| Title |
A signature of cosmic-ray increase in ad 774–775 from tree rings in Japan
|
|---|---|
| Published in |
Nature, June 2012
|
| DOI | 10.1038/nature11123 |
| Pubmed ID | |
| Authors |
Fusa Miyake, Kentaro Nagaya, Kimiaki Masuda, Toshio Nakamura |
| Abstract |
Increases in (14)C concentrations in tree rings could be attributed to cosmic-ray events, as have increases in (10)Be and nitrate in ice cores. The record of the past 3,000 years in the IntCal09 data set, which is a time series at 5-year intervals describing the (14)C content of trees over a period of approximately 10,000 years, shows three periods during which (14)C increased at a rate greater than 3‰ over 10 years. Two of these periods have been measured at high time resolution, but neither showed increases on a timescale of about 1 year (refs 11 and 12). Here we report (14)C measurements in annual rings of Japanese cedar trees from ad 750 to ad 820 (the remaining period), with 1- and 2-year resolution. We find a rapid increase of about 12‰ in the (14)C content from ad 774 to 775, which is about 20 times larger than the change attributed to ordinary solar modulation. When averaged over 10 years, the data are consistent with the decadal IntCal (14)C data from North American and European trees. We argue that neither a solar flare nor a local supernova is likely to have been responsible. |
X Demographics
The data shown below were collected from the profiles of 120 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Japan | 34 | 28% |
| United States | 15 | 13% |
| United Kingdom | 3 | 3% |
| France | 2 | 2% |
| Netherlands | 1 | <1% |
| Greece | 1 | <1% |
| Chile | 1 | <1% |
| China | 1 | <1% |
| Spain | 1 | <1% |
| Other | 3 | 3% |
| Unknown | 58 | 48% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 101 | 84% |
| Scientists | 17 | 14% |
| Practitioners (doctors, other healthcare professionals) | 1 | <1% |
| Science communicators (journalists, bloggers, editors) | 1 | <1% |
Mendeley readers
The data shown below were compiled from readership statistics for 247 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Japan | 7 | 3% |
| United States | 5 | 2% |
| Germany | 2 | <1% |
| Switzerland | 2 | <1% |
| Brazil | 2 | <1% |
| China | 2 | <1% |
| France | 1 | <1% |
| Sweden | 1 | <1% |
| Portugal | 1 | <1% |
| Other | 3 | 1% |
| Unknown | 221 | 89% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 66 | 27% |
| Student > Ph. D. Student | 35 | 14% |
| Student > Master | 26 | 11% |
| Student > Bachelor | 22 | 9% |
| Professor > Associate Professor | 22 | 9% |
| Other | 40 | 16% |
| Unknown | 36 | 15% |
| Readers by discipline | Count | As % |
|---|---|---|
| Earth and Planetary Sciences | 67 | 27% |
| Physics and Astronomy | 48 | 19% |
| Environmental Science | 20 | 8% |
| Agricultural and Biological Sciences | 19 | 8% |
| Social Sciences | 10 | 4% |
| Other | 35 | 14% |
| Unknown | 48 | 19% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1113. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 26 March 2024.
All research outputs
#13,763
of 25,791,495 outputs
Outputs from Nature
#1,387
of 98,790 outputs
Outputs of similar age
#30
of 179,590 outputs
Outputs of similar age from Nature
#6
of 981 outputs
Altmetric has tracked 25,791,495 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 99th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 98,790 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 102.7. This one has done particularly well, scoring higher than 98% of its peers.
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