Friday, 18 July 2014

Peter Hobbs – a pioneering engineer... by Hazel Gibson

Hi, I’m Hazel Gibson, a PhD researcher from PlymouthUniversity, who is interested in what people think about geology and how that affects how we as geoscientists communicate it. For the last two weeks I have been up at the British Geological Survey speaking to the scientists about their work, what makes them passionate about it and why they think it’s important to us. The following is a series of short 'people posts' about the real faces behind the BGS.

Peter, next to the SHRINKiT instrument he helped to invent.
It’s easy to look at the British Geological Survey and imagine that it has always been this way – a high-tech organisation, with precision gadgetry and computer models for any situation that may need investigation. But in fact only 40 years ago much of the equipment that today’s geologists and engineers would find indispensable didn’t even exist. In the Engineering Geology section of the BGS, the section that deals with finding solutions to engineering problems that have a geological side, much of the essential equipment introduced over the last four decades was championed by Peter Hobbs. 
Peter started his career as a civil engineer, but during his degree studies he had to complete two six month industry placements and his second was with the British Geological Survey, which at the time was based in what is now the geological section of the Natural History Museum, London. He enjoyed his experience so much that when he finished his degree and was offered a job, he took it. At that time, Engineering Geology was a subject in its infancy – it had only been an actual subject for about 10 years and there were only 10 people working in the dark and dusty basement area that focussed on it specifically. This however, was soon to change.

Archive picture of the Geological Survey Museum
in Kensington
, where the BGS was based until 1976  
The challenges of our modern society that relate to engineering geology are now very obvious to us. Anyone who remembers the train line at Dawlish collapsing into the sea, is interested in the development of HS2, has had subsidence under their house (I have – we had cracks in our wall I could put my hand in!!), even the difficulties of new builds in cities like London and Glasgow all need the solutions provided by engineering geology. Often the traditional ways of learning more about the soils and clays we build our society on, just aren’t safe anymore! For instance Peter has been instrumental as a part of the team that developed a new piece of equipment – the SHRINKiT – that measures the shrink and swell behaviour of clays. This instrument uses a laser scanner combined with a digital balance, to measure the changing volume and weight of a piece of clay as it dries out. This important information produces a value called the ‘shrinkage limit’ or the point at which the soil or clay will not lose any more volume regardless of whether it loses more moisture. The shrinkage limit helps engineers know how the soil or clay is going to behave. Previous to Peter’s team inventing the SHRINKiT, the most common way of testing this property of the clay was to dip it in mercury, which can’t have been good for anyone’s health!
This crooked house may look funny, but subsidence
causes £100s of million in damage each year.
Another technological innovation that Peter advocates for is called LiDAR, a remote sensing system that is a kind of light based radar that is used by geoscientists all over the world to help detect ground movement. In Britain it is particularly useful when looking at landslides, a type of geological investigation that really highlights the dangers of engineering geology. “There was once a rock fall on the Yorkshire coast, which landed where a colleague and I had been standing two seconds earlier and we literally just missed it by the skin of our teeth!” Peter told me, but by using LiDAR to survey the cliff faces, engineers and geologists don’t have to put themselves in these difficult and sometimes dangerous positions as often.

Despite the dangers, Peter really loves engineering geology, especially the team-working ethos! He continues to invent new technology to help engineers understand rock and soil behaviour and he is instrumental in helping to re-interpret geological maps so they are more understandable to engineers and other (non-geologist!) people that have to use them. He is even involved in speaking with the public – helping to develop a brilliant demonstration of what quicksand is by using a special sand tank and sacrificing a Playmobil Lifeguard in the name of science! 

So despite an illustrious 40 years of inventing and engineering for the BGS, Peter Hobbs shows no signs of resting on his laurels.

by Hazel

Exploring geochemistry and health in Malawi... by Kate Knights

BGS geochemists Louise and Kate recently took a trip to Malawi to join agricultural scientists and nutrition experts to study the factors that can impact the nutritional benefit of foods grown and eaten by the Malawian population (recent paper). Here they tell us more about the exciting trip and the ongoing joint research between BGS, University of Nottingham and collaborators in Malawi...

We were greeted by heavy rains when we landed in Malawi but they cleared in time for our drive to the north of the country to Mzuzu, a city with all the hustle and bustle of commerce, markets and a thriving university - where staff and students are working on programmes to ensure good sanitation and maintaining quality water supplies form pumps and well.

We visited the SMART centre at the University, where Rochelle Holm  gave us an overview of activities since our previous visit last May and Chrissie was kind enough to show us around the WASH demonstration area, with examples of wells and ground pumps and water filters, and latrines and composting solutions (photo left).

We shared experiences between our institutes on how we collect data on private drinking water supplies by travelling together to some local villages with hand-pumps installed, and demonstrating to each other the types of information we typically gather.

Kate demonstrating the filtration of a small
sample volume  typically used in BGS to
gather information on the chemistry of waters
Colleagues at the Mzuzu University Centre of Excellence in Water and Sanitation taught us about a mobile app they’d developed to perform questionnaires with a smartphone. This innovative tool allows for digital data to be collected, and referenced, for all their fieldwork in the area.

Rainy season in Malawi means being careful not to get the vehicle stuck up a road that might become impassable in heavy storms. Here is the view from the back of our 4x4 as, with perfect timing, we finish up at that village and depart with the storm clouds gathering.

We also caught up with our long-standing collaborator  Dr Allan Chilimba, Director of the Ministry of Agriculture’s Lunyangwa Research Station, Mzuzu. We walked the experimental fields, and were particularly pleased to see Edward Joy’s pot experiment of maize looking very healthy (photo below left).

Healthy looking maize
Maize is a really important crop for the people of Malawi, so improving the supply and quality can make a real difference to the people that rely on it. For more information on the importance of micronutrients and health, see one of Edward’s previous blogs. After such a great time in northern Malawi, we travelled back south via the lake road, taking time to admire the geological splendours of the southern end of the East African rift valley – and of course the lake itself!

Back in Lilongwe, we caught up with staff at the Lilongwe University of Agriculture and Natural Resources –LUANAR (formerly Bunda College) for the day and see all the exciting new initiatives that they have and current research projects on soil and crop assessment and micronutrient status.  

Storm clouds gathering

Later we meet with the LUANAR soil scientists in a visit that was an equivalent of that to Zambia and Zimbabwe, previously undertaken by some of our other colleagues (see Michael's blog). We are all involved in helping to develop a PhD training programme for Malawi, Zambia and Zimbabwe. The idea is that in the future students will have opportunities to primarily study in their home country and also benefit from additional skills transfer through annual placements in the University of Nottingham, BGS, and the partner African countries. This type of work could really strengthen the academic and scientific communities in these countries, and is a great opportunity for UK scientists to experience working with overseas counterparts too.

After two weeks we bid farewell– and it was certainly a great trip to Malawi, with the warmth and hospitality that we have come to know so well and we look forward to continuing to work with all those we visited in the years to come!

Kate & Louise

Thursday, 17 July 2014

Secrets of Ascension... by Charlotte Vye-Brown Vye-Brown, BGS volcanologist, visited the remote (but British) island of Ascension last fortnight to begin unravelling it's eruptive past. The island might look like a tropical paradise but it isn't everything it seems. The Island is actually a huge volcano that rises 3-4 km above the surrounding sea floor, 90 kilometers west of the Mid-Atlantic Ridge. It's just the very tip, 1% of it's total volume, which pokes out above the crystal blue sea. Very little is known about the eruption history of the Island and no one knows what might be in store in the future. Enter a team of researchers from the BGS, University of East Anglia, Durham University and the Scottish Universities Environmental Research Centre with a Leverhulme Grant...
I departed from Brize Norton RAF station in Oxfordshire on a chartered plane which was routed for the Falkland Islands and was only stopping off at Ascension to refuel. We flew through the night and arrived in time for sunrise over the island. As the plane circled to reach the runway at the southwest end of the island we could see the central Green Mountain towering over thick rubbly lava flows forming aprons which have extended the coastline of the island into the sea and high steep-sided cinder cones from which eruptions produced fire fountains of lava.
Vegetation is sparse and concentrated around the aptly named Green Mountain leaving the fresh-looking lava flow tops well-exposed over the remainder of the island ready for geologists to investigate. We have to share our territory with colonies of birds that leave evidence of their visit on the otherwise pristine lava surfaces and land crabs.
We're on the island to look at the volcanic deposits, to map and sample deposits to reconstruct the past volcanic eruptions which have formed this island. We also met with many people living and working on Ascension to improve our understanding of island life and how a future eruption might impact on this community.
We visited sites all over the island, from the rhyolite lava flows and trachyte domes forming Green Mountain, to cinder cones, lava flows, pumice and ash fall deposits that blanket the surrounding land. Representative samples were taken and shipped for analyses back in the UK. They will take 6 weeks to get back to the UK but once there they will be processed to disentangle the magmatic and volcanic history of the island. We will soon know much more about this fascinating island and be able to answer questions such as ‘when was the last eruption?’, ‘why is Ascension volcanic?’, ‘what have previous eruptions looked like?’, and ‘what might happen if Ascension erupts again?’
Follow me and the rest of the BGS Volcanology team on Twitter @BGSvolcanology

Tuesday, 15 July 2014

Random variables: directions, turtles and rocks... by Murray Lark

Murray Lark is our hero and master of spatial statistical methodology for earth sciences. Here's another insight into the random variables he came across whilst exercising his craft and publishing his latest paper...

Back in the late 1960s an American marine biologist captured 76 turtles and took them out to sea where he released them and noted the direction in which each swam away. You can see the directions in Figure 1 below.  This is a 'rose diagram,' which is a sort of histogram for directional data. It shows that most of the turtles headed north-east by east (the direction of home), but several headed 180 degrees the other way (as if they knew where they wanted to go, but had the map upside down).

Figure 1
This data set has become a classic in directional statistics, the methods used for variables which are measured as angles.  Such data are common in the earth sciences.  Some examples are the direction in which the bedding planes of a sedimentary rock dip, the direction of ocean waves or the orientation of horizontal faults in rocks or cracks in a drying soil. 

Directions are not as easy to analyse as you might think.  Imagine a repetition of the turtle experiment where the direction of home was due north (zero degrees).  Our turtles are all better navigators than their predecessors, so we get the following ten directions:  0, 2, 358, 355, 7, 1, 358, 0, 355, 357.  None of the turtles deviates by more than five degrees from the way home, but what is their average direction?  If you simply compute the average of the ten data above you get 179 degrees, which is almost due south.  The reason for this is that angular data don't behave like ordinary real numbers, or even real numbers with a maximum and minimum.  On the scale of compass bearings the numbers "wrap around", zero degrees is equivalent to 360, and two observations, one of 358 and one of 2 degrees are very similar.

Directional statistics has to deal with this tricky behaviour.  One tool of the trade is the von Mises distribution.  A statistical distribution is a mathematical function that we can use to compute the probability that a random variable will fall in a particular interval.  The von Mises distribution can be used for data which are "wrapped around" the circle.  However, like its relation the bell-shaped "normal" distribution that we use for non-directional random variables, it has a single peak or mode.  
At BGS we have been exploring some alternative distributions for circular data in collaboration with a colleague from the CSIRO in Australia. 

Figure 2
One distribution, of considerable interest, is called the projected normal distribution.  While the mathematical account of this distribution is a bit complex, it is not difficult to understand intuitively.  Imagine that we consider the location where the turtles were released as the origin of our map with coordinates {0,0}.  We can generate a random direction from the projected normal distribution by selecting a random coordinate pair {x,y} which have a joint normal distribution.  The random direction is that of the line which joins the origin of the map to the random pair.

Figure 2 shows the projected normal distribution fitted to the turtle data.  The area between the red line and the black circle is one, and the area between the red line and the black circle over some range of angles (e.g. between North and East) is the probability of a turtle swimming in that direction.  Notice the large bulge in the distribution in the direction of home, and the rather smaller bulge 180 degrees away.

There is an open access paper which presents our work with the projected normal distribution, its comparison with some alternative models and a new related distribution. 

By the way, I have never been able to find out whether the marine biologist rescued the turtles that set off in the wrong direction.

Stephanie Zihms – an inventive experimenter... by Hazel Gibson

Hi, I’m Hazel Gibson, a PhD researcher from PlymouthUniversity, who is interested in what people think about geology and how that affects how we as geoscientists communicate it. For the last two weeks I have been up at the British Geological Survey speaking to the scientists about their work, what makes them passionate about it and why they think it’s important to us. The following is a series of short 'people posts' about the real faces behind the BGS.

Stephanie likes to be patriotic!
At the moment, Stephanie Zihms has more on her mind than just her usual interest in how fluids move through rocks. Stephanie, who has spent most of her life in Germany, has a serious stake in Sunday night’s game. Anyone walking into the office where Stephanie’s desk is has no problems finding her; “It’s the desk with the German colours on it” were my directions and she wasn’t kidding! But besides being an enthusiastic German football supporter, Stephanie is also a Fluid Processes Geoscientist and investigates how fluids (aka liquids and gases) move through different kinds of rock. Now this might seem pretty obscure to most of us, but what Stephanie is researching right now is really important to one of our biggest problems – our energy future. She is looking at the difference in fluid movement between natural and man-made systems, so Carbon Capture and Storage (natural) and Radioactive Waste Disposal(man-made).  She is also, for the first time at BGS, investigating the effect that heat has on these processes.

In order to do this Stephanie has to design an experiment from scratch and follow it all the way through to its conclusion. She does everything from designing and helping to construct the massive experiment equipment called constant volume cells, to collecting and interpreting the data. This is no easy task; Stephanie’s last experiment ran for 200 days. The longest experiment of this kind has been going for 15 YEARS! But Stephanie really likes the control that it gives her over her experiments “It means that if anything leaks, it’s down to me, but also I think of the question – what do I want to find out, and design accordingly to find the answer” she told me. This means Stephanie is always testing her ideas – recently she had to stop using the traditional stainless steel canisters, because using heat was causing them to expand and affect her experiments. She also really likes the transparent nature of working at the British Geological Survey, in that whatever she finds out, she has a responsibility to tell people about it – her work is unbiased. 
What working in the lab is like..
Stephanie takes communicating her work very seriously. She goes to communication conferences and is interested in running tours around her lab, but also she told me about a brilliant science demo that she uses to talk about Carbon Capture and Storage – Angel Cake Storage! By ‘drilling’ a straw down through the layers of angel cake, Stephanie ‘injects’ coloured fluids into the cake, which then spread through that layer until they reach the icing. The cake is porous – like the soft rocks that the CO2 would be stored in, but the icing is impermeable – like the cap-rocks. As such, you can demonstrate how the carbon would not go into other layers. Stephanie understands the importance of talking with young people as she remembers her aunt giving her a rock and mineral collection when she was 6 that sparked her interest in Earth Sciences and the environment.
Mmmm...angel cake!
You may be wondering how Stephanie got from Germany to Nottingham, but she came to the UK during her degree, for a year’s exchange placement in Scotland and liked it so much she never left! After working for a geotechnical company and completing a PhD with Glasgow University, Stephanie finally moved to the BGS in September last year. Although she enjoys the applied nature of working here, she has found it a challenge to change her working style from the complete academic style of the PhD, where you control every aspect of your day, to the more flexible working needed in a big, multi-disciplinary team like this one. She has, however, taken on a big role in representing the Athena SWAN award here at the BGS, which encourages organisations to raise their diversity and promote equal opportunities for women. It’s a great symbol of how much at home Stephanie feels here after only a few months that she is not just challenging herself by designing experiments from scratch, but also challenging the BGS as a whole to improve opportunities for all women. 

To see Stephanie in action discussing her favourite science, don’t miss her speaking at PubHD on Wed 16th July.

Friday, 11 July 2014

Using carbon isotopes to study Lake Baikal... by Sarah Roberts

Today we're very pleased to share a guest post from Sarah Roberts, a Postgraduate Researcher at the School of Geography, University of Nottingham. Here she introduces her exciting collaborative work, to investigate changes in nutrient fluxes at Lake Baikal, Siberia, with the Baikal research team; Dr. George Swann, Prof. Anson Mackay, Dr. Suzanne McGowan and Dr. Virginia Panizzo (BGS Visiting Research Associates) and BGS staff.

Why are we researching nutrient enrichment at Lake Baikal?

Lake Baikal research expedition in March 2013 on the
ice in the South basin
Lake Baikal is the world’s oldest, deepest and most voluminous lake; forming over 25 million years ago, reaching water depths of 1,700 m and holding 20% of the world’s surface freshwater. It is listed as a UNESCO World Heritage site, as 80% of Lake Baikal’s living organisms are endemic. It is the uniqueness which gives the lake its well-known title; ‘The Galapagos of Russia.’ However, over the last half-century, this UNESCO site has undergone substantial catchment change, due to increased anthropogenic activities such as deforestation, development and industrialisation. Lake Baikal is still considered to be relatively pristine, however these threats are believed to have resulted in higher nutrient input into the lake in recent years, impacting upon Baikal’s water quality and unique ecosystem. Interlinked with this, climate change has lead to a decline in winter ice-cover thickness and duration and enhanced nutrient loading from regional permafrost thaw and fluvial input. These factors have had a direct effect upon Lake Baikal’s aquatic ecosystem. This project aims to investigate the impact of recent anthropogenic activity and natural climate variability at Lake Baikal, over the past 1000 years, through contemporary monitoring of its lake waters and analyses of its sediments from the bottom of the lake.

Lake Baikal research expedition in August 2013 on a
research vessel across the South, Central and North basins
Which nutrient enrichment proxies are we using?

To investigate changes in Lake Baikal’s primary productivity, we are analysing organic carbon (δ13Corganic) and silicon (δ30Si) isotopes at the BGS. Stable isotopes are different forms of an element, which have the same number of protons but differing number of neutrons. Carbon isotopes in lake sediments can be used to compare algal growth rates (i.e. productivity) under different nutrient dynamics while silicon isotopes tell us specifically about the cycling of silicon (a key nutrient) in the lake over time. As well as stable isotopes, algal pigments are also being analysed at the University of Nottingham. Algal pigments are produced by all photosynthetic organisms, and can be used as biomarkers to identify specific algal groups, such as diatoms, green algae and picoplankton. These varying nutrient enrichment proxies are being analysed on the sediment cores collected from across the South, Central and North basins of Lake Baikal in March 2013 and August 2013 and will be used to reconstruct past environmental conditions and anthropogenic impacts on the lake.

How do carbon isotopes infer past primary productivity?

The machines used to produce 13C/12C and C/N data by the
Stable Isotope Group led by Prof Melanie Leng at the BGS
During photosynthesis algae take up carbon, but they prefer to take up the lighter isotope (12C) rather than the heavier (13C) because the former is easier to utilise. In Lake Baikal, if there is lots of algal growth (if the algae are ‘productive’) then the algae take lots of 12C from the water. The more growth there is, the more reduced this pool becomes in 12C. Therefore, when subsequent algae grow, they have to use 13C instead. Stable isotope analyses compares the ratio (δ) between these two isotopes so that increased productivity is reflected by an increase in the δ13C of organic matter in Lake Baikal sediments. However factors other than primary productivity can influence the carbon isotopic composition of in-lake produced organic matter, such as the concentration of atmospheric CO2, lake-water pH, temperature, nutrient limitation and algal growth rates. Therefore, in addition to comparing δ13C values, the carbon to nitrogen ratio (C/N) of the organic matter can be of used to quantify/assess algal versus higher plant (e.g. terrestrial) production. In-lake organic carbon produced by algae is distinct from the terrestrial input of organic carbon from the watershed produced by vascular plants, based on their respective C/N ratios. This is as algae have a much lower C/N ratio in comparison to vascular plants, such as grasses, shrubs and trees, and aquatic macrophytes.

What will the carbon isotope records at Lake Baikal show?

location diagram
The analysed sediment cores collected from Lake Baikal (with water depths ranging from 66 m to 1,360 m) have low C/N values, suggesting the source of organic matter is predominately from an algal, rather than terrestrial, origin. Therefore δ13C values will largely provide records of aquatic productivity. As a result higher δ13C values are expected to coincide with periods of increased anthropogenic impacts over the last half-century when nutrient inputs to the lake are believed to have increased, thereby promoting more algal growth. The sediment cores collected from the South basin are expected to show a shift towards more positive δ13C values (higher values) over the last 60 years, in comparison to the sediment cores collected from the North basin. This is as the South basin sites are hypothesised to be influenced by both climate and anthropogenic effects, whereas the North basin sites are hypothesised to be influenced by climatic changes alone. Down-core reconstructions of primary productivity along the sediment cores, which are c. 50 cm long, will enable the natural variability of the system over the last c. 1000 years to be established, and will help to disentangle the recent impacts on the lake from both anthropogenic activity and natural variability. Importantly, the nutrient enrichment proxies being used (carbon and silicon isotopes and algal pigments) will enable a more holistic picture of past primary productivity response to changing environmental conditions than has been achieved in previous work on the lake.


Thursday, 10 July 2014

Leanne Hughes – a modern mapper... by Hazel Gibson

Hi, I’m Hazel Gibson, a PhD researcher from Plymouth University, who is interested in what people think about geology and how that affects how we as geoscientists communicate it. For the last two weeks I have been up at the British Geological Survey speaking to the scientists about their work, what makes them passionate about it and why they think it’s important to us. The following is a series of short 'people posts' about the real faces behind the BGS.

As a child, Leanne Hughes spent many hours on long countryside walks with her family around the hills and dales of Derbyshire, which, as it turned out, was good practice for her future career as one of the British Geological Survey’s modern mappers. Leanne is a Survey Geologist, so her job is to map places in the UK that need new geological information, some of which have never been mapped before (who knew there were such places?!). In order to make the best and most up to date maps she uses cutting edge technology, including field computers, GPS and aerial photography. In two weeks Leanne usually maps a 78km2 (30 mile2) area, which is about the size of Coventry!! This is a pretty big job, with Leanne having to record all the important information that she can see, whilst contending with overgrown paths, reluctant farmers and forests that tell her GPS she is walking on Loch Ness. Not forgetting the great British weather of course, which can switch from zero degree rain to scorching sunshine within four days!  It’s lucky that she still likes walking the wilds of Britain – in fact she says “I like places like North Wales and the North West Highlands. People call them bleak, but to me that just means that they are not crowded with people!”

Leanne in the field.
Leanne maps surface or superficial geology – this is all the rocks, soils and sediments that are on the surface (rather than the hard rocks that make up the bedrock underneath) and she is especially interested in glaciers. She recently told me that in drumlins (a hill sized, egg shaped landform left behind by glaciers), you can find examples of natural fracking! The pressure from the water at the bottom of the glacier whilst it is still in place is so strong that it forces water, mixed with sand, into the rocks beneath it. This breaks the rocks apart and props them open with sand grains the same way that drillers today do artificially. It is curious things like this that Leanne is interested in, but her work is also vitally important to all of us, even if we aren’t interested in glaciers! 

In discovering new details about the type and location of superficial geology, Leanne helps flooding planners from the Environment Agency work out where floods may go in the future. This allows people to better understand the possible risks of flooding in their area. In order to help her understand more about floodplains Leanne uses a tool called an Abney level. This is a surveying instrument used to work out elevations in the field. It has a sighting tube and a moveable spirit level and Leanne uses it to work out if terraces are on the same level as each other or if they are more complicated. As a result of the cutting edge work that Leanne does, she was invited to give a talk on 21st Century Mapping at the Royal Institution in London, the home of the Christmas Lectures!

Comparison between the Geological Indicators of Flooding and the actual flood of the River Annan in November 2009. The dark blue represents deposits that indicate areas susceptible to flooding. The blue stipple indicates the slightly elevated deposits that would potentially be susceptible to flooding in more extreme or prolonged events. (Geological Indicators of Flooding map, British Geological Survey © NERC 2010
Leanne does a lot of work teaching young people about glaciers and geology. Her favourite demo involves freezing sand and pebbles into blocks of ice and scraping them across a painted board to show the marks that glaciers leave behind. She also created a build-your-own model of the volcano Eyjafjallajökull, which erupted in 2010, which ended up as a ‘make’ on Blue Peter! Despite this, Leanne didn’t get a Blue Peter badge. She is also about to get her first geological map published, of Derby (number 125).

Leanne is also interested in trying to answer big scientific questions and the one question she would really like to answer is ‘what happened to the last British Ice Sheet?’.  For the moment though, Leanne is occupied with continuing to map new uncharted territory both here and overseas. If you want to find her I suggest you head out to a remote part of our country and look for someone, mapping computer in hand, striding out across the landscape in search of new horizons.