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...
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ftsouthampton:oai:eprints.soton.ac.uk:418606 2023-07-30T03:59:26+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 https://eprints.soton.ac.uk/418606/ English eng Annett, Amber L., Henley, Sian F., Van Beek, Pieter, Souhaut, Marc, Ganeshram, Raja, Venables, Hugh J., Meredith, Michael P. and 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. (doi:10.1017/S0954102012000892 <http://dx.doi.org/10.1017/S0954102012000892>). Article PeerReviewed 2013 ftsouthampton https://doi.org/10.1017/S0954102012000892 2023-07-09T22:21:04Z 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 ( 223 Ra and 224 Ra) measurements from Antarctic waters, both present at very low activities (mean 0.155 and 3.21 dpm m -3 , respectively), indicating much lower radium inputs than in other coastal environments. Longer-lived 228 Ra 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 223 Ra and 224 Ra. Using a simple diffusion model along a shore to mid-bay transect, effective horizontal eddy diffusivity estimates ranged from 0.22-0.83 m 2 s -1 from 223 Ra and 224 Ra, respectively, much lower than already-low mixing estimates for the Southern Ocean. Significant radium enrichment and much faster mixing (18 m 2 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 University of Southampton: e-Prints Soton Antarctic 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) Southern Ocean Antarctic Science 25 3 445 456 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
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 ( 223 Ra and 224 Ra) measurements from Antarctic waters, both present at very low activities (mean 0.155 and 3.21 dpm m -3 , respectively), indicating much lower radium inputs than in other coastal environments. Longer-lived 228 Ra 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 223 Ra and 224 Ra. Using a simple diffusion model along a shore to mid-bay transect, effective horizontal eddy diffusivity estimates ranged from 0.22-0.83 m 2 s -1 from 223 Ra and 224 Ra, respectively, much lower than already-low mixing estimates for the Southern Ocean. Significant radium enrichment and much faster mixing (18 m 2 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 |
spellingShingle |
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 |
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 |
publishDate |
2013 |
url |
https://eprints.soton.ac.uk/418606/ |
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 Antarctic Peninsula Marguerite Marguerite Bay Ryder Ryder Bay Southern Ocean |
geographic_facet |
Antarctic Antarctic Peninsula Marguerite Marguerite Bay Ryder Ryder Bay Southern Ocean |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctic Science Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctic Science Southern Ocean |
op_relation |
Annett, Amber L., Henley, Sian F., Van Beek, Pieter, Souhaut, Marc, Ganeshram, Raja, Venables, Hugh J., Meredith, Michael P. and 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. (doi:10.1017/S0954102012000892 <http://dx.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_ |
1772810246517948416 |