Abstract
THE Earth has an inner core about the size of the Moon. Convincing observations of the seismic waves PKiKP, reflected at steep angles from the inner core boundary (ICB), were announced by Engdahl et al. (annual meeting of the Seismological Society of America), using the Large Aperture Seismic Array (LASA) in Montana (epicentral distances Δ<40°). These identifications agree with expected travel times and wave slownesses1 (p = dt/dΔ), and pPKiKP minus PKiKP time lags.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Bolt, B. A., and O'Neill, M. E., Geophys. J. Roy. Astron. Soc., 9, 223 (1965).
Bolt, B. A., O'Neill, M. E., and Qamar, A., Geophys. J. Roy. Astron. Soc., 16, 475 (1968).
Jeffreys, H., Mon. Not. Roy. Astron. Soc., Geophys. Suppl., 4, 598 (1939).
Bolt, B. A., Bull. Seism. Soc. Amer., 54, 191 (1964).
Engdahl, E. R., Science, 161, 263 (1968).
Bullen, K. E., Introduction to the Theory of Seismology (Cambridge, 1963).
Bolt, B. A., Geophys. J. Roy. Astron. Soc. (in the press).
Bolt, B. A., Niazi, M., and Somerville, M. R., Geophys. J. Roy. Astron. Soc., 19, 299 (1970).
Derr, J. S., J. Geophys. Res., 74, 5202 (1969).
Bullen, K. E., Geophys. J. Roy. Astron. Soc., 9, 195 (1965).
Haddon, R. A. W., and Bullen, K. E., Phys. Earth Planet. Interiors, 2, 35 (1969).
Birch, F., Solids under Pressure, 137 (McGraw-Hill, 1963).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
BOLT, B., QAMAR, A. Upper Bound to the Density Jump at the Boundary of the Earth's Inner Core. Nature 228, 148–150 (1970). https://doi.org/10.1038/228148a0
Received:
Issue Date:
DOI: https://doi.org/10.1038/228148a0
This article is cited by
-
Research on the scatter features of the PKiKP/PcP amplitude ratio and the inner core boundary density contrasts beneath Northeast Asia
Science China Earth Sciences (2021)
-
Seismological evidence for a localized mushy zone at the Earth’s inner core boundary
Nature Communications (2017)
-
Constraining shear wave velocity and density contrast at the inner core boundary with PKiKP/P amplitude ratio
Journal of Earth Science (2013)
-
Seismological evidence for mosaic structure of the surface of the Earth's inner core
Nature (2005)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
