Background
Volcano

The Carlingford Igneous Centre, NE Ireland, erupted 60 million years ago, but a new study published in Nature Communications reveals it has much to teach us about currently active volcanoes.

Since the geological expedition of R.W. Bunsen to Iceland in the mid 19th century, scientists have been puzzled by the frequent co-occurrence of basalt and rhyolite at many volcanoes. Bunsen, who also invented of the Bunsen burner, was the first to describe this phenomenon of “bimodal volcanism”, but these fundamentally different lava types have by now been found together at sites across the planet. Crucially, the mixing of basalt and rhyolite in a volcano’s magma chamber is a major cause of violently explosive eruptions, but in the 160 years since Bunsen’s observations, no consensus has been reached on how bimodal volcanism actually originates. A new article in “Nature Communications” now re-ignites the debate and offers a fresh perspective on bimodal volcanism at continental volcanoes. Using detailed chemical analyses of rocks from the Carlingford Igneous Centre, the roots of a large, extinct volcano in northeast Ireland, an international team of scientists suggests that the key control on bimodal volcanism could, in fact, be the crustal rocks that lie below the erupting volcano.

Sixty million years ago, the North Atlantic Ocean was only beginning to form and America and Europe were slowly breaking apart. This process was exacerbated by an increased flow of molten rock from the Earth’s mantle, known as a mantle plume, which caused extensive volcanism throughout northeast Ireland, Greenland and western Scotland. Fissure-fed basaltic lava, as seen at the Giant’s Causeway in Northern Ireland, was the most common type of activity, but a number of large volcanoes also formed. A key feature of these volcanoes was that they were short-lived and bimodal, producing significant amounts of light-coloured rhyolite and granite, as well as dark basalt. One such volcano was the Carlingford Igneous Centre, Co. Louth, Ireland. As the hot basaltic magma (>1200 °C) beneath Carlingford made its way from the mantle to the surface, it passed through the Earth’s continental crust, which is 30 km thick in this part of Ireland. “Luckily rocks from the crust and rocks from the mantle have characteristic chemical compositions, like geological DNA”, explains Dr Fiona Meade, the principal author of the article, “By using cutting-edge isotope analyses on the volcanic rocks from Carlingford, we can detect that the crust began to melt and that these melts were incorporated into the ascending magmas, transforming the basalt into rhyolite and granite”.

Significantly, the team’s work has shown that the continental crust was most strongly involved during the early stages of activity at Carlingford. It appears that while a first flush of crustal melt was easy to extract, melting became increasingly difficult and granite formation quickly stalled. This is because not all minerals in crustal rocks melt at the same temperature, and while some components are readily incorporated into the magma, others are left behind and will never melt. “This research suggests that crustal melts are vital for the formation of rhyolite/granite magmas in continental volcanic systems, and that once the crust can no longer produce such melts, the volcanoes rapidly return to producing basalt – forming a bimodal rock suite” added Prof Valentin Troll, the team leader and chair of petrology at Uppsala University (Sweden). “Evidence of basalt-rhyolite magma mixing is preserved at Carlingford, indicating that violent eruptions are likely to have been triggered early in the lifetime of the volcano, and while Carlingford has not posed any danger for 60 million years, it gives us a major insight into the processes that drive currently active volcanoes”, he concludes.

This project was initiated at Trinity College Dublin by Prof Valentin Troll and Dr Fiona Meade, who are now based at Uppsala University (Sweden), and was supported by an international team of co-workers from institutions in the UK, Italy and the Netherlands. The research was funded by Science Foundation Ireland (SFI), the Irish Research Council for Science, Engineering and Technology (IRCSET) and the TEKNAT faculty at Uppsala University.

For more information please contact Prof Valentin Troll (valentin.troll@geo.uu.se) or Dr Fiona Meade (meade.fiona@gmail.com).

FameLab

Pádraic Flood, a University College Dublin (UCD) science graduate, beat off nearly 2,000 scientists from 22 countries, to be crowned the 2014 FameLab International Champion, at The Times Cheltenham Science Festival, held last week.

Pádraic, who graduated from UCD in 2008 with a BSc (Hons), is currently completing a PhD in plant genetics at Wageningen University in the Netherlands.  Earlier this year he won the FameLab Benelux competition and represented the trio of countries at the FameLab International finals in Cheltenham.

Pádraic’s winning talk discussed improving photosynthesis to prevent food scarcity. He first took the audience into the leaf and told them about the mechanics of photosynthesis, leading to where light meets water, saying “it is at this point that light becomes life”. He then told the audience about food shortages in the future and how we might combat this through improving photosynthesis.

After winning the competition Pádraic said, “FameLab is fantastic, it opens a direct dialogue between scientists and the public, and I’m so glad to have been a part of it this year.”

For more click here

Perseid Meteor

Sky-watchers are in store for a once-in-a-lifetime meteor storm when the Earth passes through the tail of a comet. Astronomers are predicting that up to 1,000 shooting stars an hour could rain down on Earth hour as our planet passes through debris from Comet 209P/LINEAR this week.

The head of Astronomy Ireland, David Moore, has urged the public to get outside tomorrow night, Friday 23rd May, to try to catch a glimpse of the celestial fireworks that will fly from dusk till dawn.

“Imagine a thousand shooting stars per hour. It could be one every five to 10 seconds. It could be really spectacular,” he said. “Shooting stars are very rare and most people accidentally see one once every few years. If they go out for five to 10 minutes on that particular night they could see more than an astronomer sees in a lifetime. It is a very big event cosmically.”

For more click here or visit astronomy.ie

pintofscience

New scientific discoveries are happening all the time, fascinating developments which will change the future of the human race. But how often are you given the chance to really understand how these discoveries are made and what they mean?

The Pint of Science festival 2014 will see some of Ireland’s best scientific researchers hit pubs in Dublin and Cork to discuss their latest findings. This is your chance to get face-to-face with the people involved in carrying out current research! You can listen to them talk, join in games and quizzes, or just enjoy a chat over a pint. Find out what’s really going on in our bodies, our minds, in technology and much more!

Check out www.pintofscience.ie for more details!

johnny_coleman

Irish scientists have outlined how they managed to make the “wonder material” graphene, incredibly using dishwashing liquid and a kitchen blender!! Graphene is thin, strong, flexible and electrically conductive, and has the potential to transform electronics as well as other technologies.

The Irish-UK team (led by Prof Jonathan Coleman from Trinity College Dublin whose research we profiled in Series One of The Science Squad) poured graphite powder into a blender, then added water and dishwashing liquid, mixing at high speed. The results are published in the journal Nature Materials and their work has been reported by BBC News.

Because of its potential uses in industry, a number of researchers have been searching for ways to make defect-free graphene in large amounts. The material comprises a one-atom-thick sheet of carbon atoms arranged in a honeycomb structure. Graphite – mixed with clay to produce the lead in pencils – is effectively made up of many layers of graphene stacked on top of one another.

Prof Coleman  and colleagues tested out a variety of laboratory mixers as well as kitchen blenders as potential tools for manufacturing the wonder material. They showed that the shearing force generated by a rapidly rotating tool in solution was sufficiently intense to separate the layers of graphene that make up graphite flakes without damaging their two-dimensional structure.

However, it’s not advisable to try this at home. The precise amount of dishwashing fluid that’s required is dependent on a number of different factors and the black solution containing graphene would need to be separated afterwards. But the researchers said their work “provides a significant step” towards deploying graphene in a variety of commercial applications.

The scientists have been working with UK-based firm Thomas Swan to scale up the process, with the aim of building a pilot plant that could produce a kilo of graphene per day by the end of the year. In addition to its potential uses in electronics, graphene might have applications in water treatment, oil spill clean-up and even in the production of thinner condoms.