Marine geophysical evidence for ice sheet extension and recession on the Malin and Northwest Irish shelves: New evidence for the western limits of the British Irish Ice Sheet: Quaternary International 279-280 (2012) 121–232

Research output: Contribution to conferenceAbstract

Abstract

Multibeam swath bathymetry data collected by the Irish National SeabedSurvey provides evidence for extensive glaciation of the Malin Shelf, north of Ireland and on the shelf northwest of County Donegal. Streamlined subglacial bedforms on the mid to outer shelf record former offshore-directed ice flow and indicate the ice sheet was grounded in a zone of confluence between ice flowing onto the shelf from northwest Ireland and southwest Scotland. The major glacial features, however, consist of well developed arcuate moraines which mark the position of former ice sheet margins on various parts of the shelf. Distal to these moraines, on the outermost shelf, prominent zones of iceberg plough marks give way to the Barra/Donegal fan and a well developed system of gullies and canyons which incise the continental slope. The moraines record the episodic retreat of lobate grounded ice sheets across this sector of the continental shelf during deglaciation. Initial retreat from the outer shelf was associated with an episode of ice sheet breakup and calving as recorded by extensive zones of iceberg plough marks distal to the outermost moraines. This initial phase of retreat may have been driven by rising sea level. The data indicate a major reorganisation of the British Irish Ice Sheet on the shelf during deglaciation; an initial elongate ice sheet configuration extending along the shelf edge changed to a pronounced lobate form during retreat.Consideration of dated, marine stratigraphic records from the wider northwest margin suggests that ice sheet advance to the shelf edge likely occurred at about 29–27 cal ka BP, but that retreat from this shelf edge position did not take place until after 24 cal ka BP. Large-scale contrasts in continental margin morphology west of Ireland, from trough mouth fans in the north to gully/canyon systems further to south, reflects a combination of factors including spatial variations in sediment flux related to palaeo-glaciology
LanguageEnglish
Pages279-280
Number of pages2
DOIs
Publication statusPublished - 21 Jul 2011
EventXVIII INQUA Congress. - Bern, Switzerland
Duration: 23 Jul 2011 → …

Conference

ConferenceXVIII INQUA Congress.
Period23/07/11 → …

Fingerprint

ice sheet
shelf break
iceberg
gully
deglaciation
canyon
glacial feature
swath bathymetry
glaciology
marine record
ice flow
bedform
geological record
confluence
continental slope
glaciation
continental margin
continental shelf
trough
spatial variation

Keywords

  • British Irish Ice Sheet
  • Malin Shelf
  • marine geophysics

Cite this

@conference{7ce13f85615740c4ae5fa28fdd2239dd,
title = "Marine geophysical evidence for ice sheet extension and recession on the Malin and Northwest Irish shelves: New evidence for the western limits of the British Irish Ice Sheet: Quaternary International 279-280 (2012) 121–232",
abstract = "Multibeam swath bathymetry data collected by the Irish National SeabedSurvey provides evidence for extensive glaciation of the Malin Shelf, north of Ireland and on the shelf northwest of County Donegal. Streamlined subglacial bedforms on the mid to outer shelf record former offshore-directed ice flow and indicate the ice sheet was grounded in a zone of confluence between ice flowing onto the shelf from northwest Ireland and southwest Scotland. The major glacial features, however, consist of well developed arcuate moraines which mark the position of former ice sheet margins on various parts of the shelf. Distal to these moraines, on the outermost shelf, prominent zones of iceberg plough marks give way to the Barra/Donegal fan and a well developed system of gullies and canyons which incise the continental slope. The moraines record the episodic retreat of lobate grounded ice sheets across this sector of the continental shelf during deglaciation. Initial retreat from the outer shelf was associated with an episode of ice sheet breakup and calving as recorded by extensive zones of iceberg plough marks distal to the outermost moraines. This initial phase of retreat may have been driven by rising sea level. The data indicate a major reorganisation of the British Irish Ice Sheet on the shelf during deglaciation; an initial elongate ice sheet configuration extending along the shelf edge changed to a pronounced lobate form during retreat.Consideration of dated, marine stratigraphic records from the wider northwest margin suggests that ice sheet advance to the shelf edge likely occurred at about 29–27 cal ka BP, but that retreat from this shelf edge position did not take place until after 24 cal ka BP. Large-scale contrasts in continental margin morphology west of Ireland, from trough mouth fans in the north to gully/canyon systems further to south, reflects a combination of factors including spatial variations in sediment flux related to palaeo-glaciology",
keywords = "British Irish Ice Sheet, Malin Shelf, marine geophysics",
author = "P Dunlop",
year = "2011",
month = "7",
day = "21",
doi = "https://doi.org/10.1016/j.quaint.2012.08.028",
language = "English",
pages = "279--280",
note = "XVIII INQUA Congress. ; Conference date: 23-07-2011",

}

TY - CONF

T1 - Marine geophysical evidence for ice sheet extension and recession on the Malin and Northwest Irish shelves: New evidence for the western limits of the British Irish Ice Sheet

T2 - Quaternary International 279-280 (2012) 121–232

AU - Dunlop, P

PY - 2011/7/21

Y1 - 2011/7/21

N2 - Multibeam swath bathymetry data collected by the Irish National SeabedSurvey provides evidence for extensive glaciation of the Malin Shelf, north of Ireland and on the shelf northwest of County Donegal. Streamlined subglacial bedforms on the mid to outer shelf record former offshore-directed ice flow and indicate the ice sheet was grounded in a zone of confluence between ice flowing onto the shelf from northwest Ireland and southwest Scotland. The major glacial features, however, consist of well developed arcuate moraines which mark the position of former ice sheet margins on various parts of the shelf. Distal to these moraines, on the outermost shelf, prominent zones of iceberg plough marks give way to the Barra/Donegal fan and a well developed system of gullies and canyons which incise the continental slope. The moraines record the episodic retreat of lobate grounded ice sheets across this sector of the continental shelf during deglaciation. Initial retreat from the outer shelf was associated with an episode of ice sheet breakup and calving as recorded by extensive zones of iceberg plough marks distal to the outermost moraines. This initial phase of retreat may have been driven by rising sea level. The data indicate a major reorganisation of the British Irish Ice Sheet on the shelf during deglaciation; an initial elongate ice sheet configuration extending along the shelf edge changed to a pronounced lobate form during retreat.Consideration of dated, marine stratigraphic records from the wider northwest margin suggests that ice sheet advance to the shelf edge likely occurred at about 29–27 cal ka BP, but that retreat from this shelf edge position did not take place until after 24 cal ka BP. Large-scale contrasts in continental margin morphology west of Ireland, from trough mouth fans in the north to gully/canyon systems further to south, reflects a combination of factors including spatial variations in sediment flux related to palaeo-glaciology

AB - Multibeam swath bathymetry data collected by the Irish National SeabedSurvey provides evidence for extensive glaciation of the Malin Shelf, north of Ireland and on the shelf northwest of County Donegal. Streamlined subglacial bedforms on the mid to outer shelf record former offshore-directed ice flow and indicate the ice sheet was grounded in a zone of confluence between ice flowing onto the shelf from northwest Ireland and southwest Scotland. The major glacial features, however, consist of well developed arcuate moraines which mark the position of former ice sheet margins on various parts of the shelf. Distal to these moraines, on the outermost shelf, prominent zones of iceberg plough marks give way to the Barra/Donegal fan and a well developed system of gullies and canyons which incise the continental slope. The moraines record the episodic retreat of lobate grounded ice sheets across this sector of the continental shelf during deglaciation. Initial retreat from the outer shelf was associated with an episode of ice sheet breakup and calving as recorded by extensive zones of iceberg plough marks distal to the outermost moraines. This initial phase of retreat may have been driven by rising sea level. The data indicate a major reorganisation of the British Irish Ice Sheet on the shelf during deglaciation; an initial elongate ice sheet configuration extending along the shelf edge changed to a pronounced lobate form during retreat.Consideration of dated, marine stratigraphic records from the wider northwest margin suggests that ice sheet advance to the shelf edge likely occurred at about 29–27 cal ka BP, but that retreat from this shelf edge position did not take place until after 24 cal ka BP. Large-scale contrasts in continental margin morphology west of Ireland, from trough mouth fans in the north to gully/canyon systems further to south, reflects a combination of factors including spatial variations in sediment flux related to palaeo-glaciology

KW - British Irish Ice Sheet

KW - Malin Shelf

KW - marine geophysics

U2 - https://doi.org/10.1016/j.quaint.2012.08.028

DO - https://doi.org/10.1016/j.quaint.2012.08.028

M3 - Abstract

SP - 279

EP - 280

ER -