Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords
Fjords act as palaeoenvironmental archives, recording past glacial histories in remarkably thick sediment accumulations. Furthermore, high primary productivity combined with rapid burial make fjords important organic carbon sinks. Reconstructing recent rates of sediment accumulation provides context...
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2023
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ftunivexeter:oai:ore.exeter.ac.uk:10871/133679 2023-08-27T04:04:10+02:00 Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords Mason, M Scourse, James Kender, Sev 2023 http://hdl.handle.net/10871/133679 unknown University of Exeter Department of Earth and Environmental Science http://hdl.handle.net/10871/133679 2024-08-01 Under embargo until 1/8/24 as currently writing up for publication and supervisor has advised an embargo until it has been published. http://www.rioxx.net/licenses/all-rights-reserved Thesis or dissertation MSc by Research in Physical Geography Masters MbyRes Dissertation 2023 ftunivexeter 2023-08-03T23:05:24Z Fjords act as palaeoenvironmental archives, recording past glacial histories in remarkably thick sediment accumulations. Furthermore, high primary productivity combined with rapid burial make fjords important organic carbon sinks. Reconstructing recent rates of sediment accumulation provides context for assessing past and future changes, and, in combination with measurements of carbon content, can inform on carbon sequestration potential. Recent research has indicated that fjords may represent areas of high carbon burial. However, these estimates are based on surface sediment carbon stocks combined with global averages of carbon preservation, without consideration of regional variability in burial efficiencies. Here, seven sediment cores from three fjords on the Antarctic Peninsula are analysed. 210Pb, a radio-isotope with a half-life of 22 years, is used to construct age-depth models and estimate rates of sediment mass accumulation. These data are then combined with measurements of core carbon content to estimate rates of modern carbon deposition and long-term carbon burial. Core-averaged sediment mass accumulation rates ranged from 0.08 to 0.42 g cm-2 yr-1. No long-term trends in accumulation rates were observed at any of the sites over the past century, though in Börgen Bay synchronous peaks in sedimentation rates were observed at similar ages across different sediment cores. At Marian Cove, South Shetland Islands, the typical proximal-distal gradient in accumulation rates was absent, suggesting a diverse source of sediments, most notably the input from pro-glacial meltwater streams from land-terminating ice. Surface deposition rates of organic carbon ranged from 3 to 26 g C m-2 yr-1. However, whilst surface sediment organic carbon flux was high, burial efficiencies were found to be significantly lower than those previously reported for other sites on the continental shelf, resulting in similar rates of long-term storage. This has important implications for our understanding of the carbon sequestration ... Master Thesis Antarc* Antarctic Antarctic Peninsula South Shetland Islands University of Exeter: Open Research Exeter (ORE) Antarctic Antarctic Peninsula Börgen ENVELOPE(-63.468,-63.468,-64.741,-64.741) Börgen Bay ENVELOPE(-63.468,-63.468,-64.741,-64.741) Marian ENVELOPE(-58.750,-58.750,-62.217,-62.217) Marian Cove ENVELOPE(-58.800,-58.800,-62.217,-62.217) South Shetland Islands The Antarctic |
institution |
Open Polar |
collection |
University of Exeter: Open Research Exeter (ORE) |
op_collection_id |
ftunivexeter |
language |
unknown |
description |
Fjords act as palaeoenvironmental archives, recording past glacial histories in remarkably thick sediment accumulations. Furthermore, high primary productivity combined with rapid burial make fjords important organic carbon sinks. Reconstructing recent rates of sediment accumulation provides context for assessing past and future changes, and, in combination with measurements of carbon content, can inform on carbon sequestration potential. Recent research has indicated that fjords may represent areas of high carbon burial. However, these estimates are based on surface sediment carbon stocks combined with global averages of carbon preservation, without consideration of regional variability in burial efficiencies. Here, seven sediment cores from three fjords on the Antarctic Peninsula are analysed. 210Pb, a radio-isotope with a half-life of 22 years, is used to construct age-depth models and estimate rates of sediment mass accumulation. These data are then combined with measurements of core carbon content to estimate rates of modern carbon deposition and long-term carbon burial. Core-averaged sediment mass accumulation rates ranged from 0.08 to 0.42 g cm-2 yr-1. No long-term trends in accumulation rates were observed at any of the sites over the past century, though in Börgen Bay synchronous peaks in sedimentation rates were observed at similar ages across different sediment cores. At Marian Cove, South Shetland Islands, the typical proximal-distal gradient in accumulation rates was absent, suggesting a diverse source of sediments, most notably the input from pro-glacial meltwater streams from land-terminating ice. Surface deposition rates of organic carbon ranged from 3 to 26 g C m-2 yr-1. However, whilst surface sediment organic carbon flux was high, burial efficiencies were found to be significantly lower than those previously reported for other sites on the continental shelf, resulting in similar rates of long-term storage. This has important implications for our understanding of the carbon sequestration ... |
author2 |
Scourse, James Kender, Sev |
format |
Master Thesis |
author |
Mason, M |
spellingShingle |
Mason, M Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords |
author_facet |
Mason, M |
author_sort |
Mason, M |
title |
Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords |
title_short |
Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords |
title_full |
Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords |
title_fullStr |
Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords |
title_full_unstemmed |
Sediment accumulation rates and carbon burial in West Antarctic Peninsula fjords |
title_sort |
sediment accumulation rates and carbon burial in west antarctic peninsula fjords |
publisher |
University of Exeter |
publishDate |
2023 |
url |
http://hdl.handle.net/10871/133679 |
long_lat |
ENVELOPE(-63.468,-63.468,-64.741,-64.741) ENVELOPE(-63.468,-63.468,-64.741,-64.741) ENVELOPE(-58.750,-58.750,-62.217,-62.217) ENVELOPE(-58.800,-58.800,-62.217,-62.217) |
geographic |
Antarctic Antarctic Peninsula Börgen Börgen Bay Marian Marian Cove South Shetland Islands The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Börgen Börgen Bay Marian Marian Cove South Shetland Islands The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula South Shetland Islands |
genre_facet |
Antarc* Antarctic Antarctic Peninsula South Shetland Islands |
op_relation |
http://hdl.handle.net/10871/133679 |
op_rights |
2024-08-01 Under embargo until 1/8/24 as currently writing up for publication and supervisor has advised an embargo until it has been published. http://www.rioxx.net/licenses/all-rights-reserved |
_version_ |
1775349803881857024 |