Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Giant 'balloon of magma' inflates under Santorini

A new survey suggests that the chamber of molten rock beneath Santorini's volcano expanded 10-20 million cubic metres – up to 15 times the size of London's Olympic Stadium – between January 2011 and April 2012.

The growth of this 'balloon' of magma has seen the surface of the island rise 8-14 centimetres during this period, a team led by Oxford University scientists has found.

The results come from an expedition, funded by the UK's Natural Environment Research Council, which used satellite radar images and Global Positioning System receivers (GPS) that can detect movements of the Earth's surface of just a few millimetres.

The findings are helping scientists to understand more about the inner workings of the volcano which had its last major explosive eruption 3,600 years ago, burying the islands of Santorini under metres of pumice. However, it still does not provide an answer to the biggest question of all: 'when will the volcano next erupt?'

A report of the research appears in this week's Nature Geoscience.

In January 2011, a series of small earthquakes began beneath the islands of Santorini. Most were so small they could only be detected with sensitive seismometers but it was the first sign of activity beneath the volcano to be detected for 25 years.

Following the earthquakes Michelle Parks, an Oxford University DPhil student, spotted signs of movement of the Earth's surface on Santorini in satellite radar images. Oxford University undergraduate students then helped researchers complete a new survey of the island.

Michelle Parks of Oxford University's Department of Earth Sciences, an author of the paper, said: 'During my field visits to Santorini in 2011, it became apparent that many of the locals were aware of a change in the behaviour of their volcano. The tour guides, who visit the volcano several times a day, would update me on changes in the amount of strong smelling gas being released from the summit, or changes in the colour of the water in some of the bays around the islands.

On one particular day in April 2011, two guides told me they had felt an earthquake while they were on the volcano and that the motion of the ground had actually made them jump. Locals working in restaurants on the main island of Thera became aware of the increase in earthquake activity due to the vibration and clinking of glasses in their bars.'

Dr Juliet Biggs of Bristol University, also an author of the paper, said: 'People were obviously aware that something was happening to the volcano, but it wasn't until we saw the changes in the GPS, and the uplift on the radar images that we really knew that molten rock was being injected at such a shallow level beneath the volcano. Many volcanologists study the rocks produced by old eruptions to understand what happened in the past, so it's exciting to use cutting-edge satellite technology to link that to what's going on in the volcanic plumbing system right now.'

Professor David Pyle of Oxford University's Department of Earth Sciences, an author of the paper, said: 'For me, the challenge of this project is to understand how the information on how the volcano is behaving right now can be squared with what we thought we knew about the volcano, based on the studies of both recent and ancient eruptions. There are very few volcanoes where we have such detailed information about their past history.'

The team calculate that the amount of molten rock that has arrived beneath Santorini in the past year is the equivalent of about 10-20 years growth of the volcano. But this does not mean that an eruption is about to happen: in fact the rate of earthquake activity has dropped off in the past few months.

Notes to editors

*A report of this research, entitled 'Evolution of Santorini Volcano dominated by episodic and rapid fluxes of melt from depth', is published in the journal Nature Geosience, embargoed until 1800 UK time / 1300 US Eastern time on Sunday 09 September.

*Recent eruptions on Santorini have usually involved two different sorts of magma: a dominant, silica-rich lava called a dacite; and a much smaller amount of a hotter, more-silica-poor lava called andesite. Previous work has shown that eruptions appear to be triggered by the arrival of the andesite, which stirs up the dacite and quickly (within perhaps a few weeks) starts an eruption. The current episode of unrest has now lasted much longer than can be explained by this sort of idea, so the working hypothesis is that the molten rock that is currently intruding beneath Santorini is dacite, and not andesite.

*This research was funded by the UK Natural Environment Research Council through an urgency grant. The work was carried out by researchers in Oxford and Bristol who are supported by the Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET+), part of the NERC-funded National Centre for Earth Observation, Dynamic Earth and Geohazards Research Group, in collaboration with colleagues from the University of Athens and the National Technical University of Athens. Satellite data were provided by the German Space Agency (DLR) and the European Space Agency (ESA).

Additional support, in kind or through the loan of equipment, was provided by, among others, The Hellenic Military Geographical Service, Santorini Bellonio Library, the Nomikos Foundation, the Boatmen Union of Santorini and the NERC Geophysical Equipment Facility.

University of Oxford press office | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

nachricht Enormous dome in central Andes driven by huge magma body beneath it
25.10.2016 | University of California - Santa Cruz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>