Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile
The crustal structure of central Iceland is modelled using data from a 310 km long refraction profile shot during summer 1995. The profile traversed Iceland from the Skagi Peninsula on the north coast (surface rocks of age 8.5–0.8 Myr) to the southeast coast (surface rocks of age 8.5–3.3 Myr), cross...
Published in: | Geophysical Journal International |
---|---|
Main Authors: | , , , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
1998
|
Subjects: | |
Online Access: | http://gji.oxfordjournals.org/cgi/content/short/135/3/1131 https://doi.org/10.1046/j.1365-246X.1998.00701.x |
id |
fthighwire:oai:open-archive.highwire.org:gji:135/3/1131 |
---|---|
record_format |
openpolar |
spelling |
fthighwire:oai:open-archive.highwire.org:gji:135/3/1131 2023-05-15T16:21:40+02:00 Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile Darbyshire, Fiona A. Bjarnason, Ingi Th. White, Robert S. Flóvenz, Ólafur G. 1998-12-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/135/3/1131 https://doi.org/10.1046/j.1365-246X.1998.00701.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/135/3/1131 http://dx.doi.org/10.1046/j.1365-246X.1998.00701.x Copyright (C) 1998, Oxford University Press Articles TEXT 1998 fthighwire https://doi.org/10.1046/j.1365-246X.1998.00701.x 2015-02-28T22:00:50Z The crustal structure of central Iceland is modelled using data from a 310 km long refraction profile shot during summer 1995. The profile traversed Iceland from the Skagi Peninsula on the north coast (surface rocks of age 8.5–0.8 Myr) to the southeast coast (surface rocks of age 8.5–3.3 Myr), crossing central Iceland (surface rocks of age 3.3–0 Myr) over the glacier Vatnajökull, below which the locus of the Iceland mantle plume is currently centred. The crustal thickness is 25 km at the north end of the profile, increasing to 38–40 km beneath southern central Iceland. The upper crust is characterized by seismic P -wave velocities from 3.2 to approximately 6.4 km s−1. At the extreme ends of the profile, the upper crust can be modelled by a two-layered structure, within which seismic velocity increases with depth, with a total thickness of 5–6 km. The central highlands of Iceland have a single unit of upper crust, with seismic velocity increasing continuously with depth to almost 10 km below the surface. Below the central volcanoes of northern Vatnajökull, the upper crust is only 3 km thick. The lower-crustal velocity structure is determined from rays that turn at a maximum depth of 24 km below central Iceland, where the seismic velocity is 7.2 km s−1. Below 24 km depth there are no first-arriving turning rays. The Moho is defined by P -and S -wave reflections observed from the shots at the extreme ends of the profile. P - to S -wave velocity ratios give a Poisson's:of 0.26 in the upper crust and 0.27 in the lower crust, indicating that, even directly above the centre of the mantle plume, the crust is well below the solidus temperature. Text glacier Iceland Vatnajökull HighWire Press (Stanford University) Vatnajökull ENVELOPE(-16.823,-16.823,64.420,64.420) Geophysical Journal International 135 3 1131 1149 |
institution |
Open Polar |
collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Articles |
spellingShingle |
Articles Darbyshire, Fiona A. Bjarnason, Ingi Th. White, Robert S. Flóvenz, Ólafur G. Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile |
topic_facet |
Articles |
description |
The crustal structure of central Iceland is modelled using data from a 310 km long refraction profile shot during summer 1995. The profile traversed Iceland from the Skagi Peninsula on the north coast (surface rocks of age 8.5–0.8 Myr) to the southeast coast (surface rocks of age 8.5–3.3 Myr), crossing central Iceland (surface rocks of age 3.3–0 Myr) over the glacier Vatnajökull, below which the locus of the Iceland mantle plume is currently centred. The crustal thickness is 25 km at the north end of the profile, increasing to 38–40 km beneath southern central Iceland. The upper crust is characterized by seismic P -wave velocities from 3.2 to approximately 6.4 km s−1. At the extreme ends of the profile, the upper crust can be modelled by a two-layered structure, within which seismic velocity increases with depth, with a total thickness of 5–6 km. The central highlands of Iceland have a single unit of upper crust, with seismic velocity increasing continuously with depth to almost 10 km below the surface. Below the central volcanoes of northern Vatnajökull, the upper crust is only 3 km thick. The lower-crustal velocity structure is determined from rays that turn at a maximum depth of 24 km below central Iceland, where the seismic velocity is 7.2 km s−1. Below 24 km depth there are no first-arriving turning rays. The Moho is defined by P -and S -wave reflections observed from the shots at the extreme ends of the profile. P - to S -wave velocity ratios give a Poisson's:of 0.26 in the upper crust and 0.27 in the lower crust, indicating that, even directly above the centre of the mantle plume, the crust is well below the solidus temperature. |
format |
Text |
author |
Darbyshire, Fiona A. Bjarnason, Ingi Th. White, Robert S. Flóvenz, Ólafur G. |
author_facet |
Darbyshire, Fiona A. Bjarnason, Ingi Th. White, Robert S. Flóvenz, Ólafur G. |
author_sort |
Darbyshire, Fiona A. |
title |
Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile |
title_short |
Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile |
title_full |
Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile |
title_fullStr |
Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile |
title_full_unstemmed |
Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile |
title_sort |
crustal structure above the iceland mantle plume imaged by the icemelt refraction profile |
publisher |
Oxford University Press |
publishDate |
1998 |
url |
http://gji.oxfordjournals.org/cgi/content/short/135/3/1131 https://doi.org/10.1046/j.1365-246X.1998.00701.x |
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 |
http://gji.oxfordjournals.org/cgi/content/short/135/3/1131 http://dx.doi.org/10.1046/j.1365-246X.1998.00701.x |
op_rights |
Copyright (C) 1998, Oxford University Press |
op_doi |
https://doi.org/10.1046/j.1365-246X.1998.00701.x |
container_title |
Geophysical Journal International |
container_volume |
135 |
container_issue |
3 |
container_start_page |
1131 |
op_container_end_page |
1149 |
_version_ |
1766009659746942976 |