Remembering Adam Dziewonski

David Simpson, President Emeritus

IRIS and the seismological community mourn the loss of Adam Dziewonski who passed away on March 1 at age 79. Dziewonski was a geophysicist with great vision who made significant contributions to understanding Earth’s interior and played a leading role in the creation and evolution of the IRIS Consortium, the Global Seismographic Network (GSN) and the international Federation of Digital Seismograph Networks (FDSN).

After graduating from the Polish Academy of Mines and Metallurgy in Krakow in 1965, Adam carried out research at the Southwest Research Center for Advanced Studies and the University of Texas at Dallas before joining Harvard University in 1972. He spent the rest of his career on the faculty at Harvard, holding the Frank B. Baird, Jr. Research Professor of Science in the Department of Earth and Planetary Sciences at the time of his death. (Harvard’s note can be read here).

Adam Dziewonski was one of the leading global seismologists of his generation. He and his students and postdocs at Harvard, along with collaborators at Berkeley, Caltech, Scripps and elsewhere, made fundamental contributions to our understanding of the internal structure and dynamics of the Earth. (Read a personal statement of his research interests). Many of these advances evolved hand-in-hand with IRIS-enabled improvements in the collection and distribution of digital seismic data. Adam explored convection currents in the Earth's mantle to better understand the cause of plate motions. With his collaborators, this research led to the development of the Preliminary Reference Earth Model (PREM) for seismic velocities, attenuation, and density. He also developed a method to map the deep interior of the Earth in three dimensions, known today as seismic tomography. With the advent of digital seismology, another area of research involved systematically determining the size and type of deformation for all major global earthquakes. The centroid moment tensor (CMT) catalog, initiated at Harvard in the 1980s and continued today at Lamont Doherty Earth Observatory as the Global CMT (GCMT) catalog, is one of the most significant "data products" derived from the GSN and has become a fundamental tool in the analysis of seismicity and global tectonics.

Adam held many leadership positions in IRIS over the years. He played a pivotal role in the initial formation of IRIS and was Vice-Chair of the original Executive Committee that submitted the first IRIS proposal to the National Science Foundation in 1984. He returned for service on the Executive Committee as Chair in 1997-98 during an important phase in the early development of USArray and EarthScope. He also served as member (1998-2000) and Chair (2001-2004) of the IRIS Planning Committee. During a term as Chair of the USArray Advisory Committee in 2004-2008, he helped to ensure a long-term legacy of the EarthScope project through contributions to permanent stations as part of the US Geological Survey’s National Seismic Network. 

While his influence was evident across IRIS programs, Adam's primary passion and most significant contributions to IRIS lay in improving the collection of high-quality digital data from permanent broadband stations across the globe. His insistence on high quality and the free and open exchange of data were hallmarks of the IRIS/USGS Global Seismographic Network (GSN) and the Federation of Digital Seismograph Networks (FDSN). He was the first Chair of the GSN Standing Committee in 1986-87 and returned as a member of that committee for two additional terms during important phases in the development of the GSN in 1999-2001 and 2008-2011. He was one of the initial proponents in establishing the FDSN and also encouraged international collaboration through service as Chair of the Governing Council of the International Seismological Centre (ISC).

There were other areas not as visible as his scientific contributions or committee service where Adam had significant impact on IRIS and seismological instrumentation. As thesis advisor and mentor during development of Joe Steim's1986 Harvard thesis (The Very Broad Band Seismograph), Adam encouraged the development and adoption of technologies in feedback seismometers and 24-bit digitizers that opened the way for a new generation of global seismographs in the GSN and eventually portable PASSCAL instruments. Adam approached issues of IRIS governance with the same tenacity and rigor that characterized his scientific research. He chaired the committee that created the original IRIS by-laws and judiciously examined any proposed changes in the Consortium's management or governance. The model of community-governed management of scientific facilities crafted by Adam and the original founders of IRIS has stood the test of time and served as a model for other large facilities in the geosciences.

Colleagues described Adam Dziewonski as kind and generous who selflessly shared his wisdom and knowledge, especially with early- and mid-career scientists. He will be greatly missed.