Lateral variations near the core- mantle boundary.

Edward Garnero, D. Helmberger, G. Engen

Research output: Contribution to journalArticle

42 Scopus citations


Differential travel times between S and SKS (TS-SKS), and SKKS and SKS (TSKKS-SKS), along with amplitude behavior have been used to study lateral variations at the core-mantle boundary. In addition to TS-SKS anomalies, SKS and SKKS are anomalously separated by 2 to 3 seconds. A model fitting TS-SKS for this anomalous region requires one or more of the following: 1) up to 5% increase in the top 300 km of outer core velocity; 2) a large scale high Vs region (2% increase) in the lower mantle NE of Tonga; 3) lateral variations in D" shear wave velocities of up to 3%. However, 1) above predicts a decrease in TSKKS-SKS, contradicting the observations. This suggests that 2) and 3) are more likely explanations in modeling this data set. -from Authors

Original languageEnglish (US)
Pages (from-to)609-612
Number of pages4
JournalGeophysical Research Letters
Issue number6
Publication statusPublished - 1988
Externally publishedYes


ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)

Cite this