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A search for lateral heterogeneity in the inner core from differential travel times near PKP‐D and PKP‐C
Author(s) -
Cormier Ver F.,
Choy George L.
Publication year - 1986
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl013i013p01553
Subject(s) - inner core , differential (mechanical device) , core (optical fiber) , geology , variation (astronomy) , outer core , travel time , range (aeronautics) , geodesy , diffraction , geophysics , optics , physics , astrophysics , materials science , engineering , transport engineering , composite material , thermodynamics
A search is made for lateral heterogeneity in the earth's inner core by analyzing the differential travel times between PKP‐DF, PKP‐CD and PKP‐C diff . These are P waves that are respectively transmitted through, reflected by, and diffracted around the inner core. From this data, heterogeneity in and near the inner core is found to be small. Residuals from PREM in the 134° to 157° range are bounded by ±0.8 sec., consistent with a ±0.9% variation in P velocity in the upper 200 km. of the inner core. The regional pattern of velocity variation inferred from the differential times is consistent with those obtained from global inversions of absolute PKP‐DF times.