Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland
Icebergs are important as agents of deposition and seafloor reworking on glacier-influenced continental margins. When the keel of an iceberg exceeds water depth it ploughs through soft sediments producing scours/ploughmarks that can be kilometres long, hundreds of metres wide and sometimes tens of m...
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Online Access: | https://www.repository.cam.ac.uk/handle/1810/261526 https://doi.org/10.17863/CAM.6722 |
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ftunivcam:oai:www.repository.cam.ac.uk:1810/261526 2024-02-04T10:00:04+01:00 Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland Linch, LD Dowdeswell, JA 2016-11-15 application/pdf https://www.repository.cam.ac.uk/handle/1810/261526 https://doi.org/10.17863/CAM.6722 eng eng Elsevier http://dx.doi.org/10.1016/j.quascirev.2016.09.013 Quaternary Science Reviews https://www.repository.cam.ac.uk/handle/1810/261526 doi:10.17863/CAM.6722 Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ iceberg scours ploughmarks gouges micromorphology diamicton ice-rafted debris (IRD) Scoresby sund East Greenland Article 2016 ftunivcam https://doi.org/10.17863/CAM.6722 2024-01-11T23:31:51Z Icebergs are important as agents of deposition and seafloor reworking on glacier-influenced continental margins. When the keel of an iceberg exceeds water depth it ploughs through soft sediments producing scours/ploughmarks that can be kilometres long, hundreds of metres wide and sometimes tens of metres deep. Because the influence of iceberg keels on sediment is a critical factor when offshore structures (e.g. pipelines, power cables) are installed, the surface morphology of iceberg scours on the seafloor is relatively well-documented. Less however, is known about sub-scour deformation below the seafloor. This is particularly true of iceberg scoured diamicton (poorly sorted sediment comprising a variety of particle sizes), which is present in many high-latitude fjords and continental shelves. The aim of this research is to examine directly (macroscopically and microscopically, with thin sections) the style and intensity of deformation caused by the scouring action of iceberg keels in diamicton offshore of East Greenland. Results show that a distinctive suite of deformation structures (individual structures and overprinted structural patterns) dominated by planar shear, sediment mixing and high porewater, and dropstones characterises iceberg scoured diamicton. In addition, diamicton from areas of high-intensity iceberg scouring tends to show a wider variety, higher frequency and distribution, more abundant and better-developed deformation structures than diamicton from areas of intermediate- and low-intensity iceberg scouring. Characterising the effects of iceberg scour in diamicton is important more widely to inform: i) reconstruction of the geometry and dynamics of former ice sheets; and ii) installation and protection of offshore engineering structures in diamicton where iceberg scouring presents a geohazard. The value of micromorphology is significant especially in the absence of macroscopic sediment exposures/outcrops where the study of cores is necessary instead. This research was primarily funded by the ... Article in Journal/Newspaper East Greenland glacier Greenland Scoresby Sund Apollo - University of Cambridge Repository Greenland Sund ENVELOPE(13.644,13.644,66.207,66.207) Scoresby ENVELOPE(162.750,162.750,-66.567,-66.567) Scoresby Sund ENVELOPE(-24.387,-24.387,70.476,70.476) |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
iceberg scours ploughmarks gouges micromorphology diamicton ice-rafted debris (IRD) Scoresby sund East Greenland |
spellingShingle |
iceberg scours ploughmarks gouges micromorphology diamicton ice-rafted debris (IRD) Scoresby sund East Greenland Linch, LD Dowdeswell, JA Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland |
topic_facet |
iceberg scours ploughmarks gouges micromorphology diamicton ice-rafted debris (IRD) Scoresby sund East Greenland |
description |
Icebergs are important as agents of deposition and seafloor reworking on glacier-influenced continental margins. When the keel of an iceberg exceeds water depth it ploughs through soft sediments producing scours/ploughmarks that can be kilometres long, hundreds of metres wide and sometimes tens of metres deep. Because the influence of iceberg keels on sediment is a critical factor when offshore structures (e.g. pipelines, power cables) are installed, the surface morphology of iceberg scours on the seafloor is relatively well-documented. Less however, is known about sub-scour deformation below the seafloor. This is particularly true of iceberg scoured diamicton (poorly sorted sediment comprising a variety of particle sizes), which is present in many high-latitude fjords and continental shelves. The aim of this research is to examine directly (macroscopically and microscopically, with thin sections) the style and intensity of deformation caused by the scouring action of iceberg keels in diamicton offshore of East Greenland. Results show that a distinctive suite of deformation structures (individual structures and overprinted structural patterns) dominated by planar shear, sediment mixing and high porewater, and dropstones characterises iceberg scoured diamicton. In addition, diamicton from areas of high-intensity iceberg scouring tends to show a wider variety, higher frequency and distribution, more abundant and better-developed deformation structures than diamicton from areas of intermediate- and low-intensity iceberg scouring. Characterising the effects of iceberg scour in diamicton is important more widely to inform: i) reconstruction of the geometry and dynamics of former ice sheets; and ii) installation and protection of offshore engineering structures in diamicton where iceberg scouring presents a geohazard. The value of micromorphology is significant especially in the absence of macroscopic sediment exposures/outcrops where the study of cores is necessary instead. This research was primarily funded by the ... |
format |
Article in Journal/Newspaper |
author |
Linch, LD Dowdeswell, JA |
author_facet |
Linch, LD Dowdeswell, JA |
author_sort |
Linch, LD |
title |
Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland |
title_short |
Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland |
title_full |
Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland |
title_fullStr |
Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland |
title_full_unstemmed |
Micromorphology of diamicton affected by iceberg-keel scouring, Scoresby Sund, East Greenland |
title_sort |
micromorphology of diamicton affected by iceberg-keel scouring, scoresby sund, east greenland |
publisher |
Elsevier |
publishDate |
2016 |
url |
https://www.repository.cam.ac.uk/handle/1810/261526 https://doi.org/10.17863/CAM.6722 |
long_lat |
ENVELOPE(13.644,13.644,66.207,66.207) ENVELOPE(162.750,162.750,-66.567,-66.567) ENVELOPE(-24.387,-24.387,70.476,70.476) |
geographic |
Greenland Sund Scoresby Scoresby Sund |
geographic_facet |
Greenland Sund Scoresby Scoresby Sund |
genre |
East Greenland glacier Greenland Scoresby Sund |
genre_facet |
East Greenland glacier Greenland Scoresby Sund |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/261526 doi:10.17863/CAM.6722 |
op_rights |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.17863/CAM.6722 |
_version_ |
1789965181879582720 |