John Fillmore Hayford (May 19, 1868 – March 10, 1925) was an eminent United States
geodesist
Geodesy ( ) is the Earth science of accurately measuring and understanding Earth's figure (geometric shape and size), orientation in space, and gravity. The field also incorporates studies of how these properties change over time and equival ...
. His work involved the study of
isostasy
Isostasy (Greek ''ísos'' "equal", ''stásis'' "standstill") or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its ...
and the construction of a
reference ellipsoid
An Earth ellipsoid or Earth spheroid is a mathematical figure approximating the Earth's form, used as a reference frame for computations in geodesy, astronomy, and the geosciences. Various different ellipsoids have been used as approximations ...
for approximating the
figure of the Earth
Figure of the Earth is a term of art in geodesy that refers to the size and shape used to model Earth. The size and shape it refers to depend on context, including the precision needed for the model. A sphere is a well-known historical approxim ...
. The crater
Hayford on the far side of the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
is named after him. Mount Hayford, a 1,871 m mountain peak near Metlakatla, Alaska, United States, is named after him.
Mountains Mounts
A biography of Hayford may be found in the Biographical Memoirs of the National Academy of Sciences, 16 (5), 1935.
See also
* Hayford ellipsoid
Bibliography
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References
External links
National Academy of Sciences Biographical Memoir
1868 births
1925 deaths
American geodesists
People from Rouses Point, New York
Cornell University College of Engineering alumni
Mathematicians from New York (state)
Victoria Medal recipients
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