An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key?
We consider the Si flux resulting from sand grain dissolution on beaches under the pressure of the intensive and continuous shaking by the waves, a potential source of oceanic DSi that is not currently considered. Today, DSi source and sink fluxes are balanced within large uncertainties, at ca. 10.4...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-09-01
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| Series: | Frontiers in Earth Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/article/10.3389/feart.2019.00231/full |
| _version_ | 1818025414944096256 |
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| author | Sébastien Fabre Catherine Jeandel Thomas Zambardi Michel Roustan Rafaël Almar |
| author_facet | Sébastien Fabre Catherine Jeandel Thomas Zambardi Michel Roustan Rafaël Almar |
| author_sort | Sébastien Fabre |
| collection | DOAJ |
| description | We consider the Si flux resulting from sand grain dissolution on beaches under the pressure of the intensive and continuous shaking by the waves, a potential source of oceanic DSi that is not currently considered. Today, DSi source and sink fluxes are balanced within large uncertainties, at ca. 10.4 ± 4.2 and 14.6 ± 7.8 × 1012 mol yr–1, respectively, underlining that some processes are not well constrained and possibly overlooked so far. To quantitatively explore this idea, we first realized an experimental dissolution of quartz grains in a stirred vessel designed to simulate the sediment orbital motion induced by the waves. These experiments lead to the calculation of a solid–liquid mass-transfer coefficient directly linked to the rotation speed of the shaker. This coefficient being itself related to the energy communicated to the liquid, we could apply the Nienow relationship to calculate a mass-transfer coefficient for beach sand exposed to 1 m height waves. Extrapolation of this value to the whole sandy beaches led us to conclude that this mechanism could be significant, shortening the calculated residence time of oceanic DSi by up to a factor 2. |
| first_indexed | 2024-12-10T04:15:44Z |
| format | Article |
| id | doaj.art-e60af43f734947beac3c25585870e09d |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-10T04:15:44Z |
| publishDate | 2019-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-e60af43f734947beac3c25585870e09d2022-12-22T02:02:36ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632019-09-01710.3389/feart.2019.00231450482An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key?Sébastien Fabre0Catherine Jeandel1Thomas Zambardi2Michel Roustan3Rafaël Almar4UMR 5277 Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, Université Paul Sabatier, Toulouse, FranceUMR 5566 Laboratoire d’Études en Géophysique et Océanographie Spatiales, Université de Toulouse, CNRS, IRD, CNES, Université Paul Sabatier, Toulouse, FranceUMR 5566 Laboratoire d’Études en Géophysique et Océanographie Spatiales, Université de Toulouse, CNRS, IRD, CNES, Université Paul Sabatier, Toulouse, FranceInstitut National des Sciences Appliquées de Toulouse, Université de Toulouse, Toulouse, FranceUMR 5566 Laboratoire d’Études en Géophysique et Océanographie Spatiales, Université de Toulouse, CNRS, IRD, CNES, Université Paul Sabatier, Toulouse, FranceWe consider the Si flux resulting from sand grain dissolution on beaches under the pressure of the intensive and continuous shaking by the waves, a potential source of oceanic DSi that is not currently considered. Today, DSi source and sink fluxes are balanced within large uncertainties, at ca. 10.4 ± 4.2 and 14.6 ± 7.8 × 1012 mol yr–1, respectively, underlining that some processes are not well constrained and possibly overlooked so far. To quantitatively explore this idea, we first realized an experimental dissolution of quartz grains in a stirred vessel designed to simulate the sediment orbital motion induced by the waves. These experiments lead to the calculation of a solid–liquid mass-transfer coefficient directly linked to the rotation speed of the shaker. This coefficient being itself related to the energy communicated to the liquid, we could apply the Nienow relationship to calculate a mass-transfer coefficient for beach sand exposed to 1 m height waves. Extrapolation of this value to the whole sandy beaches led us to conclude that this mechanism could be significant, shortening the calculated residence time of oceanic DSi by up to a factor 2.https://www.frontiersin.org/article/10.3389/feart.2019.00231/fullsilicaquartzweatheringbeachesocean chemistry |
| spellingShingle | Sébastien Fabre Catherine Jeandel Thomas Zambardi Michel Roustan Rafaël Almar An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key? Frontiers in Earth Science silica quartz weathering beaches ocean chemistry |
| title | An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key? |
| title_full | An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key? |
| title_fullStr | An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key? |
| title_full_unstemmed | An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key? |
| title_short | An Overlooked Silica Source of the Modern Oceans: Are Sandy Beaches the Key? |
| title_sort | overlooked silica source of the modern oceans are sandy beaches the key |
| topic | silica quartz weathering beaches ocean chemistry |
| url | https://www.frontiersin.org/article/10.3389/feart.2019.00231/full |
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