An official website of the United States government
We present high resolution measurements of atmospheric methane (CH4) and nitrogen isotopic composition (d15N-N2) in the Greenland Ice Sheet Project Two (GISP2) Ice core. The data span Marine Isotope Stage 3, 13 to 50 thousand years (ka) before present. These datasets enhance our understanding of abrupt climate variability during the last glacial period, with a focus on Heinrich events 1 through 5. CH4 data were analyzed between 2014 and 2020 via an established wet extraction technique (Mitchell et al. 2013). Concentrations were determined via gas chromatography measurements on an Agilent 6890N and calibrated to the NOAA04 scale. d15N-N2 data were measured between 2017 and 2020 on a Finnigan MAT Delta XP via an established technique (Petrenko et al. 2006). The methane data allow for gas-phase synchronization of the GISP2 ice core to other polar ice cores from Greenland and Antarctica. The nitrogen isotopic composition data allow for reconstruction of abrupt Greenland surface climate variations.
more »
« less
Clumped isotopic composition of oxygen in WDC06A ice core 8-18ka
Laboratory O2 clumped-isotopic composition data (as Δ36 values) for air occluded in ice core spanning gas ages of 8000-18000 ky BP. O2 clumped isotopic composition data was generated between 2017-2022 at Rice University, Houston, TX, using a Nu Perspective Isotope Ratio Mass Spectrometer (IRMS). Reported data was measured in an Antarctic ice core: West Antarctic Ice Sheet Divide Ice Core (WDC06A) . The chronology and gas ages for the core were obtained from Sigl et al., 2016 (doi:10.5194/cp-12-769-2016) and Buizert et al., 2015 (doi:10.5194/cp-11-153-2015). In addition to O2 clumped isotope data, measured δ18Ο data are also reported. Gas loss corrections to generated Δ36 data are made using previously reported raw δ18O data in Seltzer et al., 2017 (doi:10.5194/cp-13-1323-2017) and established gas loss corrections in Yeung et al., 2012 and Banerjee et al. 2022.
more »
« less
- Award ID(s):
- 2002422
- PAR ID:
- 10578081
- Publisher / Repository:
- PANGAEA
- Date Published:
- Subject(s) / Keyword(s):
- Antarctica clumped isotope deglacial Ice core Core Sample code/label Depth, ice/snow, top/minimum Depth, ice/snow, bottom/maximum DEPTH, ice/snow Gas age δ18O Δ36, oxygen clumped isotope Remote sensing reflectance at 387.5 nm Ice drill Corrected after Yeung etal., 2012
- Format(s):
- Medium: X Size: 1368 data points Other: text/tab-separated-values
- Size(s):
- 1368 data points
- Location:
- (Latitude:-79.46763; Longitude:-112.08648); Antarctica, west
- Right(s):
- Creative Commons Attribution 4.0 International
- Institution:
- Rice University
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
These data cover the penultimate glacial period (MIS 6) and parts of MIS5, in Allan Hills ice. The d18Oatm data are useful for dating the core, and the 15N is useful for inferring firn thickness. Importantly, the data have only been corrected for gas loss using published methods (i.e. Baggenstos et al. 2017), but not for recently recognized (and unpublished) effects of declining contemporary atmospheric O2/N2 due to fossil fuel burning. These changes unfortunately affect the La Jolla Air standard gas O2/N2 ratio that is used in our lab to make the measurements. Users of this data are encouraged to contact Jeff Severinghaus for help in making these novel corrections to the standard gas.more » « less
-
This data set contains measurements of carbon dioxide (CO2) amount fractions in gas bubbles from the WAIS Divide ice core WD06. All measurements were made in the Ice Core Laboratory at Oregon State University in Corvallis, Oregon USA. The data set includes the replicate-mean values and measurement precision (1 sigma standard error) from all CO2 measurements published in Wendt et al. (2024) PNAS. Bauska et al. (2021) Nature Geoscience, and Marcott et al. (2014) Nature. See respective publications for details. Ages listed in years before 1950 AD on the WD2014 timescale (see Buizert et al., 2015 and Sigl et al., 2014 for chronology details).more » « less
-
First-year sea-ice thickness, draft, salinity, temperature, and density were measured during near-weekly surveys at the main first-year ice coring site (MCS-FYI) during the MOSAiC expedition (legs 1 to 4). The ice cores were extracted either with a 9-cm (Mark II) or 7.25-cm (Mark III) internal diameter ice corers (Kovacs Enterprise, US). This data set includes data from 23 coring site visits and were performed from 28 October 2019 to 29 July 2020 at coring locations within 130 m to each other in the MOSAiC Central Observatory. During each coring event, ice temperature was measured in situ from a separate temperature core, using Testo 720 thermometers in drill holes with a length of half-core-diameter at 5-cm vertical resolution. Ice bulk practical salinity was measured from melted core sections at 5-cm resolution using a YSI 30 conductivity meter. Ice density was measured using the hydrostatic weighing method (Pustogvar and Kulyakhtin, 2016) from a density core in the freezer laboratory onboard Polarstern at the temperature of –15°C. Relative volumes of brine and gas were estimated from ice salinity, temperature and density using Cox and Weeks (1983) for cold ice and Leppäranta and Manninen (1988) for ice warmer than –2°C.The data contains the event label (1), time (2), and global coordinates (3,4) of each coring measurement and sample IDs (13, 15). Each salinity core has its manually measured ice thickness (5), ice draft (6), core length (7), and mean snow height (22). Each core section has the total length of its top (8) and bottom (9) measured in situ, as well estimated depth of section top (10), bottom (11), and middle (12). The depth estimates assume that the total length of all core sections is equal to the measured ice thickness. Each core section has the value of its practical salinity (14), isotopic values (16, 17, 18) (Meyer et al., 2000), as well as sea ice temperature (19) and ice density (20) interpolated to the depth of salinity measurements. The global coordinates of coring sites were measured directly. When it was not possible, coordinates of the nearby temperature buoy 2019T66 were used. Ice mass balance buoy 2019T66 installation is described in doi:10.1594/PANGAEA.938134. Brine volume (21) fraction estimates are presented only for fraction values from 0 to 30%. Each core section also has comments (23) describing if the sample is from a false bottom, from rafted ice or has any other special characteristics.Macronutrients from the salinity core, and more isotope data will be published in a subsequent version of this data set.more » « less
