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dc.contributor.authorFlorinski, V.
dc.contributor.authorAxford, W. I.
dc.contributor.authorZank, G. P.
dc.date.accessioned2021-02-11T21:46:23Z
dc.date.available2021-02-11T21:46:23Z
dc.date.issued2004-01-01
dc.identifier.citationFlorinski, V., Axford, W. I., & Zank, G. P. (2004). The cosmic ray increases at 35 and 60 kyr BP. Radiocarbon, 46(2), 683-690.
dc.identifier.issn0033-8222
dc.identifier.doi10.1017/S0033822200035736
dc.identifier.urihttp://hdl.handle.net/10150/654969
dc.descriptionFrom the 18th International Radiocarbon Conference held in Wellington, New Zealand, September 1-5, 2003.
dc.description.abstractConcentrations of 10Be in ice cores and marine sediments exhibit 2 peaks with significant enhancements at 35,000 and 60,000 BP. This radioisotope is produced in the upper atmosphere by spallation of cosmic-ray protons and secondary neutrons on atmospheric nitrogen and oxygen. Previously suggested explanations for the increases include geomagnetic field reversals, a decrease in solar activity, and a supernova explosion. We propose an alternative explanation which involves a change in the galactic environment of the solar system. The structure of the heliosphere is investigated for a period when the Sun enters a cold, dense, unmagnetized interstellar cloud. Under these conditions, the heliosphere contracts to 25% its present size, significantly affecting galactic cosmic ray modulation and increasing anomalous cosmic ray fluxes. A tenfold increase in anomalous cosmic ray flux and a twofold increase in galactic cosmic ray intensity at Earth are possible in this high-density case if heliosheath modulation is reduced. We show that this increase in galactic cosmic ray intensity could be responsible for the peaks in 110Be records.
dc.language.isoen
dc.publisherDepartment of Geosciences, The University of Arizona
dc.relation.urlhttp://radiocarbon.webhost.uits.arizona.edu/
dc.rightsCopyright © by the Arizona Board of Regents on behalf of the University of Arizona. All rights reserved.
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectalkaline earth metals
dc.subjectAntarctica
dc.subjectArctic region
dc.subjectBe 10
dc.subjectberyllium
dc.subjectCalifornia
dc.subjectCenozoic
dc.subjectconcentration
dc.subjectcores
dc.subjectcorrelation
dc.subjectcosmic rays
dc.subjectglobal
dc.subjectGreenland
dc.subjectHolocene
dc.subjectice cores
dc.subjectisotopes
dc.subjectmarine sediments
dc.subjectMediterranean Sea
dc.subjectmetals
dc.subjectmodels
dc.subjectMono County California
dc.subjectMono Lake
dc.subjectpaleoenvironment
dc.subjectQuaternary
dc.subjectradioactive isotopes
dc.subjectsediments
dc.subjectsolar activity
dc.subjectsolar wind
dc.subjectSun
dc.subjectUnited States
dc.subjectvariations
dc.titleThe Cosmic Ray Increases at 35 and 60 Kyr BP
dc.typeProceedings
dc.typetext
dc.identifier.journalRadiocarbon
dc.description.collectioninformationThe Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.
dc.eprint.versionFinal published version
dc.description.admin-noteMigrated from OJS platform February 2021
dc.source.volume46
dc.source.issue2
dc.source.beginpage683
dc.source.endpage690
refterms.dateFOA2021-02-11T21:46:23Z


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