Where winds blow persistently alongshore, surface waters are forced offshore and replaced by highly productive, nutrient-rich water upwelling from below. Because of this high productivity, bottom sediments beneath upwelling systems are enriched in organic matter and microfossils of planktonic organisms, the abundance of which is a signal of upwelling intensity. Changes in climate affect the intensity of upwelling and are recorded in the sediments by strong changes in indicators of upwelling activity. Thus studies of the history of upwelling from sedimentary information can give us a clearer view of local and global changes in climate through time than we might see in other areas of the ocean where the variations in oceanography induced by climate change are more subtle.
The authors focus on results from deep ocean drilling expeditions, particularly those off NW and SW Africa, Peru and Saudi Arabia. These have allowed more advanced models to be developed of the temporal and spatial palaeoenvironmental patterns associated with upwelling systems since the Early Miocene.
The editors hope that this book will help to identify and explain the causes and characteristics of persistent upwelling systems, how they respond to climatic forcing and the global teleconnection between them; and make this information accessible to a wide community.
Upwelling Systems will appeal to marine geologists and geochemists, palaeoceanographers, palaeoclimatologists and petroleum geologists.
