Zobrazeno 1 - 10
of 63
pro vyhledávání: '"J. W. Beck"'
Autor:
C. Vance Haynes, George S. Burr, Yu-Wei Chang, Chuan-Chou Shen, Weijian Zhou, Vicki Nguyen, Frederick W. Taylor, J. W. Beck
Publikováno v:
Radiocarbon. 57:507-515
This article discusses the magnitude and rate of change of radiocarbon reservoir ages from the surface ocean in the South Pacific during the Holocene. 14C reservoir ages are calculated from paired U/Th and 14C measurements. Seventeen pairs of coral d
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6e57603283d09a2a9fa93fd61dc912e8
https://doi.org/10.2458/azu_rc.57.18460
https://doi.org/10.2458/azu_rc.57.18460
Many regions of the world experienced abrupt climate variability during the last glacial period (75-15 thousand years ago1,2). These changes probably arose from interactions between Northern Hemisphere ice sheets and circulation in the North Atlantic
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6966217170bc439a3703c09f398e224f
https://ora.ox.ac.uk/objects/uuid:2a078832-c81e-426f-a481-23342368241d
https://ora.ox.ac.uk/objects/uuid:2a078832-c81e-426f-a481-23342368241d
Autor:
Frederick W. Taylor, J. W. Beck, Guy Cabioch, Thierry Corrège, Douglas J. Donahue, George S. Burr
Publikováno v:
Radiocarbon. 51:319-335
This paper presents radiocarbon results from modern South Pacific corals from the Marquesas Islands, Vanuatu, Papua New Guinea (PNG), and Easter Island. All of the measurements are from pre-bomb Porites corals that lived during the 1940s and 1950s. T
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ac7642a570928d68dc2d587dc8b22c76
https://doi.org/10.1017/s0033822200033853
https://doi.org/10.1017/s0033822200033853
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. :420-427
Radiocarbon records from modern corals have long been recognized for their usefulness as a geochemical tracer of surface ocean waters and oceanic upwelling. Pacific corals are especially interesting because of their potential relevance to El Nino –
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::43df165b7031d68e6f63d32d4b095138
https://doi.org/10.1016/j.nimb.2004.04.080
https://doi.org/10.1016/j.nimb.2004.04.080
Autor:
A. J. T. Jull, J. W. Beck, D. Lal, Nathaniel A. Lifton, Todd Lange, George S. Burr, L. R. McHargue, Douglas J. Donahue
Publikováno v:
Global and Planetary Change. 41:309-323
A wide range of climatic, geologic and archeological records can be characterized by measuring their 14 C and 10 Be concentrations, using the accelerator mass spectrometry (AMS). These records are found not only in the traditional sampling sites such
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6eacef16aefc9c07c362ad1c6c40f752
https://doi.org/10.1016/j.gloplacha.2004.01.014
https://doi.org/10.1016/j.gloplacha.2004.01.014
Autor:
J. van der Plicht, Edouard Bard, Caitlin E. Buck, David Richards, Paula J. Reimer, Konrad A Hughen, C. Bronk Ramsey, Ron W Reimer, Minze Stuiver, M. G. L. Baillie, Michael Friedrich, Sabine Remmele, Thomas P. Guilderson, John Southon, F. G. McCormac, Paul G. Blackwell, J. W. Beck, Bernd Kromer, C. E. Weyhenmeyer
Publikováno v:
Radiocarbon. 46:1225-1238
The radiocarbon calibration curve IntCal04 extends back to 26 cal kyr B P. While several high-resolution records exist beyond this limit, these data sets exhibit discrepancies of up to several millennia. As a result, no calibration curve for the time
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b319796f453db35278ba0b6b002c7c0b
https://doi.org/10.1017/s0033822200033117
https://doi.org/10.1017/s0033822200033117
Autor:
J. W. Beck, A. J. T. Jull, Douglas J. Donahue, L. R. McHargue, George S. Burr, D. Biddulph, Todd Lange, A L Hatheway
Publikováno v:
Journal of Environmental Radioactivity. 69:3-19
There are many diverse uses of accelerator mass spectrometry (AMS). Carbon-14 studies at our laboratory include much research related to paleoclimate, both with 14C as a tracer of past changes in environmental conditions as observed in corals, marine
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9f544d7060ae6d81f8f294148425764f
https://doi.org/10.1016/s0265-931x(03)00083-3
https://doi.org/10.1016/s0265-931x(03)00083-3
Publikováno v:
Scopus-Elsevier
With the recent addition of a high-energy analysis beam line, the capability to measure 129I has been developed at the NSF-Arizona AMS Laboratory. Preliminary measurements have been made using the +4 and +5 charge states at 2.1 MV with a gas stripper
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0e2221cd7075d2e5d6189150ba0249ad
https://doi.org/10.1016/s0168-583x(00)00140-3
https://doi.org/10.1016/s0168-583x(00)00140-3
Publikováno v:
Science. 279:366-369
Stepped-heating experiments on martian meteorites Allan Hills 84001 (ALH84001) and Elephant Moraine 79001 (EETA79001) revealed low-temperature (200 to 430 degrees Celsius) fractions with a carbon isotopic composition δ 13 C between −22 and −33 p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3939d05d5560318a7a8187b3021d3ad6
https://doi.org/10.1126/science.279.5349.366
https://doi.org/10.1126/science.279.5349.366
Autor:
Todd Lange, Paul E. Damon, Nathaniel A. Lifton, L. R. McHargue, R. Maddock, L. J. Toolin, D. Biddulph, George S. Burr, A. J. T. Jull, Douglas J. Donahue, L. Hewitt, C. Courtney, J. M. O'Malley, J. W. Beck, A L Hatheway
Publikováno v:
Scopus-Elsevier
The operation of the NSF-Arizona Laboratory is summarized. The methods used to determine accuracy and precision of radiocarbon measurements, and to make corrections for background contaminations are presented. An insulating support which has been ins
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::da41333c69f29af884f6206c69426fa5
https://doi.org/10.1016/s0168-583x(96)00729-x
https://doi.org/10.1016/s0168-583x(96)00729-x