The field you helped pioneer—plate tectonics—has greatly influenced the natural sciences and, with it, our understanding of climate change, the shifting seas, and the evolution of the human race. Through your decades of teaching and research in seismology, Professor Lynn R. Sykes, you have vastly expanded our understanding of the physical world and reshaped the direction of scientific inquiry in your field. As a child in Pittsburgh, Pennsylvania, you became intensely interested in the mysteries of the earth’s makeup, and then followed this precocious fascination to the Massachusetts Institute of Technology, where you earned degrees in geology and geophysics, and then here to Columbia, earning your Ph.D. in geology in 1965. Your achievements at the University’s Lamont-Doherty Earth Observatory and as Columbia’s Higgins Professor Emeritus of Earth and Environmental Sciences have been widely recognized with fellowships and awards from institutions including the Carnegie Institution for Science, the Seismological Society, and the American Geophysical Union. Columbia awarded you its G. Unger Vetlesen Prize in 2000. Over your career, your scientific prowess has been informed and elevated by a great love of humanity. You have described the abolition of nuclear arms as “the major issue of my lifetime” and have worked tirelessly to end nuclear weapons testing and to eliminate the possibility of nuclear war. You were early to this human rights cause, grounding your advocacy in rigorous science and hard facts. Your leadership was instrumental in turning Lamont-Doherty into one of the world’s most trusted centers of technical expertise for informing the development of test ban treaties and gaining their public acceptance. Professor Sykes, we are indebted to you not only for the many ways your scholarship has helped reveal the earth’s secrets, but also for your commitment to safeguarding us against humanity’s most dangerous impulses. Columbia is therefore proud to call you one of its own and to honor you with the degree of Doctor of Science, honoris causa.