Adam Marian Dziewoński (November 15, 1936 – March 1, 2016) was a Polish-American geophysicist who made seminal contributions to the determination of the large-scale structure of the Earth's interior and the nature of earthquakes using seismological methods. He spent most of his career at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

, where he was the Frank B. Baird, Jr. Professor of Science.

Life and main scientific contributions

Dziewonski was born in Lwów, which was then a part of Poland, currently a part of Ukraine. After having earned a master's degree from the University of Warsaw, Poland (1960), and a Doctorate of Technical Sciences from the Academy of Mines and Metallurgy, Cracow, Poland (1965) Dziewonski taught at the University of Texas at Dallas for several years before settling at Harvard. In the 1960s and 1970s, Dziewonski and his collaborators laid the foundation to understanding the underlying cause of tectonic plate motions by exploring

convection Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ...

currents in the Earth's mantle with radial maps of seismic property variations, based on measurements of

seismic waves A seismic wave is a mechanical wave of acoustic wave, acoustic energy that travels through the Earth or another planetary body. It can result from an earthquake (or generally, a quake (natural phenomenon), quake), types of volcanic eruptions ...

. These studies led to the development of the Preliminary reference Earth model (PREM) in collaboration with Don Anderson; PREM established an accurate radial model of the Earth for seismic velocities,

attenuation In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a Transmission medium, medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and ...

, and

density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

. Starting in the 1980s, Dziewonski led two original and powerful research efforts. He extended the radial Earth models to be fully three-dimensional, along the way mapping and interpreting four "grand" structures. The four include two regions of higher-than-average wavespeed, inferred to be cold and sinking mantle, one under the western edge of the Americas and the other under southern Eurasia. The two other features are large-scale regions of slower-than-average wavespeed, inferred to be hot and rising superplumes, located at the bottom of the mantle under the middle of the Pacific Ocean and Africa. His other research direction systematically determined the orientation and magnitude of the deformation for most of the significant earthquakes that have been well-recorded. These results are known as the Harvard CMTs (centroid moment tensor solutions) and are continued today at

Lamont–Doherty Earth Observatory The Lamont-Doherty Earth Observatory (LDEO) is a research, research institution specializing in the Earth science and climate change. Though part of Columbia University, it is located on a separate closed campus in Palisades, New York. The obs ...

by Göran Ekström and Meredith Nettles as the Global CMT Project. Dziewonski received numerous honours and awards for his scientific achievements, among them the Gold Medal of Ettore Majorana Foundation and Centre for Scientific Culture (1999), the Harry Fielding Reid Medal of the Seismological Society of America (1999), the

Crafoord Prize The Crafoord Prize () is an annual science prize established in 1980 by Holger Crafoord, a Swedish industrialist, and his wife Anna-Greta Crafoord following a donation to the Royal Swedish Academy of Sciences. It is awarded jointly by the Acade ...

of the Royal Swedish Academy of Sciences (1998), and the Bowie Medal of the

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, Atmospheric science, atmospheric, Oceanography, ocean, Hydrology, hydrologic, Astronomy, space, and Planetary science, planetary scientists and enthusiasts that ...

(2002). In 1995 he was also elected a member of the

United States National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

.Dziewonski, Adam M. - Member profile.

. Accessed September 12, 2008. He died in

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, ...

, on March 1, 2016.

Important publication

* A. M. Dziewonski, D. L. Anderson: Preliminary reference Earth model. ''Physics of the Earth and Planetary Interiors 25, S.297–356'' (1981)

References

External links

Dziewonski's webpage at HarvardOral history interview transcript with Adam Dziewonski on 26 January 1994, American Institute of Physics, Niels Bohr Library & ArchivesGlobal Centroid Moment Tensor project
{{DEFAULTSORT:Dziewonski, Adam Marian 1936 births 2016 deaths American seismologists University of Warsaw alumni University of Texas at Austin faculty Harvard University faculty Members of the United States National Academy of Sciences

Life and main scientific contributions

See also

Important publication

References

External links