An investigation of mantle Rayleigh waves
- Creators
- Ewing, Maurice
- Press, Frank
Abstract
Dispersion of Rayleigh waves for a new range of periods ranging from 1 to 7 minutes is described. The group velocity curve shows a long-period and a short-period branch merging at a minimum value of 3.54 km/sec. with a corresponding period of about 225 sec. It is suggested that the known variation of velocity with depth in the mantle can account for the observed dispersion. The small scatter in the velocities and the absorption of these waves suggests that, unlike shorter-period surface waves, refraction and attenuation effects are negligible at the continental margins. From the absorption of mantle Rayleigh waves the internal friction in the upper mantle for periods of 140 and 215 sec. is found to be given by 1/Q = 670 × 10^(−5). This is of the same order as that reported from vibration measurements at audio frequencies on laboratory samples of crystalline rocks at normal pressure and temperature.
Additional Information
© 1954 The Seismological Society of America. Manuscript received for publication October 20, 1952. This research has been supported by the Geophysics Research Division of the Air Force Cambridge Research Center under Contract AF 19(122)441.Attached Files
Published - 127.full.pdf
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Additional details
- Eprint ID
- 49997
- Resolver ID
- CaltechAUTHORS:20140924-123829978
- AF 19(122)-441
- Air Force Cambridge Research Center Geophysics Research Division
- Created
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2014-09-25Created from EPrint's datestamp field
- Updated
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2019-10-03Created from EPrint's last_modified field