Don Lynn Anderson (born March 5, 1933) is an American geophysicist who has made important contributions to the determination of the large-scale structure of the Earth's interior, especially using seismological methods. He is Eleanor and John R. McMillan Professor emeritus of geophysics at the California Institute of Technology (Caltech). In 1998 he was awarded the Crafoord Prize along with Adam Dziewonski.[1]
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Born in Frederick, Maryland, Anderson moved to Baltimore when he was six. He graduated from Baltimore Polytechnic Institute[2] then attended Rensselaer Polytechnic Institute where he earned a B.Sc. in geology/geophysics in 1955. He then worked in industry and for the military before moving to Caltech, where he received a Ph.D. in geophysics and mathematics in 1962. He spent most of his subsequent academic career at Caltech's Seismological Laboratory.
In the 1960s and 1970s, Anderson and his collaborators investigated the relations between the behavior of mantle rock under high pressures and temperatures, phase transformations of mantle minerals, and the generation of earthquakes. Furthermore, they contributed significantly to the understanding of tectonic plate motions by exploring convection currents in the Earth's mantle with seismological methods. Among other, these studies have led to the development of the Preliminary Reference Earth Model (PREM) in collaboration with Adam Dziewonski; PREM establishes a consistent radial model of the Earth for several important geophysical parameters (e.g. seismic velocities, attenuation, and density).
Since the 1980s he has also been known as the originator of some unconventional, provocative, and controversial ideas which depart from the views of the scientific mainstream. For instance, he has developed an alternative model of the mineralogical composition of the upper mantle, according to which its deeper parts consist of piclogite, a relatively pyroxene- and garnet-rich rock, rather than olivine-dominated peridotite with the chemical composition of pyrolite. Another of his hypotheses is that the theory of convective mantle plumes in the Earth, as proposed by W. Jason Morgan, is invalid and that hotspots and oceanic islands such as Hawaii or Iceland are rather caused by chemical/mineralogical anomalies in the upper mantle.
Don Anderson also considered that plate tectonics could not happen without the calcium carbonate laid down by living beings at the edges of subduction zones. The massive weight of these sediments could be softening the underlying rocks, making them pliable enough to plunge.[3]
He has also authored Theory of the Earth, a widely known textbook.