Mathematics – Logic
Scientific paper
Jan 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011an....332...24d&link_type=abstract
Astronomische Nachrichten, Vol.332, Issue 1, p.24
Mathematics
Logic
2
Scientific paper
In this paper, we study quantitatively the effect of the Earth's core formation on the secular rate of change of the length of day (LOD). We find that for the present epoch, a growth rate of the core comprised between 1 and 10 mm/cy seems to be a plausible guess, leading to a relative decrease of LOD comprised roughly between 10 and 100 μs/cy. Such values do not affect significantly the observed secular increase of LOD caused by tidal braking, which amounts to about 1.79 ms/cy. However, in the remote geological past, before the Phanerozoic, the effects of core growth may have been much more important, because the total change of LOD associated with core formation has been estimated by Birch in 1965 to be 2.4 hours for an initially undifferentiated cold Earth, and 3.1 hours for an initially undifferentiated hot Earth. We consider a number of scenarios, some of them corresponding to very early and/or very fast core formation, others corresponding to slow and/or late core formation. We show that palaeo-LOD measurements seem to favour slow core formation during the Proterozoic, contrarily to the now largely prevailing hypothesis based on geochemical arguments that the iron core formed very early in the Earth's history and during a geologically short time interval.
Denis Collange
Rybicki Kacper R.
Schreider Anatoly
Tomecka-Suchoń S.
Varga Peter
No associations
LandOfFree
Length of the day and evolution of the Earth's core in the geological past does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Length of the day and evolution of the Earth's core in the geological past, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Length of the day and evolution of the Earth's core in the geological past will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1207819