Features

In this guest post David Ferguson of Oxford University's Department of Earth Sciences writes about his research into volcanoes:

Earlier this summer I took an unexpected journey to the Afar Depression, a vast remote desert in the north of Ethiopia.

The Afar region is famed among adventure tourists for it’s sweltering temperatures, saline lakes and numerous (and often active) volcanoes. It was the latter of these that was responsible for my impromptu trip.

On the 28th June an instrument carried by a NASA satellite, designed to measure temperatures on the Earth’s surface, detected a new area of intense heat emissions whilst flying over Afar. The most likely cause of this thermal signature was an active lava flow, the product of a new volcanic eruption. As soon as we received this data we raced out to Ethiopia to try and catch the eruption in progress. You can read about our trip on The Guardian's Science Blog.

A week after our sudden departure we were back in the UK. The souvenirs from our unexpected trip: a box of fresh lava samples, visual and thermal images of a newly formed volcanic fissure and some slightly melted shoes (new lava flows require very sturdy footwear!).

Afar is the site of intense geological activity, a manifestation of the Earth’s crust being split apart by the movement of tectonic plates. The key to why so much of this geological activity is concentrated here is the presence of great volumes of magma beneath the surface. Periodically, a batch of this magma surges upwards from deep in the crust, splitting the ground apart as it forces its way upwards and, in some cases, reaching the surface and erupting out onto the desert floor.

During the past few years Afar has seen a marked increase in this magmatic activity and every so often we get the opportunity to try and collect some samples of the magma from new lava flows. By studying the chemical composition and physical characteristics of these, currently rare, eruptions we hope to learn about the magma reservoir beneath the surface and also whether we can expect more eruptions in the near future.

A problem in forecasting volcanic eruptions in this part of Afar is that this type of volcanism is not often seen on dry land. As tectonic plates are split apart they tend to sink down into the Earth’s mantle (much of Afar is currently below sea level) and as such the areas where this geological process occurs (called ‘rifting’) are typically found at the bottom of the oceans.

There is, however, one other region on Earth we can use as a comparison to Afar without the need for a submarine. That is Iceland, where the fracture zone that splits apart the oceanic crust beneath the Atlantic Ocean takes a brief detour onto land. In the late 1970s Iceland experienced, over a nine-year period, a series of events similar to those currently happening in Ethiopia.  Using the data we gathered on the size and duration of this recent eruption (and also a previous one in 2007) we can compare our data to the pattern of eruptions seen in Iceland during that time.

Similar to Afar, the Icelandic activity began with several pulses of magma forcing their way upwards into the shallow crust, which, despite causing earthquakes and ground fractures, did not make it all the way up to erupt at the surface. 

However, as the magma continued to surge upwards over several years more and more eruptions occurred, most of these lasting longer and erupting more lava than the previous one. By comparing the patterns of earthquakes and eruptions observed in Afar over the past few years with the Icelandic data we have forecast that there is a high likelihood that over the next ten or so years this part of Ethiopia will experience several more (and potential much larger) volcanic eruptions.

Our findings on this are currently being peer-reviewed for publication in an academic journal. In the meantime, however, we will continue to monitor this part of Afar and to catalogue and study future activity.

You can read more about this work on the Afar Consortium website.

David Ferguson is based at Oxford University's Department of Earth Sciences.

How can some sportsmen and women, in the heat of the moment, play on through pain that would floor anyone else?

Bert Trautmann, the Manchester City goalkeeper, famously played on through to the end of the 1956 FA Cup final - holding on for a 3-1 win - despite suffering a broken neck from a collision in the second half.

Similarly, why do some people seem to suffer long-lasting debilitating pain when others are better able to cope? Each of us individually can also experience pain differently at different times.

Pain of course is a subjective, variable and very personal experience that involves far more than a simple reaction to injury or damage. And although doctors can only rely on what each patient says about the pain that they’re experiencing, it is important to try and diagnose, monitor and manage that pain effectively.

Professor Irene Tracey’s group at the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain has used brain imaging techniques for a number of years, aiming to provide an objective measure of individual experiences of pain.

By understanding how the brain processes the information coming from all the body’s senses as pain, they can begin to pick out differences between people.

Their latest results, reported this week in the journal PNAS, demonstrate that people’s personalities matter in their experience of pain. People that are more anxious, or worried about feeling pain, have differences in connectivity within their brains that make them more susceptible to actually feeling pain.

The team applied short laser pulses to the feet of 16 willing and healthy volunteers just at the point where they started to experience the pulses as being painful (‘you can ratchet up the laser pulses so you feel them as warm, then hot, then the point where you say “yeah, actually, that hurts now,”’ explains Irene.) These brief laser pulses were applied 120 times to each volunteer, and around half the time the volunteer would declare it was painful and half the time not - even though the pulse was exactly the same every time.

MRI brain scans during these experiments show that the volunteers’ brains were more active in pain-processing regions when they described the laser pulses as being painful - so this was a real experience and not down to any report bias or artefact.

But the researchers wanted to understand exactly what made one stimulus painful at one time while the very same stimulus at another time was fine.

‘We looked at the period just before the stimulus and asked “is there a difference in the way certain regions of the brain are connected or communicating before the stimulus is applied?”’ explains Irene. ‘The answer is that there is a striking difference.’

The researchers focused on the connection between ‘higher’ parts of the brain involved in the processing of pain, and part of the brain stem that can powerfully alter the experience of pain - turning its level up or down.

When there was good coupling between the two areas before a laser pulse, the volunteer felt no pain, and when the connectivity was poor, the pulse was experienced as painful.

Most interestingly of all, however, was that people that were more likely to be anxious or vigilant about pain (as scored on their answers to a questionnaire for these traits), showed poorer connectivity in general between these brain regions.

This difference in the hardwiring of the brain could account for how people with different personalities respond to pain, suggests Irene.

‘We now want to know whether we are born with this, or whether the brain becomes wired like this as it develops,’ she says. ‘It’s a chicken and the egg situation. We only have a snapshot in time with this experiment. We can’t tell what comes first.’

Yesterday what started out as an exchange on Twitter blossomed into a full scale debate on the future for basic and curiosity-driven research.

The debate, Blue skies ahead?, was organised by THE and featured a panel including Science Minister Lord Drayson, Suzie Sheehy from Oxford University's Department of Physics, Colin Stuart, Alom Shaha, and Lewis Dartnell, with Brian Cox chairing the lively discussion.

One of the main topics was the new Research Excellence Framework (REF) with its emphasis on putting a greater emphasis on the 'impact' of proposed research projects.

Suzie said: 'Meeting Lord Drayson again was a good experience, and I commend his interaction with real scientists through forums such as Twitter and the blue skies debate.'

'It was certainly an intense experience for me to have to speak directly after Lord Drayson initially, particularly as most of the points I had prepared were very well addressed in his opening remarks. It certainly made me think on my feet!'

She cites the effect on scientific output when it is assessed with regards to impact as the most interesting point raised during the debate. This morning physicist Brian Cox commented on his Twitter stream about the difficulties of measuring 'impact' in any meaningful way.

Asked about the questions she wished had come up, but didn't, Suzie told me:

'The first point I wish had been raised was my concern that making the outlook of scientific research 'impact' focused brings up the issue of how much scientists earn. I was offered a job straight out of undergraduate that would have paid me more than I will earn in research science for possibly the next 10 years.'

'We don't do science for money, we do it because it is interesting and we think it is important. Shifting the focus to 'impact' may be the final straw for many good scientists who may either leave the field, or leave the country to 'greener pastures'.

'It would have also been good to discuss the issues of under-represented groups in science, particularly the issues of women in physics and the possibility of programs to support more flexible working arrangements such as part-time postdoctoral fellowships.'

In September we reported how research into the hydrogen-making enzyme (iron-iron hydrogenase) in green algae revealed the mechanism by which oxygen irreversibly halts its hydrogen production.

It was a set-back for those hoping to use such photosynthetic microorganisms to make 'green' hydrogen fuel from just sunlight and water.

But in a recent paper in PNAS the same team, led by Fraser Armstrong of Oxford University's Department of Chemistry, report complementary research into the hydrogen-producing enzyme found in blue-green algae (nickel-iron hydrogenase) that gives important clues to how it can survive oxygen's onslaught.

I asked Fraser about his team's work and what it might mean for those working towards 'solar hydrogen farms':

OxSciBlog: How do these enzymes react differently to oxygen compared to those in green algae?
Fraser Armstrong: The enzymes we have studied contain a different type of active site: they are called nickel-iron [NiFe]-hydrogenases as opposed to iron-iron [FeFe] hydrogenases that occur in green algae.

The [FeFe] hydrogenase have an iron-sulphur cluster linked directly to the active site: iron sulphur clusters are rapidly degraded by oxygen or reactive oxygen species (such as superoxide) and this cluster is thought to be the group at which oxygen causes irreversible damage.

The [NiFe]-hydrogenases do not have a directly linked iron sulphur cluster, so when oxygen attacks the active site there need not be any permanent damage.

OSB: Why do we think these enzymes have a higher oxygen tolerance?
FA: We are not exactly sure, at the molecular level; but our electrochemical studies show that two properties/aspects are particularly important:

The first of these is that when oxygen attacks the active site, there are sufficient electrons available to ensure that the oxygen molecule can be reduced all the way to water molecules; this requires initially three electrons giving a harmless state known as Ni-B in which the Ni has been oxidised to the Ni(III) state and coordinates a hydroxide ion. 

The second aspect is that Ni-B can be rapidly reduced back to Ni(II) releasing the hydroxide and re-activating the enzyme. Rapid reduction is favoured by a high reduction potential for this step. The [NiFe]-hydrogenases that we regard as oxygen tolerant have a high reduction potential, and re-activation is therefore spontaneous, allowing the hydrogenase to function even in the presence of oxygen, as in air.

OSB: What new avenues of research do your findings suggest?
FA: They show how it could be possible to ‘design’ hydrogenases in cyanobacteria that have improved oxygen tolerance, and so use these genetically altered organisms for photosynthetic hydrogen production (where oxygen is produced).

The results also suggest that organisms operating at higher temperatures should be more successful because a determining factor for the hydrogenase’s oxygen tolerance is the rate of re-activation.

OSB: What do you hope might be the end result of research into similar oxygen-tolerant enzymes?
FA: Crystal structure studies of an oxygen tolerant hydrogenase are now crucial because they would provide a molecular understanding of the mechanism of oxygen tolerance, for example modification of the region around the active site that can steer oxygen reaction away from producing reactive oxygen species, and modifications of the electron transfer relay system (a series of iron-sulphur clusters) that enable it to ‘hold’ more electrons.

Professor Fraser Armstrong is based at Oxford University's Department of Chemistry

But then yesterday saw a series of special events for schools and the public, organised by Oxford University’s Department for Continuing Education, to celebrate Marcus du Sautoy’s inaugural lecture as Charles Simonyi Professor for the Public Understanding of Science.

The core message of Marcus’s evening lecture, which he sets out in this article in The Times, is that maths is the language of the universe, and that it binds scientific and artistic cultures together.

What I think anyone attending any of the day’s events took away with them was that maths and science are our culture, that they can’t be separated from everyday life: if you’ve ever played a game of chance, or listened to music, or been awestruck by the beautiful shapes in nature or architecture then you’ve experienced some of the same mathematical structures that fascinate mathematicians and scientists.

Mathemagicians & winning streaks
Yesterday morning saw 50 pupils aged 11-14 from schools in Oxford, Leamington Spa, Leicester, Brighton and Hackney arrive ready to have fun, and learn something.

Their first stop was the University’s Museum of Natural History and the Pitt Rivers Museum. Both do excellent work with families and schools and the Madagascan hissing cockroaches, some of the stars of this year’s Oxford Science Roadshow, once again stole the show.

After the museum tours it was time for lunch with the post-lunch entertainment provided by Marcus’s Marvellous Mathemagicians [M3].

The Mathemagicians are Oxford maths students on a mission: to communicate their passion for their subject to the next generation. Their show was inspired by Marcus’s Christmas Lecture on the winning streak and how to win – or stand less chance of losing – at various games.

Thomas Woolley kicked off proceedings, explaining how, in the unlikely event you do get lucky in the National Lottery, a truly random choice of numbers could snag you the jackpot.

Then Christina Goodwin took charge of a giant Monopoly board and, using a sparkly top hat for a counter and getting volunteers to roll giant dice, demonstrated how probability makes some properties better earners than others.

David Blane played the chocolate game, in which contestants had to learn how not to be stuck with a poisoned chocolate bar, and Jamie Humphries challenged all comers to beat him at the pie game – then explained his secret winning strategy.

Picking primes
In the afternoon it was off to hear Marcus give his interactive talk on ‘Why Beckham Chose 23’, an exploration of the power of prime numbers in nature, and on the way we think.

With the numbers 1-100 spread across the floor of Holywell Music Room, it was up to the pupils to move a toy monkey as a marker, playing prime number hopscotch to understand the patterns behind the number sequences.

They also learnt about cicadas, and how these insects have evolved a life cycle based around prime numbers in order to outwit predators. By appearing only every 17 years cicadas are guaranteed to avoid a predator most often – in fact they’re so successful that the predator they evolved to avoid may have died out.

Yesterday evening Marcus returned to prime numbers and cicadas in his inaugural lecture as part of a discussion of the relationship between music, art, maths, and science.

In his Quartet for the End of Time Messiaen used the prime numbers 17 and 19 to create harmonies that, like the cicada and its predator, would be out of step and so sound timeless. Marcus said: ‘I cannot believe that he was aware that the 12-note sequences he uses are the basis for generating one of the strangest mathematical objects… But it is a sensitivity to similar structures that drew him to these two themes.’

The sound of a cube
Some composers take a more consciously mathematical approach: we heard an excerpt from Xenakis’s Nomos Alpha in which the composer attempts to reproduce the sound of a cube on the cello.

Because symmetry controls the shapes we can create, architects and painters have long been fascinated by mathematical ideas.

Marcus gave the example of how Renaissance painters recovered the Archimedean solids and Dali tried to create on his 2D canvas a representation of a 4-dimensional object – the tesseract. Anyone too who has enjoyed the feeling of space in one of Palladio’s villas or marvelled at a Corbusier building is witnessing mathematical ideas transformed into physical space.

As he pointed out, understanding maths and science is now more important than ever, as we need to use it to make predictions about how diseases will spread, how our climate will change, or what new particles may pop into existence inside the LHC.

Marcus commented: ‘It is one of my aspirations during the tenure of my professorship to encourage government, research councils and universities that the more scientific ambassadors we can support the better chance we have of integrating the foreign world of science with the rest of society.'

'Without an understanding of the language of science and mathematics, as Galileo once wrote, we will all be wandering around lost in a dark labyrinth.’

For more about the Simonyi Professorship go to the Simonyi homepage 

Find out more about the mathemagicians and how to book them here

Photos from the day courtesy of Gail Anderson