Impact Origin of 775 AD Radiocarbon Spike (Anomaly) Disputed

Impact Origin of 775 AD Radiocarbon Spike (Anomaly) Disputed

Usoskin, I. G., and G. A. Kovaltsov, 2015, The carbon-14
spike in the 8th century was not caused by a cometary
impact on Earth. Icarus. vol. 260, pp. 475–476

Abstract at
http://www.sciencedirect.com/science/article/pii/S0019103514003200
PDF file at http://cc.oulu.fi/~usoskin/personal/Icarus_2015.pdf
and preprint at http://arxiv.org/abs/1401.5945 .

More Papers In List of publications: Ilya G. Usoskin at
http://cc.oulu.fi/~usoskin/personal/List.html

For background information about the 775 AD
Radiocarbon Spike, look at:

774–775 carbon-14 spike
https://en.wikipedia.org/wiki/774–775_carbon-14_spike

Jull, A. J. T., I. P. Panyushkina, T. E. Lange, V. V. Kukarskih,
V. S. Myglan, K. J. Clark, M. W. Salzer, G. S. Burr, and S. W.
Leavitt, 2014, Excursions in the 14C record at A.D. 774–775
in tree rings from Russia and America. Geophysical Research
Letters. vol. 41, no. 8, pp. 3004-3010.
Abstract at
http://onlinelibrary.wiley.com/doi/10.1002/2014GL059874/abstract
PDF file at
http://www.geo.arizona.edu/sites/www.geo.arizona.edu/files/JullAGU.pdf

Neuhauser, R., and D. L. Neuhauser, 2011, Variations of
14C around AD 775 and AD 1795 – due to solar activity.
Astronomische Nachrichten / AN 999, no. 88, 789 – 813.
PDF at http://arxiv.org/pdf/1508.06745.pdf and
http://www.science-media.org/userfiles/87/presentations/87_presentation_33.pdf


This is my 9th try at posting this post. All of the previous
ones have disappeared into the ether never to seen of
acknowledged.

Yours,

Paul H.