Louis B. Slichter

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Louis Byrne Slichter (born May 19, 1896 in Madison , Wisconsin , † March 25, 1978 in Los Angeles , California ) was an American geophysicist and professor at the University of California, Los Angeles (UCLA).

Life

Slichter was one of the sons of Charles Sumner Slichter (mathematics professor at the University of Wisconsin – Madison and physicist) and studied physics at the University of Wisconsin – Madison with a bachelor's degree in 1917, a master's degree in 1920 and a doctorate in 1922. During the First World War he developed sonar for anti-submarine defense. His dissertation also dealt with acoustics : he developed a device to represent the shape of an acoustic wave (a conical aluminum membrane coupled to a mirror with a photograph of the deflection), which also included solving the complex differential equation of the membrane. In 1922 at 1924 he worked on echo sounders at the Submarine Signal Corporation in Boston. He then founded an engineering office with his former teacher Max Mason , which developed geophysical methods (especially geomagnetics , geoelectrics ) for ore exploration for mining companies such as United Verde Copper. He himself prospected in Canada and Peru, among others. In 1925 he succeeded in locating a dangerous leak in the Dix Dam in Kentucky, at that time the world's highest earth dam on a reservoir, using an echo sounder method . With the onset of the Great Depression , the company had to give up as mining companies scaled back exploration, and he turned back to academic research at Caltech in 1930 . From 1931 he was associate professor and from 1932 he was professor of geophysics at the Massachusetts Institute of Technology , where he built up geophysics at the invitation of Waldemar Lindgren . In the Second World War he was again involved in research on anti-submarine defense. 1945 to 1947 he was a professor at the University of Wisconsin – Madison and from 1947 director of the newly founded Institute for Geophysics at UCLA. In 1963 he retired . But he remained scientifically active and promoted the construction of measuring stations for his study of the natural vibrations of the earth and earth tides at the South Pole, whereby the choice of Antarctica was advantageous for various geophysical reasons.

Slichter was the uncle of the physicist Charles P. Slichter . He was a hobby sailor.

plant

Among other things, Slichter dealt with earth tides , free oscillation of the earth's body, heat flow from the earth's interior and cooling of the earth, inverse problems of geophysics (especially for the calculation of properties of the earth's interior from measured values ​​on the surface), seismology of the earth's crust and exploration geophysics. He was a pioneer in many of these areas. He was active both as an applied mathematician and in the development of measuring instruments. He patented some of his measuring methods and sold them to Schlumberger .

In 1934 he undertook a major experiment to create a profile of the electrical conductivity of the earth down to a depth of 8 km. For this purpose, around 30 miles of electrical lines from the supply network were converted during the night for the experiment to introduce current surges of 10 to 25 amperes into the ground once per second and the cables of a telephone company were used as detectors. In 1936 he developed portable seismographs with which he carried out the first experiments in New England and Wisconsin for the seismic exploration of the earth's crust in its entire depth and the upper mantle with the help of artificial explosions. He was able to measure the local thickness of the earth's crust and found in 1939 a thickness of 23 km under the Connecticut River and 42 km under the Upper Michigan Peninsula. His theoretical studies on the heat flow in the earth's interior from 1941 showed that convection of the mantle material had to be assumed to explain the history of the earth's cooling. From 1950 he dealt with the measurement of the earth's tides with gravitometers. With these, the natural vibrations of the earth could be measured at UCLA during the great earthquake in Chile in 1960.

Memberships and honors

In 1969 he received an honorary doctorate from UCLA and in 1967 from the University of Wisconsin. In 1944 he became a Fellow of the National Academy of Sciences . In 1957 he was elected to the American Academy of Arts and Sciences . In 1966 he received the William Bowie Medal , in 1946 the Presidential Certificate of Merit and in 1960 the Jackling Award from the American Institute of Mining and Metallurgical Engineers. In 1959 he became an honorary member of the Society of Exploration Geophysicists . In 1946 he was a Fellow of the Rockefeller Foundation . The Slichter Foreland , a peninsula on the Walgreen Coast of Marie Byrd Land in Antarctica, bears his name.

Fonts

  • The theory of the interpretation of seismic travel time curves in horizontal structures. In: Physics. Volume 3, 1932, pp. 273-295
  • The interpretation of the resistivity prospecting method for horizontal structures. In: Physics. Volume 4, 1933, pp. 307-322
  • An inverse boundary value problem in electrodynamics. In: Physics. Volume 4, 1933, pp. 411-418
  • with JT Pettit, L. LaCoste: Earth Tides. In: Trans. American Geophysical Union. Volume 34, 1953, pp. 174-184
  • Geophysics applied to prospecting for ores. In: Economic Geology. 1955, pp. 885-969
  • with NF Ness, JC Harrison: Observation of the free oscillations of the earth. In: J. Geophys. Res. Vol. 66, 1961, pp. 621-629
  • The fundamental free mode of the earth's inner core. In: Proceedings of the National Academy of Sciences . Volume 47, 1961, pp. 186-190

literature

Web links

Individual evidence

  1. ↑ Slichter: Investiation of electrical resistivity of earth's crust at great depth by use of power line and telephone line facilities. In: Techn. Eng. News. Volume 15, 1934, pp. 8-10
  2. ^ Slichter: Seismic study of crustal structure in New England by means of quarry blasts. In: Geolog. Soc. At the. Bulletin. Volume 50, 1939, p. 1934
  3. ^ Slichter: Cooling of the earth. In: Bulletin Geolog. Soc. America. Volume 52, 1941, pp. 561-600
personal data
SURNAME Slichter, Louis B.
ALTERNATIVE NAMES Slichter, Louis Byrne (full name)
BRIEF DESCRIPTION American geophysicist
DATE OF BIRTH May 19, 1896
PLACE OF BIRTH Madison , Wisconsin
DATE OF DEATH March 25, 1978
Place of death Los Angeles , California