Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014
Networks of seismographs of high sensitivity have been in use in the vicinity of active volcanoes in Iceland since 1973. During this time, 21 confirmed eruptions have occurred and several intrusions where magma did not reach the surface. All these events have been accompanied by characteristic seism...
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ftdoajarticles:oai:doaj.org/article:3bb61712bf914d9994be95dfb40faec8 2023-05-15T16:33:59+02:00 Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 Páll Einarsson 2018-05-01T00:00:00Z https://doi.org/10.3389/feart.2018.00045 https://doaj.org/article/3bb61712bf914d9994be95dfb40faec8 EN eng Frontiers Media S.A. http://journal.frontiersin.org/article/10.3389/feart.2018.00045/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2018.00045 https://doaj.org/article/3bb61712bf914d9994be95dfb40faec8 Frontiers in Earth Science, Vol 6 (2018) seismic precursors eruption precursors volcanoes in Iceland pre-eruption warning eruption forecasting precursor time Science Q article 2018 ftdoajarticles https://doi.org/10.3389/feart.2018.00045 2022-12-31T10:39:37Z Networks of seismographs of high sensitivity have been in use in the vicinity of active volcanoes in Iceland since 1973. During this time, 21 confirmed eruptions have occurred and several intrusions where magma did not reach the surface. All these events have been accompanied by characteristic seismic activity. Long-term precursory activity is characterized by low-level, persistent seismicity (months-years), clustered around an inflating magma body. Whether or not a magma accumulation is accompanied by seismicity depends on the tectonic setting, interplate or intraplate, the depth of magma accumulation, the previous history and the state of stress. All eruptions during the time of observation had a detectable short-term seismic precursor marking the time of dike propagation toward the surface. The precursor times varied between 15 min and 13 days. In half of the cases the precursor time was <2 h. Three eruptions stand out for their unusually long duration of the immediate seismic precursory activity, Heimaey 1973 with 30 h, Gjálp 1996 with 34 h, and Bárðarbunga 2014 with 13 days. In the case of Heimaey the long time is most likely the consequence of the great depth of the magma source, 15–25 km. The Gjálp eruption had a prelude that was unusual in many respects. The long propagation time may have resulted from a complicated triggering scenario involving more than one magma chamber. The Bárðarbunga eruption at Holuhraun issued from the distal end of a dike that took 13 days to propagate laterally for 48 km before it opened to the surface. Out of the 21 detected precursors 14 were noticed soon enough to lead to a public warning of the coming eruption. In four additional cases the precursory signal was noticed before the eruption was seen. In only three cases was the eruption seen or detected before the seismic precursor was verified. In general, eruptions are preceded by identifyable short-term seismic precursors that, under favorable conditions, may be used for pre-eruption warnings. In some cases, however, ... Article in Journal/Newspaper Heimaey Iceland Directory of Open Access Journals: DOAJ Articles Holuhraun ENVELOPE(-16.831,-16.831,64.852,64.852) Heimaey ENVELOPE(-22.486,-22.486,65.099,65.099) Frontiers in Earth Science 6 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
seismic precursors eruption precursors volcanoes in Iceland pre-eruption warning eruption forecasting precursor time Science Q |
spellingShingle |
seismic precursors eruption precursors volcanoes in Iceland pre-eruption warning eruption forecasting precursor time Science Q Páll Einarsson Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 |
topic_facet |
seismic precursors eruption precursors volcanoes in Iceland pre-eruption warning eruption forecasting precursor time Science Q |
description |
Networks of seismographs of high sensitivity have been in use in the vicinity of active volcanoes in Iceland since 1973. During this time, 21 confirmed eruptions have occurred and several intrusions where magma did not reach the surface. All these events have been accompanied by characteristic seismic activity. Long-term precursory activity is characterized by low-level, persistent seismicity (months-years), clustered around an inflating magma body. Whether or not a magma accumulation is accompanied by seismicity depends on the tectonic setting, interplate or intraplate, the depth of magma accumulation, the previous history and the state of stress. All eruptions during the time of observation had a detectable short-term seismic precursor marking the time of dike propagation toward the surface. The precursor times varied between 15 min and 13 days. In half of the cases the precursor time was <2 h. Three eruptions stand out for their unusually long duration of the immediate seismic precursory activity, Heimaey 1973 with 30 h, Gjálp 1996 with 34 h, and Bárðarbunga 2014 with 13 days. In the case of Heimaey the long time is most likely the consequence of the great depth of the magma source, 15–25 km. The Gjálp eruption had a prelude that was unusual in many respects. The long propagation time may have resulted from a complicated triggering scenario involving more than one magma chamber. The Bárðarbunga eruption at Holuhraun issued from the distal end of a dike that took 13 days to propagate laterally for 48 km before it opened to the surface. Out of the 21 detected precursors 14 were noticed soon enough to lead to a public warning of the coming eruption. In four additional cases the precursory signal was noticed before the eruption was seen. In only three cases was the eruption seen or detected before the seismic precursor was verified. In general, eruptions are preceded by identifyable short-term seismic precursors that, under favorable conditions, may be used for pre-eruption warnings. In some cases, however, ... |
format |
Article in Journal/Newspaper |
author |
Páll Einarsson |
author_facet |
Páll Einarsson |
author_sort |
Páll Einarsson |
title |
Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 |
title_short |
Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 |
title_full |
Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 |
title_fullStr |
Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 |
title_full_unstemmed |
Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 |
title_sort |
short-term seismic precursors to icelandic eruptions 1973–2014 |
publisher |
Frontiers Media S.A. |
publishDate |
2018 |
url |
https://doi.org/10.3389/feart.2018.00045 https://doaj.org/article/3bb61712bf914d9994be95dfb40faec8 |
long_lat |
ENVELOPE(-16.831,-16.831,64.852,64.852) ENVELOPE(-22.486,-22.486,65.099,65.099) |
geographic |
Holuhraun Heimaey |
geographic_facet |
Holuhraun Heimaey |
genre |
Heimaey Iceland |
genre_facet |
Heimaey Iceland |
op_source |
Frontiers in Earth Science, Vol 6 (2018) |
op_relation |
http://journal.frontiersin.org/article/10.3389/feart.2018.00045/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2018.00045 https://doaj.org/article/3bb61712bf914d9994be95dfb40faec8 |
op_doi |
https://doi.org/10.3389/feart.2018.00045 |
container_title |
Frontiers in Earth Science |
container_volume |
6 |
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1766023736307220480 |