Showing papers by "Xianfeng Wang published in 2013"
TL;DR: In this paper, the authors used multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) to measure the half-life of stalagmite stalagmites.
982 citations
TL;DR: These absolute-dated speleothem oxygen isotope records that characterize hydroclimate variation in western and eastern Amazonia over the past 250 and 20 ka are presented, suggesting that higher biodiversity in western Amazonia, contrary to 'Refugia Hypothesis', is maintained under relatively stable climatic conditions.
Abstract: Precise characterization of hydroclimate variability in Amazonia on various timescales is critical to understanding the link between climate change and biodiversity. Here we present absolute-dated speleothem oxygen isotope records that characterize hydroclimate variation in western and eastern Amazonia over the past 250 and 20 ka, respectively. Although our records demonstrate the coherent millennial-scale precipitation variability across tropical– subtropical South America, the orbital-scale precipitation variability between western and eastern Amazonia exhibits a quasi-dipole pattern. During the last glacial period, our records imply a modest increase in precipitation amount in western Amazonia but a significant drying in eastern Amazonia, suggesting that higher biodiversity in western Amazonia, contrary to ‘Refugia Hypothesis’, is maintained under relatively stable climatic conditions. In contrast, the glacial–interglacial climatic perturbations might have been instances of loss rather than gain in biodiversity in eastern Amazonia, where forests may have been more susceptible to fragmentation in response to larger swings in hydroclimate.
445 citations
University of Washington1, Desert Research Institute2, Oregon State University3, University of Colorado Boulder4, Pennsylvania State University5, Xi'an Jiaotong University6, University of Minnesota7, United States Geological Survey8, South Dakota State University9, University of California, Berkeley10, Curtin University11, University of Wisconsin-Madison12, Victoria University of Wellington13, University of California, San Diego14, University of Copenhagen15, Lake Superior State University16, Nanyang Technological University17, Dartmouth College18
TL;DR: Results from a new, annually resolved ice-core record from West Antarctica suggest a more active role for the Southern Ocean in the onset of deglaciation than is inferred from ice cores in the East Antarctic interior, which are largely isolated from sea-ice changes.
Abstract: An annually resolved ice-core record from West Antarctica indicates that warming driven by local insolation resulting from sea-ice decline began in that region about 2,000 years before warming in East Antarctica, reconciling two alternative explanations for deglacial warming in the Southern Hemisphere.
284 citations
TL;DR: In this paper, the authors compile 283 U/Th dates on 21 stalagmites from six cave systems in the NW coast of Spain to evaluate if there are patterns in stalagmite growth that are evidence of climatic forcing.
71 citations
19 Mar 2013
29 citations
01 Jan 2013
TL;DR: In this article, a multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) was used to measure the atomic ratios of U and Th on Faraday cups with precisions of 1-3 epsilon units (1 e-unit¼1 part in 10 4 ) using a ThermoScientific Neptune with desolvation nebulization.
Abstract: We have developed techniques for measuring 234 U and 230 Th on Faraday cups with precisions of 1–3 epsilon units (1 e-unit¼1 part in 10 4 ) using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Using a Thermo-Scientific Neptune with desolvation nebulization, we obtained ionization/transmission efficiencies of 1–2% for both U and Th. We set up protocols to correct for tailing, prepared U and Th gravimetric standards, tested a Th mass fractionation correction procedure based on U isotopes, and identified natural calcite samples likely to be in U–Th isotopic secular equilibrium. The measured atomic ratios,
9 citations
Journal Article•
2 citations
TL;DR: A red-clay core from north of New Zealand contains a 21 cm-thick layer of the 340thousand-year old Rangitawa ash in the nepheloid layer that has steadily re-deposited at the core site ever since the Whakamaru super-eruption as discussed by the authors.
1 citations