The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea
The caldera-forming eruption of the Aniakchak volcano in the Aleutian Range on the Alaskan Peninsula at 3.6 cal kyr BP was one of the largest Holocene eruptions worldwide. The resulting ash is found as a visible sediment layer in several Alaskan sites and as a cryptotephra on Newfoundland and Greenl...
Published in: | Climate of the Past |
---|---|
Main Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2017
|
Subjects: | |
Online Access: | https://pure.au.dk/portal/da/publications/the-36ka-aniakchak-tephra-in-the-arctic-ocean(a2a3eac4-e0e5-4071-8cf4-4c3b945b6406).html https://doi.org/10.5194/cp-13-303-2017 |
id |
ftuniaarhuspubl:oai:pure.atira.dk:publications/a2a3eac4-e0e5-4071-8cf4-4c3b945b6406 |
---|---|
record_format |
openpolar |
spelling |
ftuniaarhuspubl:oai:pure.atira.dk:publications/a2a3eac4-e0e5-4071-8cf4-4c3b945b6406 2023-10-09T21:47:42+02:00 The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea Pearce, Christof Varhelyi, Aron Wastegård, Stefan Muschitiello, Francesco Barrientos, Natalia O'Regan, Matt Cronin, Thomas M. Gemery, Laura Semiletov, Igor Backman, Jan Jakobsson, Martin 2017-04-05 https://pure.au.dk/portal/da/publications/the-36ka-aniakchak-tephra-in-the-arctic-ocean(a2a3eac4-e0e5-4071-8cf4-4c3b945b6406).html https://doi.org/10.5194/cp-13-303-2017 eng eng info:eu-repo/semantics/openAccess Pearce , C , Varhelyi , A , Wastegård , S , Muschitiello , F , Barrientos , N , O'Regan , M , Cronin , T M , Gemery , L , Semiletov , I , Backman , J & Jakobsson , M 2017 , ' The 3.6ka Aniakchak tephra in the Arctic Ocean : A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea ' , Climate of the Past , vol. 13 , no. 4 , pp. 303-316 . https://doi.org/10.5194/cp-13-303-2017 article 2017 ftuniaarhuspubl https://doi.org/10.5194/cp-13-303-2017 2023-09-13T22:58:30Z The caldera-forming eruption of the Aniakchak volcano in the Aleutian Range on the Alaskan Peninsula at 3.6 cal kyr BP was one of the largest Holocene eruptions worldwide. The resulting ash is found as a visible sediment layer in several Alaskan sites and as a cryptotephra on Newfoundland and Greenland. This large geographic distribution, combined with the fact that the eruption is relatively well constrained in time using radiocarbon dating of lake sediments and annual layer counts in ice cores, makes it an excellent stratigraphic marker for dating and correlating mid-late Holocene sediment and paleoclimate records. This study presents the outcome of a targeted search for the Aniakchak tephra in a marine sediment core from the Arctic Ocean, namely Core SWERUS-L2-2-PC1 (2PC), raised from 57m water depth in Herald Canyon, western Chukchi Sea. High concentrations of tephra shards, with a geochemical signature matching that of Aniakchak ash, were observed across a more than 1.5m long sediment sequence. Since the primary input of volcanic ash is through atmospheric transport, and assuming that bioturbation can account for mixing up to ca. 10cm of the marine sediment deposited at the coring site, the broad signal is interpreted as sustained reworking at the sediment source input. The isochron is therefore placed at the base of the sudden increase in tephra concentrations rather than at the maximum concentration. This interpretation of major reworking is strengthened by analysis of grain size distribution which points to ice rafting as an important secondary transport mechanism of volcanic ash. Combined with radiocarbon dates on mollusks in the same sediment core, the volcanic marker is used to calculate a marine radiocarbon reservoir age offset δR = 477 ± 60 years. This relatively high value may be explained by the major influence of typically "carbon-old" Pacific waters, and it agrees well with recent estimates of δR along the northwest Alaskan coast, possibly indicating stable oceanographic conditions during the ... Article in Journal/Newspaper Arctic Arctic Arctic Ocean Chukchi Chukchi Sea Greenland Newfoundland Aarhus University: Research Arctic Arctic Ocean Chukchi Sea Greenland Pacific Climate of the Past 13 4 303 316 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
description |
The caldera-forming eruption of the Aniakchak volcano in the Aleutian Range on the Alaskan Peninsula at 3.6 cal kyr BP was one of the largest Holocene eruptions worldwide. The resulting ash is found as a visible sediment layer in several Alaskan sites and as a cryptotephra on Newfoundland and Greenland. This large geographic distribution, combined with the fact that the eruption is relatively well constrained in time using radiocarbon dating of lake sediments and annual layer counts in ice cores, makes it an excellent stratigraphic marker for dating and correlating mid-late Holocene sediment and paleoclimate records. This study presents the outcome of a targeted search for the Aniakchak tephra in a marine sediment core from the Arctic Ocean, namely Core SWERUS-L2-2-PC1 (2PC), raised from 57m water depth in Herald Canyon, western Chukchi Sea. High concentrations of tephra shards, with a geochemical signature matching that of Aniakchak ash, were observed across a more than 1.5m long sediment sequence. Since the primary input of volcanic ash is through atmospheric transport, and assuming that bioturbation can account for mixing up to ca. 10cm of the marine sediment deposited at the coring site, the broad signal is interpreted as sustained reworking at the sediment source input. The isochron is therefore placed at the base of the sudden increase in tephra concentrations rather than at the maximum concentration. This interpretation of major reworking is strengthened by analysis of grain size distribution which points to ice rafting as an important secondary transport mechanism of volcanic ash. Combined with radiocarbon dates on mollusks in the same sediment core, the volcanic marker is used to calculate a marine radiocarbon reservoir age offset δR = 477 ± 60 years. This relatively high value may be explained by the major influence of typically "carbon-old" Pacific waters, and it agrees well with recent estimates of δR along the northwest Alaskan coast, possibly indicating stable oceanographic conditions during the ... |
format |
Article in Journal/Newspaper |
author |
Pearce, Christof Varhelyi, Aron Wastegård, Stefan Muschitiello, Francesco Barrientos, Natalia O'Regan, Matt Cronin, Thomas M. Gemery, Laura Semiletov, Igor Backman, Jan Jakobsson, Martin |
spellingShingle |
Pearce, Christof Varhelyi, Aron Wastegård, Stefan Muschitiello, Francesco Barrientos, Natalia O'Regan, Matt Cronin, Thomas M. Gemery, Laura Semiletov, Igor Backman, Jan Jakobsson, Martin The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea |
author_facet |
Pearce, Christof Varhelyi, Aron Wastegård, Stefan Muschitiello, Francesco Barrientos, Natalia O'Regan, Matt Cronin, Thomas M. Gemery, Laura Semiletov, Igor Backman, Jan Jakobsson, Martin |
author_sort |
Pearce, Christof |
title |
The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea |
title_short |
The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea |
title_full |
The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea |
title_fullStr |
The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea |
title_full_unstemmed |
The 3.6ka Aniakchak tephra in the Arctic Ocean:A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea |
title_sort |
3.6ka aniakchak tephra in the arctic ocean:a constraint on the holocene radiocarbon reservoir age in the chukchi sea |
publishDate |
2017 |
url |
https://pure.au.dk/portal/da/publications/the-36ka-aniakchak-tephra-in-the-arctic-ocean(a2a3eac4-e0e5-4071-8cf4-4c3b945b6406).html https://doi.org/10.5194/cp-13-303-2017 |
geographic |
Arctic Arctic Ocean Chukchi Sea Greenland Pacific |
geographic_facet |
Arctic Arctic Ocean Chukchi Sea Greenland Pacific |
genre |
Arctic Arctic Arctic Ocean Chukchi Chukchi Sea Greenland Newfoundland |
genre_facet |
Arctic Arctic Arctic Ocean Chukchi Chukchi Sea Greenland Newfoundland |
op_source |
Pearce , C , Varhelyi , A , Wastegård , S , Muschitiello , F , Barrientos , N , O'Regan , M , Cronin , T M , Gemery , L , Semiletov , I , Backman , J & Jakobsson , M 2017 , ' The 3.6ka Aniakchak tephra in the Arctic Ocean : A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea ' , Climate of the Past , vol. 13 , no. 4 , pp. 303-316 . https://doi.org/10.5194/cp-13-303-2017 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/cp-13-303-2017 |
container_title |
Climate of the Past |
container_volume |
13 |
container_issue |
4 |
container_start_page |
303 |
op_container_end_page |
316 |
_version_ |
1779310761095462912 |