Friday, 19 December 2014

Reading the signals in sediments... by Jonathan Dean

Jonathan Dean has just published a paper in the Journal of Hydrology, where he brought together measurements made at the British Geological Survey over two decades, to better understand how climate change is recorded in lake sediments. Here he discusses why this was such important work...


Nar Gölü in April 2014. The lake formed in an old volcano.
In the Stable Isotope Facility at the BGS, a lot of our work is focussed on using lake sediments to reconstruct how climate has changed in the past. In lakes, sediment deposited every year records what was going on in the lake, which is often related to climate, and by looking at variability in the chemical signature of lake sediments over time we can therefore reconstruct how climate changed in the past. But every lake records climate differently: some lakes have sediments that record how temperature is changing whereas others respond to how precipitation amounts are varying. Therefore, before we can use lake sediments to reconstruct climate, we need to calibrate the signal from the lake we are working on.

Over the past couple of decades, researchers from the Universities of Nottingham, Plymouth, Birmingham and Ankara have been collecting water samples and lake sediments from a lake in central Turkey called Nar Gölü. We then analysed the samples here at the BGS to look at how the oxygen isotope ratio has changed over recent times and what aspect of climate they are recording.

Isotopes are different types of an element, and oxygen has two main types. We compared how the oxygen isotope ratio in the lake sediments has changed over recent times compared to our measurements of lake level and the local meteorological record. Over the 2000s, lake level fell by 3 metres as precipitation decreased and high summer temperatures increased evaporation in central Turkey.

We were able to show that oxygen isotopes recorded this shift well: there was a strong correlation between the oxygen isotope ratio and the lake level (which was responding to the drying climate), with an increase in the ratio as the lake level fell.

Assuming this relationship was consistent into the past, we can therefore infer than if the oxygen isotope ratio in the sediments decreases the climate was getting wetter, whereas if the ratio increases the climate was getting drier.

Our study will allow us to better interpret a long sediment core sequence spanning roughly the last 15,000 years that we collected in 2010. It will hopefully also demonstrate to other scientists working with lake sediments that monitoring how the lake responds to climate change in the present allows us to better use lake sediments to reconstruct how climate changed in the past.

The photo on the right is a recent sediment core from Nar Gölü, with the top the present day, and a light and dark band representing 1 year of sedimentation.
Jonathan
@jrdean_uk

Live monitoring of flood basalts... by Evgenia Ilyinskaya

Evgenia at the eruption site in Holuhraun, Iceland
September 2014
 
Remember the volcanic eruption at Holuhraun, Iceland which started back in the summer? Now, three months later, it’s still ongoing and has reached a size category called ‘flood basalts’  (>1 km3 erupted lava). It is now the largest flood basalt in Iceland since the Laki eruption in 1783-84, which caused the deaths of >20% of the Icelandic population by environmental pollution and famine and likely increased European levels of mortality through air pollution by sulphur-bearing gas and aerosol.

This is the first time in the modern age we have the opportunity to study the environmental impact of a flood basalt  as it happens. Now Dr Evgenia Ilyinskaya (pictured above), from the BGS Volcanology team, has led and won her first ever NERC research grant to allow a multidisciplinary team to continue this cutting edge research. Here she explains more about the work and why it's so important...

Flood basalt eruptions are one of the most hazardous volcanic scenarios in Iceland and have had enormous societal and economic consequences across the northern hemisphere. In 2012 the UK not only included an Icelandic flood basalt eruption in our National Risk Register but listed it as one of the highest priority risks. Such an eruption is hazardous not because of ash (for instance, Holuhraun is not producing any ash at all) but because of volcanic gases and aerosol which can cause air pollution and even impact the climate.

The air pollution from Holuhraun has been intense since the beginning, repeatedly reaching hazardous levels of SO2 gas in populated areas in Iceland. Moreover, elevated concentrations (albeit not at dangerous levels) have been detected in the UK and mainland Europe.

Holuhraun, Iceland, October 2014
The blue colour of the eruption plume is typical for sulphur-rich emissions
The available measurements from Holuhraun suggest that the sulphur emissions (per kg of erupted magma) may be exceeding both that of other recent eruptions in Iceland and perhaps also other historic basaltic eruptions globally, raising questions regarding the origin of these prodigious quantities of sulphur.

A lack of understanding of the source of this ‘prodigious’ sulphur, the conversion rates of SO2 gas into aerosol, the residence times of aerosol in the plume and the dependence of these on meteorological factors is limiting our confidence in the ability of atmospheric models to forecast gas and aerosol concentrations in the near- and far-field from Icelandic flood basalt eruptions.


Our project will contribute to two broad issues with sulphur:

  • The magmatic controls on the sulphur content of flood basalt eruptions. There is evidence to suggest we may have underestimated the sulphur output from older eruptions by several orders of magnitude.
  • The lifetime of sulphur in the atmosphere which is critical for both the magnitude and scale of the environmental perturbation.

We propose to address these questions both through petrological analysis of the erupted rocks, measurements of gases and aerosol in the volcanic plume, as well as plume dispersion modelling.

This project involves collaboration between a number of institutes in the UK (British Geological Survey, Universities of Cambridge, Oxford, Leeds, Birmingham and Manchester, and the UK Cabinet Office Civil Contingencies Secretariat) and Iceland (Icelandic Meteorological Office, University of Iceland and Icelandic Civil Protection). The first step is to plan some very challenging fieldwork in winter time Iceland (January 2015), and again in the summer if the eruption is still ongoing.

Evgenia

On Twitter follow Evgenia @EIlyinskaya and the BGS Volcanology team @BGSvolcanology

Wednesday, 17 December 2014

Random variables, uncertainty and decisions... by Murray Lark

Here's Murray Lark, our environmental statistician, to talk about the uncertainty in three dimensions. How do different people interpret the same information and how can we make that information about uncertainty useful to you, the valuable user...
 
Rocks are three-dimensional objects, and computer technology has revolutionized the way in which geologists can present their understanding of the subsurface in 3D.  Where once geological information was presented on a flat map, with a few judiciously-chosen cross sections, a computer model can now represent the rocks beneath our feet in full 3D.  This is useful to planners, engineers, regulators and others who want to build a tunnel or explore the complexity of groundwater flows. 
 
However, all geological information has an uncertainty attached, and 3-D models are no exception to this.  In a recent paper, published open-access in the journal Solid Earth, we examined the uncertainty in interpretations of boreholes along a cross-section by a group of more than 20 geologists.  This is a key stage in the development of the 3-D model.  But in this blog I want to focus on the question, how can this information on uncertainty be made comprehensible and relevant to the end user?
 
It is relatively straightforward to make a statistical description of the uncertainty in some information.  Well, in fact it can be quite a complex task, but the real challenge is always to ensure that the resulting account of uncertainty is useable.  The figure (right), from the Solid Earth paper, shows a 95% confidence interval for the elevation of the base of the London Clay formation along a 4-km section.  At any location the probability is 95% that the base lies between the two blue lines.  The lines narrow near boreholes, and widen away from them.
 
This is interesting, but how should the user apply it?  In my view this can be done only by analysing the decision that the user wants to make.  We consider the hypothetical case of an engineer who wants to dig a tunnel along the route of the section, and to minimize the risk that the tunnel goes under the London Clay into the less-suitable Lambeth Group below.  The engineer might specify that the route of the tunnel should impinge on the Lambeth Group for no more than 1% of its length.  If the model is perfect, with no uncertainty, then the tunnel can be planned to follow the modelled base of the London Clay.  Because of the uncertainty, however, a safety margin should be applied.  We can use the uncertainty model to answer the question, "how close to the modelled base can the route be planned such that the risk of failing to meet the 1% criterion is small?"

 

Now this question cannot be answered from the confidence limits shown above, but it can be answered from the statistical model of uncertainty from which the limits are generated.  The graph (left) shows the probability of achieving the 1% criterion as a function of how far above the modelled base of the London Clay the route is planned.  This shows that the safety margin must be 8m or so if we are to have a high level of confidence.
 
This graph is tailor-made for the particular user question.  Other information users need to analyse their questions and then come up with risk assessments built on the uncertainty model.  In short, there are no identikit solutions, but many powerful ways to explore the implications of uncertainty for the users of information in earth sciences.

We will be talking about how to communicate uncertainty effectively to information users at the 2015 EGU general assembly in Vienna (12th-17th April).  Details of the session are below, and anyone interested is invited to submit an abstract by 7th January via the congress website.
 
SESSION: Communication of uncertain information in the earth sciences
(SSS11.5/ESSI3.6/HS12.7/NH9.17) Uncertainty impinges on most information that earth scientists generate, whether this is by observation, measurement, interpretation, process modelling or some combination of these.... read more on the EGU website.
 
Murray

Monday, 15 December 2014

BGS visits Westminster... by Lorraine Field

Freya Horsfield (left) & myself (right)
(c) Royal Society
Lorraine Field, BGS Petrologist, visited Westminster for a whole week to observe parliament in action as part of The Royal Society MP Pairing scheme. Here's what she made of it...
 
I wanted to take part in the scheme because I had no idea how science fed into policy making – Westminster seemed to be something of a faceless black box.

The four days I spent in central London as part of the scheme brought Westminster to life, starting with a lively history and anecdotal-filled tour of the Palace of Westminster.  A series of lectures followed, organised by the Royal Society, around how Parliament works and how science fits into the day to day business. These formed a basic insight for the scheme participants into understanding of how the different departments, process (including select committees) and science itself fit together within the policy process. Talks and discussions from Parliamentarians, such as the Rt Hon The Earl of Selborne, Chair of the House of Lords Science and Technology Select Committee and Dr Sarah Barber, Library Clerk, Science and Environment Section, House of Commons Library were invaluable in understanding the ways in which scientific information is gathered into the policy and decision making process. A clear message which came across is that there is an invaluable role for scientists to play, but also a responsibility on the scientific community to become involved within this process.

Within the week, there is opportunity to shadow your paired civil servant or MP and visit their offices. I was one of three scientists visiting the Government Office for Science, and an energy and climate change workshop was organised for civil servants from several different departments. This gave each of the visiting scientists the opportunity to present an introduction to both our scientific research and our respective organisations.

Here are some of the scientist participants enjoying a lively tour around the Palace of Westminster at the start of our ‘Week in Westminster’
The MP Pairing Scheme participants took part in a mock select committee within the real surroundings of a House of Lords committee room which was an informative insight into one of the major ways scientific evidence is provided to MPs. We also had the opportunity to view the process for real when we attended a House of Commons Science and Technology Select Committee as observers. It was also a fantastic opportunity to be able to attend debates in both the House of Commons and House of Lords as part of this visit.

GO Science organised a final day of talks and activities including a SAGE exercise, which helped us understand the process by which Government reacts to a crisis, and the resulting requirement for rapid scientific input.

The mock select committee within one of the splendid House of Lords committee rooms preparing questions for the scientific witnesses
My paired civil servant, Freya Horsfield, Senior Policy Advisor for GO Science [in full, Government Office for Science], was invited to the BGS HQ at Keyworth on a reciprocal visit on a freezing cold day in early December. She was joined by two of her colleagues who were also able to take the opportunity to visit: Dr Rupert Wilmouth, Head of Energy, and Dr Neil Waby, Policy Advisor for Energy. A packed day began with an informative discussion with Professor Mike Stephenson, Director of Science and Technology at BGS, followed by a variety of meetings and facilities tours to give a flavour of the work that BGS are involved in. We saw everything from actual core held within the National Geoscience Data Centre, to ‘flying’ across, around and under the UK geology within our 3D Visualisation Suite, and being able to see many of our laboratories in action.

Here I am explaining to Freya Horsfield the process of isotopic analysis of fallow deer teeth in the clean labs of the National Isotope Geological Laboratories (NIGL) at BGS, Keyworth
The aim of the scheme is to increase communications and awareness between Parliament and Scientists. From my perspective it has certainly done that - Parliament is less of black box and more of a multicoloured jigsaw! I now have a far better perception of how the different departments and processes fit together, and the role that science can play. I hope that some of the links and introductions made between the two organisations will become the basis for long term working relationships.

Lorraine

[This blog has also been submitted to The Royal Society's In Verba science policy blog]

Sunday, 14 December 2014

Searching for abandoned mines: breaking new ground, literally! ... by Kirstin Lemon

Ballylig in Northern Ireland is home to one of many abandoned mines found in Co. Antrim. Worked from as early as 1872 it was originally exploited for its iron ore before closing just after the First World War. As is the case with many abandoned mines, there are no mine plans for Ballylig, although a brief inspection during the Second World War led to the creation of a partial sketched plan indicating that the mine workings extended at a shallow depth under a public road.

Given the lack of knowledge about the site, it is not surprising that farmers living near by didn’t give a second thought to the dangers posed by underlying mine workings.  However, in  2013, disaster struck when part of the mine collapsed as a tractor and its slurry tank working on the overlying field, and fell in to the underlying void. The farmer was uninjured but quite shaken by the experience.

Kieran Parker on site at Ballylig
The Geological Survey of Northern Ireland (GSNI) work with the Department of Enterprise, Trade and Investment (DETI) to look after abandoned mines and survey work began immediately to try and find out whether there was the potential for further mine collapses. The results were conclusive; there was a strong possibility that this could happen again. A programme of works was put in place to stabilize the area, with the public road being the prime area of concern. However, with no mine plan and access through the mine deemed unsafe, this was going to prove difficult.

BGS scientist, Kieran Parker with responsibility for monitoring abandoned mines in Northern Ireland, had been looking after the site at Ballylig. The solution seemed to be to drill ‘blind’ holes into the approximate location of the mine and hope that it was found before the cost of the works escalated. But Kieran decided to bring in the help of BGS scientist, geophysicist Mohammednur Desissa, and use a potentially more effective method.

Results of the geophysical magnetic survey showing the proposed
location of mines /adits with suggested locations for drill sites
Kieran and Mohammednur conducted a geophysical magnetic survey on site to see if they could detect the shallow underground voids that would indicate the location of the mines. The theory behind this is well-known but this method of mine location had never been used in Northern Ireland. The results indicated a ‘room and pillar’ mining method with the extent of the mine roadways greater than previously thought. Confident in the results, targets were chosen to locate the mine location at the points either side of the road.

It was time to put this theory to the test and work began to try and locate the mine. Kieran Parker gave a brief update from the site:

The drill rig on site at Ballylig 
“Using the map produced using the data from the geophysical survey, drilling started on Monday 8th December 2014. The first target on the first day was a success with the mine roof encountered at 11m depth and mine floor at 12.5m. A further two boreholes had to be drilled and each of them was successful. Given the fact that the mine voids are no greater than 2m in width, precision was of utmost importance and was made possible by the geophysical survey beforehand.”

With the mine roadways now located, remedial work is currently ongoing to stabilize the public road.

By using this groundbreaking technique of mine location, a huge amount of time and money was saved, as the alternative was to drill ‘blind holes’.  In the current economic climate it is more important than ever to be innovative and makes the work at Ballylig an important example of the practical applications of geoscience. 

For more information on the abandoned mine work carried out by BGS scientists at the GSNI then please contact Kieran Parker at kieran.parker@detini.gov.uk 

Friday, 12 December 2014

Life in our ancient oceans... by Sonja Felder

Sonja is just starting out on a journey, travelling back through millions of years of Earth's history, to understand what impacts past climate changes had on the delicate life in our oceans...
 
Hi, I’m Sonja and I recently took up a PhD project (through IAPETUS, a Doctoral Training Partnership between the Newcastle University and BGS). My research is aimed at investigating past climate changes and the impact on marine life through millions of years of Earth’s history…Specifically I will be analysing cores of marine sediments which were collected from the Sea of Japan by the Integrated Ocean Drilling Program (IODP), a major international scientific ocean drilling programme. Some samples have already arrived in Newcastle and I have begun to look at the numbers and types of tiny fossils that occur in the sediments.

You probably know that in Earth’s history there have been times of colder and warmer climate. We call the really cold periods “glacials” (large ice caps on the Poles) and the really warm periods “interglacials” (small or no ice caps on the Poles). Currently, as we enjoy warm summers (well, not necessarily in the UK!) we live in an “interglacial” period (the ice caps are relatively small). The changes between glacial and interglacial periods have been cyclical. These natural climate changes happen due to variations in the astronomical parameters, such as how close the earth is to the sun during summer (precession) or how strongly the earth is tilted towards the sun (obliquity). These astronomical settings are also called “orbital parameters” as they refer to the earth’s orbit, its position in the universe. About one million years ago there was a major reorganisation in the timing of the cyclicity from 41,000 year cycles to 100,000 year cycles. This period is the so called Mid-Pleistocene Transition (MPT). What caused the MPT is one question I will be trying to tackle!

Back to my PhD site. I will be working on sediments collected from the Sea of Japan. This area is nowadays strongly influenced by the monsoon over Asia (the greater the monsoon the greater the amount of freshwater into the Sea which vary between glacial and interglacial periods), so I will need to think about both the effects of changes in the oceans and on the continents. To investigate these two systems I will use various methods, one of them is to measure the chemistry of foraminifera. These are tiny planktonic organisms which produce shells of the mineral calcite. The chemistry is dependent on parameters such as temperature or salinity of the ocean water. When the foraminifera die, the shells sink to the ocean floor and accumulate in the sediment in a time ordered way (i.e. oldest at the bottom of the sediment core).

 So far for now, I will be back to you with news on my project in a couple of months after having generated some (hopefully) super awesome data!

Sonja
@Sonja_Felder
Newcastle University and the British Geological Survey, supervised by Dr Andy Henderson and Prof Melanie Leng

Weather Bombed in Iceland... by Jez Everest

On Monday Heiko Buxel and Hugh Barron set out from Murchison House, Edinburgh for Iceland. Their mission was a relatively simple one- routine data downloads and site maintenance for the BGS Glacier Observatory Project, which has operated at Virkisjökull and Falljökull in southeast Iceland since 2009.

As Jez Everest (Project leader) illustrates through the boys latest field photos, the #weatherbomb has slightly upset their plans, but rewarded them with some staggering scenery!...



A flight from Glasgow taking an hour and a half longer than it ought due to incredible headwinds, was a taster of what has become a far from routine trip for our intrepid explorers. Two days of preparation in Reykjavik followed, working with our colleagues at the Icelandic Meteorological Office, and then the 250 mile drive eastwards to the field site on Wednesday.

As we know from the UK weather reports over the last few days, conditions in the Atlantic have been extreme, and Iceland, sitting as it does, unprotected from the full force of the ocean and atmosphere, has borne the brunt of this pounding. Hugh and Heiko drove through 70mph blizzards in the BGS truck, as temperatures sank far below zero. They made it to the field site unscathed after an arduous drive, to stay with our friends Oli and Palla, in their comfortable flat for the next week of sampling, monitoring and repairs.

The boys' schedule looks like it will be disrupted however, as the river is frozen over, making stream gauging impossible, and water sampling difficult. The extreme weather has caused some damage to our equipment, which will need fixing before they leave, and all the time they will be battling worsening weather and limited daylight.



 




Though it must be said, the pair are seasoned Icelandic winter campaigners, revelling in the conditions, and never shirking a challenge. Already they've re-installed a camera and solar panel to monitor proglacial lake levels, and have downloaded three of the four seismometers arranged around the glacier. It looks like they may get everything done, despite the conditions, and still have time for a well deserved beer, and a rest in a hot pool somewhere.

Well done chaps!

Keep an eye on the BGS YouTube channel as we'll be adding videos from Heiko and Hugh's adventures. Check us installing the equipment in 2011 and meet the whole team as they explored Iceland last year:


Jez.
Project Leader: Virkisjökull Observatory, Iceland

Thursday, 11 December 2014

School seismology on tour... by John Stevenson


Since 2006, Paul Denton  has managed the
UK School 
Seismology Project. Working with
partners, he'
s developed a number of resources,
promoting
this project and delivering training
courses to
school science teachers .
In late October 2014, I was asked to help Paul Denton, UK School Seismology project manager, to assist him deliver some teacher training workshops in Sion, Switzerland. Paul mentioned there would be a ‘full size’ shaking table demo, lots of fondue and we’d be staying in a ski-lodge at the foot of the Veysonnaz ski lift. I’m not sure which captured my attention most, but cheese was on the menu for every meal!
Funded by the EC’s NERA programme, it brought together scientists, civil engineers, civil protection officers and teachers from around Europe and the Middle East. The workshop was kindly hosted and organised  by HES-SO Valais Wallis; a further education college that specialises in engineering at its Sion campus.
So, about the workshop, four days of lectures interspersed with practical workshops followed by a field trip to a local hydro-electric dam to look at the local geology and faulting/folding processes at work.

The workshop programme strolled through the seismology basics for the ‘first-timers’ to the NERA workshops, followed by a couple of afternoons of hands-on activities for the teachers and educators to get to grips with the equipment and software they would be using in the classroom. The lectures also covered hazard/risk, earthquake modelling, civil engineering and building codes.

Training with SeisGram2K, which is an
easy-to-use software package for visualisation
and analysis of earthquake seismograms.

This is where Paul and I came in; we demonstrated how to use the educational version of the free software SeisGram2K. Using data from a recent large earthquake, teachers were asked to place P and S wave ‘data squiggles’ from three seismic stations on the software’s time-travel graphs to work out the distance the earthquake waves had travelled.  The teachers then entered this distance data into the BGS Earthquake locator to plot the earthquake epicentre at the intersection between the three circles.
 

What is NERA?

*NERA is a 4-year European Community project that integrates key research infrastructures in Europe for monitoring earthquakes and assessing their hazard and risk. 

The BGS has a partner role to help integrate school seismology projects across Europe so that new national projects can be initiated and to join in. There are 28 European NERA participants, four of which operate their ‘flavour’ of school seismology or seismo@school. In total we know of 10 countries in Europe actively pursuing educational seismology programs (not all involved in NERA)

Under the table, where most of the hard work
happened, featuring
the two low-cost, simple,
seismometers; foreground 
TC1, background
Mindsets 
'Slinky seismomter'

So what does it mean for schools?

Schools that engage and get to grips with school seismology get a truly cross-curricular activity that investigates a real world hazard, using real world data. It provokes teachers to ask students to put together real world solutions to monitor, detect, record and analyse earthquakes, using skills that can be developed beyond the understanding of seismic waves in the physics lab, but also using maths, IT and geography skills. For example:
  • make a seismometer from scrap materials
  • develop a data logging application for a Raspberry Pi computer
  • use online data to model seismic activity of volcanoes in Iceland

Schools develop a European partnership

The ‘Swiss  workshop’ also facilitated a partnership between two schools in England, with two schools Italy and France to develop low cost, reliable seismometers to be used by schools in Kenya. 

During the project, the schools will be asked to communicate with each other via Skype, share their data and visit each other to discuss project objectives. Like a ‘real’ EC project, the schools will be given individual tasks that they will need to produce to a deadline and integrate their results with the work of the other partner schools. 

Schools interested in developing similar partnerships can get further information about the 'mobility' funding that is available from the Erasmus Plus program. 

So why do we take part in school seismology projects?

Is something that we discussed as part of the workshop.  I’ll attempt to summarise the different perspectives of the European partners that attended the ‘Swiss workshop’ in  part two of this blog topic.

John


Paul Denton (left) UK School Seismology project manager and John Stevenson (right) BGS Public Engagement Lead, during the field trip to the Tseuzier Dam, Sion, Switzerland.
 
NERA Network of European Research Infrastructures for Earthquake Risk Assessment and Mitigation

Wednesday, 10 December 2014

Ancient floods on the Thames... by Raquel Santos

Raquel
Dr Raquel Santos is an organic geochemist working within the Centre for Environmental Geochemistry. Today we discover the exciting project she's working on with BGS colleague Dr Christopher Vane investigating past flooding events and the carbon cycle of the London Thames, an area housing a fifth of the UK population...

My current work with Chris is exploring if GDGTs (Glycerol Dialkyl Glycerol Tetraethers - more about these later!) will identify past climate variations and flooding events by determining changes in the organic matter in the soils.

Molecular structure of branched GDGTs (right) and Crenarchaeol (left) used to calculate the BIT index in tidal Thames.

Location of the surface samples from the intertidal foreshore of the River Thames to be analysed in this project. (c) Google
The project will increase our knowledge of how human activities have impacted on the transport of carbon from the land into the North Sea, ultimately leading to a better understanding of the global carbon cycle. It is also important to understand the fate of the terrestrial organic matter in the Thames estuary because the particulate fraction (the percentage that has not dissolved in the water) has the potential to adsorb organic micropollutants (pesticides, pharmaceutical residues, hormones, etc) and heavy metals (mercury, lead, etc) that can cause health concerns.  

GDGTs explained!

The Organic Chemistry Team; from right to left:
Alex Kim, Vicky Moss-Hayes, Chris Vane, Raquel Santos
GDGTs are membrane lipids produced by Archaea and bacteria that provide information on the biogeochemistry and environmental conditions of modern and past environments. They have been used specially in paleoclimate reconstructions to recreate changes in sea surface temperatures, mean annual temperatures and soil acidity (pH). Another important application of these compounds is to track the amount of soil organic matter input into the aquatic environments using the Branched Isoprenoid Tetraether index (BIT index). The BIT index is the ratio between branched GDGTs that are produced by soil bacteria, and Crenarchaeol, an isoprenoid GDGT produced by marine Archaea of the phylum Thaumarchaeota. The index was first described by Hopmans et al., 2004 and was originally used to estimate the amount of soil organic matter input to marine environments. Recently, the BIT index has been applied in rivers and lakes. Although, it has been mainly applied in large river settings (e.g. yellow river, Amazon, etc.), it has fewer applications in smaller rivers like river Têt in France where it showed to be a useful proxy for flood reconstruction.

Why use GDGTs to track soil organic matter?

Most studies that aim to track the origin and fate of organic carbon in estuaries have been predominantly based on bulk organic parameters. However, the interpretation of these data can be compromised by the wide range of potential end-member compositions and preferential remineralisation. Some of these limitations can be overcome with the application of molecular biomarkers that are specific to organisms. GDGTs are ubiquitous compounds that are specific to certain groups of organisms and that are not expected to be strongly affected by the industrial activities that take place along the river margins. Therefore, they are good biomarkers to be used at these settings.

If you would like to contact me, please write to Dr. Raquel Santos.

For information about current and future projects at the Organic Geochemical Laboratory, please write to Dr. Christopher Vane.


Tuesday, 9 December 2014

Paul Witney, BGS Photographer... by Catherine Pennington

Paul Witney at the coast in Holderness helping to develop
a new method of 3D photogrammetry
After several years teaching photography, Paul joined BGS in 2005 and is responsible for photography and video in Southern Britain.  He is called upon to photograph every aspect of BGS work from the
core store to fieldwork, from microscopic fossils to aerial photography.

Whilst on fieldwork, scientists are not always able to record good images of the work they are doing as they are often busy with the science itself.  The time constraints imposed by a rising tide, for example, means care and consideration for photography are easily missed.  Paul is on hand to do this job.  This frees up the scientists from having to think about photos and videos, but also means that the very best images are captured with the expertise and equipment only a professional photographer has.  It also provides the opportunity for Paul to record BGS staff doing their jobs.
Paul is not fishing here, he is taking photographs down a sinkhole in Kent!

Paul has worked on a huge range of projects and has been on many fieldtrips with BGS scientists both in the UK and abroad.  He has photographed landslides and coastal erosion, ground water flooding in action and he has even found safe(r) ways to photograph geohazards such as sinkholes. 

He has also found himself in some challenging environments such as training photographers at the Afghan Geological Survey in Kabul or being stood on top of glaciers in Iceland. 

Sometimes the weather has its greatest impact as he explains:
Most of the fieldwork, whilst always interesting, seems to be either freezing cold or red hot!  There’s no point photographing in the rain as the photographs are usually poor and it can damage equipment.  I think some of the BGS staff claim I’m water soluble!” 
Whilst in Iceland, battery power was hugely affected by the cold.  I had to warm the camera batteries in my gloves otherwise they’d go flat.  In other places, such as Afghanistan, dust storms are more of the issue as dust particles can easily get inside the camera and onto the sensor.  Before you know it, there’s a speck on every photograph.”
Chilly

Up, up and away!

Paul is also a pilot and has taken light aircraft up into the sky to capture photographs of events such as the flooding in 2007.  Large parts of England were under water at this time including Tewksbury Abbey in Gloucestershire; Paul’s photograph won him the Press and PR 2007 award.

Left: Paul Witney as pilot. Right: Tewksbury Abbey, Gloucestershire, surrounded by the flood waters of 2007.
His latest equipment purchase is a hexacopter.  This is an unmanned aerial vehicle, also known more widely in the press as a 'drone', and is similar to the one used by BGS's  Earth and Planetary Observation and Mapping and Engineering Geology teams. This will mean Paul can take aerial photos and video at, for example, locations where it is too dangerous for anyone to walk over, such as a landslide or sink hole, or where flying aircraft is also not an option. The UAV is a DJI S900 with a hi-resolution camera capable of capturing stills up to 16 megapixels and video up to 4k.
 
The new Hexacopter

In the lab

Sometimes, it’s the smaller aspects of science that need to be photographed.  Here you can see Paul using specialist equipment (Nikon Multiphot and 80 megapixel scanning back) to photograph trilobite eye facets:
 
 Paul using specialist equipment (Nikon Multiphot and 80 megapixel scanning back) to photograph trilobite eye facets


The YouTube Generation

BGS is trying to put more video footage of our science in action on the web.  The public’s demand for video is increasing so Paul now spends a large part of his time shooting and editing videos of the science at work.  You can view some of these videos on BGS’s YouTube Channel.

Paul has won several awards for his work including the British Institute of Professional Photography Annual Print Competition, Architectural Section, for the last two years.  To see more of the work Paul does, you can follow him on Twitter @bgspixpaul

Paul has won several awards for his work including the British Institute of Professional Photography Annual Print Competition, Architectural Section, for the last two years.
Catherine