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| Titel |
North Pacific-wide spreading of isotopically heavy nitrogen during the last deglaciation: Evidence from the western Pacific |
| VerfasserIn |
S. J. Kao, K. K. Liu, S. C. Hsu, Y. P. Chang, M. H. Dai |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 5, no. 6 ; Nr. 5, no. 6 (2008-12-06), S.1641-1650 |
| Datensatznummer |
250002929
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| Publikation (Nr.) |
 copernicus.org/bg-5-1641-2008.pdf |
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| Zusammenfassung |
| Sedimentary δ15 N records in two IMAGES cores (MD012404 and
MD012403) retrieved from the Okinawa Trough (OT) in the western North
Pacific reveal deglacial increases with two peaks occurring during the
Bølling/Allerød and the Preboreal/early Holocene periods. These peaks
are synchronous with previously reported δ15 N peaks in the
Eastern Tropical North Pacific, although the amplitudes (from 3.8 to 5.8‰)
are much smaller in the OT. Similar δ15 N values for the last
glacial maximum and the late-Holocene observed by us at a site far from the
present-day zones of water-column denitrification (WCD) indicate that the
mean 15 N/14 N of nitrate in the upper ocean did not differ much
between the two climate states. The accumulation rate of organic carbon and
total sulfur content are used as indices of the local WCD potential. The
results suggest that enhancement of global WCD rather than local
denitrification should be responsible for the deglacial maxima of
sedimentary δ15 N in the Okinawa Trough. Our data could provide
additional constraints to better understand changes in nitrogen budget
during the glacial to interglacial transition. |
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