Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland
The Bárðarbunga eruption in Iceland in 2014 and 2015 produced about 1.6 km3 of lava. Magma propagated away from Bárðarbunga to a distance of 48 km in the subsurface beneath Vatnajökull glacier, emerging a few kilometres beyond the glacier's northern rim. A puzzling observation is the lack of sh...
Published in: | Nature Geoscience |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Nature
2017
|
Subjects: | |
Online Access: | http://hdl.handle.net/10197/8740 https://doi.org/10.1038/NGEO2906 |
id |
ftunivcolldublin:oai:researchrepository.ucd.ie:10197/8740 |
---|---|
record_format |
openpolar |
spelling |
ftunivcolldublin:oai:researchrepository.ucd.ie:10197/8740 2023-05-15T16:21:46+02:00 Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland Eibl, Eva P. S. Bean, Christopher J. Vogfjörð, Kristín Ying, Yingzi Lokmer, Ivan Möllhoff, Martin O'Brien, G. S. Pálsson, Finur 2017-08-24T14:50:13Z http://hdl.handle.net/10197/8740 https://doi.org/10.1038/NGEO2906 en eng Nature Nature Geoscience http://hdl.handle.net/10197/8740 10 299 304 doi:10.1038/NGEO2906 Earthquakes Dyke propagation Tremor models Magma flow Journal Article 2017 ftunivcolldublin https://doi.org/10.1038/NGEO2906 2022-04-08T14:19:03Z The Bárðarbunga eruption in Iceland in 2014 and 2015 produced about 1.6 km3 of lava. Magma propagated away from Bárðarbunga to a distance of 48 km in the subsurface beneath Vatnajökull glacier, emerging a few kilometres beyond the glacier's northern rim. A puzzling observation is the lack of shallow (<3 km deep), high-frequency earthquakes associated Q.1 with shallow dyke formation near the subaerial and subglacial eruptive sites, suggesting that near-surface dyke formation is seismically quiet. However, seismic array observations and seismic full wavefield simulations reveal the presence and nature of shallow, pre-eruptive, long-duration seismic tremor activity. Here we use analyses of seismic data to constrain therelationships between seismicity, tremor, dyke propagation and magma flow during the Bárðarbunga eruption. We show that although tremor is usually associated with magma flow in volcanic settings, pre-eruptive tremor at Bárðarbunga was probably caused by swarms of microseismic events during dyke formation, and hence is directly associated with fracturing of the upper 2-3 km of the crust. Subsequent magma flow in the newly formed shallow dyke was seismically silent, with almost a complete absence of seismicity or tremor. Hence, we suggest that the transition from temporarily isolated, large, deep earthquakes to many smaller, shallower, temporally overlapping earthquakes (< magnitude 2) that appear as continuous tremor announces the arrival of a dyke opening in the shallow crust, forming a pathway for silent magma flow to the Earth's surface. European Commission - Seventh Framework Programme (FP7) Geological Survey of Ireland Article in Journal/Newspaper glacier Iceland Vatnajökull University College Dublin: Research Repository UCD Vatnajökull ENVELOPE(-16.823,-16.823,64.420,64.420) Nature Geoscience 10 4 299 304 |
institution |
Open Polar |
collection |
University College Dublin: Research Repository UCD |
op_collection_id |
ftunivcolldublin |
language |
English |
topic |
Earthquakes Dyke propagation Tremor models Magma flow |
spellingShingle |
Earthquakes Dyke propagation Tremor models Magma flow Eibl, Eva P. S. Bean, Christopher J. Vogfjörð, Kristín Ying, Yingzi Lokmer, Ivan Möllhoff, Martin O'Brien, G. S. Pálsson, Finur Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland |
topic_facet |
Earthquakes Dyke propagation Tremor models Magma flow |
description |
The Bárðarbunga eruption in Iceland in 2014 and 2015 produced about 1.6 km3 of lava. Magma propagated away from Bárðarbunga to a distance of 48 km in the subsurface beneath Vatnajökull glacier, emerging a few kilometres beyond the glacier's northern rim. A puzzling observation is the lack of shallow (<3 km deep), high-frequency earthquakes associated Q.1 with shallow dyke formation near the subaerial and subglacial eruptive sites, suggesting that near-surface dyke formation is seismically quiet. However, seismic array observations and seismic full wavefield simulations reveal the presence and nature of shallow, pre-eruptive, long-duration seismic tremor activity. Here we use analyses of seismic data to constrain therelationships between seismicity, tremor, dyke propagation and magma flow during the Bárðarbunga eruption. We show that although tremor is usually associated with magma flow in volcanic settings, pre-eruptive tremor at Bárðarbunga was probably caused by swarms of microseismic events during dyke formation, and hence is directly associated with fracturing of the upper 2-3 km of the crust. Subsequent magma flow in the newly formed shallow dyke was seismically silent, with almost a complete absence of seismicity or tremor. Hence, we suggest that the transition from temporarily isolated, large, deep earthquakes to many smaller, shallower, temporally overlapping earthquakes (< magnitude 2) that appear as continuous tremor announces the arrival of a dyke opening in the shallow crust, forming a pathway for silent magma flow to the Earth's surface. European Commission - Seventh Framework Programme (FP7) Geological Survey of Ireland |
format |
Article in Journal/Newspaper |
author |
Eibl, Eva P. S. Bean, Christopher J. Vogfjörð, Kristín Ying, Yingzi Lokmer, Ivan Möllhoff, Martin O'Brien, G. S. Pálsson, Finur |
author_facet |
Eibl, Eva P. S. Bean, Christopher J. Vogfjörð, Kristín Ying, Yingzi Lokmer, Ivan Möllhoff, Martin O'Brien, G. S. Pálsson, Finur |
author_sort |
Eibl, Eva P. S. |
title |
Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland |
title_short |
Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland |
title_full |
Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland |
title_fullStr |
Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland |
title_full_unstemmed |
Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland |
title_sort |
tremor-rich shallow dyke formation followed by silent magma flow at bárðarbunga in iceland |
publisher |
Nature |
publishDate |
2017 |
url |
http://hdl.handle.net/10197/8740 https://doi.org/10.1038/NGEO2906 |
long_lat |
ENVELOPE(-16.823,-16.823,64.420,64.420) |
geographic |
Vatnajökull |
geographic_facet |
Vatnajökull |
genre |
glacier Iceland Vatnajökull |
genre_facet |
glacier Iceland Vatnajökull |
op_relation |
Nature Geoscience http://hdl.handle.net/10197/8740 10 299 304 doi:10.1038/NGEO2906 |
op_doi |
https://doi.org/10.1038/NGEO2906 |
container_title |
Nature Geoscience |
container_volume |
10 |
container_issue |
4 |
container_start_page |
299 |
op_container_end_page |
304 |
_version_ |
1766009748869611520 |