Suigetsu, Sediment and Silica: Embarking on my PHD / / by Charlie Rex

Charlie Rex is a NERC IAPETUS2 PhD student at the Scottish Universities Environmental Research Centre (SUERC). Her research examines past environmental change in Japan. Here she reflects on the first two months of her PhD…

Aerial photo of Lake Suigetsu, part of the Mikata-goko (Mikata Five Lakes)

“If we knew what we were doing, it wouldn’t be called research.” - Albert Einstein 
Anyone who has started researching something new is well aware of the challenges involved: vast amounts of literature, creating sensible hypotheses and selecting a suitable methodology (among other hurdles!). For new PhD students, this can also involve a totally new setting, such as a new city, country, or continent. Thankfully I didn’t have to move continent, but I did make the move to Scotland and start fresh on a PhD topic that I found fascinating and unfamiliar in equal measure. Though this was daunting, I am incredibly fortunate to be surrounded by a multidisciplinary, multi-continental academic network who have helped me get off to a good start!

My research is focused on the development of a 'palaeoenvironmental reconstruction from Lake Suigetsu, Japan'. I will be applying a variety of proxies (indicators of past climate) to cores of sediment retrieved from the bottom of Lake Suigetsu. The lake is located in Fukui Prefecture, Central Japan, and has gathered significant scientific attention since a geological drilling project began in 2006. In 2009, the changes in pollen species recorded within the sediment were critical in defining the global onset of the Holocene. More recently, radiocarbon dating of plant fossils within the sediment have been used to extend the international consensus radiocarbon calibration curve. All this work, and other related studies, have been conducted by a team of researchers from across the globe; a team I am now a part of. Add to this my supervisors: Dr Richard Staff (SUERC), Prof Melanie Leng (British Geological Survey), Dr Emma Pearson (University of Newcastle) and Prof Jaime Toney (University of Glasgow), and you will agree that I am surrounded by a fantastic groups of collaborators.

The Lake Suigetsu cores provide a fantastic opportunity to produce a multi-proxy reconstruction of past environmental change in Japan. My research is predominantly focused on developing records of hydrological change using isotopes from the sediment. Isotopes are atoms of the same element, such as oxygen, with different masses. Each isotope has a natural abundance however, certain processes can act to alter those abundances, such as condensation, evaporation and biological uptake. By measuring the relative isotopic abundances of certain elements (my focus is oxygen and hydrogen), we can learn more about these processes and therefore what changes have occurred through time.

Visiting the labs at BGS's Keyworth HQ

My work at the British Geological Survey will involve measuring isotope ratios trapped in diatoms, which are algae with silica (SiO2) shells. I will be extracting the oxygen from this SiO2 using the equipment in the National Environment Isotope Facility, converting that oxygen to CO2 using graphite (carbon) and then measuring the isotope ratios present in that CO2 using a mass spectrometer. I recently visited BGS with my supervisor Richard Staff, to meet with Prof Melanie Leng and tour the facility. This was a fantastic opportunity to gain some insight into the processes I will be applying to the diatoms from Lake Suigetsu in the future. Rest assured I will be back to the BGS in the new year, once I have returned from my sampling trip to Japan!

Everyone and anyone will tell you that a PhD is not straightforward, and I am prepared to hit hurdles during the research process. But meeting my supervisors, speaking to the wider Suigetsu team and having their support fills me with a certainty that the next 3 and a half years will be both rewarding and enjoyable!