New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean
To date observations on a single location indicate that cryogenic gypsum (Ca[SO 4 ]·2H 2 O) may constitute an efficient but hitherto overlooked ballasting mineral enhancing the efficiency of the biological carbon pump in the Arctic Ocean. In June–July 2017 we sampled cryogenic gypsum under pack-ice...
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ftcopernicus:oai:publications.copernicus.org:tcd80495 2023-05-15T14:54:41+02:00 New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean Wollenburg, Jutta E. Iversen, Morten Katlein, Christian Krumpen, Thomas Nicolaus, Marcel Castellani, Giulia Peeken, Ilka Flores, Hauke 2019-12-03 application/pdf https://doi.org/10.5194/tc-2019-229 https://www.the-cryosphere-discuss.net/tc-2019-229/ eng eng doi:10.5194/tc-2019-229 https://www.the-cryosphere-discuss.net/tc-2019-229/ eISSN: 1994-0424 Text 2019 ftcopernicus https://doi.org/10.5194/tc-2019-229 2019-12-24T09:48:08Z To date observations on a single location indicate that cryogenic gypsum (Ca[SO 4 ]·2H 2 O) may constitute an efficient but hitherto overlooked ballasting mineral enhancing the efficiency of the biological carbon pump in the Arctic Ocean. In June–July 2017 we sampled cryogenic gypsum under pack-ice in the Nansen Basin north of Svalbard using a plankton net mounted on a Remotely Operated Vehicle (ROVnet). Cryogenic gypsum crystals were present at all sampled stations, which suggested a persisting cryogenic gypsum release from melting sea ice throughout the investigated area. This was supported by a sea ice backtracking model that indicated that gypsum release was not related to a specific region of sea ice formation. The observed cryogenic gypsum crystals exhibited a large variability in morphology and size, with the largest crystals exceeding a length of 1 cm. Preservation, temperature and pressure laboratory studies revealed that gypsum dissolution rates accelerated with increasing temperature and pressure, ranging from 6 % d −1 by mass in Polar Surface Water (-0.5 °C) to 81 % d −1 by mass in Atlantic Water (2.5 °C at 65 bar). When testing the preservation of gypsum in Formaldehyde-fixed samples we observed immediate dissolution. Dissolution at warmer temperatures and through inappropriate preservation media may thus explain why cryogenic gypsum was not observed in scientific samples previously. Direct measurements of gypsum crystal sinking velocities ranged between 200 and 7000 m d −1 indicated that gypsum-loaded marine aggregates could rapidly sink from the surface to abyssal depths, supporting the hypothesised potential as a ballasting mineral in the Arctic Ocean. Text Arctic Arctic Ocean Nansen Basin Sea ice Svalbard Copernicus Publications: E-Journals Arctic Arctic Ocean Svalbard |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
To date observations on a single location indicate that cryogenic gypsum (Ca[SO 4 ]·2H 2 O) may constitute an efficient but hitherto overlooked ballasting mineral enhancing the efficiency of the biological carbon pump in the Arctic Ocean. In June–July 2017 we sampled cryogenic gypsum under pack-ice in the Nansen Basin north of Svalbard using a plankton net mounted on a Remotely Operated Vehicle (ROVnet). Cryogenic gypsum crystals were present at all sampled stations, which suggested a persisting cryogenic gypsum release from melting sea ice throughout the investigated area. This was supported by a sea ice backtracking model that indicated that gypsum release was not related to a specific region of sea ice formation. The observed cryogenic gypsum crystals exhibited a large variability in morphology and size, with the largest crystals exceeding a length of 1 cm. Preservation, temperature and pressure laboratory studies revealed that gypsum dissolution rates accelerated with increasing temperature and pressure, ranging from 6 % d −1 by mass in Polar Surface Water (-0.5 °C) to 81 % d −1 by mass in Atlantic Water (2.5 °C at 65 bar). When testing the preservation of gypsum in Formaldehyde-fixed samples we observed immediate dissolution. Dissolution at warmer temperatures and through inappropriate preservation media may thus explain why cryogenic gypsum was not observed in scientific samples previously. Direct measurements of gypsum crystal sinking velocities ranged between 200 and 7000 m d −1 indicated that gypsum-loaded marine aggregates could rapidly sink from the surface to abyssal depths, supporting the hypothesised potential as a ballasting mineral in the Arctic Ocean. |
format |
Text |
author |
Wollenburg, Jutta E. Iversen, Morten Katlein, Christian Krumpen, Thomas Nicolaus, Marcel Castellani, Giulia Peeken, Ilka Flores, Hauke |
spellingShingle |
Wollenburg, Jutta E. Iversen, Morten Katlein, Christian Krumpen, Thomas Nicolaus, Marcel Castellani, Giulia Peeken, Ilka Flores, Hauke New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean |
author_facet |
Wollenburg, Jutta E. Iversen, Morten Katlein, Christian Krumpen, Thomas Nicolaus, Marcel Castellani, Giulia Peeken, Ilka Flores, Hauke |
author_sort |
Wollenburg, Jutta E. |
title |
New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean |
title_short |
New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean |
title_full |
New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean |
title_fullStr |
New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean |
title_full_unstemmed |
New observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the Arctic Ocean |
title_sort |
new observations of the distribution, morphology, and dissolution dynamics of cryogenic gypsum in the arctic ocean |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-2019-229 https://www.the-cryosphere-discuss.net/tc-2019-229/ |
geographic |
Arctic Arctic Ocean Svalbard |
geographic_facet |
Arctic Arctic Ocean Svalbard |
genre |
Arctic Arctic Ocean Nansen Basin Sea ice Svalbard |
genre_facet |
Arctic Arctic Ocean Nansen Basin Sea ice Svalbard |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2019-229 https://www.the-cryosphere-discuss.net/tc-2019-229/ |
op_doi |
https://doi.org/10.5194/tc-2019-229 |
_version_ |
1766326450058690560 |