A 17,000 yr paleomagnetic secular variation record from the southeast Alaskan margin: regional and global correlations
A 17,000 yr paleomagnetic secular variation record from the southeast Alaskan margin: regional and global correlations
High-resolution sedimentary records on two cores from the Gulf of Alaska margin allow development of a ∼17,400-yr reconstruction of paleomagnetic secular variation (PSV). General agreement between the two records on their independent chronologies confirms that local PSV is recorded, demonstrating that such archives, notwithstanding complexities due to variable sedimentary regimes, deposition rates, and diagenetic conditions, provide meaningful information on past changes of the geomagnetic field. Comparisons with other independently dated sedimentary paleomagnetic records from the NE Pacific indicate largely coherent inclination records that in combination create a NE Pacific sedimentary inclination anomaly stack (NEPSIAS) capturing the common signal over an area spanning >30° longitude and latitude from Alaska through Oregon to Hawaii. Comparisons of NEPSIAS with high quality declination records from the northern North Atlantic (NNA) show that negative (shallow) inclination anomalies in NEPSIAS are associated with eastward NNA declinations while positive (steep) inclination anomalies in NEPSIAS are associated with westward NNA declinations. Comparison of these directional records to regional geomagnetic intensities over the past ∼3000 yrs in North America and back nearly 8000 yrs in the Euro/Mediterranean region, are consistent with a driving mechanism of oscillations in the relative strength of the North American and Euro/Mediterranean flux lobes. The persistence of these dynamics through the Holocene implicates a long-lived organizing structure likely imposed on the geomagnetic field by the lower mantle and/or inner core. These observations underscore a fundamental connection between directional PSV in the North Pacific with that of the North Atlantic, supporting the potential for long-distance correlation of directional PSV as a chronostratigraphic tool.
177-189
Walczak, M.H.
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Stoner, J.S.
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Mix, A.C.
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Jaeger, J.
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Rosen, G.P.
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Channell, J.E.T.
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Heslop, D.
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Xuan, C.
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1 September 2017
Walczak, M.H.
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Stoner, J.S.
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Mix, A.C.
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Jaeger, J.
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Rosen, G.P.
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Channell, J.E.T.
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Heslop, D.
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Xuan, C.
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Walczak, M.H., Stoner, J.S., Mix, A.C., Jaeger, J., Rosen, G.P., Channell, J.E.T., Heslop, D. and Xuan, C.
(2017)
A 17,000 yr paleomagnetic secular variation record from the southeast Alaskan margin: regional and global correlations.
Earth and Planetary Science Letters, 473, .
(doi:10.1016/j.epsl.2017.05.022).
Abstract
High-resolution sedimentary records on two cores from the Gulf of Alaska margin allow development of a ∼17,400-yr reconstruction of paleomagnetic secular variation (PSV). General agreement between the two records on their independent chronologies confirms that local PSV is recorded, demonstrating that such archives, notwithstanding complexities due to variable sedimentary regimes, deposition rates, and diagenetic conditions, provide meaningful information on past changes of the geomagnetic field. Comparisons with other independently dated sedimentary paleomagnetic records from the NE Pacific indicate largely coherent inclination records that in combination create a NE Pacific sedimentary inclination anomaly stack (NEPSIAS) capturing the common signal over an area spanning >30° longitude and latitude from Alaska through Oregon to Hawaii. Comparisons of NEPSIAS with high quality declination records from the northern North Atlantic (NNA) show that negative (shallow) inclination anomalies in NEPSIAS are associated with eastward NNA declinations while positive (steep) inclination anomalies in NEPSIAS are associated with westward NNA declinations. Comparison of these directional records to regional geomagnetic intensities over the past ∼3000 yrs in North America and back nearly 8000 yrs in the Euro/Mediterranean region, are consistent with a driving mechanism of oscillations in the relative strength of the North American and Euro/Mediterranean flux lobes. The persistence of these dynamics through the Holocene implicates a long-lived organizing structure likely imposed on the geomagnetic field by the lower mantle and/or inner core. These observations underscore a fundamental connection between directional PSV in the North Pacific with that of the North Atlantic, supporting the potential for long-distance correlation of directional PSV as a chronostratigraphic tool.
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Walczak_et_al._including_Xuan_2017_EPSL
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Accepted/In Press date: 16 May 2017
e-pub ahead of print date: 26 June 2017
Published date: 1 September 2017
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Local EPrints ID: 413173
URI: http://eprints.soton.ac.uk/id/eprint/413173
ISSN: 0012-821X
PURE UUID: a9ce1403-f7f2-4b1e-bc94-1b9796790829
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Date deposited: 17 Aug 2017 16:30
Last modified: 16 Mar 2024 05:39
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Author:
M.H. Walczak
Author:
J.S. Stoner
Author:
A.C. Mix
Author:
J. Jaeger
Author:
G.P. Rosen
Author:
J.E.T. Channell
Author:
D. Heslop
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