Diatom data from multicores collected during voyage 1 of the Investigator, 2017 (IN2017_V01)

Brief description

These data were generated by Alexa Russo, undergraduate student at Colgate University, and Amy Leventer (aleventer@colgate.edu). All questions regarding the specifics of these data should be directed to Amy Leventer. These data are based on samples collected during research cruise IN2017_V01 of the RV Investigator, co-chief scientists, Leanne Armand and Phil O’Brien. The IN2017-V01 post-cruise report is available through open access via the e-document portal through the ANU library. https://openresearch-repository.anu.edu.au/handle/1885/142525 The document DOI: 10.4225/13/5acea64c48693 The preferred citation is: L.K. Armand, P.E. O’Brien and On-board Scientific Party. 2018. Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report, Research School of Earth Sciences, Australian National University: Canberra, http://dx.doi.org/10.4225/13/5acea64c48693 The three multicores studied were extruded on board ship, every 1 cm in the top 20 cm, and then at 2 cm intervals to the bottom of the cores. In the lab at Colgate University, 20-25 mg of sediment were weighed to the tenth of a mg and placed in 20 ml glass vials. Vials were placed on a warming tray set to 50 degrees C and 1 mL of hydrogen peroxide was added to each vial, followed by RH2O. This was done to oxidize organic material. Successive additions of 1 mL of hydrogen peroxide were done until samples had stopped reacting. RH2O was added as needed to avoid samples drying out. Slides then were made using the random settling and slide preparation methods in Warnock and Scherer (2015). Diatoms were observed with an Olympus BX50 microscope using the 100x/1.30 oil immersion objective and 10x eyepieces, for a total magnification of 1000x. For each slide, at least 400 diatom valves were counted along non-overlapping transects. Valves were only counted if greater than 50% complete, and diatoms were identified to the species level when possible using identifications from Cremer et al. (2003), Cefarelli et al. (2010), and Al-Handal et al. (2022). Unidentified diatoms were placed in either the unidentified centric diatom or unidentified pennate diatom category. The three multicores studied are listed below: Station_core Longitude Latitude A005_MC01 115.623 -64.471 C012_MC03 119.3012 -64.675 C015_MC06 118.696 -64.729 References: Al-Handal, A., Torstensson, A. and Wulff, A. (2022). Revisiting Potter Cove, King George Island, Antarctica, 12 years later: new observations of marine benthic diatoms. Botanica Marina, 65(2), 81-103. https://doi.org/10.1515/bot-2021-0066 Cefarelli, A., Ferrario, M., Almandoz, G., Atencio, A., Akselman, R. and Vernet, M. (2010). Diversity of the diatom genus Fragilariopsis in the Argentine Sea and Antarctic waters: Morphology, distribution and abundance. Polar Biology, 33. 10.1007/s00300-010-0794-z. Cremer, H., Roberts, D., McMinn, A., Gore, D. and Melles, M. (2003). The Holocene Diatom Flora of Marine Bays in the Windmill Islands, East Antarctica. Botanica Marina, 46(1), 82-106. https://doi.org/10.1515/BOT.2003.010 Warnock, J. and Scherer, R. (2015). A revised method for determining the absolute abundance of diatoms. Journal of Paleolimnology, 53, 157-163. 10.1007/s10933-014-9808-0.

Lineage

Progress Code: completed

Statement: No problems with data collection or analysis

Notes

Purpose
The diatom data were acquired to evaluate changes in paleoceanography during the mid-to-late-Holocene.