Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data
Late Miocene to Recent sediments offshore from the Antarctic Peninsula are predominantly lithogenic, having originated through glacial erosion. Sediments that accumulated during interglacial periods commonly have a greater biogenic component, but deposits in which this constitutes a substantial frac...
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ftawi:oai:epic.awi.de:50269 2023-05-15T13:45:21+02:00 Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data Larter, Robert D. Hillenbrand, Claus-Dieter Graham, Alastair G. C. Hernandez-Molina, F. J. Crowhurst, S. J. Hodell, David A. Channell, James E. T. Xuan, Chuang Allen, Claire Ehrmann, Werner Hogan, Kelly McCave, Ian Nick Rodrigues, Sara Williams, Maricel Gohl, Karsten Uenzelmann-Neben, Gabriele Rebesco, Michele 2019 https://epic.awi.de/id/eprint/50269/ https://hdl.handle.net/10013/epic.71ff53b6-47f8-4802-8d31-3230c766f624 unknown Larter, R. D. , Hillenbrand, C. D. , Graham, A. G. C. , Hernandez-Molina, F. J. , Crowhurst, S. J. , Hodell, D. A. , Channell, J. E. T. , Xuan, C. , Allen, C. , Ehrmann, W. , Hogan, K. , McCave, I. N. , Rodrigues, S. , Williams, M. , Gohl, K. orcid:0000-0002-9558-2116 , Uenzelmann-Neben, G. orcid:0000-0002-0115-5923 and Rebesco, M. (2019) Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data , 34th IAS Meeting of Sedimentology, Rome, 10 September 2019 - 13 September 2019 . hdl:10013/epic.71ff53b6-47f8-4802-8d31-3230c766f624 EPIC334th IAS Meeting of Sedimentology, Rome, 2019-09-10-2019-09-13 Conference notRev 2019 ftawi 2021-12-24T15:44:56Z Late Miocene to Recent sediments offshore from the Antarctic Peninsula are predominantly lithogenic, having originated through glacial erosion. Sediments that accumulated during interglacial periods commonly have a greater biogenic component, but deposits in which this constitutes a substantial fraction are rare. Only a small fraction of the continental block is above sea level and even during interglacial periods temperatures are only warm enough to generate significant melt at low elevations for a few weeks each summer, so sediment input to the sea from surface runoff is minor. Sediment transport to the continental margin takes place mainly at the ice bed during glacial periods when the grounding line advances to the shelf edge. On the Pacific margin, downslope transport from the shelf edge region occurs mainly through gravitational mass transport processes. These processes are likely most active during glacial periods when rapid delivery of glacial sediment leads to instability on the uppermost slope and discharge of sediment-laden subglacial meltwater at the shelf edge grounding line initiates turbidity currents. The lack of obvious large slide scars along most of the relatively steep continental slope suggests that most individual failures are small in volume. Dendritic networks of small channels on the lower slope feed into large turbidity current channels that run out across the continental rise for hundreds of kilometres. Between the channels are giant sediment drifts, some with more than a kilometre of relief, which are composed predominantly of finely-bedded silt and clay layers. The drifts have been produced through entrainment of the fine-grained components of turbidity currents in the ambient bottom current that flows southwestward along the margin. Results from Ocean Drilling Program Leg 178 showed that these drifts contain high-resolution records of ice sheet and oceanographic changes, although unfortunately insufficient core material was recovered to generate continuous composite sections. During a 2015 research cruise on RRS James Clark Ross (JR298) we obtained new data over several of the drifts and channels, including high-resolution multichannel seismic reflection data, piston cores and box cores. We will present results from these new data, interpreting them in terms of sedimentary processes that operated during the development of the giant sediment drifts, and links between depositional systems on the continental rise, palaeo-ice-sheet dynamics and palaeoceanographic processes. Conference Object Antarc* Antarctic Antarctic Peninsula Ice Sheet Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Antarctic Peninsula Pacific The Antarctic |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Late Miocene to Recent sediments offshore from the Antarctic Peninsula are predominantly lithogenic, having originated through glacial erosion. Sediments that accumulated during interglacial periods commonly have a greater biogenic component, but deposits in which this constitutes a substantial fraction are rare. Only a small fraction of the continental block is above sea level and even during interglacial periods temperatures are only warm enough to generate significant melt at low elevations for a few weeks each summer, so sediment input to the sea from surface runoff is minor. Sediment transport to the continental margin takes place mainly at the ice bed during glacial periods when the grounding line advances to the shelf edge. On the Pacific margin, downslope transport from the shelf edge region occurs mainly through gravitational mass transport processes. These processes are likely most active during glacial periods when rapid delivery of glacial sediment leads to instability on the uppermost slope and discharge of sediment-laden subglacial meltwater at the shelf edge grounding line initiates turbidity currents. The lack of obvious large slide scars along most of the relatively steep continental slope suggests that most individual failures are small in volume. Dendritic networks of small channels on the lower slope feed into large turbidity current channels that run out across the continental rise for hundreds of kilometres. Between the channels are giant sediment drifts, some with more than a kilometre of relief, which are composed predominantly of finely-bedded silt and clay layers. The drifts have been produced through entrainment of the fine-grained components of turbidity currents in the ambient bottom current that flows southwestward along the margin. Results from Ocean Drilling Program Leg 178 showed that these drifts contain high-resolution records of ice sheet and oceanographic changes, although unfortunately insufficient core material was recovered to generate continuous composite sections. During a 2015 research cruise on RRS James Clark Ross (JR298) we obtained new data over several of the drifts and channels, including high-resolution multichannel seismic reflection data, piston cores and box cores. We will present results from these new data, interpreting them in terms of sedimentary processes that operated during the development of the giant sediment drifts, and links between depositional systems on the continental rise, palaeo-ice-sheet dynamics and palaeoceanographic processes. |
format |
Conference Object |
author |
Larter, Robert D. Hillenbrand, Claus-Dieter Graham, Alastair G. C. Hernandez-Molina, F. J. Crowhurst, S. J. Hodell, David A. Channell, James E. T. Xuan, Chuang Allen, Claire Ehrmann, Werner Hogan, Kelly McCave, Ian Nick Rodrigues, Sara Williams, Maricel Gohl, Karsten Uenzelmann-Neben, Gabriele Rebesco, Michele |
spellingShingle |
Larter, Robert D. Hillenbrand, Claus-Dieter Graham, Alastair G. C. Hernandez-Molina, F. J. Crowhurst, S. J. Hodell, David A. Channell, James E. T. Xuan, Chuang Allen, Claire Ehrmann, Werner Hogan, Kelly McCave, Ian Nick Rodrigues, Sara Williams, Maricel Gohl, Karsten Uenzelmann-Neben, Gabriele Rebesco, Michele Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data |
author_facet |
Larter, Robert D. Hillenbrand, Claus-Dieter Graham, Alastair G. C. Hernandez-Molina, F. J. Crowhurst, S. J. Hodell, David A. Channell, James E. T. Xuan, Chuang Allen, Claire Ehrmann, Werner Hogan, Kelly McCave, Ian Nick Rodrigues, Sara Williams, Maricel Gohl, Karsten Uenzelmann-Neben, Gabriele Rebesco, Michele |
author_sort |
Larter, Robert D. |
title |
Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data |
title_short |
Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data |
title_full |
Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data |
title_fullStr |
Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data |
title_full_unstemmed |
Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data |
title_sort |
sedimentary processes on the antarctic peninsula pacific margin: new geophysical and sediment core data |
publishDate |
2019 |
url |
https://epic.awi.de/id/eprint/50269/ https://hdl.handle.net/10013/epic.71ff53b6-47f8-4802-8d31-3230c766f624 |
geographic |
Antarctic Antarctic Peninsula Pacific The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Pacific The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Ice Sheet |
op_source |
EPIC334th IAS Meeting of Sedimentology, Rome, 2019-09-10-2019-09-13 |
op_relation |
Larter, R. D. , Hillenbrand, C. D. , Graham, A. G. C. , Hernandez-Molina, F. J. , Crowhurst, S. J. , Hodell, D. A. , Channell, J. E. T. , Xuan, C. , Allen, C. , Ehrmann, W. , Hogan, K. , McCave, I. N. , Rodrigues, S. , Williams, M. , Gohl, K. orcid:0000-0002-9558-2116 , Uenzelmann-Neben, G. orcid:0000-0002-0115-5923 and Rebesco, M. (2019) Sedimentary processes on the Antarctic Peninsula Pacific margin: new geophysical and sediment core data , 34th IAS Meeting of Sedimentology, Rome, 10 September 2019 - 13 September 2019 . hdl:10013/epic.71ff53b6-47f8-4802-8d31-3230c766f624 |
_version_ |
1766221759181225984 |