Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland
Contemporary understanding of the behaviour of surging glaciers and ice streams is hampered by the lack of data on landsystem evolution and sedimentary environments. This study concerns the ice-marginal environment of the surge-type Brúarjökull in Iceland. The sediment distribution in the glacier fo...
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ftulundlup:oai:lup.lub.lu.se:8627a97e-11b9-47d0-ba8d-ec93bd356646 2023-05-15T16:21:39+02:00 Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland Benediktsson, Ivar Möller, Per Ingólfsson, Ólafur van der Meer, Jaap Kjær, Kurt Krüger, Johannes 2008 https://lup.lub.lu.se/record/620324 https://doi.org/10.1016/j.quascirev.2007.10.007 eng eng Elsevier https://lup.lub.lu.se/record/620324 http://dx.doi.org/10.1016/j.quascirev.2007.10.007 wos:000255534600003 scopus:39149113468 Quaternary Science Reviews; 27(3-4), pp 209-234 (2008) ISSN: 0277-3791 Geology contributiontojournal/article info:eu-repo/semantics/article text 2008 ftulundlup https://doi.org/10.1016/j.quascirev.2007.10.007 2023-02-01T23:32:53Z Contemporary understanding of the behaviour of surging glaciers and ice streams is hampered by the lack of data on landsystem evolution and sedimentary environments. This study concerns the ice-marginal environment of the surge-type Brúarjökull in Iceland. The sediment distribution in the glacier forefield as well as the morphology, sedimentology and tectonic architecture of the 1890 end moraine is investigated for highlighting the interaction between very dynamic ice and sediment/landform associations. As a result of substrate/bedrock decoupling during the 1890 surge, subglacial sediment was dislocated across the bedrock surface and deformed compressively, leading to gradual substrate thickening and the formation of a sediment wedge in the marginal zone. A drop in subglacial porewater pressure at the very end of the surge led to substrate/bedrock coupling and a stress transfer up into the sediment sequence causing brittle deformation of the substrate. Simultaneously, the glacier toe ploughed into the topmost part of the marginal sediment wedge initiating the moraine-ridge construction. Fine-grained and incompetent sediment deformed in ductile manner, resulting in a narrow moraine dominated by rooted folds, while coarse-grained and competent sediment deformed in brittle fashion, resulting in a wider moraine dominated by thrust blocks. A new sequential model of subglacial and ice-marginal processes operating during a glacier surge is proposed, illustrating the stepwise formation of a marginal sediment wedge and an end moraine—a twofold, inseparable marginal end-product that formed during the last days of the 1890 surge. Article in Journal/Newspaper glacier Iceland Lund University Publications (LUP) Brúarjökull ENVELOPE(-16.157,-16.157,64.682,64.682) Moraine Ridge ENVELOPE(168.050,168.050,-72.300,-72.300) Quaternary Science Reviews 27 3-4 209 234 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology |
spellingShingle |
Geology Benediktsson, Ivar Möller, Per Ingólfsson, Ólafur van der Meer, Jaap Kjær, Kurt Krüger, Johannes Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland |
topic_facet |
Geology |
description |
Contemporary understanding of the behaviour of surging glaciers and ice streams is hampered by the lack of data on landsystem evolution and sedimentary environments. This study concerns the ice-marginal environment of the surge-type Brúarjökull in Iceland. The sediment distribution in the glacier forefield as well as the morphology, sedimentology and tectonic architecture of the 1890 end moraine is investigated for highlighting the interaction between very dynamic ice and sediment/landform associations. As a result of substrate/bedrock decoupling during the 1890 surge, subglacial sediment was dislocated across the bedrock surface and deformed compressively, leading to gradual substrate thickening and the formation of a sediment wedge in the marginal zone. A drop in subglacial porewater pressure at the very end of the surge led to substrate/bedrock coupling and a stress transfer up into the sediment sequence causing brittle deformation of the substrate. Simultaneously, the glacier toe ploughed into the topmost part of the marginal sediment wedge initiating the moraine-ridge construction. Fine-grained and incompetent sediment deformed in ductile manner, resulting in a narrow moraine dominated by rooted folds, while coarse-grained and competent sediment deformed in brittle fashion, resulting in a wider moraine dominated by thrust blocks. A new sequential model of subglacial and ice-marginal processes operating during a glacier surge is proposed, illustrating the stepwise formation of a marginal sediment wedge and an end moraine—a twofold, inseparable marginal end-product that formed during the last days of the 1890 surge. |
format |
Article in Journal/Newspaper |
author |
Benediktsson, Ivar Möller, Per Ingólfsson, Ólafur van der Meer, Jaap Kjær, Kurt Krüger, Johannes |
author_facet |
Benediktsson, Ivar Möller, Per Ingólfsson, Ólafur van der Meer, Jaap Kjær, Kurt Krüger, Johannes |
author_sort |
Benediktsson, Ivar |
title |
Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland |
title_short |
Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland |
title_full |
Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland |
title_fullStr |
Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland |
title_full_unstemmed |
Instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of Brúarjökull, Iceland |
title_sort |
instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of brúarjökull, iceland |
publisher |
Elsevier |
publishDate |
2008 |
url |
https://lup.lub.lu.se/record/620324 https://doi.org/10.1016/j.quascirev.2007.10.007 |
long_lat |
ENVELOPE(-16.157,-16.157,64.682,64.682) ENVELOPE(168.050,168.050,-72.300,-72.300) |
geographic |
Brúarjökull Moraine Ridge |
geographic_facet |
Brúarjökull Moraine Ridge |
genre |
glacier Iceland |
genre_facet |
glacier Iceland |
op_source |
Quaternary Science Reviews; 27(3-4), pp 209-234 (2008) ISSN: 0277-3791 |
op_relation |
https://lup.lub.lu.se/record/620324 http://dx.doi.org/10.1016/j.quascirev.2007.10.007 wos:000255534600003 scopus:39149113468 |
op_doi |
https://doi.org/10.1016/j.quascirev.2007.10.007 |
container_title |
Quaternary Science Reviews |
container_volume |
27 |
container_issue |
3-4 |
container_start_page |
209 |
op_container_end_page |
234 |
_version_ |
1766009653384183808 |