UPPER MANTLE STRUCTURE UNDER OCEANS AND CONTINENTS FROM RAYLEIGH WAVES,
Abstract
Theoretical seismograms of Rayleigh waves based on several models of mantle structure are compared with actual records for various paths. It is found that the model 8099 of Dorman, Ewing and Oliver explains seismograms for Pacific paths but does not agree with records from Indian-Atlantic ocean paths in the period range shorter than about 100s. The velocity of the Airy phase corresponding to the group velocity maximum is about 0 times 10 km/s lower for the Indian-Atlantic path than for the Pacific. This difference can be accounted for by reducing the shear velocity at the top of the mantle under the Indian and Atlantic oceans by about 0 times I0 times 2 km/s. The difference between the Pacific mantle and the Continental mantle can be explained either by a reduction in shear velocity of the low-velocity layer under the Pacific ocean or by making the lowvelocity zone shallower. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 07, 1961
- Accession Number
- AD0613745
Entities
People
- Frank Press
- Keiti Aki
Organizations
- California Institute of Technology