Download or read book Diatom Stratigraphy and Evidence of Holocene Environmental Changes in Selected Lake Basins in the Antarctic and South Georgia written by Anders Wasell and published by . This book was released on 1993 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quaternary Glaciations Extent and Chronology written by J. Ehlers and published by Elsevier. This book was released on 2004-10-02 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the last of three volumes in which the recent knowledge of the extent and chronology of Quaternary glaciations has been compiled on a global scale. This information is seen as a fundamental requirement, not only for the glacial community, but for the wider user-community of general Quaternary workers. In particular the need for accurate ice-front positions is a basic requirement for the rapidly growing field of palaeoclimate modelling. In order to provide the information for the widest-possible range of users in the most accessible form, a series of digital maps was prepared. The glacial limits were mapped in ArcView, the Geographical Information System (GIS) used by the work group. Included with the publication is a CD with digital maps, showing glacial limits, end moraines, ice-dammed lakes, glacier-induced drainage diversions and the locations of key sections through which the glacial limits are defined and dated. Where controversial interpretations are possible, such as for High Asia, they are indicated. All information on Quaternary glaciations worldwide is presented for the first time in a uniform format, including the mountain glaciations of regions such as Costa Rica, Ethiopia or Taiwan. The digital maps in this volume cover Latin America, Asia, Africa, Australasia, Antarctica. Both overview maps and more detailed maps at a scale 1: 1,000,000 are provided. Also available: Part I: Europe, ISBN 0-444-51462-7 Part II: North America, ISBN 0-444-51592-5
Download or read book The Diatoms written by E. F. Stoermer and published by Cambridge University Press. This book was released on 2001-07-19 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Timely synopsis of applications in environment and industry using ubiquitous microscopic algae.
Download or read book Arctic Antarctic and Alpine Research written by and published by . This book was released on 2003 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diatoms of the Saline Lakes of the Vestfold Hills Antarctica written by Donna Roberts and published by . This book was released on 1999 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diatoms are an important element of many polar marine microbial communities and particularly abundant in Antarctic lakes. However, few comprehensive studies, such as the study presented in this volume are available on Antarctic communities. The diatom floras encountered in surface sediment samples from 33 lakes of the Vestfold Hills, Antarctica are presented. 67 distinct diatom species were identified in these sediments. They include cosmopolitan, Southern Ocean, endemic Antarctic and new diatoms. Each species encountered is described and illustrated; autecological information on the species is included where possible. Epilimnion water chemistry of the lakes sampled was determined to investigate their influence on diatom distribution. The studied lakes span a very large range of salinities from 0.5 to 165 permil. The authors show that salinity seems to have a strong influence on the observed diatom taxa.
Download or read book Antarctic Journal of the United States written by and published by . This book was released on 1995 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Freshwater Diatoms from Ile de la Possession Crozet Archipelago Subantarctica written by Bart Van de Vijver and published by . This book was released on 2002 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: The freshwater and terrestrial diatom composition of the Subantarctic island Ile de la Possession is investigated in detail. The island is part of the Crozet Archipelago, situated in the southern Indian Ocean. A total of 220 diatom taxa, belonging to 44 genera have been identified after surveying more than 500 samples, taken from all over the island. The most diverse genera are Pirmularia (41 taxa), Nitzschia (19 taxa), Psammothidium (13 taxa) and Diadesmis (11 taxa). Detailed SEM analysis of all observed taxa resulted in the description of several new species and varieties, especially in the genera Diadesmis and Pinnularia, whereas several others need further observations to be described later on as new taxa. In addition, the taxonomy of the so-called Subantarctic taxa has been thoroughly revised based on the most recent insights. All taxa are morphologically and ecologically characterized and elaborately documented with both LM and SEM micrographs.
Download or read book Antarctic Peninsula Climate Variability written by Eugene Domack and published by American Geophysical Union. This book was released on 2003-01-10 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Antarctic Research Series, Volume 79. The Antarctic Peninsula region represents our best natural laboratory to investigate how earth's major climate systems interact and how such systems respond to rapid regional warming. The scale of environmental changes now taking place across the region is large and their pace rapid but the subsystems involved are still small enough to observe and accurately document cause and affect mechanisms. For example, clarification of ice shelf stability via the Larsen Ice Shelf is vital to understanding the entire Antarctic Ice Sheet, its climate evolution, and its response to and control of sea level. By encompassing the broadest range of interdisciplinary studies, this volume provides the global change research and educational communities a framework in which to advance our knowledge of the causes behind regional warming, the dramatic glacial and ecological responses, and the potential uniqueness of the event within the region's paleoclimate record. The volume also serves as a vital resource for public policy and governmental funding agencies as well as a means to educate the large number of ecotourists that visit the region each austral summer.
Download or read book Lake Diatoms as a Proxy for Holocene Environmental Change West Greenland written by Louise Alice Best and published by . This book was released on 2013 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract:There is great interest over the Greenland Ice Sheet in terms of future climate change, though there is a lack of understanding of climate change during the Holocene. Lakes can provide continuous and detailed records of paleoclimate; the distinct taxonomy and preservation potential of diatoms makes them a particularly useful proxy within paleoenvironmental reconstructions. Contemporary diatom assemblages and the environmental conditions of 25 lakes from a localized area in the Godthåbsfjord region, southwest Greenland, as well as a fossil core from one of the lakes, are studied. Multivariate analysis is undertaken to establish the relationships between the contemporary diatoms and environmental conditions, and the addition of another dataset from Søndre Strømfjord, west Greenland, provided an insight into lake and diatom variability. Transfer functions are then developed for several environmental variables, including pH, temperature and lake depth, and applied to the fossil diatom assemblages from the lake core. The fossil diatom assemblages and quantitative reconstructions indicate an acidification of the lake through the Holocene, and the quantitative reconstructions, along with additional proxy data of pollen, provide a record of several warming and cooling phases through the Holocene, including the Little Ice Age. There are however several issues, including multiple forcing variables acting on the contemporary diatoms, the provision of modern analogues for the fossil assemblages, as well as preservation problems, that raise several questions over the reliability of lake diatoms as a proxy for Holocene environmental change in southwest Greenland.
Download or read book Tracking Environmental Change Using Lake Sediments written by John P. Smol and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: This third volume in the Developments in Paleoenvironmental Research series deals with the major terrestrial, algal, and siliceous indicators used in paleolimnology. Other volumes deal with the acquisition and archiving of lake sediment cores, chronological techniques, and large-scale basin analysis methods (Volume 1), physical and geochemical parameters and methods (Volume 2), zoological techniques (Volume 4), and statistical and data handling methods (Volume 5). These monographs will provide sufficient detail and breadth to be useful handbooks for both seasoned practitioners as well as newcomers to the area of paleolimnology. Although the chapters in these volumes target mainly lacustrine settings, many of the techniques described can also be readily applied to fluvial, glacial, marine, estuarine, and peatland environments.
Download or read book Holocene Paleolimnology and Diatom Bacillariophyta Succession in Lakes of the Central Highlands Region of Florida U S A written by Christopher M. Donar and published by . This book was released on 1999 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1983 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diatom Stratigraphy and Human Settlement in Minnesota written by John Platt Bradbury and published by Geological Society of America. This book was released on 1975 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long term Environmental Change in Arctic and Antarctic Lakes written by Reinhard Pienitz and published by Springer Science & Business Media. This book was released on 2005-05-03 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concerns about the effects of global climate change have focused attention on the vulnerability of circumpolar regions. This book offers a synthesis of the spectrum of techniques available for generating long-term environmental records from circumpolar lakes.
Download or read book Late Pleistocene and Holocene Sediments Around South Georgia written by Nina-Marie Lešić and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The island of South Georgia, along with a number of other smaller islands, is part of a microcontinent surrounded by oceanic crust in the Atlantic sector of the sub-Antarctic. Oceanographically, South Georgia lies within the Antarctic Circumpolar Current (ACC), the broad oceanic current system that is driven by the Southern Hemisphere Westerlies (SHW) and climatically isolates the Antarctic continent from the warmer Northern Hemisphere. Its location in the middle of the ACC and its isolation from continental influences makes South Georgia a sensitive region, where climate changes are registered earlier than on the more thermally isolated Antarctic continent. So far, however, the timing and extent of the Last Glacial Maximum on South Georgia have not been completely resolved, mostly because radiocarbon dated sediment investigations are missing. This is mainly due to the lack of marine geological studies on the continental shelf of the southern side of the island, which is climatically much harsher and therefore less accessible than the northern side. This information, however, is important to create and evaluate reliable climate and ice sheet models. This thesis, based on the investigations of sediment cores, sediment echosounder profiles and high-resolution bathymetry data, closes important knowledge gaps in the King Haakon Trough System and Drygalski Fjord System on the southern shelf of South Georgia. For the latter, the radiocarbon-dated sediments reveal an extensive ice cap before 30 ka BP during the Local Last Glacial Maximum. In the King Haakon Trough System, the bathymetric and sediment echo-graphic mapping of this thesis also reveal shelf-wide glaciation, possibly related to the last glacial period. Furthermore, this thesis investigates the subsequent deglaciation and the traces left by climate variability and its drivers within the sedimentary records in the two cross-shelf troughs. The results show that the southern shelf environments were ice-free since before the Antarctic Cold Reversal and thus exposed to currents at least since the start of the Holocene. These likely reacted to climate fluctuations of the present interglacial and, therefore, impacted trough sedimentation. Thus, this thesis does not only provide evidence for past ice-extent, which is crucial for benchmarking modelling approaches, but also gives further insight into the Holocene climate variability and sedimentary processes around South Georgia, potentially even archiving shelf-intruding behaviour of the nearby Southern Antarctic Circumpolar Current Front (SACCF) for at least the last 8 ka BP.
Download or read book The Diatom Stratigraphy of the Eemian Baltic Sea on the Basis of Sediment Discoveries in Ostrobothnia Finland written by Tuulikki Grönlund and published by . This book was released on 1991 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeography and Ecology in Antarctica written by J. van Mieghem and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 825 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the third in aseries of publications devoted to the biogeographieal and ecological research in the Southern Hemisphere, published in the "Monographiae Biologicae". After dealing with Australia (vol. VIII) and Southern Africa (Vol. XIV) it was thought essential to include Antarctiea in this series. Ever since the expedition of the "Belgiea" made the first suc cessful wintering within the antarctie circle in 1898 and brought back a very rieh harvest of scientific data, Belgium kept a vivid interest in Antarctiea and took an active part in the modern and international exploration of this vast continent. As part of their programs for the International Geophysieal Year (I. G. Y. ) twelve nations established permanent or semi-permanent bases on the Antarctie Continent or on subantarctie islands. Thus a new era of vast and free international scientific collaboration in the Antarctie was opened and it culminated in the formulation and the signing of the Antarctic Treaty (Washington 1959). It was recognized and accepted that "Antarctiea" shall be used for peaceful purposes only and "Freedom of scientific investigation in Antarctiea and coopera tion toward that end, as applied during the I. G. Y. , shall continue . . " In order to organize this collaboration e. g. by full exchange of programs and resuIts a "Special Committee on Antarctie Research" (S. C. A. R. ) was founded in 1957.
