Gerold Wefer – författare

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.

Europe is a continent with a high coast-to-surface ratio, and European seas encompass a broad range of settings and regimes. The sustainable development of living and non-living marine resources, the protection of the marine environment and the provision of marine-based services are critical to economic prosperity and to the quality of life of European citizens. Addressing these concerns, marine-science researchers conducted a workshop reviewing major topics of European marine research. This publication contains overview and thematic background papers, as well as reports and recommendations for future research covering topics such as ocean-climate coupling, biogeochemistry, coastal and shelf processes, and ecosystem functioning/biodiversity.

Ocean margins are the transitional zones between the oceans and continents. They represent dynamic systems in which numerous processes shape the environment and result in impacting the utilization and hazard potentials for humans. These processes are influenced by a variety of steering mechanisms, from mountain building and climate on the land to tectonics and sea-level fluctuations in ocean margins. This book examines various aspects of regulation for the long-term development of ocean margins, of the impact of fluids and of the dynamics of benthic life at and below the seafloor in ocean margin systems.

Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox­ ies are measurable descriptors for desired but unobservable environmental variables such as tempera­ ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan­ isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

The global environment is changing rapidly under the impact of human activities. An important element in this change is related to global climate modification. Experts from the natural and social sciences with a strong interest in history discussed common topics of great interest to society. Can the study of climate and history help in devising strategies for coping with this change? What might be the type of information most useful in this context? What are the pitfalls awaiting the unwary? These and similar questions were discussed during a four-day workshop. The resulting proceedings contain comprehensive papers of broad interest, thematic back-ground papers and reports of study groups. Apart from scientists, the papers should interest graduate students and lecturers.

Ocean margins are the transitional zones between the oceans and continents. They represent dynamic systems in which numerous processes shape the environment and result in impacting the utilization and hazard potentials for humans. These processes are influenced by a variety of steering mechanisms, from mountain building and climate on the land to tectonics and sea-level fluctuations in ocean margins. This book examines various aspects of regulation for the long-term development of ocean margins, of the impact of fluids and of the dynamics of benthic life at and below the seafloor in ocean margin systems.

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.

Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox­ ies are measurable descriptors for desired but unobservable environmental variables such as tempera­ ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan­ isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

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.

Europe is a continent with a high coast-to-surface ratio, and European seas encompass a broad range of settings and regimes. The sustainable development of living and non-living marine resources, the protection of the marine environment and the provision of marine-based services are critical to economic prosperity and to the quality of life of European citizens. Addressing these concerns, marine-science researchers conducted a workshop reviewing major topics of European marine research. This publication contains overview and thematic background papers, as well as reports and recommendations for future research covering topics such as ocean-climate coupling, biogeochemistry, coastal and shelf processes, and ecosystem functioning/biodiversity.

Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox­ ies are measurable descriptors for desired but unobservable environmental variables such as tempera­ ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan­ isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

As connecting link between the Antarctic and the North Atlantic, the South Atlantic plays an important role in the distribution of heat in the North Atlantic and in the biogeochemical budget of all oceans. Oceanographers and geologists as well as micropaleontologists and meteorologists will find a wealth of information in this

As connecting link between the Antarctic and the North Atlantic, the South Atlantic plays an important role in the distribution of heat in the North Atlantic and in the biogeochemical budget of all oceans. Oceanographers and geologists as well as micropaleontologists and meteorologists will find a wealth of information in this

The global environment is changing rapidly under the impact of human activities, and an important element of this change is related to global c1imate modification. Can the study of c1imate and history help in devising strategies for coping with this change? What might be the type of information most useful in this context? What are the pitfalls awaiting the unwary? These are the kinds of questions that led us to bring together experts from the natural and social sci­ ences with a strong interest in history, to promote discussion between workers in different disciplines by focussing on a common topic of great interest to society. The meeting was arranged in the framework of a "Hanse Conference" within the interdisciplinary program of the Hanse-Wissenschaftskolleg, a foundation set up to promote interdisciplinary studies in collaboration between the universities ofBremen and Oldenburg. The aim ofthe Hanse Conferences in general is to provide opportunities for experts from different fields of the sciences and humanities to come together and explore the larger framework oftopics of common interest. What unites the partici­ pants is their desire to look over the fence to neighboring disciplines. Young colleagues who wish to build an interdisciplinary career are particularly welcome. In the Hanse Conference on Climate and History, we have endeavoured to build bridges between the c1imate sciences and the sociological sciences concemed with environmental impacts on human activities. The geological sciences, we feIt, are especially well suited to the purpose because they al­ ready comprise historical aspects.

Ocean margins are the transitional zones between the oceans and continents. They represent dynamic systems in which numerous processes shape the environment and result in impacting the utilization and hazard potentials for humans. These processes are influenced by a variety of steering mechanisms, from mountain building and climate on the land to tectonics and sea-level fluctuations in ocean margins. This book examines various aspects of regulation for the long-term development of ocean margins, of the impact of fluids and of the dynamics of benthic life at and below the seafloor in ocean margin systems.