The Galactic Cosmic Ray Intensity over the Past 106–109 Years as Recorded by Cosmogenic Nuclides in Meteorites and Terrestrial Samples

Wieler, Rainer; Beer, Jürg; Leya, Ingo (2013). The Galactic Cosmic Ray Intensity over the Past 106–109 Years as Recorded by Cosmogenic Nuclides in Meteorites and Terrestrial Samples. Space science reviews, 176(1-4), pp. 351-363. Kluwer Academic Publishers 10.1007/s11214-011-9769-9

[img] Text
art%3A10.1007%2Fs11214-011-9769-9.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (478kB) | Request a copy

Concentrations of stable and radioactive nuclides produced by cosmic ray particles in meteorites allow us to track the long term average of the primary flux of galactic cosmic rays (GCR). During the past ∼10 Ma, the average GCR flux remained constant over timescales of hundreds of thousands to millions of years, and, if corrected for known variations in solar modulation, also during the past several years to hundreds of years. Because the cosmic ray concentrations in meteorites represent integral signals, it is difficult to assess the limits of uncertainty of this statement, but they are larger than the often quoted analytical and model uncertainties of some 30%. Time series of concentrations of the radionuclide 10Be in terrestrial samples strengthen the conclusions drawn from meteorite studies, indicating that the GCR intensity on a ∼0.5 million year scale has remained constant within some ±10% during the past ∼10 million years. The very long-lived radioactive nuclide 40K allows to assess the GCR flux over about the past one billion years. The flux over the past few million years has been the same as the longer-term average in the past 0.5–1 billion years within a factor of ∼1.5. However, newer data do not confirm a long-held belief that the flux in the past few million years has been higher by some 30–50% than the very long term average. Neither does our analysis confirm a hypothesis that the iron meteorite data indicate a ∼150 million year periodicity in the cosmic ray flux, possibly related to variations in the long-term terrestrial climate.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences

UniBE Contributor:

Leya, Ingo

Subjects:

500 Science > 520 Astronomy
600 Technology > 620 Engineering
500 Science > 530 Physics

ISSN:

0038-6308

Publisher:

Kluwer Academic Publishers

Language:

English

Submitter:

Cléa Serpollier

Date Deposited:

26 Sep 2014 14:54

Last Modified:

08 Oct 2015 09:30

Publisher DOI:

10.1007/s11214-011-9769-9

Web of Science ID:

000320379200026

BORIS DOI:

10.7892/boris.48844

URI:

https://boris.unibe.ch/id/eprint/48844

Actions (login required)

Edit item Edit item
Provide Feedback