with bears, and countless blackfly bites, convinced me that I should rekindle my aspiration for physics and switch to geophysics. I did that when I went to the University of Arizona for my Ph.D. studies with Clem Chase, who was best known for his work in plate kinematics, but he was also a pioneer in the studies of geochemical evolution of the mantle and landscape changes. Working with Andrew and Clem, I never saw the fence between geology and geophysics. After Ph.D. I did a postdoc with Dave Yuen at the University of Minnesota on mantle convection, and with Kevin Furlong at Penn State on thermal modeling. Both Dave and Kevin have broad interests in geophysics and geology.
As my wife may tell you, I’m clumsy with tools. That’s probably why I picked up numerical analysis as my main research tool. It gives me the freedom to study any geological processes if their underlying physics can be described by a set of partial differential equations. I have studied mantle dynamics, mountain building, basin formation, magmatism, faulting, and earthquakes. It’s always fun and exciting to step into new fields, especially when you have good tour guides and partners. I’ve been lucky to have worked with some of the best scientists including Seth Stein, who got me interested in the problems of intraplate earthquakes. I have been blessed by having wonderful students, postdocs, and visiting scholars. While I cannot name you all here, I want you to know that this award is also in recognition of your outstanding work. Thank you!