High precision radiocarbon concentrations in tree rings from Northeastern Mexico: A new record with annual resolution for dating the recent past
Por:
Beramendi-Orosco, Laura E., Johnson, Kathleen R., Noronha, Alexandra L., Gonzalez-Hernandez, Galia, Villanueva-Diaz, Jose
Publicada:
1 oct 2018
Resumen:
We present a new record of atmospheric 14C from 1926–2002 AD constructed from annual measurements of dendrochronologically dated tree rings from Nuevo Leon in Northeast (NE) Mexico. The results are very similar to the Northern Hemisphere Zone 2 compilation, indicating that this location provides a suitable record of background atmospheric 14C. Closer examination of the atmospheric bomb peak years (1962–1965 AD), however reveals subtle differences from the Zone 2 compilation that may reflect transport of 14C-depleted air from the south during the summer season influenced not only by the northward migration of the Intertropical Convergence Zone but also by the North American Monsoon system and tropical storms and hurricanes over the Gulf of Mexico. These differences decrease after 1965 indicating that Northern Hemisphere atmospheric mixing had largely occurred by this point. Examination of the pre-bomb peak period reveals a steady decrease in F14C associated with fossil fuel derived CO2 emissions from 1922–1950 AD. The NE Mexico record is enriched in 14C relative to a record from the Pacific Northwest during this period, potentially reflecting a greater impact of fossil fuel emissions and/or release of aged CO2 from Pacific upwelling in this region. This record from NE Mexico represents the longest such record from North America and will contribute to improved characterization of the spatial and temporal variability of atmospheric 14C in the Northern Hemisphere. © 2018 Elsevier B.V.
Filiaciones:
Beramendi-Orosco, Laura E.:
Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
Laboratorio Nacional de Geoquímica y Mineralogía, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
Univ Nacl Autonoma Mexico, Inst Geol, Ciudad Univ, Ciudad De Mexico 04510, Mexico
Univ Nacl Autonoma Mexico, Lab Nacl Geoquim & Mineral, Ciudad Univ, Ciudad De Mexico 04510, Mexico
Johnson, Kathleen R.:
Department of Earth System Science, University of California, Irvine, United States
Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA
Noronha, Alexandra L.:
Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States
Univ Texas Austin, Dept Geol Sci, Jackson Sch Geosci, Austin, TX 78712 USA
Gonzalez-Hernandez, Galia:
Laboratorio Nacional de Geoquímica y Mineralogía, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
Univ Nacl Autonoma Mexico, Lab Nacl Geoquim & Mineral, Ciudad Univ, Ciudad De Mexico 04510, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Ciudad Univ, Ciudad De Mexico 04510, Mexico
Villanueva-Diaz, Jose:
Instituto Nacional de Investigaciones Forestales y Agropecuarias, CENID-RASPA, Gómez Palacio, Durango, Mexico
CENID RASPA, Inst Nacl Invest Forestales & Agr, Gomez Palacio 35140, Durango, Mexico
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