Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153
In the years 2000 and 2001 we measured methane concentrations exceeding up to two orders of magnitude the equilibrium with the atmosphere in the water column on the SW-Spitsbergen continental shelf. This methane anomaly extended from its centre on the shelf westwards over the upper slope and eastwar...
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2005
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.323819 2024-09-15T17:50:48+00:00 Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153 Damm, Ellen Mackensen, Andreas Budéus, Gereon Faber, Eckhard Hanfland, Claudia MEDIAN LATITUDE: 77.508750 * MEDIAN LONGITUDE: 14.362500 * SOUTH-BOUND LATITUDE: 76.720000 * WEST-BOUND LONGITUDE: 11.900000 * NORTH-BOUND LATITUDE: 77.870000 * EAST-BOUND LONGITUDE: 16.730000 * DATE/TIME START: 2001-09-01T00:00:00 * DATE/TIME END: 2001-09-06T00:00:00 * MINIMUM DEPTH, water: 5 m * MAXIMUM DEPTH, water: 402 m 2005 text/tab-separated-values, 46 data points https://doi.pangaea.de/10.1594/PANGAEA.323819 https://doi.org/10.1594/PANGAEA.323819 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.323819 https://doi.org/10.1594/PANGAEA.323819 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Damm, Ellen; Mackensen, Andreas; Budéus, Gereon; Faber, Eckhard; Hanfland, Claudia (2005): Pathways of methane in seawater: Plume spreading in an Arctic shelf environment (SW-Spitsbergen). Continental Shelf Research, 25(12-13), 1453-1472, https://doi.org/10.1016/j.csr.2005.03.003 Alpha-scintillation AWI_EcolChem CTD/Rosette CTD-RO Date/Time of event DEPTH water Ecological Chemistry @ AWI Elevation of event Event label HE153 HE153/1247-1 HE153/1249-1 HE153/1253-1 HE153/1255-1 HE153/1257-1 HE153/1260-1 HE153/1264-1 HE153/1271-1 Heincke Latitude of event Longitude of event Radon-222 excess standard deviation dataset 2005 ftpangaea https://doi.org/10.1594/PANGAEA.32381910.1016/j.csr.2005.03.003 2024-07-24T02:31:25Z In the years 2000 and 2001 we measured methane concentrations exceeding up to two orders of magnitude the equilibrium with the atmosphere in the water column on the SW-Spitsbergen continental shelf. This methane anomaly extended from its centre on the shelf westwards over the upper slope and eastwards well into the inner basins of the two southernmost Spitsbergen fjords, the Hornsundfjord and the van Mijenfjord. Methane concentrations and stable carbon isotopic ratios varied between 2 and 240 nM, and between -53 per mill and -20 per mill VPDB, respectively. Methane in high concentrations was depleted in 13C whereas in low concentrations d13CCH4 values were highly variable. On the continental shelf we found that methane discharged from seeps on top of sandy and gravelly banks is isotopically heavier than methane escaping from troughs filled with silty and clayey sediments. These distinct isotopic signatures suggest that methane is gently released from several inter-granular seepages or micro-seepages widely spread over the shelf. A potential migration path for thermogenic or hydrate methane may be the Hornsund Fracture Zone, a south–north running reactivated fault system created by stretching of the continental crust. After discharge into the water column, local water currents fed by Atlantic water, coastal water, and freshwater outflows from the fjords further determine pathways and fate of the methane. We used d18Owater and 222Rn data to trace origin and advection of the local water masses and water mixing processes. Methane spreads predominantly along pycnoclines and by vertical mixing. During transport methane is influenced simultaneously by oxidation and dilution, as well as loss into the atmosphere. Together these processes cause the spatial variability of the anomaly and heterogeneity in d13CCH4 in this polar shelf environment. Dataset Arctic Hornsund Van Mijenfjord Spitsbergen PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(11.900000,16.730000,77.870000,76.720000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Alpha-scintillation AWI_EcolChem CTD/Rosette CTD-RO Date/Time of event DEPTH water Ecological Chemistry @ AWI Elevation of event Event label HE153 HE153/1247-1 HE153/1249-1 HE153/1253-1 HE153/1255-1 HE153/1257-1 HE153/1260-1 HE153/1264-1 HE153/1271-1 Heincke Latitude of event Longitude of event Radon-222 excess standard deviation |
spellingShingle |
Alpha-scintillation AWI_EcolChem CTD/Rosette CTD-RO Date/Time of event DEPTH water Ecological Chemistry @ AWI Elevation of event Event label HE153 HE153/1247-1 HE153/1249-1 HE153/1253-1 HE153/1255-1 HE153/1257-1 HE153/1260-1 HE153/1264-1 HE153/1271-1 Heincke Latitude of event Longitude of event Radon-222 excess standard deviation Damm, Ellen Mackensen, Andreas Budéus, Gereon Faber, Eckhard Hanfland, Claudia Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153 |
topic_facet |
Alpha-scintillation AWI_EcolChem CTD/Rosette CTD-RO Date/Time of event DEPTH water Ecological Chemistry @ AWI Elevation of event Event label HE153 HE153/1247-1 HE153/1249-1 HE153/1253-1 HE153/1255-1 HE153/1257-1 HE153/1260-1 HE153/1264-1 HE153/1271-1 Heincke Latitude of event Longitude of event Radon-222 excess standard deviation |
description |
In the years 2000 and 2001 we measured methane concentrations exceeding up to two orders of magnitude the equilibrium with the atmosphere in the water column on the SW-Spitsbergen continental shelf. This methane anomaly extended from its centre on the shelf westwards over the upper slope and eastwards well into the inner basins of the two southernmost Spitsbergen fjords, the Hornsundfjord and the van Mijenfjord. Methane concentrations and stable carbon isotopic ratios varied between 2 and 240 nM, and between -53 per mill and -20 per mill VPDB, respectively. Methane in high concentrations was depleted in 13C whereas in low concentrations d13CCH4 values were highly variable. On the continental shelf we found that methane discharged from seeps on top of sandy and gravelly banks is isotopically heavier than methane escaping from troughs filled with silty and clayey sediments. These distinct isotopic signatures suggest that methane is gently released from several inter-granular seepages or micro-seepages widely spread over the shelf. A potential migration path for thermogenic or hydrate methane may be the Hornsund Fracture Zone, a south–north running reactivated fault system created by stretching of the continental crust. After discharge into the water column, local water currents fed by Atlantic water, coastal water, and freshwater outflows from the fjords further determine pathways and fate of the methane. We used d18Owater and 222Rn data to trace origin and advection of the local water masses and water mixing processes. Methane spreads predominantly along pycnoclines and by vertical mixing. During transport methane is influenced simultaneously by oxidation and dilution, as well as loss into the atmosphere. Together these processes cause the spatial variability of the anomaly and heterogeneity in d13CCH4 in this polar shelf environment. |
format |
Dataset |
author |
Damm, Ellen Mackensen, Andreas Budéus, Gereon Faber, Eckhard Hanfland, Claudia |
author_facet |
Damm, Ellen Mackensen, Andreas Budéus, Gereon Faber, Eckhard Hanfland, Claudia |
author_sort |
Damm, Ellen |
title |
Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153 |
title_short |
Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153 |
title_full |
Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153 |
title_fullStr |
Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153 |
title_full_unstemmed |
Radon 222 excess measured on water bottle samples during HEINCKE cruise HE153 |
title_sort |
radon 222 excess measured on water bottle samples during heincke cruise he153 |
publisher |
PANGAEA |
publishDate |
2005 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.323819 https://doi.org/10.1594/PANGAEA.323819 |
op_coverage |
MEDIAN LATITUDE: 77.508750 * MEDIAN LONGITUDE: 14.362500 * SOUTH-BOUND LATITUDE: 76.720000 * WEST-BOUND LONGITUDE: 11.900000 * NORTH-BOUND LATITUDE: 77.870000 * EAST-BOUND LONGITUDE: 16.730000 * DATE/TIME START: 2001-09-01T00:00:00 * DATE/TIME END: 2001-09-06T00:00:00 * MINIMUM DEPTH, water: 5 m * MAXIMUM DEPTH, water: 402 m |
long_lat |
ENVELOPE(11.900000,16.730000,77.870000,76.720000) |
genre |
Arctic Hornsund Van Mijenfjord Spitsbergen |
genre_facet |
Arctic Hornsund Van Mijenfjord Spitsbergen |
op_source |
Supplement to: Damm, Ellen; Mackensen, Andreas; Budéus, Gereon; Faber, Eckhard; Hanfland, Claudia (2005): Pathways of methane in seawater: Plume spreading in an Arctic shelf environment (SW-Spitsbergen). Continental Shelf Research, 25(12-13), 1453-1472, https://doi.org/10.1016/j.csr.2005.03.003 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.323819 https://doi.org/10.1594/PANGAEA.323819 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.32381910.1016/j.csr.2005.03.003 |
_version_ |
1810292597601599488 |