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Adam Marian Dziewoński (born November 15, 1936 in Lwów,〔(Dziewonski Receives 2002 William Bowie Medal. ) American Geophysical Union. Accessed September 12, 2008〕 then a part of Poland, currently a part of Ukraine) is a Polish-American geophysicist who has 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 is the Frank B. Baird, Jr. Professor of Science at Harvard University. == Life and main scientific contributions == After having earned a Masters 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 the understanding of tectonic plate motions by exploring convection currents in the Earth's mantle with radial maps of seismic property variations, based on measurements of seismic waves. These studies led to the development of the Preliminary reference Earth model (PREM) in collaboration with Don Anderson; PREM establishes an accurate radial model of the Earth for seismic velocities, attenuation, and density. Since the 1980s he has led two original and powerful research efforts. He has extended the radial 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 has 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 by Goran Ekstrom as the Global CMT Project. Dziewonski has 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 Harry Fielding Reid Medal. ) Seismological Society of America. Accessed September 12, 2008〕 the Crafoord Prize of the Royal Swedish Academy of Sciences (1998),〔(The Crafoord Prize 1998. ) April 25, 1998. Accessed September 12, 2008.〕 and the Bowie Medal of the American Geophysical Union (2002).〔 In 1995 he was also elected a member of the United States National Academy of Sciences.〔(Dziewonski, Adam M. - Member profile. ) United States National Academy of Sciences. Accessed September 12, 2008.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Adam Dziewonski」の詳細全文を読む スポンサード リンク
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