Zhongwen Zhan is an inspiring young seismologist who has fundamentally advanced our understanding of earthquakes and Earth structure while inventing seismic ocean thermometry. Among observationalists Zhongwen has been pushing seismic methods forward at a breathtaking pace while addressing a remarkable range of geophysical problems. Emerging as a leader in the resurgence of work on deep-focus earthquakes, Zhan has made important discoveries, stitched them together with existing ones, and advanced the hypothesis that two different styles of rupture occur in concert, one in the cold core of slabs and another outside in the warm mantle. Zhongwen discovered that deep-focus earthquakes can exhibit rupture at supershear speeds and that great deep events initially rupture rapidly before propagating slowly outside of the cold core of subducted slabs. A pathfinder in the explosive growth of ambient noise seismology, Zhongwen was one of the first to demonstrate the emergence of seismic body waves from noise correlations, allowing detection of features at depth. Zhongwen Zhan has rapidly accelerated the use of fiber-optic cables as seismic sensors. Although these cables were originally developed in industry, seismologists have surged ahead to explore applications to fundamental geophysics, and many important firsts have been made by Zhongwen and his students. Illuminating dark fiber, they showed that distributed acoustic sensing could detect teleseisms and surface waves from remote earthquakes. Following the 2019 Ridgecrest, California, earthquakes, they created the largest fiber deployment to date and studied aftershocks and near-field seismic shaking in remarkable detail. But with existing methods limited to fiber lengths less than 100 kilometers, Zhongwen, never at rest, obtained access to fiber between Los Angeles and Chile and detected earthquakes and ocean-induced changes along the entire cable by monitoring anisotropy of the normal communication signals — a potentially transformative method for geophysical monitoring. A long-sought-after target of physical oceanography is the monitoring of acoustic waves in the SOFAR channel to obtain stable averages of changes in ocean temperature. In an extraordinary breakthrough with his then postdoc Wenbu Wu, Zhongwen and others demonstrated that by using small repeating earthquakes they could infer subtle changes in wave speed and ocean temperature over 3,000 kilometers — a novel tool that promises to provide averages of changes in ocean temperature over an ocean basin. — Michael Gurnis California Institute of Technology Pasadena, California

Thanks, Mike, for the kind words and the nomination. I am a seismologist, so it is my great honor to receive the AGU medal named after James Macelwane, a pioneering American seismologist, the first one west of the Mississippi River. I was drawn to seismology in 2005 after hearing an excellent public lecture by then a new professor at the University of Science and Technology of China, Sidao Ni, about the 2004 Sumatra earthquake. I was amazed by how much seismologists can learn from seismograms about structures and processes deep inside the Earth. After advising me on my master’s thesis, Sidao suggested I get a Ph.D. abroad. Eventually, I chose to work with his Ph.D. adviser, Don Helmberger, at the California Institute of Technology (Caltech) Seismo Lab. I am forever grateful for my student time with Sidao and Don. Since my student time, I have been curious about many topics in seismology, such as ambient seismic noise, deep Earth structure, earthquake ruptures, deep earthquakes, the subduction zone and glaciers. I was lucky to get mentoring from various domain experts like Rob Clayton, Hiroo Kanamori, Mike Gurnis, Jennifer Jackson, Mark Simons, Victor Tsai and Peter Shearer. The curiosity has only expanded since I became a faculty member, and I am indebted to close collaborators like Jorn Callies, Alireza Marandi, Ruby Fu, Valey Kamalov, Miguel Gonzalez-Herraez, who are all outside geophysics and tolerated my ignorance in their fields. I have also been fortunate to work with an amazing team of students and postdocs at the Caltech Seismo Lab, who made all the accomplishments possible. I am super proud of them! Finally, I want to thank my family, especially my parents; my wife, Qiong; and two daughters, Sophie and Mia, for their love and support. —Zhongwen Zhan California Institute of Technology Pasadena, California

Zhongwen Zhan will receive the 2016 Keiiti Aki Young Scientist Award at the 2016 American Geophysical Union Fall Meeting, to be held 12–16 December in San Francisco, Calif. The award recognizes the scientific accomplishments of a young scientist who makes outstanding contributions to the advancement of seismology.  

Dr. Zhongwen Zhan received his bachelor’s and master’s degrees in the Special Class for the Gifted Young from the University of Science and Technology of China in Hefei, and his Ph.D. from the California Institute of Technology in 2013. As a graduate student, he received several outstanding student presentation awards from the AGU. After a 2-year postdoctoral appointment at the University of California, San Diego, he joined the Caltech Faculty in 2015.
Zhongwen has published an exceptional number of papers on a wide range of topics in both source and structural seismology. He has developed detailed images of rupture complexity for deep focus earthquakes and in doing so uncovered clear evidence for supershear rupture propagation based on the difference in pulse-width for downgoing versus surface-reflected phases. He has constrained the sharpness of seismic wavespeed anomalies in subduction zones and demonstrated that tomographic images greatly underpredict the strength of those anomalies. He is one of the first to demonstrate the existence of reflected body-wave arrivals in observations of the ambient seismic field using array beam-forming of ambient-field measurements to discern reflections off both the Moho and the core. While his research portfolio is already broad, he is working to broaden it further through studies of intermediate-depth earthquakes and the seismological signature of cryospheric processes.

Zhongwen Zhan is a creative and exceptionally productive scientist who is making significant contributions to a wide range of seismological problems. He is a worthy choice for the Aki award, which recognizes the significance of his early-career accomplishments, and anticipates further outstanding contributions in the future.

—Gregory C. Beroza, Stanford University, Stanford, Calif.

I am very honored to receive the Aki award of this year. I am deeply indebted to many mentors, collaborators, and friends. I thank Sidao Ni and Don Helmberger for bringing me to the field of seismology and teaching me the art of reading seismograms. I have benefited greatly from inspiring collaborations with Hiroo Kanamori, Mark Simons, Rob Clayton, Peter Shearer, and Victor Tsai over the years. I am also grateful for the very supportive environment at Caltech allowing me to pursue new research directions. As a seismologist, I enjoy reading the wiggles. Nowadays, numerous seismograms can be accessed easily, thanks to the unselfish seismology community and progresses in technology. Meanwhile, the explosion of data also poses new challenges and opportunities to the old art of seismogram reading. I would like to thank all the pioneers, inside or outside the field of seismology, for developing new ways of analyzing large amounts of seismic waveforms. I hope more young seismologists can continue to read seismograms, invent new methods, and bring the art of seismogram reading to a new level. —Zhongwen Zhan, California Institute of Technology, Pasadena