dc.contributor |
Háskóli Íslands |
dc.contributor |
University of Iceland |
dc.contributor.author |
Einarsson, Páll |
dc.date.accessioned |
2020-01-31T14:00:06Z |
dc.date.available |
2020-01-31T14:00:06Z |
dc.date.issued |
2018-05-08 |
dc.identifier.citation |
Einarsson P (2018) Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014. Front. Earth Sci. 6:45. doi: 10.3389/feart.2018.00045 |
dc.identifier.issn |
2296-6463 |
dc.identifier.uri |
https://hdl.handle.net/20.500.11815/1494 |
dc.description |
Publisher's version (útgefin grein). |
dc.description.abstract |
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 15min and 13 days. In half of the cases the precursor time was <2h. Three eruptions stand out for their unusually long duration of the immediate seismic precursory activity, Heimaey 1973 with 30h, Gjálp 1996 with 34h, 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, 15–25km. The Gjálp eruption had a prelude that was unusual in many respects. The long propagation time may have resulted froma 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 48kmbefore 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, the time may be too short to be useful. The Hekla volcano stands out for its short precursory times. |
dc.description.sponsorship |
This study is the result of more than four decades of work on the seismicity of volcanoes and monitoring their activity. Funding for different aspects of the work has come from various sources, mostly the Icelandic government budget through the Science Institute, University of Iceland.
This paper is a compilation of the work of many individuals involved with the monitoring of the Icelandic volcanoes and operation of the seismograph networks. The seismograms of Figures 3–5 are from the stations at Reynihlíð, Skinnastaður, and Akureyri, stations attendants were Ármann Pétursson, Sigurvin Elíasson, and Gísli Ólafsson, respectively. Ásta Rut Hjartardóttir made Figure 1. The paper benefitted from the constructive comments by two reviewers and the editors. |
dc.format.extent |
45 |
dc.language.iso |
en |
dc.publisher |
Frontiers Media SA |
dc.relation.ispartofseries |
Frontiers in Earth Science;6 |
dc.rights |
info:eu-repo/semantics/openAccess |
dc.subject |
Eruption forecasting |
dc.subject |
Eruption precursors |
dc.subject |
Pre-eruption warning |
dc.subject |
Precursor time |
dc.subject |
Seismic precursors |
dc.subject |
Volcanoes in Iceland |
dc.subject |
Eldfjöll |
dc.subject |
Eldgos |
dc.subject |
Jarðskjálftar |
dc.subject |
Jarðskjálftaspár |
dc.title |
Short-Term Seismic Precursors to Icelandic Eruptions 1973–2014 |
dc.type |
info:eu-repo/semantics/article |
dcterms.license |
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
dc.description.version |
Peer Reviewed |
dc.identifier.journal |
Frontiers in Earth Science |
dc.identifier.doi |
10.3389/feart.2018.00045 |
dc.relation.url |
http://journal.frontiersin.org/article/10.3389/feart.2018.00045/full |
dc.contributor.department |
Jarðvísindastofnun (HÍ) |
dc.contributor.department |
Institute of Earth Sciences (UI) |
dc.contributor.school |
Verkfræði- og náttúruvísindasvið (HÍ) |
dc.contributor.school |
School of Engineering and Natural Sciences (UI) |