Author: Katharina Teresa StreuffPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Glacimarine Sedimentary Processes and Products at Fjord-terminating Tidewater Glacier Margins
Author: Katharina Teresa StreuffPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Glacial Sedimentary Processes and Products
Author: Michael J. HambreyPublisher: Wiley-Blackwell
ISBN:
Category : Science
Languages : en
Pages : 432
Book Description
""The wide range of time periods, methods and concepts discussed should be of interest across many subject areas ... A wide mix of research published in this volume."" (Holocene, December 2008).
Glacimarine Environments
Author: J. A. DowdeswellPublisher:
ISBN:
Category : Science
Languages : en
Pages : 440
Book Description
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.
Glacier-influenced Sedimentation on High-latitude Continental Margins
Author: J. A. DowdeswellPublisher: Geological Society of London
ISBN: 9781862391208
Category : Nature
Languages : en
Pages : 398
Book Description
This book examines the process and patterns of glacier-influenced sedimentation on high-latitude continental margins and the geophysical and geological signatures of the resulting sediments and landforms. It contains a range of papers concerning modern and glacially-influenced sedimentation in high-latitude areas from both hemispheres, many of which discuss the relationship between glacier dynamics and the sediments and landforms preserved in the glacimarine environment.
Glaciated Margins
Author: D.P. Le HeronPublisher: Geological Society of London
ISBN: 1786203979
Category : Science
Languages : en
Pages : 289
Book Description
Understanding the sedimentary and geophysical archive of glaciated margins is a complex task that requires integration and analysis of disparate sedimentological and geophysical data. Their analysis is vital for understanding the dynamics of past ice sheets and how they interact with their neighbouring marine basins, on timescales that cannot be captured by observations of the cryosphere today. As resources, sediments deposited on the inner margins of glaciated shelves also exhibit resource potential where more sand-dominated systems occur, acting as reservoirs for both hydrocarbons and water. This book surveys the full gamut of glaciated margins, from deep time (Neoproterozoic, Ordovician and Carboniferous–Permian) to modern high-latitude margins in Canada and Antarctica. This collection of papers is the first attempt to deliberately do this, allowing not only the similarities and differences between modern and ancient glaciated margins to be explored, but also the wide spectrum of their mechanisms of investigation to be probed. Together, these papers offer a high-resolution, spatially and temporally diverse blueprint of the depositional processes, ice sheet dynamics, and basin architectures of the world’s former glaciated margins; a vital resource in advancing understanding of our present and future marine-terminating ice sheet margins.
A Practical Guide to the Study of Glacial Sediments
Author: David J. A. EvansPublisher: Routledge
ISBN: 1444119141
Category : Science
Languages : en
Pages : 297
Book Description
Sediments are the most valuable form of physical evidence for past Earth surface processes. They have the potential to build up an archive of events and provide a window into the past. Through careful examination of sediments the shifting patterns of surface processes across space and time are revealed, allowing us to reconstruct past environments and environmental change. A Practical Guide to the Study of Glacial Sediments is a guide to the standard techniques employed to read the sedimentary record of former glaciers and ice sheets. It demonstrates that the often complex and fragmentary glacial sedimentary record can, when examined systematically and rationally, provide detailed insights into former environments and climates in places where no other evidence is available. The complementary techniques covered in this book include: facies description, grain size analysis, clast form assessment, clast macrofabric analysis, micromorphology, particle lithology and assessment of engineering properties. They yield consistent and meaningful results in a range of glacial depositional environments throughout the world, from the high Arctic to the Himalayas. A Practical Guide to the Study of Glacial Sediments provides students and researchers with a clear and accessible guide to recording and interpreting glacial successions wherever the location.
Fjord Sedimentation During the Rapid Retreat of Tidewater Glaciers
Author: Katherine V. BoldtPublisher:
ISBN:
Category : Glacial erosion
Languages : en
Pages : 162
Book Description
Ice-ocean interactions remain poorly understood despite the growing recognition that they play significant roles in the complex behavior of glaciers that reach the oceans, which is of broad interest because it contributes substantially to the challenge of predicting global sea-level rise. This research focuses on the dynamics of sediment accumulation near the calving fronts of tidewater glaciers across a climatic continuum from polar to temperate conditions. Rates and spatial patterns of sediment accumulation merit close attention because they can affect glacier stability by reducing the water depth that controls the calving rate, the surface area available for submarine melting, and the ability of tidewater glaciers to advance into deep water. The sediments produced by these glaciers are also of considerable interest because they record changes in glacial, environmental, and tectonic conditions. In light of the recent, well documented changes in climate and glacier extent along the Antarctic Peninsula through much of the last century, a detailed study was developed to understand how modern sediments have recorded these regional changes. Sediment accumulation rates for sixteen cores collected in fjords across a 15° N-S transect from the Antarctic Peninsula to southern Chile were calculated using the decay of naturally occurring radioisotope 210Pb. Records from the Antarctic Peninsula show surprisingly constant rates of sediment accumulation (1-7 mm/yr) throughout the past century despite rapid warming, increase in surface melt, and glacial retreat. Cores from the South Shetland Islands, on the other hand, reveal accelerated sediment accumulation over the past few decades, likely due to warming and an increase in surface melt in this region, which straddles the boundary between subpolar and temperate conditions. In the temperate fjords of southern Chile, sediment accumulates faster (11-24 mm/yr). This increase in sediment accumulation with decreasing latitude reflects the gradient from subpolar to temperate climates, and is consistent with glacial erosion being much faster in the very wet, temperate climate of southern Chile than along the colder Antarctic Peninsula. Links between rates of glacier retreat, ice motion, sediment flux, and the evolution of glacial sediment deposits in a temperate setting are explored using a large existing dataset for Columbia Glacier, Alaska and new oceanographic data from the fjord recently exposed by its retreat. High-resolution seismic data indicate that 3.2 x 108 m3 of sediment has accumulated over the last three decades; this volume corresponds to erosion at 5.1 ± 1.8 mm/yr averaged over the entire ~1000 km2 area of the glacier. A numerical model is developed to relate known patterns of sedimentation and changes in the glacier terminus position to the accumulation of sediment in the fjord during the 30-year period of retreat. The model, which represents both primary sedimentation and secondary reworking, is used to produce a history of the sediment flux from the glacier that is compatible with the observed post-retreat sediment deposit thickness and architecture. The bathymetric history and model results corroborate that the sediment flux increased sixfold within the 1997-2000 period; interestingly this increase is not correlated with concurrent changes in glacier dynamics. It is suggested that the increase resulted from the sediment transport capacity of subglacial rivers increasing due to the retreat-related steepening of the glacier surface over a deep subglacial basin. That major variations in the sediment flux can be controlled by changes in subglacial sediment storage, in addition to changes in climate and the erosion rate, adds richness and complexity to the interpretation of the glacimarine sediment record. The sediment-flux model is also applied to Jorge Montt Glacier, a Patagonian tidewater glacier with very similar behavior to Columbia Glacier, but without the detailed record of its retreat history and other complementary glaciological data. Sediment volume calculations for both glaciers indicate that the effective erosion rate necessary to sustain the mean sediment fluxes during their respective periods of retreat is surprisingly similar, ~5 mm/yr, despite differences in the geographic, tectonic, and geologic settings. For both rapidly retreating glaciers, the numerical model yields a sediment-flux history that produces sediment packages generally consistent with observed bathymetry and internal stratigraphic architecture. On the time scale of retreat, temporal variations in the modeled sediment flux from both glaciers are not related to concurrent variations in ice velocity, as expected. Rather, changes in the sediment flux are attributed to the tendency for sediment to be flushed from subglacial basins due to the progressive steepening of the glacier terminus during retreat. In both fjords, model results corroborate that sediment accumulates rapidly (>1 m/yr) near the ice front. In addition, the model suggests that gravity-driven processes are essential for delivering and redistributing sediment within the fjords to create the observed bathymetry and internal stratigraphic architecture.
Glacial Marine Sedimentation
Author: John B. AndersonPublisher: Geological Society of America
ISBN: 9780813722610
Category : Science
Languages : en
Pages : 244
Book Description
The papers in this collection are based on a symposium held at the 1988 annual meeting of the Geological Society of America, with the objective of identifying sedimentary criteria and facies models that can be used to characterize the glacial-climate setting of ancient sedimentary sequences. Includes papers on Antarctica, Alaska, and Ellesmere Island, and a brief literature review.
Sedimentary Processes, Facies, and Accumulation Rates at Alaskan Temperate Tidewater Glaciers
Author: Jonathan P. CooperPublisher:
ISBN:
Category : Facies (Geology)
Languages : en
Pages : 560
Book Description
Glacial-marine Sedimentation
Author: John B. AndersonPublisher:
ISBN:
Category : Science
Languages : en
Pages : 144
Book Description