The Paleoceanography of the Bering Sea During the Last Glacial Cycle
In this thesis, I present high-resolution stable-isotope and planktonic-fauna records from Bering Sea sediment cores, spanning the time period from 50,000 years ago to the present. During Marine Isotope Stage 3 (MIS3) at 30-20 ky BP (kiloyears before present) in a core from 1467 m water depth near U...
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ftdtic:ADA455003 2023-05-15T15:43:24+02:00 The Paleoceanography of the Bering Sea During the Last Glacial Cycle Cook, Mea S. MASSACHUSETTS INST OF TECH CAMBRIDGE JOINT PROGRAM IN APPLIED OCEAN SCIENCE AND ENGINEERING 2006-02 text/html http://www.dtic.mil/docs/citations/ADA455003 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA455003 en eng http://www.dtic.mil/docs/citations/ADA455003 Approved for public release; distribution is unlimited. DTIC Physical and Dynamic Oceanography *CLIMATE *SEDIMENTATION *BERING SEA THESES OXIDATION METHANE RADIOCARBON DATING ANAEROBIC PROCESSES SEDIMENTS ISOTOPES ORGANIC MATERIALS ANAEROBIC OXIDATION DEGLACIATION NORTH PACIFIC PALEOCEANOGRAPHY Text 2006 ftdtic 2016-02-22T05:23:29Z In this thesis, I present high-resolution stable-isotope and planktonic-fauna records from Bering Sea sediment cores, spanning the time period from 50,000 years ago to the present. During Marine Isotope Stage 3 (MIS3) at 30-20 ky BP (kiloyears before present) in a core from 1467 m water depth near Umnak Plateau, there were episodic occurrences of diagenetic carbonate minerals with very low deltaC13 (-22.4%0), high deltaO18 (6.5%0), and high [Mg]/[Ca], which seem associated with sulfate reduction of organic matter and possibly anaerobic oxidation of methane. The episodes lasted less than 1000 years and were spaced about 1000 years apart. During MIS3 at 55-20 ky BP in a core from 2209 m water depth on Bowers Ridge, N. pachyderma (s.) and Uvigerina deltaO18 and deltaC13 show no coherent variability on millennial time scales. Bering Sea sediments are dysoxic or laminated during the deglaciation. A high sedimentation rate core (200cm/ky) from 1132 m on the Bering Slope is laminated during the Boelling warm phase, Alleroed warm phase, and early Holocene, where the ages of lithological transitions agree with the ages of those climate events in Greenland (GISP2) to well within the uncertainty of the age models. The subsurface distribution of radiocarbon was estimated from a compilation of published and unpublished North Pacific benthic-planktonic C14 measurements (475-2700 m water depth). There was no consistent change in C14 profiles between the present and the Last Glacial Maximum, Boelling-Alleroed, or the Younger Dryas cold phase. N. pachyderma (s.) deltaO18 in the Bering Slope core decreases rapidly (in less than 220 y) by 0.7-0.8%0 at the onset of the Boelling and the end of the Younger Dryas. These isotopic shifts are accompanied by transient decreases in the relative abundance of N. pachyderma (s.), suggesting that the isotopic events are transient warmings and sustained freshenings. The original document contains color images. Text Bering Sea Greenland Defense Technical Information Center: DTIC Technical Reports database Bering Sea Greenland Pacific Bowers ENVELOPE(164.083,164.083,-85.000,-85.000) Umnak Plateau ENVELOPE(-170.250,-170.250,54.250,54.250) |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Physical and Dynamic Oceanography *CLIMATE *SEDIMENTATION *BERING SEA THESES OXIDATION METHANE RADIOCARBON DATING ANAEROBIC PROCESSES SEDIMENTS ISOTOPES ORGANIC MATERIALS ANAEROBIC OXIDATION DEGLACIATION NORTH PACIFIC PALEOCEANOGRAPHY |
spellingShingle |
Physical and Dynamic Oceanography *CLIMATE *SEDIMENTATION *BERING SEA THESES OXIDATION METHANE RADIOCARBON DATING ANAEROBIC PROCESSES SEDIMENTS ISOTOPES ORGANIC MATERIALS ANAEROBIC OXIDATION DEGLACIATION NORTH PACIFIC PALEOCEANOGRAPHY Cook, Mea S. The Paleoceanography of the Bering Sea During the Last Glacial Cycle |
topic_facet |
Physical and Dynamic Oceanography *CLIMATE *SEDIMENTATION *BERING SEA THESES OXIDATION METHANE RADIOCARBON DATING ANAEROBIC PROCESSES SEDIMENTS ISOTOPES ORGANIC MATERIALS ANAEROBIC OXIDATION DEGLACIATION NORTH PACIFIC PALEOCEANOGRAPHY |
description |
In this thesis, I present high-resolution stable-isotope and planktonic-fauna records from Bering Sea sediment cores, spanning the time period from 50,000 years ago to the present. During Marine Isotope Stage 3 (MIS3) at 30-20 ky BP (kiloyears before present) in a core from 1467 m water depth near Umnak Plateau, there were episodic occurrences of diagenetic carbonate minerals with very low deltaC13 (-22.4%0), high deltaO18 (6.5%0), and high [Mg]/[Ca], which seem associated with sulfate reduction of organic matter and possibly anaerobic oxidation of methane. The episodes lasted less than 1000 years and were spaced about 1000 years apart. During MIS3 at 55-20 ky BP in a core from 2209 m water depth on Bowers Ridge, N. pachyderma (s.) and Uvigerina deltaO18 and deltaC13 show no coherent variability on millennial time scales. Bering Sea sediments are dysoxic or laminated during the deglaciation. A high sedimentation rate core (200cm/ky) from 1132 m on the Bering Slope is laminated during the Boelling warm phase, Alleroed warm phase, and early Holocene, where the ages of lithological transitions agree with the ages of those climate events in Greenland (GISP2) to well within the uncertainty of the age models. The subsurface distribution of radiocarbon was estimated from a compilation of published and unpublished North Pacific benthic-planktonic C14 measurements (475-2700 m water depth). There was no consistent change in C14 profiles between the present and the Last Glacial Maximum, Boelling-Alleroed, or the Younger Dryas cold phase. N. pachyderma (s.) deltaO18 in the Bering Slope core decreases rapidly (in less than 220 y) by 0.7-0.8%0 at the onset of the Boelling and the end of the Younger Dryas. These isotopic shifts are accompanied by transient decreases in the relative abundance of N. pachyderma (s.), suggesting that the isotopic events are transient warmings and sustained freshenings. The original document contains color images. |
author2 |
MASSACHUSETTS INST OF TECH CAMBRIDGE JOINT PROGRAM IN APPLIED OCEAN SCIENCE AND ENGINEERING |
format |
Text |
author |
Cook, Mea S. |
author_facet |
Cook, Mea S. |
author_sort |
Cook, Mea S. |
title |
The Paleoceanography of the Bering Sea During the Last Glacial Cycle |
title_short |
The Paleoceanography of the Bering Sea During the Last Glacial Cycle |
title_full |
The Paleoceanography of the Bering Sea During the Last Glacial Cycle |
title_fullStr |
The Paleoceanography of the Bering Sea During the Last Glacial Cycle |
title_full_unstemmed |
The Paleoceanography of the Bering Sea During the Last Glacial Cycle |
title_sort |
paleoceanography of the bering sea during the last glacial cycle |
publishDate |
2006 |
url |
http://www.dtic.mil/docs/citations/ADA455003 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA455003 |
long_lat |
ENVELOPE(164.083,164.083,-85.000,-85.000) ENVELOPE(-170.250,-170.250,54.250,54.250) |
geographic |
Bering Sea Greenland Pacific Bowers Umnak Plateau |
geographic_facet |
Bering Sea Greenland Pacific Bowers Umnak Plateau |
genre |
Bering Sea Greenland |
genre_facet |
Bering Sea Greenland |
op_source |
DTIC |
op_relation |
http://www.dtic.mil/docs/citations/ADA455003 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766377497448939520 |