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.
Leave a Comment
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 the Minister speaking of the Netherlands model, with its focus on fundamental research questions - this approach has informed the DIAS strategy. thecurrency.news/articles/27275… @SimonHarrisTD @DeptofFHed
"Going on the puca..." Instead big Trick or Treating
"they should be revered as well as feared"
@LallySteve has started his talk
Our second event is underway! #SamhainagusScience #DIASdiscovers
This afternoon! Some tickets still available for this talk on various subject matters such as the sídhe, pookas, changelings, banshees, fairy doctors, curses, cures and fairy landmarks. eventbrite.ie/e/98001883271/
Starting this Monday 26 October and running through to the 03 November, join us for 👻✨🔥 Samhain agus Science 🥼🧪🧨 Full programme and how to book at the below link: dias.ie/2020/10/26/sam… Please RT and share far and wide! #DIASdiscovers #SamhainagusScience
Starting NOW! Come and join our first event of Samhain agus Science! No link no problem, just DM and we will send it to you. #DIASdiscovers #SamhainagusScience
Tonight! twitter.com/DIAS_Dublin/st…
@tcdgenmicro We are looking forward to it ☺️ As this year's theme is 'the boundaries of space and time and the secrets that lie there' Mark's talk will definitely be a highlight of Samhain agus Science this year. Check out this & some of the other online events here: dias.ie/samhain-agus-s…