The Airy phase of shallow-focus submarine earthquakes
- Creators
- Press, Frank
- Ewing, Maurice
- Tolstoy, Ivan
Abstract
An extension of the theoretical work of Lamb and Pekeris shows that a prominent phase (Airy phase) consisting of a group of waves of period 9-11 seconds, traveling across the ocean with a velocity of approximately 0.7 of the speed of sound in water, should be present on the seismograms of shallow-focus submarine earthquakes. This arrival corresponds to normal mode propagation at a stationary value of group velocity through the acoustic system consisting of the ocean and the rigid ocean bottom. A phase fitting this description has been observed on the Milne-Shaw instruments at Bermuda for a series of Dominican Republic shocks. The Wenner seismographs at Huancayo recorded the Airy phase of a shock southwest of the Galapagos Islands. The study of the Airy phase of a sufficient number of sea quakes would provide information concerning the nature of the ocean bottom since the latter affects both the periods and velocities of the Airy phase.
Additional Information
© 1950, by the Seismological Society of America. Manuscript received for publication May 3, 1949. The research reported in this document has been made possible through support and sponsorship extended by the Geophysical Research Directorate of the Cambridge Field Station, AMC, U. S. Air Force, under Contract W-28-099 ac-396. It is published for technical information only and does not represent recommendations or conclusions of the sponsoring agency. The authors wish to express their thanks to the offices of the U. S. Coast and Geodetic Survey, Section of Seismology, for making the Bermuda records available. Professors B. Gutenberg and C. F. Richter of the California Institute of Technology were extremely helpful during this investigation. We wish to thank Father Daniel Linehan, S.J., of the Weston Seismological Observatory, Dr. E. A. Hodgson of the Dominion Observatory of Canada, Professor Perry Byerly of the University of California, Father Joseph J. Lynch, S.J., and Dr. William A. Lynch of Fordham University for permission to study records of the respective observatories. We are indebted to Marie Flanagan for computing and drafting the graphs presented in this paper.Attached Files
Published - 111.full.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:cfe7a02da2bcedd6d9d2c874f57c42e0
|
2.0 MB | Preview Download |
Additional details
- Eprint ID
- 50012
- Resolver ID
- CaltechAUTHORS:20140924-153353476
- W-28-099 ac-396
- Cambridge Field Station Geophysical Research Directorate
- Created
-
2014-09-24Created from EPrint's datestamp field
- Updated
-
2019-10-03Created from EPrint's last_modified field