CIRES Distinguished Lecture Series (DLS): Dr. Paul G. Richards

Diverse applications of “Precision Seismology” to assess inner core motions, North Korean nuclear testing, the TRINITY origin time (1945), and Much Besides

Abstract:

Seismologists can now measure with high precision the differences in time between signals from neighboring earthquakes -- or explosions.  I shall describe applications and discoveries based on such relative arrival-time data, ranging from: changes occurring in the Earth’s inner core; patterns of seismicity in regions of damaging earthquakes; and details of nuclear explosive tests and their aftershocks in North Korea.  

Applying the new methods to old (analog) data, at last we have an accurate origin time for the very first nuclear explosion (TRINITY, July 16, 1945).  Precise measurements are now being made on millions of pairs of seismic events, most of them discovered by searching years of continuous data using numerous templates.  Modern methods applied to data old and new will improve our understanding of seismicity and earthquake hazard.

Brief Bio:

PGR has taught at Columbia since 1971 in the Earth Sciences; co-authored an advanced textbook in seismology (in English, Russian, Chinese, and Japanese) that has been in print since 1980; chaired Columbia’s Geological Sciences Department; and (with Xiaodong Song in 1996) discovered evidence that the Earth’s inner core is detectably moving on a human time scale. So: a scientist, whose career changed in 1984 when he joined the unit writing President Reagan’s Report to Congress on Soviet Noncompliance with Arms Control Agreements. In 1987 Columbia promoted him to Mellon Professor of the Natural Sciences, recognizing his mid-career move toward policy issues. He took another service leave from Columbia in the Clinton Administration, joining the U.S. team that negotiated (in Geneva) the Comprehensive Nuclear-Test-Ban Treaty (CTBT). He continues in scientific research, and advising national and international agencies monitoring for nuclear test explosions. He has held Guggenheim and MacArthur Fellowships and has been a Council on Foreign Relations member since 1992.
 

A full recording of this event will be availble following the talk. Please contact lornay.hansen@colorado.edu.