The rigidity of the Earth’s inner core
Main Article Content
Abstract
The evidence for the existence of significant rigidity in the Earth's inner core is summarised and discussed in the light of recent work. Quantum-mechanical calculations, based on a Thomas-Fermi-Dirac model, suggest that an earlier estimate of 3.6 × 10¹² dyn/cm² for this rigidity may need to be reduced by 0.5 × 10¹² dyn/cm². The theoretical travel-times of the phase PKJKP would then need to be increased by amounts ranging from zero to 40 seconds. It is shown that the use of Gutenberg's seismic data in place of that of Jeffreys would reduce the estimated rigidity of the inner core by a further 1.6 × 10¹² dyn/cm², approximately. It is suggested that Gutenberg's data lead to the lowest likely value for the rigidity of the inner core, namely 1.5 × 10¹² dyn/cm², so that, on all present evidence, it is improbable that the inner core is less than about twice as rigid as steel is at zero pressure.
Article Details
How to Cite
Bullen, K. E. (2010) “The rigidity of the Earth’s inner core”, Annals of Geophysics, 53(1), pp. 1–5. doi: 10.4401/ag-4586.
Issue
Section
OLD
Open-Access License
No Permission Required
Istituto Nazionale di Geofisica e Vulcanologia applies the Creative Commons Attribution License (CCAL) to all works we publish.
Under the CCAL, authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, so long as the original authors and source are cited. No permission is required from the authors or the publishers.
In most cases, appropriate attribution can be provided by simply citing the original article.
If the item you plan to reuse is not part of a published article (e.g., a featured issue image), then please indicate the originator of the work, and the volume, issue, and date of the journal in which the item appeared. For any reuse or redistribution of a work, you must also make clear the license terms under which the work was published.
This broad license was developed to facilitate open access to, and free use of, original works of all types. Applying this standard license to your own work will ensure your right to make your work freely and openly available. For queries about the license, please contact ann.geophys@ingv.it.