672 research outputs found
Dating late Quaternary planktonic foraminifer Neogloboquadrina pachyderma from the Arctic Ocean using amino acid racemization
No full textThe long-term rate of racemization for amino acids preserved in planktonic foraminifera was determined by using independently dated sediment cores from the Arctic Ocean. The racemization rates for aspartic acid (Asp) and glutamic acid (Glu) in the common taxon, Neogloboquadrina pachyderma, were calibrated for the last 150 ka using 14C ages and the emerging Quaternary chronostratigraphy of Arctic Ocean sediments. An analysis of errors indicates realistic age uncertainties of about ±12% for Asp and ±17% for Glu. Fifty individual tests are sufficient to analyze multiple subsamples, identify outliers, and derive robust sample mean values. The new age equation can be applied to verify and refine age models for sediment cores elsewhere in the Arctic Ocean, a critical region for understanding the dynamics of global climate change
Radiocarbon ages for sediment core EN22502 from Salmon Lake, Alaska
No full textRadiocarbon (14C) ages were measured on 49 samples of macrofossils extracted from a sediment core extending back to roughly 30,000 calendar years before present (cal yr BP) from Salmon Lake, on Seward Peninsula, northwest Alaska. The 16.7-m-long core was collected in August 2022 by the Alfred Wegener Institute, Potsdam, Germany in collaboration with Northern Arizona University (NAU), Flagstaff, USA. The 14C ages were combined with age constrains from short-lived isotopes to generate an age-depth model (doi:10.1594/PANGAEA.984002) for the core using rBacon software. It serves as the timeline for sediment samples from the core, which have been used for a large suite of biological, geochemical and physical analyses
Dr Darrell Lewis
No full textNorthern Territory author and anthropologist, Dr Darrell LewisDonated by David Ritchie, 22/06/2016Photographs of the Kenbi Handover 2016, the resolution of the 37 year Kenbi Land Claim over the Cox Peninsula. The handback, presided over by Prime Minister Malcolm Turnbull, took place at Mandorah on 21 June 2016 and was attended by many of the people who had worked on, or been involved in the landclaim processes
STRATIGRAPHIC PALEOBIOLOGY AND HISTORICAL ECOLOGY OF THE QUATERNARY DEPOSYSTEM OF PO PLAIN
No full textDepth versus age for sediment core EN22502 from Salmon Lake, Alaska
No full textRadiocarbon (14C) ages were measured on 49 samples of macrofossils extracted from a sediment core extending back to roughly 30,000 calendar years before present (cal yr BP) from Salmon Lake, on Seward Peninsula, northwest Alaska (doi:10.1594/PANGAEA.983998). The 16.7-m-long core was collected in August 2022 by the Alfred Wegener Institute, Potsdam, Germany in collaboration with Northern Arizona University (NAU), Flagstaff, USA. The 14C ages were combined with age constrains from short-lived isotopes to generate an age-depth model for the core using rBacon software. It serves as the timeline for sediment samples from the core, which have been used for a large suite of biological, geochemical and physical analyses
Alaska PaleoGlacier Atlas: A Geospatial Compilation of Pleistocene Glacier Extents
No full textThe Alaska PaleoGlacier (APG) Atlas is a recently released, web-based summary of Pleistocene glaciation across Alaska. Students can access a gallery of maps depicting the extent of glaciers during the late Wisconsin glaciation in Alaska as well as the maximum extent reached during the last 3 million years by valley glaciers, ice caps, and the northwestern Cordilleran Ice Sheet. a set of links is also provided to sites on galcial geology and glacial geospatial data. Educational levels: High school, Undergraduate lower division
Characterization of Climatic Influences on Modern Sedimentation in an Arctic Lake, Svalbard, Norway
No full textNick, was the first student to study the sediment traps recovered from Lake Linne' and to relate the measured textural changes from trap to trap and to measured weather parameters in the valle
Darrell Huff and Fifty Years of How to Lie with Statistics
No full textOver the last fifty years, How to Lie with Statistics has sold more copies than any other statistical text. This note explores the factors that contributed to its success and provides biographical sketches of its creators: author Darrell Huff and illustrator Irving Geis
jpc-19-0087 – Supplemental material for Identifying Opportunities for Advancing Weight Management in Primary Care
No full textSupplemental material, jpc-19-0087 for Identifying Opportunities for Advancing Weight Management in Primary Care by Ivana T. Croghan, Jon O. Ebbert, Jane W. Njeru, Tamim I. Rajjo, Brian A. Lynch, Ramona S. DeJesus, Michael D. Jensen, Karen M. Fischer, Sean Phelan, Tara K. Kaufman, Darrell R. Schroeder, Lila J. Finney Rutten, Sarah J. Crane and Sidna M. Tulledge-Scheitel in Journal of Primary Care & Community Health</p
Technical note: Open-paleo-data implementation pilot – the PAGES 2k special issue
No full textData stewardship is an essential element of the publication process. Knowing how to enact data polices that are described only in general terms can be difficult, however. Examples are needed to model the implementation of open-data polices in actual studies. Here we explain the procedure used to attain a high and consistent level of data stewardship across a special issue of the journal Climate of the Past. We discuss the challenges related to (1) determining which data are essential for public archival, (2) using data generated by others, and (3) understanding data citations. We anticipate that open-data sharing in paleo sciences will accelerate as the advantages become more evident and as practices that reduce data loss become the accepted convention
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