Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula
In the western Antarctic Peninsula region, micronutrient injection facilitates strong plankton blooms that support productive food webs, unlike large areas of the low-productivity Southern Ocean.We use naturally occurring radioisotopes of radium to constrain rates of chemical fluxes into Ryder Bay (...
Published in: | Antarctic Science |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press
2013
|
Subjects: | |
Online Access: | http://nora.nerc.ac.uk/id/eprint/500524/ https://nora.nerc.ac.uk/id/eprint/500524/1/-ANS-ANS25_03-S0954102012000892a.pdf https://doi.org/10.1017/S0954102012000892 |
id |
ftnerc:oai:nora.nerc.ac.uk:500524 |
---|---|
record_format |
openpolar |
spelling |
ftnerc:oai:nora.nerc.ac.uk:500524 2023-05-15T13:48:07+02:00 Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula Annett, Amber L. Henley, Sian F. Van Beek, Pieter Souhaut, Marc Ganeshram, Raja Venables, Hugh J. Meredith, Michael P. Geibert, Walter 2013-06 text http://nora.nerc.ac.uk/id/eprint/500524/ https://nora.nerc.ac.uk/id/eprint/500524/1/-ANS-ANS25_03-S0954102012000892a.pdf https://doi.org/10.1017/S0954102012000892 en eng Cambridge University Press https://nora.nerc.ac.uk/id/eprint/500524/1/-ANS-ANS25_03-S0954102012000892a.pdf Annett, Amber L.; Henley, Sian F.; Van Beek, Pieter; Souhaut, Marc; Ganeshram, Raja; Venables, Hugh J.; Meredith, Michael P. orcid:0000-0002-7342-7756 Geibert, Walter. 2013 Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula. Antarctic Science, 25 (3). 445-456. https://doi.org/10.1017/S0954102012000892 <https://doi.org/10.1017/S0954102012000892> Chemistry Publication - Article PeerReviewed 2013 ftnerc https://doi.org/10.1017/S0954102012000892 2023-02-04T19:36:24Z In the western Antarctic Peninsula region, micronutrient injection facilitates strong plankton blooms that support productive food webs, unlike large areas of the low-productivity Southern Ocean.We use naturally occurring radioisotopes of radium to constrain rates of chemical fluxes into Ryder Bay (a small coastal embayment in northern Marguerite Bay), and hence to evaluate possible sources of sediment-derived micronutrients and estimate sediment-ocean mixing rates. We present the first coupled, short-lived radium isotope (223Ra and 224Ra) measurements from Antarctic waters, both present at very low activities (mean 0.155 and 3.21 dpmm-3, respectively), indicating much lower radium inputs than in other coastal environments. Longer-lived 228Ra activity was also lower than existing nearshore values, but higher than open ocean waters, indicating some degree of coastal radium input on timescales exceeding the week-to-month range reflected by 223Ra and 224Ra. Using a simple diffusion model along a shore to mid-bay transect, effective horizontal eddy diffusivity estimates ranged from 0.22–0.83m2 s-1 from 223Ra and 224Ra, respectively, much lower than already-low mixing estimates for the Southern Ocean. Significant radium enrichment and much faster mixing (18m2 s-1) was found near a marine-terminating glacier and consequently any sediment-derived micronutrient inputs in this location are more probably dominated by glacial processes than groundwater, land runoff, or marine sediment sources. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctic Science Southern Ocean Natural Environment Research Council: NERC Open Research Archive Antarctic Southern Ocean Antarctic Peninsula Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Marguerite Bay ENVELOPE(-68.000,-68.000,-68.500,-68.500) Ryder ENVELOPE(-68.333,-68.333,-67.566,-67.566) Ryder Bay ENVELOPE(-68.333,-68.333,-67.567,-67.567) Antarctic Science 25 3 445 456 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
topic |
Chemistry |
spellingShingle |
Chemistry Annett, Amber L. Henley, Sian F. Van Beek, Pieter Souhaut, Marc Ganeshram, Raja Venables, Hugh J. Meredith, Michael P. Geibert, Walter Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula |
topic_facet |
Chemistry |
description |
In the western Antarctic Peninsula region, micronutrient injection facilitates strong plankton blooms that support productive food webs, unlike large areas of the low-productivity Southern Ocean.We use naturally occurring radioisotopes of radium to constrain rates of chemical fluxes into Ryder Bay (a small coastal embayment in northern Marguerite Bay), and hence to evaluate possible sources of sediment-derived micronutrients and estimate sediment-ocean mixing rates. We present the first coupled, short-lived radium isotope (223Ra and 224Ra) measurements from Antarctic waters, both present at very low activities (mean 0.155 and 3.21 dpmm-3, respectively), indicating much lower radium inputs than in other coastal environments. Longer-lived 228Ra activity was also lower than existing nearshore values, but higher than open ocean waters, indicating some degree of coastal radium input on timescales exceeding the week-to-month range reflected by 223Ra and 224Ra. Using a simple diffusion model along a shore to mid-bay transect, effective horizontal eddy diffusivity estimates ranged from 0.22–0.83m2 s-1 from 223Ra and 224Ra, respectively, much lower than already-low mixing estimates for the Southern Ocean. Significant radium enrichment and much faster mixing (18m2 s-1) was found near a marine-terminating glacier and consequently any sediment-derived micronutrient inputs in this location are more probably dominated by glacial processes than groundwater, land runoff, or marine sediment sources. |
format |
Article in Journal/Newspaper |
author |
Annett, Amber L. Henley, Sian F. Van Beek, Pieter Souhaut, Marc Ganeshram, Raja Venables, Hugh J. Meredith, Michael P. Geibert, Walter |
author_facet |
Annett, Amber L. Henley, Sian F. Van Beek, Pieter Souhaut, Marc Ganeshram, Raja Venables, Hugh J. Meredith, Michael P. Geibert, Walter |
author_sort |
Annett, Amber L. |
title |
Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula |
title_short |
Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula |
title_full |
Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula |
title_fullStr |
Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula |
title_full_unstemmed |
Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula |
title_sort |
use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern marguerite bay, antarctic peninsula |
publisher |
Cambridge University Press |
publishDate |
2013 |
url |
http://nora.nerc.ac.uk/id/eprint/500524/ https://nora.nerc.ac.uk/id/eprint/500524/1/-ANS-ANS25_03-S0954102012000892a.pdf https://doi.org/10.1017/S0954102012000892 |
long_lat |
ENVELOPE(141.378,141.378,-66.787,-66.787) ENVELOPE(-68.000,-68.000,-68.500,-68.500) ENVELOPE(-68.333,-68.333,-67.566,-67.566) ENVELOPE(-68.333,-68.333,-67.567,-67.567) |
geographic |
Antarctic Southern Ocean Antarctic Peninsula Marguerite Marguerite Bay Ryder Ryder Bay |
geographic_facet |
Antarctic Southern Ocean Antarctic Peninsula Marguerite Marguerite Bay Ryder Ryder Bay |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctic Science Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctic Science Southern Ocean |
op_relation |
https://nora.nerc.ac.uk/id/eprint/500524/1/-ANS-ANS25_03-S0954102012000892a.pdf Annett, Amber L.; Henley, Sian F.; Van Beek, Pieter; Souhaut, Marc; Ganeshram, Raja; Venables, Hugh J.; Meredith, Michael P. orcid:0000-0002-7342-7756 Geibert, Walter. 2013 Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula. Antarctic Science, 25 (3). 445-456. https://doi.org/10.1017/S0954102012000892 <https://doi.org/10.1017/S0954102012000892> |
op_doi |
https://doi.org/10.1017/S0954102012000892 |
container_title |
Antarctic Science |
container_volume |
25 |
container_issue |
3 |
container_start_page |
445 |
op_container_end_page |
456 |
_version_ |
1766248632461295616 |