|From left to right: Ellie, Martha Sefton (another student who was here for
two days working with us) and Will in the clean laboratory.
This week, two 6th form students carried out some work experience at BGS in Keyworth. Will Atkin, from Loughborough, and Ellie Glover, from Newcastle upon Tyne, worked within the Stable Isotope Facility. Here they tell us a little bit about what they were up to...
The Stable Isotope Facility at the BGS is the largest UK producer of stable isotope data; particularly specialising in climate, environmental and archaeological studies. The laboratory has preparative and mass spectrometry facilities for determining stable isotope ratios. Within this area of the BGS, we worked on water and carbonate isotopes within climate and science based archaeology research. The facility also works on other areas, including solid earth geoscience, geochronology, pollution, hydrology, and forensic/medical studies.
The week started with the usual health and safety talk that we expected to find on work experience. Following the health and safety information, we were taken on a laboratory tour to see our working areas and facilities for the week a head. We had to produce a "mock" risk assessment using a hypothetical situation of someone changing a light bulb on a 10 foot high ceiling. We had to consider all the things that could possibly go wrong, and then rate the problems and figure out how to reduce the risks of an accident. We then undertook our first piece of lab work, which was the analysis of water oxygen isotopes. This involved preparing water samples from the Antarctic (how exciting is that!) before setting them in a mass spectrometer to analyse the oxygen isotope ratios (18O and 16O). These water samples were collected from the sea around the western coast of the Antarctic Peninsula as well as samples from ice cores taken from the Antarctic ice sheet. The Stable Isotope Facility analyses ice cores going back thousands of years. The oxygen isotopes from the waters are from the time period in which the ice was formed and the ratio is related to temperature, so this is how the BGS reconstruct the past climates! Wow…
|Will attaching samples to the vacuum line
while we were doing our experiment.
The next day we moved onto science based archaeology. Neither of us knew what we were going to do but it turned out very exciting because it was very hands on and we quickly gained the skills needed. We were analysing deer teeth from various countries around the world. Ammonia and silver nitrate was added to the powdered teeth, which reacted to make silver phosphate. Whilst we let this react, we were shown the clean laboratories. To enter these we had to wear full protection, including a lab coat, a hair net and shoe covers to ensure we didn't contaminate the laboratory (we think we looked quite cool in this gear, have a look at the picture). The labs are completely isolated, with their own air supply. To get into the labs we had to open one door and close it before entering – there is a "sticky pad" to take dirt off the bottom of our shoes, which we actually did get stuck to! We were also introduced to weighing out tiny tiny samples (micrograms are less than a grain of sugar) which was very frustrating at first! Weighing seemed impossible with the measurement we were given but it became easier due to the good equipment we were using. Eventually the silver nitrate created crystals which we had to filter. This involved removing the silver nitrate and rinsing the crystals with pure water called MilliQ (all the salts had been removed). To finish off the day, Dr Angela Lamb (who worked with us on the science based archaeology) presented her findings to us from the Richard III analysis from when she worked on his bones and teeth to confirm the body found in the Leicester car park was him. Angela discovered information on the foods he ate and where he lived in different periods of his life from the different isotopes in his teeth and bones.
|Ellie taking samples off of the vacuum line
while we were doing our experiment.
Our biggest project this week involved understanding where some particular carbonates had formed, i.e. were they fresh (a lake) or marine water precipitates. We had to prepare and extract the samples using a vacuum line (see the pictures). The full process from preparing the samples to extracting the data took a total of 2 days to complete due to samples needing to react and machines needed to process data. Whilst waiting for reactions and machines to do their thing, we did various other things. This included filling up solvents such as acetone and collecting liquid nitrogen from the tank. We also used the freezer mill to powder some organic samples of plants from Malaysia, as well as manually grinding other sediment samples. We did a lot of weighing, with samples needing to be weighted between 0.05 to 0.1 micrograms, which is very small and took a lot of patience. Due to our precision and accuracy, we were awarded certificates from Hilary Sloane for successful standard weighing! Our superb weighing allowed the machines to be calibrated correctly. Once the data was ready, we looked at it to see how the climate has changed over the last 100,000 years. Overall our data showed that the carbonates formed in a lake that had been affected by the melting of glaciers, which caused the sea levels to rise and therefore overflow into the lake, meaning the lake was full of marine water for a certain period of times. Sea level changes on these time scales are due to the growth and decline of ice caps in the polar regions.
Overall, we both enjoyed learning about the science behind climate change, sea level change and archaeology and we now appreciate how much work goes into producing scientific data. We would like to thank Chris Kendrick, Hilary Sloane, Carol Arrowsmith, Angela Lamb, Holly Millar and Jon Dean for allowing us to experience this area of geoscience.
Thank you for reading,
Will Aitken (Sixth form student at De Lisle College, studying Geography, Physics and Maths)
Ellie Glover (Sixth form student at Cramlington Learning Village, studying Geography, Biology and Sociology)