Astronomy:993–994 carbon-14 spike
The 993–994 carbon-14 spike was a rapid 0.91% increase in carbon-14 isotope content from tree rings dated 993-994 CE.[2][3] This event was also confirmed with an associated increase of beryllium-10 in Antarctic ice core samples, supporting the hypothesis that this event was of solar origin.[2][4] There were several astronomical observations during this time that correspond with the 14C and 10Be spikes, but these texts are few and far between.[4][5][6]
In 2021, a scientific paper used the 993–994 carbon-14 spike as a benchmark in dendrochronology (tree-ring studies) to precisely determine that Vikings were present in L'Anse aux Meadows in Newfoundland exactly 1000 years prior, in 1021 AD.[7]
Historical observations
The solar storm hypothesis is heavily supported by several observations of aurora events from late 992 in Korea, Germany and Ireland, usually describing a red sky, presumably because of major auroras.[4][5][6] The historical observations do not completely prove the cause of the 993-994 14C spike but show evidence of a strong solar event taking place late 992, as they were recorded within a relatively short time frame.[4][6]
In the Korean Peninsula, between December 992 and January 993, a text described "heaven's gate" opening one night.[4][6]
In the Saxony region of present-day Germany in late 992, several aurora observations were made. One set of observations, recorded October 21, 992, noted that the sky reddened three times.[4] Another set of observations, made December 26, 992, mentioned a light as bright as the sun shining for an hour, then reddening the sky, before vanishing completely.[4]
In the Ulster region of present-day Northern Ireland on December 26, 992, texts described the sky as "blood-red" and having a "fiery hue".[4]
Similar events
The 993–994 carbon-14 spike was one of only a few well-documented 14C events. There had been a considerably larger one, the 774-775 carbon-14 spike, which was around 1.7 times as strong than the 993-994 event.[2] Both events also had subsequent 10Be spikes, which further proves that they are from strong solar activity.[5]
See also
References
- ↑ Miyake, Fusa; Hakozaki, Masataka; Kimura, Katsuhiko; Tokanai, Fuyuki; Nakamura, Toshio; Takeyama, Mirei; Moriya, Toru (2022-07-04). "Regional Differences in Carbon-14 Data of the 993 CE Cosmic Ray Event". Frontiers in Astronomy and Space Sciences 9: 886140. doi:10.3389/fspas.2022.886140. ISSN 2296-987X.
- ↑ 2.0 2.1 2.2 Miyake, Fusa; Masuda, Kimiaki; Nakamura, Toshio (2013-06-26). "Another rapid event in the carbon-14 content of tree rings" (in en). Nature Communications 4 (1): 1748. doi:10.1038/ncomms2783. ISSN 2041-1723. PMID 23612289.
- ↑ Dee, Michael W.; Pope, Benjamin J. S. (August 2016). "Anchoring historical sequences using a new source of astro-chronological tie-points" (in en). Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472 (2192): 20160263. doi:10.1098/rspa.2016.0263. ISSN 1364-5021. PMID 27616924.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Hayakawa, Hisashi; Tamazawa, Harufumi; Uchiyama, Yurina; Ebihara, Yusuke; Miyahara, Hiroko; Kosaka, Shunsuke; Iwahashi, Kiyomi; Isobe, Hiroaki (January 2017). "Historical Auroras in the 990s: Evidence of Great Magnetic Storms" (in en). Solar Physics 292 (1): 12. doi:10.1007/s11207-016-1039-2. ISSN 0038-0938. http://link.springer.com/10.1007/s11207-016-1039-2.
- ↑ 5.0 5.1 5.2 Mekhaldi, Florian; Muscheler, Raimund; Adolphi, Florian; Aldahan, Ala; Beer, Jürg; McConnell, Joseph R.; Possnert, Göran; Sigl, Michael et al. (2015-10-26). "Multiradionuclide evidence for the solar origin of the cosmic-ray events of ᴀᴅ 774/5 and 993/4". Nature Communications 6: 8611. doi:10.1038/ncomms9611. ISSN 2041-1723. PMID 26497389.
- ↑ 6.0 6.1 6.2 6.3 Stephenson, F. Richard (2015-03-15). "Astronomical evidence relating to the observed 14C increases in A.D. 774–5 and 993–4 as determined from tree rings" (in en). Advances in Space Research 55 (6): 1537–1545. doi:10.1016/j.asr.2014.12.014. ISSN 0273-1177. https://www.sciencedirect.com/science/article/pii/S027311771400773X.
- ↑ Kuitems, Margot; Wallace, Birgitta L.; Lindsay, Charles; Scifo, Andrea; Doeve, Petra; Jenkins, Kevin; Lindauer, Susanne; Erdil, Pınar et al. (2022-01-20). "Evidence for European presence in the Americas in ad 1021" (in en). Nature 601 (7893): 388–391. doi:10.1038/s41586-021-03972-8. ISSN 0028-0836. PMID 34671168.
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