A map of topography on the 410-km discontinuity from PP precursors
Article first published online: 7 DEC 2012
Copyright 1999 by the American Geophysical Union.
Geophysical Research Letters
Volume 26, Issue 5, pages 549–552, 1 March 1999
How to Cite
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 6 JAN 1999
- Manuscript Received: 3 NOV 1998
We derive a new map of global topography on the 410-km discontinuity from observations of precursors to PP obtained by stacking almost 25,000 long-period seismograms. The inferred ‘410’ topography exhibits average peak-to-peak amplitude of about 30 km, has a strong degree-one component, and is highly correlated with previous results obtained from SS precursors [Flanagan and Shearer, 1998]. Spatial variations in ‘410’ topography appear unrelated to ocean-continent differences, suggesting that continental roots are not a significant factor in observed global temperature variations at 410 km depth.