Show simple item record

dc.contributor.authorWoods, Jenniferen
dc.contributor.authorDonaldson, Clareen
dc.contributor.authorWhite, Roberten
dc.contributor.authorCaudron, Cen
dc.contributor.authorBrandsdóttir, Ben
dc.contributor.authorHudson, Thomasen
dc.contributor.authorÁgústsdóttir, Ten
dc.date.accessioned2018-05-31T12:13:46Z
dc.date.available2018-05-31T12:13:46Z
dc.date.issued2018-05-15en
dc.identifier.issn0012-821X
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/276391
dc.description.abstractThe 2014-15 Bárðarbunga-Holuhraun rifting event comprised the best-monitored dyke intrusion to date and the largest eruption in Iceland in 230 years. A huge variety of seismicity was produced, including over 30,000 volcano-tectonic earthquakes (VTs) associated with the dyke propagation at ∼ 6 km depth below sea level, and large-magnitude earthquakes accompanying the collapse of Bárðarbunga caldera. We here study the long-period seismicity associated with the rifting event. We systematically detect and locate both long-period events (LPs) and tremor during the dyke propagation phase and the first week of the eruption. We identify clusters of highly similar, repetitive LPs, which have a peak frequency of ∼ 1 Hz and clear P and S phases followed by a long-duration coda. The source mechanisms are remarkably consistent between clusters and also fundamentally different to those of the VTs. We accurately locate LP clusters near each of three ice cauldrons (depressions formed by basal melting) that were observed on the surface of Dyngjujökull glacier above the path of the dyke. Most events are in the vicinity of the northernmost cauldron, at shallower depth than the VTs associated with lateral dyke propagation. At the two northerly cauldrons, periods of shallow seismic tremor following the clusters of LPs are also observed. Given that the LPs occur at ∼ 4 km depth and in swarms during times of dyke-stalling, we infer that they result from excitation of magmatic fluid-filled cavities and indicate magma ascent. We suggest that the tremor is the climax of the vertical melt movement, arising from either rapid, repeated excitation of the same LP cavities, or sub-glacial eruption processes. This long-period seismicity therefore represents magma pathways between the depth of the dyke-VT earthquakes and the surface. Notably, we do not detect tremor associated with each cauldron, despite melt reaching the base of the overlying ice cap, a concern for hazard forecasting.
dc.publisherElsevier
dc.rightsAttribution 4.0 International*
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/*
dc.titleLong-period seismicity reveals magma pathways above a laterally propagating dyke during the 2014–15 Bárðarbunga rifting event, Icelanden
dc.typeArticle
prism.endingPage229
prism.publicationDate2018en
prism.publicationNameEarth and Planetary Science Lettersen
prism.startingPage216
prism.volume490en
dc.identifier.doi10.17863/CAM.23695
dcterms.dateAccepted2018-03-12en
rioxxterms.versionofrecord10.1016/j.epsl.2018.03.020en
rioxxterms.versionVoR*
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserveden
rioxxterms.licenseref.startdate2018-05-15en
dc.contributor.orcidWoods, Jennifer [0000-0003-2954-9323]
dc.contributor.orcidDonaldson, Clare [0000-0003-4181-0555]
dc.contributor.orcidWhite, Robert [0000-0002-2972-397X]
dc.contributor.orcidCaudron, C [0000-0002-3748-0007]
dc.contributor.orcidHudson, Thomas [0000-0003-2944-883X]
dc.contributor.orcidÁgústsdóttir, T [0000-0001-5406-0971]
dc.identifier.eissn1385-013X
rioxxterms.typeJournal Article/Reviewen
pubs.funder-project-idNERC (1508772)
pubs.funder-project-idNERC (NE/F011407/1)
pubs.funder-project-idNERC (NE/H025006/1)
pubs.funder-project-idNERC (NE/M017427/1)
pubs.funder-project-idNERC (NE/L002507/1)
pubs.funder-project-idEC FP7 CP (308377)
cam.orpheus.successThu Jan 30 13:04:25 GMT 2020 - The item has an open VoR version.*
rioxxterms.freetoread.startdate2100-01-01


Files in this item

Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record

Attribution 4.0 International
Except where otherwise noted, this item's licence is described as Attribution 4.0 International