Download or read book Image Analysis Sediments and Paleoenvironments written by Pierre Francus and published by Springer Science & Business Media. This book was released on 2007-01-19 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a guide to imaging techniques for sedimentologists, paleolimnologists, paleoceanographers and microscopists involved in paleoenvironmental reconstruction. Case studies illustrate the range of information obtainable from different sediments (marine, lacustrine, aeolian) and different types of samples (cores, embedded blocks, microscopic slides) using different regions of the electromagnetic spectrum (visible, UV, IR, X-ray). Includes comprehensive protocols, guidelines, and recommendations for the use of low cost image analysis techniques.

Download or read book Palaeoclimatology and Palaeoceanography from Laminated Sediments written by Alan E. S. Kemp and published by Geological Society of London. This book was released on 1996 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: The magnitude and causes of decadal to century-scale changes in climate are major issues of global concern. The separation of anthropogenically driven change from natural 'baseline' variability within the atmosphere/ocean system is a prerequisite to identifying human impact on global climate. An understanding of past climate variability is therefore a key to predicting future climate change. The sedimentary record of the oceans, seas and lakes is produced by a series of depositional events that occur on seasonal timescales but can rarely be resolved due to mixing of the sediment by bottomdwelling organisms. Where they are preserved, laminated sediments act like tree rings to record these seasonal-scale processes, such as plankton blooms and floods, and provide a uniquely high-resolution record of environmental change. In addition, annually laminated or 'varved' sediment sequences act as geochronometers against which other timescales can be tested. Laminated sediments may therefore be used to develop records of interannual and decadal-scale variability which serve to test models of climate change. The authors cover a range of topics that include strategies for study and techniques of analysis. A series of case studies, dealing with a variety of lacustrine and marine records, illustrates the wide potential of laminated sediments as palaeoclimatic and palaeoceanographic indicators.

Download or read book Late Quaternary Palaeoceanography of the North Atlantic Margins written by and published by . This book was released on 1996 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title focuses on ice sheet/ocean interactions, on oceanic climate change during the last deglaciation period and on the high temporal resolution that can be obtained from sediment records at continental margin sites. Many of the papers present high-resolution stratigraphic data, supported by accelerator mass spectrometry (AMS) radiocarbon dates, which demonstrate the advantages of continental margin records in resolving the palaeoceanography of the North Atlantic Ocean and in regional reconstructions of climate change.

Download or read book Use of Proxies in Paleoceanography written by Gerhard Fischer and published by Springer Science & Business Media. This book was released on 1999-11-02 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.