Tuesday, 24 November 2015

New appointment in the Stable Isotope Facility...by Andi Smith

Me in the lab preparing lake sediments for
O and C analysis of carbonate
In early November Andi Smith was appointed as a Stable Isotope Geochemist in the Stable Isotope Facility (SIF) in Keyworth. Here Andi explains a bit more about his new role and some of the work undertaken within the SIF.

My Background… 
Before moving to the SIF I undertook a PhD at Lancaster University focused on the use of cave speleothem (stalagmite) deposits to reconstruct past climatic conditions in Northern Spain. As part of this project, I worked with staff at the SIF (my CASE studentship partner), undertaking the analysis of O and H isotopes in karst aquifer waters and O and C isotopes from speleothem carbonate. We used these stable isotope measurements to help trace seasonally variable water infiltration into the cave system and to reveal millennial scale fluctuations in European rainfall intensity over the last 12,000 years.

Following the completion of my PhD I moved to the SIF as the Isotope Intern. This position offered an excellent opportunity to get involved with a range of new sample preparation and analytical techniques and allowed me to diversify my areas of research interest. My new Isotope Geochemist role within the facility will allow me to continue to work in new areas of scientific interest, focussing mainly on the use of stable isotopes as tracers of environmental pollution, nutrient cycling and monitoring subsurface processes.

Me at my cave research site (Cueva de Asiul) in northern Spain
But what exactly do we do at the Stable Isotope facility?

SIF capabilities 
The Stable Isotope Facility provides analytical and scientific support for projects and scientists who wish to use stable isotopes to help answer a wide variety of environmental questions. This means that the current science team work on a diverse range of topics, from tracing the impact of modern environmental pollution within delicate ecosystems to the reconstruction of past climatic conditions over 500 thousand years ago. To cater for these projects the facility specialises in the analysis of different light stable isotopes in a number of materials; including O and H in waters, O and C in sedimentary carbonates, N, C and S in bulk organics (including soils and plants), Phosphate-O in soils, bones and teeth (soon also in carbonates) and N and O in nitrates. This diversity in techniques and our cutting edge analytical facilities means that the SIF works with a large number of collaborators both within the BGS and UK Universities, supporting a number of PhD students and postdoctoral researchers in the process.

Recent and future projects
To try and highlight the diversity of stable isotope applications I have selected two of our published projects from 2015.

The first, published in Environmental Science and Technology (led by Darren Goody, BGS) uses the oxygen isotope composition in phosphate (PO4), a relatively new stable isotope tracer, to assess sources of phosphate in drinking waters. The study conducted a series of tests on UK drinking waters and showed that the O isotope composition of P-O is primarily dependent upon the isotope composition of orthophosphoric acid used for dosing the waters, rather than original water source P-O composition. This study highlights the potential problems with phosphate pollution due to leaking mains water distribution systems.

The second study, published in Geology (with Andy Farrant, BGS) presents the first terrestrial climate record from southeast Arabia. This climate archive highlights several periods of increased rainfall and vegetation expansion during Marine Isotope Stage (MIS) 6 (ca. 160–150 ka), MIS 5 (ca. 130–75 ka), and during early MIS 3 (ca. 55 ka). These finding lead us to believe that there were multiple windows of opportunity for human dispersal out of Africa, linked to climate amelioration.
In the future, we hope that the SIF can also offer invaluable support to the wider projects within BGS, including using C and H isotopes of methane (CH4) to monitor methane pollution in groundwater’s and importantly help distinguish between biogenic and thermogenic methane sources.

How to work with SIF?
We work with a wide range of collaborators so if you think that your environmental research could be improved or diversified through the use of stable isotopes get in contact with one of the team!

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