The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day
The Iceland hotspot has profoundly influenced the creation of oceanic crust throughout the North Atlantic basin. Enigmatically, the geographic extent of the hotspot influence along the Mid-Atlantic Ridge has been asymmetric for most of the spreading history. This asymmetry is evident in crustal thic...
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Online Access: | http://hdl.handle.net/10125/41133 https://doi.org/10.1016/j.epsl.2014.02.020 |
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ftunivhawaiimano:oai:scholarspace.manoa.hawaii.edu:10125/41133 2023-05-15T16:48:02+02:00 The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day Howell, Samuel M. Ito, Garrett Breivik, Asbjørn J. Rai, Abhishek Mjelde, Rolf Hanan, Barry Sayit, Kaan Vogt, Peter 2014-03 11 pages application/pdf http://hdl.handle.net/10125/41133 https://doi.org/10.1016/j.epsl.2014.02.020 en-US eng Elsevier http://www.sciencedirect.com/science/article/pii/S0012821X14000934 doi:10.1016/j.epsl.2014.02.020 http://hdl.handle.net/10125/41133 ©2014 Elsevier B.V. All rights reserved. North Atlantic mantle plumes mid-ocean ridges continental rifting hotspots dehydration Article Text 2014 ftunivhawaiimano https://doi.org/10.1016/j.epsl.2014.02.020 2022-07-17T13:12:41Z The Iceland hotspot has profoundly influenced the creation of oceanic crust throughout the North Atlantic basin. Enigmatically, the geographic extent of the hotspot influence along the Mid-Atlantic Ridge has been asymmetric for most of the spreading history. This asymmetry is evident in crustal thickness along the present-day ridge system and anomalously shallow seafloor of ages ∼49–25 Ma created at the Reykjanes Ridge (RR), SSW of the hotspot center, compared to deeper seafloor created by the now-extinct Aegir Ridge (AR) the same distance NE of the hotspot center. The cause of this asymmetry is explored with 3-D numerical models that simulate a mantle plume interacting with the ridge system using realistic ridge geometries and spreading rates that evolve from continental breakup to present-day. The models predict plume-influence to be symmetric at continental breakup, then to rapidly contract along the ridges, resulting in widely influenced margins next to uninfluenced oceanic crust. After this initial stage, varying degrees of asymmetry along the mature ridge segments are predicted. Models in which the lithosphere is created by the stiffening of the mantle due to the extraction of water near the base of the melting zone predict a moderate amount of asymmetry; the plume expands NE along the AR ∼70–80% as far as it expands SSW along the RR. Without dehydration stiffening, the lithosphere corresponds to the near-surface, cool, thermal boundary layer; in these cases, the plume is predicted to be even more asymmetric, expanding only 40–50% as far along the AR as it does along the RR. Estimates of asymmetry and seismically measured crustal thicknesses are best explained by model predictions of an Iceland plume volume flux of ∼100–200 m^3/s, and a lithosphere controlled by a rheology in which dehydration stiffens the mantle, but to a lesser degree than simulated here. The asymmetry of influence along the present-day ridge system is predicted to be a transient configuration in which plume influence along the Reykjanes ... Article in Journal/Newspaper Iceland North Atlantic ScholarSpace at University of Hawaii at Manoa Aegir Ridge ENVELOPE(-4.125,-4.125,66.167,66.167) Mid-Atlantic Ridge Reykjanes ENVELOPE(-22.250,-22.250,65.467,65.467) Earth and Planetary Science Letters 392 143 153 |
institution |
Open Polar |
collection |
ScholarSpace at University of Hawaii at Manoa |
op_collection_id |
ftunivhawaiimano |
language |
English |
topic |
North Atlantic mantle plumes mid-ocean ridges continental rifting hotspots dehydration |
spellingShingle |
North Atlantic mantle plumes mid-ocean ridges continental rifting hotspots dehydration Howell, Samuel M. Ito, Garrett Breivik, Asbjørn J. Rai, Abhishek Mjelde, Rolf Hanan, Barry Sayit, Kaan Vogt, Peter The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day |
topic_facet |
North Atlantic mantle plumes mid-ocean ridges continental rifting hotspots dehydration |
description |
The Iceland hotspot has profoundly influenced the creation of oceanic crust throughout the North Atlantic basin. Enigmatically, the geographic extent of the hotspot influence along the Mid-Atlantic Ridge has been asymmetric for most of the spreading history. This asymmetry is evident in crustal thickness along the present-day ridge system and anomalously shallow seafloor of ages ∼49–25 Ma created at the Reykjanes Ridge (RR), SSW of the hotspot center, compared to deeper seafloor created by the now-extinct Aegir Ridge (AR) the same distance NE of the hotspot center. The cause of this asymmetry is explored with 3-D numerical models that simulate a mantle plume interacting with the ridge system using realistic ridge geometries and spreading rates that evolve from continental breakup to present-day. The models predict plume-influence to be symmetric at continental breakup, then to rapidly contract along the ridges, resulting in widely influenced margins next to uninfluenced oceanic crust. After this initial stage, varying degrees of asymmetry along the mature ridge segments are predicted. Models in which the lithosphere is created by the stiffening of the mantle due to the extraction of water near the base of the melting zone predict a moderate amount of asymmetry; the plume expands NE along the AR ∼70–80% as far as it expands SSW along the RR. Without dehydration stiffening, the lithosphere corresponds to the near-surface, cool, thermal boundary layer; in these cases, the plume is predicted to be even more asymmetric, expanding only 40–50% as far along the AR as it does along the RR. Estimates of asymmetry and seismically measured crustal thicknesses are best explained by model predictions of an Iceland plume volume flux of ∼100–200 m^3/s, and a lithosphere controlled by a rheology in which dehydration stiffens the mantle, but to a lesser degree than simulated here. The asymmetry of influence along the present-day ridge system is predicted to be a transient configuration in which plume influence along the Reykjanes ... |
format |
Article in Journal/Newspaper |
author |
Howell, Samuel M. Ito, Garrett Breivik, Asbjørn J. Rai, Abhishek Mjelde, Rolf Hanan, Barry Sayit, Kaan Vogt, Peter |
author_facet |
Howell, Samuel M. Ito, Garrett Breivik, Asbjørn J. Rai, Abhishek Mjelde, Rolf Hanan, Barry Sayit, Kaan Vogt, Peter |
author_sort |
Howell, Samuel M. |
title |
The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day |
title_short |
The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day |
title_full |
The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day |
title_fullStr |
The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day |
title_full_unstemmed |
The origin of the asymmetry in the Iceland hotspot along the Mid-Atlantic Ridge from continental breakup to present-day |
title_sort |
origin of the asymmetry in the iceland hotspot along the mid-atlantic ridge from continental breakup to present-day |
publisher |
Elsevier |
publishDate |
2014 |
url |
http://hdl.handle.net/10125/41133 https://doi.org/10.1016/j.epsl.2014.02.020 |
long_lat |
ENVELOPE(-4.125,-4.125,66.167,66.167) ENVELOPE(-22.250,-22.250,65.467,65.467) |
geographic |
Aegir Ridge Mid-Atlantic Ridge Reykjanes |
geographic_facet |
Aegir Ridge Mid-Atlantic Ridge Reykjanes |
genre |
Iceland North Atlantic |
genre_facet |
Iceland North Atlantic |
op_relation |
http://www.sciencedirect.com/science/article/pii/S0012821X14000934 doi:10.1016/j.epsl.2014.02.020 http://hdl.handle.net/10125/41133 |
op_rights |
©2014 Elsevier B.V. All rights reserved. |
op_doi |
https://doi.org/10.1016/j.epsl.2014.02.020 |
container_title |
Earth and Planetary Science Letters |
container_volume |
392 |
container_start_page |
143 |
op_container_end_page |
153 |
_version_ |
1766038120669642752 |