Open AccessUpper Mantle Structure under Oceans and Continents from Rayleigh Waves *
Author(s) -
Akit Keiti,
Press Frank
Publication year - 1961
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1961.tb00338.x
Subject(s) - geology , mantle (geology) , seismogram , rayleigh wave , seismology , shear velocity , geophysics , surface wave , meteorology , physics , astronomy , turbulence
Summary 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 100 s. The velocity of the Airy phase corresponding to the group velocity maximum is about 0.10km/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 0‐1‐0.2km/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 low‐velocity zone shallower.