Miyake event

Sharp increase in cosmogenic isotopes

A Miyake event is an observed sharp enhancement of the production of cosmogenic isotopes by cosmic rays. It can be marked by a spike in the concentration of radioactive carbon isotope 14
C in tree rings, as well as 10
Be and 36
Cl in ice cores, which are all independently dated. At present, five significant events are known (7176 BCE, 5259 BCE, 660 BCE, 774 CE, 993 CE) for which the spike in 14
C is quite remarkable, i.e. above 1% rise over a period of 2 years, and four more events (12,350 BCE,[1] 5410 BCE, 1052 CE, 1279 CE) need independent confirmation. It is not known how often Miyake events occur, but from the available data it is estimated to be every 400–2400 years.[2]

There is strong evidence that Miyake events are caused by extreme solar particle events[3][4] and they are likely related to super-flares discovered on solar-like stars.[4][5] Although Miyake events are based on extreme year-to-year rises of 14
C concentration, the duration of the periods over which the 14
C levels increase or stay at high levels is longer than one year.[6][7] However, a universal cause and origin of all the events is not yet established in science, and some of the events may be caused by other phenomena coming from outer space (such as a gamma-ray burst).[8]

A recently reported sharp spike in 14
C that occurred between 12,350 and 12,349 BCE may represent the largest known Miyake event. This event was identified during a study conducted by an international team of researchers who measured radiocarbon levels in ancient trees recovered from the eroded banks of the Drouzet River, near Gap, France, in the Southern French Alps.[9][10][11] According to the initial study the new event is roughly twice the size of the Δ14
C increase for more recent 774 CE and 993 CE events, but the strength of the corresponding solar storm is not yet assessed. However, the newly discovered 12,350 BCE event has not yet been independently confirmed in wood from other regions, nor it is reliably supported by a clear corresponding spike in other isotopes[10] (such as beryllium-10) that are usually used in combination for absolute radiometric dating.

A Miyake event occurring in modern conditions might have significant impacts on global technological infrastructure such as satellites, telecommunications, and power grids.[7][12][13]

## Discovery[edit]

The events are named after the Japanese physicist Fusa Miyake who, as a doctoral student, was the first one to identify these radiocarbon spikes and published the results with co-authors in 2012 in the journal Nature.[14] The investigation at that time found a strong 14
C increase in the annual rings of Japanese cedars for the years 774/775. The event of 775 was independently discovered, using the low-resolution IntCal data.[15] In 2013, Miyake and co-authors published the discovery of another similar radiocarbon spike in the years 993/994.[16] In December 2013, Miyake received her Doctor of Science degree from Nagoya University.[17]

## Time benchmark[edit]

After a Miyake event is well-studied and confirmed, it can serve as a reference time benchmark, a "year-stamp", enabling more precise dating of historical events. Six diverse historical occurrences, from archaeological sites to natural disasters, have thus been dated to a specific year, using Miyake events as benchmarks and counting tree rings.[18] For example, wooden houses in the Viking site at L'Anse aux Meadows in Newfoundland were dated by finding the 993 CE Miyake event and then counting tree rings, which showed that the wood is from a tree felled in 1021 CE.[19]

## See also[edit]

* Carrington Event
* Coronal mass ejection
* Dendrochronology
* Geomagnetic storm
* Solar storm

## References[edit]

1. ^ Kirby, Jane (9 October 2023). "Biggest ever solar storm identified using ancient tree rings". The Independent. Retrieved 9 October 2023.
2. ^ Brehm, Nicolas; Christl, Marcus; Knowles, Timothy D. J.; Casanova, Emmanuelle; Evershed, Richard P.; Adolphi, Florian; et al. (7 March 2022). "Tree-rings reveal two strong solar proton events in 7176 and 5259 BCE". Nature Communications. 13 (1): 1196. Bibcode:2022NatCo..13.1196B. doi:10.1038/s41467-022-28804-9. PMC 8901681. PMID 35256613.
3. ^ Usoskin, I. G.; Kromer, B.; Ludlow, F.; Beer, J.; Friedrich, F.; Kovaltsov, G.; Solanki, S.; Wacker, L. (2013). "The AD775 cosmic event revisited: the Sun is to blame". Astronomy and Astrophysics Letters. 552: L3. arXiv:1302.6897. Bibcode:2013A&A...552L...3U. doi:10.1051/0004-6361/201321080.
4. ^ a b Cliver, Edward W.; Schrijver, Carolus; Shibata, Kazunari; Usoskin, Ilya G. (2022). "Extreme solar events". Living Reviews in Solar Physics. 19 (1): 2. arXiv:2205.09265. Bibcode:2022LRSP...19....2C. doi:10.1007/s41116-022-00033-8.
5. ^ Maehara, Hiroyuki; Shibayama, Tayuka; Notsu, Shota; Notsu, Yuta; Nagao, Takashi; Kusaba, Satoshi; et al. (2012). "Super-flares on solar-type stars". Nature. 485 (7399): 478–481. Bibcode:2012Natur.485..478M. doi:10.1038/nature11063. PMID 22622572.
6. ^ Zhang, Qingyuan; Sharma, Utkarsh; Dennis, Jordan A.; Scifo, Andrea; Kuitems, Margot; Büntgen, Ulf; et al. (2022). "Modelling cosmic radiation events in the tree-ring radiocarbon record". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 478 (2266). arXiv:2210.13775. Bibcode:2022RSPSA.47820497Z. doi:10.1098/rspa.2022.0497. S2CID 253107601.
7. ^ a b Miyake, Fusa; Usoskin, Ilya; Poluianov, Stepan (2020). Miyake, Fusa; Usoskin, Ilya; Poluianov, Stepan (eds.). Extreme Solar Particle Storms: the hostile Sun. Bristol, UK: Institute of Physics. doi:10.1088/2514-3433/ab404a. ISBN 978-0-7503-2232-4.
8. ^ Kornei, Katherine (6 March 2023). "Mystery of Ancient Space Superstorms Deepens: A fresh analysis of tree-ring data suggests barrages of cosmic radiation that washed over Earth centuries ago may have come from sources besides our sun". Scientific American. Retrieved 3 October 2023.
9. ^ Alex Wilkins (October 9, 2023). "Largest known solar storm struck Earth 14,300 years ago". New Scientist. Vol. 260, no. 3460\. p. 9\. Bibcode:2023NewSc.260Q...9W. doi:10.1016/S0262-4079(23)01892-4.
10. ^ a b Bard, Edouard; et al. (October 9, 2023). "A radiocarbon spike at 14 300 cal yr BP in subfossil trees provides the impulse response function of the global carbon cycle during the Late Glacial". Philosophical Transactions of the Royal Society A. 381 (2261). Bibcode:2023RSPTA.38120206B. doi:10.1098/rsta.2022.0206. PMC 10586540. PMID 37807686.
11. ^ "Largest Ever Solar Storm Identified in Ancient Tree Rings – Could Devastate Modern Technology and Cost Billions". SciTechDaily. 9 October 2023. Retrieved 9 October 2023.
12. ^ Brehm, Nicolas; Christl, Marcus; Knowles, Timothy D. J.; Casanova, Emmanuelle; Evershed, Richard P.; Adolphi, Florian; et al. (2022). "Tree-rings reveal two strong solar proton events in 7176 and 5259 BCE". Nature Communications. 13 (1): 1196. Bibcode:2022NatCo..13.1196B. doi:10.1038/s41467-022-28804-9. PMC 8901681. PMID 35256613.
13. ^ Cosmic-ray Research Division (17 November 2021). "Radiocarbon (14C)". Nagoya, Japan: Institute for Space–Earth Environmental Research, Nagoya University. Retrieved 2023-03-06.
14. ^ Miyake, F.; Nagaya, K.; Masuda, K.; Nakamura, T. (2012). "A signature of cosmic-ray increase in AD 774–775 from tree rings in Japan". Nature. 486 (7402): 240–242. Bibcode:2012Natur.486..240M. doi:10.1038/nature11123. PMID 22699615.
15. ^ Usoskin, Ilya; Kovaltsov, Gennady (2012). "Occurrence of Extreme Solar Particle Events: Assessment from Historical Proxy Data". Astrophysical Journal. 757 (1): 92. arXiv:1207.5932. Bibcode:2012ApJ...757...92U. doi:10.1088/0004-637X/757/1/92.
16. ^ Miyake, Fusa; Masuda, Kimiaki; Nakamura, Toshio (2013). "Another rapid event in the carbon-14 content of tree rings". Nature Communications. 4: 1748. Bibcode:2013NatCo...4.1748M. doi:10.1038/ncomms2783. PMID 23612289. S2CID 256624509.
17. ^ "Faculty Profiles: MIYAKE Fusa". Nagoya University. Retrieved 17 October 2023. "Degree: 博士（理学）（ 2013.12 名古屋大学 ）"
18. ^ Price, Michael (13 April 2023). "Marking time: Radiocarbon timestamps left in ancient tree rings by cosmic ray bombardments can date historical events with unprecedented precision". Science. "A previous version "Marking time: Cosmic ray storms can pin precise dates on history from ancient Egypt to the Vikings" appeared in Science, Vol 380, Issue 6641."
19. ^ Kuitems, Margot; et al. (20 October 2021). "Evidence for European presence in the Americas in AD 1021" (PDF). Nature. 601 (7893): 388–391. doi:10.1038/s41586-021-03972-8. PMC 8770119. PMID 34671168. S2CID 239051036. Archived (PDF) from the original on 2022-10-09.

## External links[edit]

* Researchers succeed for first time in accurately dating a 7,000-year-old prehistoric settlement using cosmic rays - May 21, 2024 - University of Bern
* "Young Researcher in the Spotlight: Fusa Miyake at the Solar-Terrestrial Environment Laboratory". Nagoya University. 27 May 2013. Retrieved 17 October 2023.
* Carlson, Erika K. (29 May 2020). "Sun's Past Hidden in Tree Rings • Physicist Fusa Miyake measures isotope abundances in ancient tree rings to uncover solar eruptions from thousands of years ago". Physics. 13. Physics 13, 78: 78. Retrieved 17 October 2023. "Q&A"
* "José A. Boninsegna Frontiers in Dendrochronology Award was given to Associate Professor Fusa Miyake". Institute for Space-Earth Environmental Research, Nagoya University. 26 July 2022. Retrieved 17 October 2023.