Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard
We present stable isotope and geochemical data from four sediment cores from west of Prins Karls Forland (ca. 340 m water depth), offshore western Svalbard, recovered from close to sites of active methane seepage, as well as from shallower water depths where methane seepage is not presently observed...
Published in: | Geochemistry, Geophysics, Geosystems |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2016
|
Subjects: | |
Online Access: | https://eprints.soton.ac.uk/388820/ https://eprints.soton.ac.uk/388820/1/ggge20940.pdf |
id |
ftsouthampton:oai:eprints.soton.ac.uk:388820 |
---|---|
record_format |
openpolar |
spelling |
ftsouthampton:oai:eprints.soton.ac.uk:388820 2023-07-30T04:04:55+02:00 Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard Panieri, Giuliana Graves, Carolyn A. James, Rachael 2016-02-26 text https://eprints.soton.ac.uk/388820/ https://eprints.soton.ac.uk/388820/1/ggge20940.pdf en English eng https://eprints.soton.ac.uk/388820/1/ggge20940.pdf Panieri, Giuliana, Graves, Carolyn A. and James, Rachael (2016) Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard. Geochemistry, Geophysics, Geosystems, 17 (2), 521-537. (doi:10.1002/2015GC006153 <http://dx.doi.org/10.1002/2015GC006153>). Article PeerReviewed 2016 ftsouthampton https://doi.org/10.1002/2015GC006153 2023-07-09T22:05:05Z We present stable isotope and geochemical data from four sediment cores from west of Prins Karls Forland (ca. 340 m water depth), offshore western Svalbard, recovered from close to sites of active methane seepage, as well as from shallower water depths where methane seepage is not presently observed. Our analyses provide insight into the record of methane seepage in an area where ongoing ocean warming may be fueling the destabilization of shallow methane hydrate. The ?13C values of benthic and planktonic foraminifera at the methane seep sites show distinct intervals with negative values (as low as ?27.8‰) that do not coincide with the present-day depth of the sulfate methane transition zone (SMTZ). These intervals are interpreted to record long-term fluctuations in methane release at the present-day landward limit of the gas hydrate stability zone (GHSZ). Shifts in the radiocarbon ages obtained from planktonic foraminifera toward older values are related to methane-derived authigenic carbonate overgrowths of the foraminiferal tests, and prevent us from establishing the chronology of seepage events. At shallower water depths, where seepage is not presently observed, no record of past methane seepage is recorded in foraminifera from sediments spanning the last 14 ka cal BP (14C-AMS dating). ?13C values of foraminiferal carbonate tests appear to be much more sensitive to methane seepage than other sediment parameters. By providing nucleation sites for authigenic carbonate precipitation, foraminifera thus record the position of even a transiently stable SMTZ, which is likely to be a characteristic of temporally variable methane fluxes. Article in Journal/Newspaper Methane hydrate Planktonic foraminifera Prins Karls Forland Svalbard University of Southampton: e-Prints Soton Prins Karls Forland ENVELOPE(11.175,11.175,78.543,78.543) Svalbard Geochemistry, Geophysics, Geosystems 17 2 521 537 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
We present stable isotope and geochemical data from four sediment cores from west of Prins Karls Forland (ca. 340 m water depth), offshore western Svalbard, recovered from close to sites of active methane seepage, as well as from shallower water depths where methane seepage is not presently observed. Our analyses provide insight into the record of methane seepage in an area where ongoing ocean warming may be fueling the destabilization of shallow methane hydrate. The ?13C values of benthic and planktonic foraminifera at the methane seep sites show distinct intervals with negative values (as low as ?27.8‰) that do not coincide with the present-day depth of the sulfate methane transition zone (SMTZ). These intervals are interpreted to record long-term fluctuations in methane release at the present-day landward limit of the gas hydrate stability zone (GHSZ). Shifts in the radiocarbon ages obtained from planktonic foraminifera toward older values are related to methane-derived authigenic carbonate overgrowths of the foraminiferal tests, and prevent us from establishing the chronology of seepage events. At shallower water depths, where seepage is not presently observed, no record of past methane seepage is recorded in foraminifera from sediments spanning the last 14 ka cal BP (14C-AMS dating). ?13C values of foraminiferal carbonate tests appear to be much more sensitive to methane seepage than other sediment parameters. By providing nucleation sites for authigenic carbonate precipitation, foraminifera thus record the position of even a transiently stable SMTZ, which is likely to be a characteristic of temporally variable methane fluxes. |
format |
Article in Journal/Newspaper |
author |
Panieri, Giuliana Graves, Carolyn A. James, Rachael |
spellingShingle |
Panieri, Giuliana Graves, Carolyn A. James, Rachael Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard |
author_facet |
Panieri, Giuliana Graves, Carolyn A. James, Rachael |
author_sort |
Panieri, Giuliana |
title |
Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard |
title_short |
Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard |
title_full |
Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard |
title_fullStr |
Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard |
title_full_unstemmed |
Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard |
title_sort |
paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western svalbard |
publishDate |
2016 |
url |
https://eprints.soton.ac.uk/388820/ https://eprints.soton.ac.uk/388820/1/ggge20940.pdf |
long_lat |
ENVELOPE(11.175,11.175,78.543,78.543) |
geographic |
Prins Karls Forland Svalbard |
geographic_facet |
Prins Karls Forland Svalbard |
genre |
Methane hydrate Planktonic foraminifera Prins Karls Forland Svalbard |
genre_facet |
Methane hydrate Planktonic foraminifera Prins Karls Forland Svalbard |
op_relation |
https://eprints.soton.ac.uk/388820/1/ggge20940.pdf Panieri, Giuliana, Graves, Carolyn A. and James, Rachael (2016) Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard. Geochemistry, Geophysics, Geosystems, 17 (2), 521-537. (doi:10.1002/2015GC006153 <http://dx.doi.org/10.1002/2015GC006153>). |
op_doi |
https://doi.org/10.1002/2015GC006153 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
17 |
container_issue |
2 |
container_start_page |
521 |
op_container_end_page |
537 |
_version_ |
1772816564123336704 |