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Me standing on the front helideck of the ship in the
North Atlantic. |
Hello, my name is James and I have recently started my PhD at the School of Earth and Ocean Sciences, Cardiff University and the British Geological Survey. During my PhD, I will investigate the mechanisms that have driven glacial retreat along the Antarctic Peninsula coastline over the last 2,000 years. In order to do this, I will utilise the geochemistry of diatoms collected from a suite of British Antarctic Survey sediment cores. Diatoms produce a hard shell (frustule) of silicate that is preserved in the sediment record, the geochemistry of which can be used as a proxy of glacial discharge and meltwater input to the ocean as a result of melting.
During the third year of my undergraduate degree, I studied at Stockholm's Universitet as part of the ERASMAS programme. It was here that I became fascinated with palaeoclimate, palaeoceanography and all things diatom! For my Bachelors thesis, I chose to reconstruct sea ice concentrations using marine diatom assemblages. It was whilst looking down the microscope at these beautiful, ornate, fossil algae that I decided that I wanted to pursue research within the field of palaeoclimate.
I have been very lucky during the beginning months of my PhD. In October, I attended the ‘Applications of Stable Isotope Geochemistry’ workshop at the Scottish University Environmental Research Centre laboratory in East Kilbride. Whilst there, I learned about some of the fascinating applications of stable isotope geochemistry beyond palaeoclimate. These applications include using stable isotopes in mineral exploration, ecology and (arguably the most fascinating) in reconstructing the movement of King Richard the 3rd across the United Kingdom during his lifetime. Moreover, participants were taken on a guided tour of the lab facilities, and were able to gain hands on experience of the preparation methods used for analysis of stable isotopes. I took part in the preparation of samples using the carbonate line, which involved some very exciting liquid nitrogen and a very hot hairdryer! The workshop was a fantastic opportunity to meet other like-minded early career stable isotope geochemists, and was rounded off with a tour to the very impressive, gargantuan, Accelerated Mass Spectrometer laboratory.
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From L-R: The Akademik Tryoshnikov in all her glory which was my home for the 4 week expedition from Bemerhaven
(pictured) to Cape Town; the CTD wet lab and the Niskin Bottle rosette where I conducted most of my work. |
In November, I took part in the Antarctic Circumnavigation Expedition (ACE) Maritime University. The ACE cruise has been organized by the Swiss Polar Institute, with the aim of conducting science in the Southern Ocean and Antarctic Islands. I boarded the Akademik Tryoshnikov, a Russian ice breaker, in the cold and grey of Bremerhaven and was bound for Cape Town. We set sail during storm Abigail, and I had to find my sea legs very quickly as we transited through the English Channel. Upon reaching the Atlantic Ocean, we began with the lecture series that formed the Maritime University. These lectures were a fantastic introduction to the various aspects of physical oceanography, ocean chemistry and biology that play a fundamental role in the climate system. As part of the seagoing University, I was able to shadow a scientist who conducted research in a field of my interest and assist in their lab work. Given my interest in diatoms and ocean chemistry, I naturally gravitated towards the Conductivity Temperature Depth (CTD) profiler. Everyday, at 8 am and 3 pm, I would go to the wet lab and prepare the Niskin bottles on the CTD rosette for deployment. These Niskin bottles are closed at specific depths within the water column, bring water samples from depth to the scientists onboard. I would then oversee the deployment of the rosette, and take my position of at the helm of the computer. The CTD was lowered to 500 m, whilst recording profiles of oxygen saturation, salinity, temperature and chlorophyll concentrations analysed, and the Niskin bottles closed on the return to the surface. I would then distribute the water samples to the scientists. Being the only geologist onboard, everyone was interested in just what it is that we do, and how we do it.
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| Southern Ocean diatoms. |
Upon returning to Cardiff, I have been reviewing the literature previously published from the Antarctic Peninsula, with the aim of placing my research into the context of the work already conducted. I have also spent time at BAS sampling cores, and learned the sample preparation methods for stable isotope analysis at Nottingham. In the coming weeks, I will be setting up the lab for cleaning diatoms at Cardiff and will be running my very first samples on the Stepwise Fluorination Line at BGS. Stay tuned over the coming months for updates on the progress of these first analyses, as well as some more insight into why scientists are concerned by melting glaciers along the Antarctic Peninsula, and how we can develop records of melting using diatom stable oxygen isotopes.
My supervisory team consists of Jennifer Pike and Elizabeth Bagshaw (Cardiff University), George Swann (Nottingham University), Melanie Leng (BGS) and Claire Allen (BAS). James can be found on twitter using the handle @jameswilliams108
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