|
|
|
|
|
| Collins, J. A.; Govin, A.; Mulitza, S.; Heslop, D.; Zabel, M.; Hartmann, J.; Roehl, U.; Wefer, G.. |
| Relict dune fields that are found as far south as 14 N in the modern-day African Sahel are testament to equatorward expansions of the Sahara desert during the Late Pleistocene. However, the discontinuous nature of dune records means that abrupt millennial-timescale climate events are not always resolved. High-resolution marine core studies have identified Heinrich stadials as the dustiest periods of the last glacial in West Africa although the spatial evolution of dust export on millennial timescales has so far not been investigated. We use the major-element composition of four high-resolution marine sediment cores to reconstruct the spatial extent of Saharan-dust versus river-sediment input to the continental margin from West Africa over the last 60 ka.... |
| Tipo: Text |
|
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00181/29240/27635.pdf |
| |
|
|
| Berger, W.H.; Lange, C.B.; Wefer, G.. |
| A central finding of the ocean drilling expedition off Namibia and South Africa (Leg 175, 1997) is that the history of the intense coastal upwelling in that region is intimately tied into global climate change and the geochemistry of the deep ocean. The high productivity associated with this flow of cool, nutrient-dense deep water upwards along the coast cannot simply be described as a progressive increase of productivity that began ten million years ago. Instead, physical upwelling of cold water follows global cooling rather closely, while silicate content of the water (crucial for diatom production) runs out of phase with upwelling but is highly correlated with changes in thermohaline circulation. |
| Tipo: Working Paper |
Palavras-chave: Coastal upwelling; Climate change; Http://aims.fao.org/aos/agrovoc/c_35367. |
| Ano: 2001 |
URL: http://hdl.handle.net/1834/552 |
| |
|
|
|
