The detection of PKIIKP and damping in the inner core
| Autor: | B. A. BOLT |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1977 |
| Předmět: | |
| Zdroj: | Annals of Geophysics, Vol 30, Iss 3-4, Pp 507-520 (1977) |
| Druh dokumentu: | article |
| ISSN: | 1593-5213 2037-416X |
| DOI: | 10.4401/ag-4835 |
| Popis: | SUMMARY - The phase PKIIKP, reflected once from the lower surface of theinner core boundary, was most probably recorded by LAS A from the Faultlessunderground nuclear explosion at 10°.9 angular distance. The array beam detecteda P onset, with the correct slowness, within 2 sees of the theoretical travel time.The ground amplitude is 3 + 1 millimicrons at a dominant period of 1.5 sec.By comparison, the PKiKP ground amplitude from Faultless is 75 millimicronsat a dominant period of 1.1 sec.This detection again confirms the sharpness of the inner core boundaryand the 1968 core travel times for PKiKP. The additional attenuation ofPKIIKP over PKiKP yields, from direct and spectral measurements, Q = 4 5 0 + 1 00for P waves in the inner core. This value sharpens the earlier estimates of I.Sacks, G. Buchbinder, A. Qamar, and A. Eisenberg and is almost independentof core structure and rigidity.On the assumption of a constant velocity in the inner core, the observeddifferential PKIIKP minus PKiKP travel time requires an average P velocityof 11.4 + 0.02 km/sec for an inner core radius of 1216 km. |
| Databáze: | Directory of Open Access Journals |
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