In the recently published Nature Geoscience paper a diverse group of scientists based at DIAS and other research institutes in Ireland and Iceland developed a new understanding of seismic signals prior to an eruption. The focus of the study is an eruption in Iceland in 2014/15 that was preceded by two weeks of increased, migrating seismicity. This seismicity is the noise of the breaking crust at depth and gave scientists the possibility to ‘watch’ how magma propagated horizontally until it eventually made it to the Earth’s surface. However, the puzzling observation was that no earthquakes occurred at less than 3 km depth, although magma passed through this region. We found that a long-lasting continuous seismic signal, called tremor, exists at this depth instead. This tremor was usually understood as being caused by moving fluids, but it seems that it consists instead of millions of tiny earthquakes that are so closely spaced that they merge into one another and appear as tremor. It seems that the uppermost part of the crust is too weak to generate big earthquakes and it therefore breaks through many small earthquakes. In our paper we describe how the crust beneath the ice opened little by little in about 19 hours at a speed of 220 m/h. As such eruptions beneath ice can distribute huge amounts of ash in the air, understanding these signals is important for volcano monitoring and eruption early-warning.
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Last Updated: 23rd May 2018 by Anna
New insights into how continuous seismic signals announce an eruption
In the recently published Nature Geoscience paper a diverse group of scientists based at DIAS and other research institutes in Ireland and Iceland developed a new understanding of seismic signals prior to an eruption. The focus of the study is an eruption in Iceland in 2014/15 that was preceded by two weeks of increased, migrating seismicity. This seismicity is the noise of the breaking crust at depth and gave scientists the possibility to ‘watch’ how magma propagated horizontally until it eventually made it to the Earth’s surface. However, the puzzling observation was that no earthquakes occurred at less than 3 km depth, although magma passed through this region. We found that a long-lasting continuous seismic signal, called tremor, exists at this depth instead. This tremor was usually understood as being caused by moving fluids, but it seems that it consists instead of millions of tiny earthquakes that are so closely spaced that they merge into one another and appear as tremor. It seems that the uppermost part of the crust is too weak to generate big earthquakes and it therefore breaks through many small earthquakes. In our paper we describe how the crust beneath the ice opened little by little in about 19 hours at a speed of 220 m/h. As such eruptions beneath ice can distribute huge amounts of ash in the air, understanding these signals is important for volcano monitoring and eruption early-warning.
Category: Geophysics, Geophysics Section News & Events, News
Great to see our very own Dr Rebeca Garcia Lopez featured in both the @irishexaminer and the @Independent_ie as one of 20 @scienceirel Starting Investigator Research Grant awardees. #DIASdiscovers
Great piece by @KOSullivanIT in the @IrishTimes today on the unveiling of Shei;a Tinney's portrait yesterday at DIAS with @mitchelloconnor and the family of Dr Tinney. Read it online here: bit.ly/2FvErVs
We were delighted to have @mitchelloconnor , Minister of State for Higher Education, with us on this special occasion today. twitter.com/DIAS_Dublin/st…
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Today we’re hosting a very special lunchtime reception to unveil a portrait of former DIAS Fellow and renowned scientist, Sheila Tinney #DIASdiscovers
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Congrats to @StKiliansDS team Roan Batard, Ethan McQuaid & Marilou Gerbelot-Barillon on winning the Group 2nd place in Physical, Chemical & Mathematical Sci at @BTYSTE lfor their project: 'What makes Dublin shake?' @dias_geophysics were delighted to support you with your project! twitter.com/NBourgeois_Pro…
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Fantastic to hear this @BTYSTE project from Lycée Francais d'Irlande featured on @morningireland this morning. @dias_geophysics were delighted to support your work on this project. Go n-éirí libh sa chomortas! #DIASdiscovers twitter.com/NBourgeois_Pro…
Since winning @BTYSTE comp 50 yrs ago @Luke_Drury has dedicate his life to science: studying experimental physics & pure maths @tcddublin; later undertaking a PhD in astrophysics in Cambridge and then acting as head of the astrophysics section at School of Cosmic Physics at DIAS.
As the @BTYSTE kicks off today, it marks 50 years since our very own @Luke_Drury , Emeritus Professor of Astrophysics at DIAS, won the competition for a piece of equipment he built that assessed the amount of metal in a compund. #BTYSE