Author: Peter Graham MortynPublisher:
ISBN:
Category :
Languages : en
Pages : 356
Book Description
Planktonic Foraminifera and Upper Water Column Variability in the South Atlantic
Author: Peter Graham MortynThe Northern North Atlantic
Author: Priska SchäferPublisher: Springer Science & Business Media
ISBN: 9783540672319
Category : Science
Languages : en
Pages : 520
Book Description
The northern North Atlantic is one of the regions most sensitive to past and present global changes. This book integrates the results of an interdisciplinary project studying the properties of the Greenland-Iceland-Norwegian Seas and the processes of pelagic and benthic particle formation, particle transport, and deposition in the deep-sea sediments. Ice-related and biogeochemical processes have been investigated to decipher the spatial and temporal variability of the production and fate of organic carbon in this region. Isotopic stratigraphy, microfossil assemblages and paleotemperatures are combined to reconstruct paleoceanographic conditions and to model past climatic changes in the Late Quaternary. The Greenland-Iceland-Norwegian Seas can now be considered one of the best studied subbasins of the world`s oceans.
The South Atlantic in the Late Quaternary
Author: Gerold WeferPublisher: Springer Science & Business Media
ISBN: 9783540210283
Category : Science
Languages : en
Pages : 742
Book Description
The South Atlantic plays a significant role as a link between the Antarctic Ocean and the North Atlantic, both in terms of the heat budget of the North Atlantic and the circulation of the entire ocean. The heat and mass exchanges between the Antarctic Ocean and the South Atlantic during the Late Quaternary have been investigated over the past ten years, including their impact on world climate. This has required the study of present-day early diagenetic processes in the water column and sediments, as well as sediment properties that have a close relationship to environmental parameters ("proxies"), which can be used to decipher past conditions (temperature, salinity, productivity, etc.). The interdisciplinary research project "The South Atlantic in the Late Quaternary - Reconstruction of material budgets and current systems" was a long-term scientific program at Bremen University. This program benefited from the sample material gained on several expeditions with the research vessels Meteor and Polarstern. This book presents the summarized results of the various topics of study in 30 articles arranged in seven sections. TOC:Particle Flux in the South Atlantic.- Documentation of the Marine Environment in Microfossil Assemblages and Stable Isotopes.- Physical Sedimentary Records of Palaeoenvironmental and Depositional Conditions.- Source and Transport Signatures of the Terrigenous Sediment Fraction.-Early Diagenetic Processes and Preservation of Primary Signals.-History of Upper Ocean Circulation.- History of Bottom and DeepWater Circulation.-
The South Atlantic in the Late Quaternary
Author: Gerold WeferPublisher: Springer Science & Business Media
ISBN: 3642189172
Category : Science
Languages : en
Pages : 742
Book Description
The South Atlantic plays a critical role in the couplingofoceanic processes between the Antarctic and the lower latitudes. The Antarctic Ocean, along with the adjacent southern seas, is of substantial importance for global climate and for the distributionofwater masses because itprovides large regions ofthe world ocean with intermediate and bottom waters. In contrast to the North Atlantic, the Southern Ocean acts more as an "information distributor", as opposed to an amplifier. Just as the North Atlantic is influencedby the South Atlantic through the contributionofwarm surface water,the incomingsupply ofNADW - in the area of the Southern Ocean as Circumantarctic Deep Water - influences the oceanography ofthe Antarctic. The competing influences from the northern and southern oceans on the current and mass budget systems can be best studied in the South Atlantic. Not only do changes in the current systems in the eastern Atlantic high-production regions affect the energy budget, they also influence the nutrient inventories, and therefore impact the entire productivity ofthe ocean. In addition, the broad region of the polar front is a critical area with respect to productivity-related circulation since it is the source of Antarctic Intermediate Water. Although theAntarctic Intermediate Watertoday liesdeeper than the water that rises in the upwelling regions, it is the long-term source ofnutrients that are ultimately responsible for the supply oforganic matter to the sea floor and to sediments.
Satellite-derived Sea Surface Temperature, Mesoscale Variability, and Foraminiferal Production in the North Atlantic
Author: Carl Martin WolfteichPublisher:
ISBN:
Category : Foraminifera
Languages : en
Pages : 182
Book Description
Planktonic foraminiferal flux was collected at four sediment trap locations spanning a 34° latitude range in the North Atlantic during 1988-1990. Satellite-derived sea surface temperature (SST) and CTD data were integrated with time-corrected flux data to determine the effects of seasonal hydrographic changes on foraminiferal production and species succession in surface waters. The thermal structure of the upper water column controls foraminiferal production by regulating levels of phytoplankton production and by directly influencing the preferred temperature habitats of individual species in the community. Sediment traps deployed at the two southern sites (34°N and 48°N) were part of the U.S. Joint Global Ocean Flux Study (JGOFS) and were located in regions influenced by upwelling events induced by mesoscale eddy activity. The timing of maximum foraminiferal production at each trap location coincides with the northward progression of the spring bloom in the North Atlantic. The magnitude of total flux during bloom periods varies considerably with location and is positively correlated with the amount of primary productivity in surface waters. Foraminiferal production is highest at JGOFS 48 and probably results from the greater influence of mesoscale variability in this region on local hydrographic conditions. The upwelling associated with cyclonic cold-core eddies appears to be an effective mechanism for increasing local foraminiferal production in the North Atlantic by enhancing food availability. The preferred production of individual species during upwelling periods may depend on the vertical distribution of chlorophyll in the water column. Seasonal variation in SST is also an important factor controlling the relative abundance of species with preferred thermal habitats. A distinct seasonal species succession occurs at both JGOFS sites but is absent at higher latitudes due to decreases in both faunal diversity and seasonal temperature variations with increasing latitude in the North Atlantic. Foraminiferal :flux data, expressed in terms of relative abundance, is the best direct method of comparing species distributions of living populations with fossil assemblages in the sedimentary record. Preferred temperature ranges for G. ruber, G. bulloides, and N. pachyderma are estimated in this study. The tolerance limits for these species and other ecological inferences derived from these flux data may prove useful for paleoceanographic reconstruction in deep-sea cores. Future studies will be necessary, however, to establish the consistency of these results among different ocean basins.
Planktic Foraminifers in the Modern Ocean
Author: Ralf SchiebelPublisher: Springer
ISBN: 9783662502952
Category : Science
Languages : en
Pages : 358
Book Description
This book provides a comprehensive overview of the taxonomy, biology, sedimentation, and carbonate geochemistry of modern species. Students, early career and advanced scientists alike will profit from a broad synthesis of the current understanding of planktic foraminifers as an ecological indicator, biogeochemical factories, and proxies in paleoceanography. The classification of modern species is amply illustrated with electron and light microscope images of morphotypes, addresses the state-of-the-art of molecular genetics of species, and provides a detailed guide for any laboratory analyses. The biology of planktic foraminifers is extensively discussed in chapters dedicated to the cellular ultrastructure, nutrition, symbionts, reproduction, ontogeny, and test architecture. Building on the biological prerequisites, the distribution of planktic foraminifers is discussed at regional to global scale. The geochemistry and sedimentation of tests are considered in relation to the ecology of the living animal. In the final chapter, which examines the most common methods in planktic foraminifer research, hands-on information is provided on sampling, processing and analyzing samples in the laboratory, as well as selected established methods for data interpretation. The various topics discussed in this book are aimed at the application of planktic foraminifers as sensitive indicators of the changing climate and marine environment.
Explorations
Author: Planktonic Foraminifera as Indicators of Different Water Masses in the South Atlantic
Author: Esteban BoltovskoySeasonal Variability in the Flux and Stable Isotopic Composition of Planktonic Foraminifera from the Upwelling Region
Author: Leslie Reynolds SautterPublisher:
ISBN:
Category : Marine ecology
Languages : en
Pages : 194
Book Description
Author: David Buursma Field