This data set comprises sea ice-related biomarkers for three time intervals, corresponding to the pre-MPT (1.53-1.36 Ma), the MPT (1.22-0.8 Ma), and the post-MPT (0.5-0.34 Ma) climate cycles from International Ocean Discovery Program (IODP) Site U1343 in the eastern Bering Sea (57deg33.4'N, 176deg49.0'W, 1950 m water depth). The biomarkers are the Arctic sea ice biomarker IP25, together with HBI III and brassicasterol, indicative of open water in the ice marginal zone and general phytoplankton production, respectively.
Funding was provided by the NERC grant NE/L002434/1.
Bering Sea, Biomarker, IP25, Mid-Pleistocene transition, Sea ice
doi:10.5285/9caf74c4-7054-4539-81b8-d4f942afc358 \ short-doi:10/ch73
|Access Constraints:||No restrictions apply.|
|Use Constraints:||This data is governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.|
|ISO Topic Categories:||
|Organisation||British Antarctic Survey|
|Role(s)||Investigator, Technical Contact|
|Name||Prof Simon T Belt|
|Name||Dr Sindia M Sosdian|
|Name||Dr Lukas Smik|
|Name||Prof Caroline H Lear|
|Name||Prof Ian R Hall|
|Name||Dr Patricia Cabedo-Sanz|
|Name||Dr Katrine Husum|
|Organisation||Norwegian Polar Institute|
|Name||Dr Sev Kender|
|Organisation||University of Exeter|
|Reference:||Detlef, H., Belt, S. T., Sosdian, S. M., Smik, L., Lear, C. H., Hall, I. R., Cabedo-Sanz, P., Husum K., & Kender, S. 2018. Sea ice dynamics across the Mid-Pleistocene transition in the Bering Sea. Nature Communications 9, 941, doi:10.1038/s41467-018-02845-5
Belt, S. T. et al. 2012. A reproducible method for the extraction, identification and quantification of the Arctic sea ice proxy IP25 from marine sediments. Analytical Methods 4(3), pp. 705-713.
Cabedo-Sanz, P. and Belt, S. T. 2015. Identification and characterisation of a novel mono-unsaturated highly branched isoprenoid (HBI) alkene in ancient Arctic sediments. Organic Geochemistry 81, pp. 34-39.
|Quality:||A procedural blank was added to each extraction batch to screen for contamination. The 4-year instrumental uncertainty is < 10%.
The average sample resolution for all three time intervals is 5 ka, however, the sample resolution is highly variable.
|Lineage:||The data was generated using samples from International Ocean Discovery Program Site U1343 (Leg 323) in the eastern Bering Sea. The samples were freeze dried at -45°C and 0.2 mbar for 48 hours using a Thermo Savant Modulyo D freeze drier and an Edwards K4 Modulyo freeze drier at Plymouth and Cardiff University, respectively. The highly branched isoprenoid (HBI) lipids were extracted from 3g freeze dried sediment as described in Belt et al. (2012). Additionally sulphur removal using tetrabutylammonium sulphite reagent (TBA) (Cabedo-Sanz and Belt 2015) was performed for all samples prior to silica column chromatographic purification of the total organic extracts. The samples were measured on the gas chromatography mass spectrometer (Agilent 7890A GC coupled to a 5975 series mass selective detector fitted with an Agilent HP-5ms column) at Plymouth University using the operating conditions specified in Belt et al. 2012. The identification of individual lipids was based on their characteristic retention time and mass spectra and quantification was achieved by integrating the peak area of selected ions (m/z 350 (IP25); 346 (HBI III); 470 (brassicasterol)) in comparison to the peak area of the internal standards added to each sample (Belt et al. 2012). Quantification of individual lipids also considers an instrumental response factor obtained from known concentrations of biomarker lipids in the standard sediments (Belt et al. 2012). The data is provided in ng g-1 dry sediment (sed).|
|Paleo Temporal Coverage:|
|Paleo Start Date||1.53Ma|
|Paleo End Date||0.34Ma|
|Horizontal Resolution Range||N/A|
|Vertical Resolution Range||N/A|
|Temporal Resolution||5 ka on average|
|Temporal Resolution Range||N/A|
|Detailed Location||Bering Sea|
|Data Storage:||The data format is excel.|