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| Titel |
Shelf erosion and submarine river canyons: implications for deep-sea oxygenation and ocean productivity during glaciation |
| VerfasserIn |
I. Tsandev, C. Rabouille, C. P. Slomp, P. Cappellen |
| 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 ; 7, no. 6 ; Nr. 7, no. 6 (2010-06-22), S.1973-1982 |
| Datensatznummer |
250004849
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| Publikation (Nr.) |
 copernicus.org/bg-7-1973-2010.pdf |
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| Zusammenfassung |
| The areal exposure of continental shelves during glacial sea level lowering
enhanced the transfer of erodible reactive organic matter to the open ocean.
Sea level fall also activated submarine canyons thereby allowing large rivers
to deposit their particulate load, via gravity flows, directly in the deep-sea.
Here, we analyze the effects of shelf erosion and particulate matter re-routing
to the open ocean during interglacial to glacial transitions, using a coupled model
of the marine phosphorus, organic carbon and oxygen cycles. The results indicate that
shelf erosion and submarine canyon formation may significantly lower deep-sea oxygen
levels, by up to 25%, during sea level low stands, mainly due to the supply of new
material from the shelves, and to a lesser extent due to particulate organic matter
bypassing the coastal zone. Our simulations imply that deep-sea oxygen levels can
drop significantly if eroded shelf material is deposited to the seafloor. Thus the
glacial ocean's oxygen content could have been significantly lower than during
interglacial stages. Primary production, organic carbon burial and dissolved phosphorus
inventories are all affected by the erosion and rerouting mechanisms. However,
re-routing of the continental and eroded shelf material to the deep-sea has
the effect of decoupling deep-sea oxygen demand from primary productivity in the
open ocean. P burial is also not affected showing a disconnection between the
biogeochemical cycles in the water column and the P burial record. |
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