Shear velocity and density of an attenuating earth
Abstract
The dispersion that must accompany absorption is taken into account in many recent body-wave investigations but has been largely ignored in surface-wave and free-oscillation studies. In order to compare body-wave and free-oscillation data a correction must be made to travel times or periods to account for absorption-related physical dispersion. The correction depends on the frequency and Q of the data and can be as high as 1% which is much larger than the uncertainty of the raw data. Corrected toroidal mode data is inverted to obtain shear velocity and density versus depth. The average shear velocity in the upper 600 km is ∼2% greater than obtained from the uncorrected data. The resulting shear-wave travel times oscillate about the Jeffreys-Bullen values with an average baseline of only +0.5 second. Thus, the discrepancy between body-wave and free-oscillation studies is eliminated.
Additional Information
© 1976 Elsevier Scientific Publishing Company. Received April 14, 1976; Revised version received June 14, 1976. This research was supported by the Advanced Research Projects Agency of the Department of Defense and was monitored by the Air Force Office of Scientific Research under Contract F44620-72-C-0078. We would like to acknowledge helpful discussions with H.P. Liu and to credit M. Randall with reopening interest in this problem which has lain fallow in spite of the obvious implications of the work of Jeffreys, Futterman, Lomnitz, Strick, Davies and Carpenter.Attached Files
Published - 1-s2.0-0012821X76901801-main.pdf
Files
Name | Size | Download all |
---|---|---|
md5:7dd86a0ac0d40f293a1609421f1d1737
|
537.2 kB | Preview Download |
Additional details
- Eprint ID
- 54741
- Resolver ID
- CaltechAUTHORS:20150211-144235072
- Advanced Research Projects Agency (ARPA)
- Air Force Office of Scientific Research (AFOSR)
- F44620-72-C-0078
- Created
-
2015-02-11Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences
- Other Numbering System Name
- Caltech Division of Geological and Planetary Sciences
- Other Numbering System Identifier
- 2743