Download or read book Fingerprinting Quaternary Subglacial Processes on Hall Peninsula Baffin Island Using Multiproxy Data written by Cassia Johnson and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is important to study subglacial environments in northern Canada for many reasons, such as to develop a more comprehensive understanding of glacial landscape development and to aid in mineral exploration. The purpose of this research is improve understanding of the Quaternary Geology of north central Hall Peninsula, Baffin Island, the subglacial dynamics record in particular, in order to provide industry with new knowledge, maps and interpretations to aid in mineral exploration. The glacial history of north-central Hall Peninsula, Baffin Island is very complex. By studying the subglacial landscape using both remote- and field- based techniques it was possible to develop a subglacial landscape map and a flowset map which highlighted areas with different glacial histories and basal thermal regimes. The subglacial dynamics and how they changed spatially and temporally shaped the landscape to what it is today with a mixture of cold, intermediate, and warm-based ice. Through mapping using remote sensing and field methods, seven glacial landform and striation directions were found and grouped into four ice flow events. The identified ice flows include regional flows, northern and eastern fjord influenced areas, central deglacial flows, and modern icecap flows. Subglacial erosion was investigated using several proxies including streamlined hill elongation ratios, streamlined hill density, and bedrock controlled lake density studies. These proxies together with the subglacial landscape map were overlaid to select discrete zones, termed glacial terrain zones (GTZs), in an attempt to analyze the subglacial dynamics and how different basal thermal regimes interacted with the landscape. Five glacial terrain zones (GTZs) were identified, with different spatio-temporal basal ice regimes and landform assemblages. The first zone (GTZ 1) is characterized by an expansive flowset of parallel paleo-flow indicators trending northeast. This zone has the highest degree of areal scour with thin, discontinuous and relatively unweathered till. The second zone, GTZ 2, is an area where the broad northeast flowset is crosscut locally by ice flow indicators that converge into troughs that now form a series of north trending fjords in the north of the study area. This overprinted landscape is found to propagate inland forming a channelized system, leading way to linear erosion. The modern icecap resides in GTZ 3, which inherited the broad northeast flowset, but is overprinted in valleys by eastern flows funneling into the fjords to the east, as well as western flows flowing from the modern icecap. In the central area, there is a rolling terrain of thicker till (GTZ 4) that is distinguished by its lack of subglacial features. The final contrasting landscape (GTZ 5) is characterized by southeast trending bedrock features (most likely enhanced by southeast flowing ice) and associated perpendicular moraines. GTZ 5 is also characterized by highly weathered bedrock, and locally by landform assemblages recording late deglacial readvances of thin lobes including moraines and striated outcrops. Geochemical studies for each of these landscapes lead to additional insights, characterizing the five zones further. The geochemical studies took advantage of two till sample databases taken over the study area for exploration purposes by Peregrine Diamonds LTD. The chemical index of alteration (CIA) was applied to compare erosion in the different zones. High CIA values indicate high weathering, where low CIA values low weathering. GTZ 1 is characterized by low CIA values (low weathering footprint), and GTZ 5 is characterized by high CIA value (highly weathered). To study if the GTZs had a distinct geochemical signature, as well as a signature landscape, multivariate geochemical statistics (Principal Component Analysis and Linear Discriminant Analysis) were done over the study area. Interestingly, it was found that the GTZs have geochemical signatures, which reflect the role of underlying bedrock, weathering patterns, glacial dispersal, and the complex relationships between subglacial dynamics and landscape evolution. To determine if the GTZs could be predicted by the till geochemistry, linear discriminant analysis was subsequently applied. The results indicate that the till geochemical data has a predictive capacity with an accuracy of 83.78%, which brings insight into the relationship between glacial landscapes and till composition. With this multi-proxy approach and building from previous studies, a conceptual model was developed for the study area. During the Last Glacial Maximum (LGM), the study area was inundated by the Laurentide Ice Sheet (LIS), with the Hall Ice Divide parallel to the axis of the peninsula with ice flowing from the divide to the northeast and southwest. As ice thinned, GTZ 1, an area once inundated with warm-based ice, as shown by evidence of areal scour and low CIA values, switched to being cold-based ice preserving an older landscape. Though GTZ 1 was under cold-based ice, warm-based conditions still prevailed within the channelized flow zones, which characterize GTZ 2. Evidence of this is found in the striation record, as well as the low CIA value indicative of low weathering (or high erosion). This may reflect a transition from LGM (thick-based ice) to thinner, topographically controlled ice, with cold-based ice in interfluves and hilltops, during early deglaciation. The catchment zones of the channelized system locally extend near the central area (GTZ 4) which is reflected in dispersal patterns and the striation record. As the LIS retreated, it went through a series of southeastward readvances and surges (GTZ 5). Though the ice was warm-based near the moraines in GTZ 5, prevailing cold-based conditions prevailed during most of the last glacial cycle, and the late deglacial readvances had limited erosion capacity and did not overprint the cold-based landscape significantly. This is shown by the CIA values indicative of high weathering, and lack of subglacial landforms. Series of pro-glacial lakes also formed in front of the retreating lobe. Ice is needed over GTZ 1 to prevent these lakes from draining northward. This thin ice was most likely cold-based, preserving the older GTZ 1 landscape of areal scouring. The glacial landscape of Hall Peninsula appears to record a switch from uniform warm-based LGM ice, which was laterally extensive, to localized channel flows in the fjords during deglaciation and intervening cold-based ice. The change in the geometry and basal thermo-mechanical conditions may be the prologue to the separation of the modern day ice cap from the LIS.

Download or read book Glacier Science and Environmental Change written by Peter G. Knight and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Glacier Science and Environmental Change is an authoritative and comprehensive reference work on contemporary issues in glaciology. It explores the interface between glacier science and environmental change, in the past, present, and future. Written by the world’s foremost authorities in the subject and researchers at the scientific frontier where conventional wisdom of approach comes face to face with unsolved problems, this book provides: state-of-the-art reviews of the key topics in glaciology and related disciplines in environmental change cutting-edge case studies of the latest research an interdisciplinary synthesis of the issues that draw together the research efforts of glaciologists and scientists from other areas such as geologists, hydrologists, and climatologists color-plate section (with selected extra figures provided in color at www.blackwellpublishing.com/knight). The topics in this book have been carefully chosen to reflect current priorities in research, the interdisciplinary nature of the subject, and the developing relationship between glaciology and studies of environmental change. Glacier Science and Environmental Change is essential reading for advanced undergraduates, postgraduate research students, and professional researchers in glaciology, geology, geography, geophysics, climatology, and related disciplines.

Download or read book Satellite Image Atlas of Glaciers of the World Asia U S Geological Survey Professional Paper 1386 F written by U.S. Geological Survey and published by . This book was released on 2012-11-01 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Anthropocene as a Geological Time Unit written by Jan Zalasiewicz and published by Cambridge University Press. This book was released on 2019-03-07 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews the evidence underpinning the Anthropocene as a geological epoch written by the Anthropocene Working Group investigating it. The book discusses ongoing changes to the Earth system within the context of deep geological time, allowing a comparison between the global transition taking place today with major transitions in Earth history.

Download or read book Submerged Landscapes of the European Continental Shelf written by Nicholas C. Flemming and published by John Wiley & Sons. This book was released on 2017-08-07 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quaternary Paleoenvironments examines the drowned landscapes exposed as extensive and attractive territory for prehistoric human settlement during the Ice Ages of the Pleistocene, when sea levels dropped to 120m-135m below their current levels. This volume provides an overview of the geological, geomorphological, climatic and sea-level history of the European continental shelf as a whole, as well as a series of detailed regional reviews for each of the major sea basins. The nature and variable attractions of the landscapes and resources available for human exploitation are examined, as are the conditions under which archaeological sites and landscape features are likely to have been preserved, destroyed or buried by sediment during sea-level rise. The authors also discuss the extent to which we can predict where to look for drowned landscapes with the greatest chance of success, with frequent reference to examples of preserved prehistoric sites in different submerged environments. Quaternary Paleoenvironments will be of interest to archaeologists, geologists, marine scientists, palaeoanthropologists, cultural heritage managers, geographers, and all those with an interest in the drowned landscapes of the continental shelf.

Download or read book Sea Ice and Iceberg Sedimentation in the Ocean written by Alexander P. Lisitzin and published by Springer Science & Business Media. This book was released on 2002-10-02 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference book for researchers working on glacial sediments provides a complete overview of the various glacial deposits in the ocean. It presents a collection of worldwide data on glacio-marine phenomena.

Download or read book Ecosystem Dynamics in a Polar Desert written by and published by . This book was released on 1998 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Key Concepts in Geomorphology written by Paul R. Bierman and published by Macmillan Higher Education. This book was released on 2019-11-18 with total page 1715 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed with extensive community involvement and support from the US National Science Foundation, it is about our planet’s dynamic surface, a place where Earth and atmosphere meet and life thrives. Key Concepts in Geomorphology takes an integrative science approach that applies principles of physics, chemistry, biology, and mathematics in the understanding of Earth surface processes and the evolution of topography over short and long timescales to solve problems important to people and societies. The authors also hone in on practical applications, showing how scientists are using geomorphological research to tackle critical societal issues (natural disaster response, safer infrastructure, protecting species, and more).

Download or read book Early Middle Pleistocene Transitions written by Geological Society of London and published by Geological Society of London. This book was released on 2005 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Early-Middle Pleistocene transition (around 1.2 to 0.5 Ma) marks a profound shift in Earth's climate state. Low-amplitude 41 ka climate cycles, dominating the earlier part of the Pleistocene, gave way progressively to a 100 ka rhythm of increased amplitude that characterizes our present glacial-interglacial world. This volume assesses the biotic and physical response to this transition both on land and in the oceans: indeed it examines the very nature of Quaternary climate change. Milankovitch theory, palaeoceanography using isotopes and microfossils, marine organic geochemistry, tephrochronology, the record of loess and soil deposition, terrestrial vegetational change, and the migration and evolution of hominins as well as other large and small mammals, are all considered. These themes combine to explore the very origins of our present biota.

Download or read book Global Land Ice Measurements from Space written by Jeffrey S. Kargel and published by Springer. This book was released on 2014-07-08 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt: An international team of over 150 experts provide up-to-date satellite imaging and quantitative analysis of the state and dynamics of the glaciers around the world, and they provide an in-depth review of analysis methodologies. Includes an e-published supplement. Global Land Ice Measurements from Space - Satellite Multispectral Imaging of Glaciers (GLIMS book for short) is the leading state-of-the-art technical and interpretive presentation of satellite image data and analysis of the changing state of the world's glaciers. The book is the most definitive, comprehensive product of a global glacier remote sensing consortium, Global Land Ice Measurements from Space (GLIMS, http://www.glims.org). With 33 chapters and a companion e-supplement, the world's foremost experts in satellite image analysis of glaciers analyze the current state and recent and possible future changes of glaciers across the globe and interpret these findings for policy planners. Climate change is with us for some time to come, and its impacts are being felt by the world's population. The GLIMS Book, to be released about the same time as the IPCC's 5th Assessment report on global climate warming, buttresses and adds rich details and authority to the global change community's understanding of climate change impacts on the cryosphere. This will be a definitive and technically complete reference for experts and students examining the responses of glaciers to climate change. World experts demonstrate that glaciers are changing in response to the ongoing climatic upheaval in addition to other factors that pertain to the circumstances of individual glaciers. The global mosaic of glacier changes is documented by quantitative analyses and are placed into a perspective of causative factors. Starting with a Foreword, Preface, and Introduction, the GLIMS book gives the rationale for and history of glacier monitoring and satellite data analysis. It includes a comprehensive set of six "how-to" methodology chapters, twenty-five chapters detailing regional glacier state and dynamical changes, and an in-depth summary and interpretation chapter placing the observed glacier changes into a global context of the coupled atmosphere-land-ocean system. An accompanying e-supplement will include oversize imagery and other other highly visual renderings of scientific data.

Download or read book Alluvial Geoarchaeology written by A. G. Brown and published by Cambridge University Press. This book was released on 1997-03-27 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive technical manual aimed at archaeologists, physical geographers, geologists and environmental scientists.

Download or read book Glacial Environments written by M. J. Hambrey and published by UBC Press. This book was released on 1994 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enhanced by many photographic illustrations of extraordinaryquality, this textbook will provide students with a completeintroduction to the scientific study of environments dominated by snowand ice. Glacial environments are scenically and scientifically amongthe most exciting on Earth, and at the same time they are among themost complex. Apart from the processes associated directly with movingice, other processes -- fluvial, acolian, lacustrine, and marine --frequently interact with ice. Glacial environments therefore exhibit awide variety of landforms and sediment associations. Today, some ten per cent of the land surface of the Earth is coveredby ice, whereas in the Pleistocene the figure exceeded thirty per cent.In earlier geological history, the Earth underwent glaciations ofcontinent-wide extent on several occasions, some of them even moreintense than those of the Pleistocene. By examining the processesoperating within glacial settings and their resulting products,Glacial Environments provides the foundation for investigationof both the ancient and the modern record. Emphasizing the range of erosional and depositional landforms,drawing on the older geological record, according due attention to theexciting recent developments in research on the marine environment,incorporating illustrations from both contemporary and ancientenvironments and covering all relevant parts of the world, thisattractive book will find a wide readership among students ofgeography, geology and environmental science.

Download or read book Antarctic Journal of the United States written by and published by . This book was released on 1976 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book East Greenland Caledonides written by A. K. Higgins and published by . This book was released on 2004 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Principles of Sequence Stratigraphy written by Octavian Catuneanu and published by Newnes. This book was released on 2022-07-22 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Sequence Stratigraphy, Second Edition presents principles to practical workflow that guide applications in a consistent manner that is independent of model, geological setting and the types and resolution of the data available. The book explains the points of agreement and difference between the various approaches to sequence stratigraphy, while also defining the common ground that affords the standard application of the method. This enables the practitioner to avoid nomenclatural and methodological confusions and apply sequence stratigraphy. The text is richly illustrated with hundreds of full-color diagrams and examples of outcrop, borehole and seismic data. The book's balanced approach helps students and professionals acquire a sound understanding of the concepts and methodology. It will appeal to geologists, geophysicists and engineers with interest in basin analysis, stratigraphy and sedimentology, as well as in all economic applications that concern the exploration and production of natural resources, including water, hydrocarbons, coal and sediment-hosted mineral deposits. - Updates the award-winning first edition in all aspects of sequence stratigraphy, from the underlying theory to the practical applications - Presents the standard approach to sequence stratigraphic methodology, nomenclature, and classification; the role of modeling in sequence stratigraphy, and the difference between modeling and methodology - Discusses the roles of scale and stratigraphic resolution in sequence stratigraphy, and the workflow that affords a consistent application of the method irrespective of the types of data available - Describes the three-dimensional nature of the stratigraphic architecture, and the variability of stratigraphic sequences with the tectonic setting, depositional setting, and the climatic regime - Illustrates all concepts with high-quality, full-color diagrams, outcrop photographs, and subsurface well data and seismic images

Download or read book A Prehistory of the North written by John F. Hoffecker and published by Rutgers University Press. This book was released on 2005 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Early humans did not drift north from Africa as their ability to cope with cooler climates evolved. Settlement of Europe and northern Asia occurred in relatively rapid bursts of expansion. This study tells the complex story, spanning almost two million years, of how humans inhabited some of the coldest places on earth.

Download or read book Glacimarine Environments written by J. A. Dowdeswell and published by . This book was released on 1990 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume examines the processes responsible for sedimentation in modern glaciomarine environments, and how such modern studies can be used as analogues in the interpretation of ancient glaciomarine sequences. Sediments released from glaciers grounded in tidewater, floating ice shelves, ice tongues, icebergs and sea ice form complex sequences governed by glaciological, oceanographic, sedimentary and biogenic controls. Ten per cent of the world's oceans and epicontinental seas contain such active glacimarine environments, but during Cenozoic glacial periods this area was doubled. This book will, therefore, be of relevance to all scientists concerned with high and middle latitude marine environments. The early chapters are concerned largely with processes of sedimentation in modern glacimarine environments; examples are drawn from Alaska, the Canadian Arctic, Svalbard and Antarctica. Studies of ancient sequences, both Cenozoic and pre-Cenozoic, from the Barents Sea, Greenland, Sweden, Alaska and the northwest European continental shelf, form the latter part of the book.