Download or read book Gravity Analyses for the Crustal Structure and Subglacial Geology of West Antarctica Particularly Beneath Thwaites Glacier written by Theresa Marie Diehl and published by . This book was released on 2008 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Crustal Structure Beneath Ice Stream C and Ridge BC West Antarctica from Seismic Refraction and Gravity Measurements written by Clifford G. Munson and published by . This book was released on 1991 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Exploration of Subsurface Antarctica written by M.J. Siegert and published by Geological Society of London. This book was released on 2018-01-08 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our appreciation of glaciological processes in Antarctica suffers from a lack of observations in regions where numerical models indicate the ice sheet to be susceptible to ocean and/or atmospheric warming. The solution lies in the use and development of glacier geophysics. In this volume we present a series of papers that demonstrate how geophysics can be deployed in Antarctica to comprehend: (1) boundary conditions that influence ice flow such as subglacial topography, the distribution of basal water and ice-sheet rheology; (2) phenomena that might affect ice-flow processes, such as complex internal ice-sheet structures and the proposition of large stores of hitherto unappreciated groundwater; and (3) how glacigenic sediments and formerly glaciated terrain on, and surrounding, the continent can inform us about past ice-sheet dynamics. The volume also takes a historical view on developments leading to current knowledge, examines active ice-sheet processes, and points the way forward on how geophysics can advance quantitative understanding of Antarctic ice-sheet behaviour.

Download or read book A Crustal scale Seismic Study of the Byrd Subglacial Basin Antarctica written by Ted. S. Clarke and published by . This book was released on 1996 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gravity Studies Over West Antarctica written by Svetlana Gennadiyevna Burris and published by . This book was released on 2012 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the results of new analysis of gravity studies over West Antarctica. Set on the Siple Coast, an airborne geophysical survey was flown between 1994 and 1997 that covered the trunk of Bindschadler Ice Stream and the up-stream areas, including Whitmore Accommodation Zone and Byrd Subglacial Basin. The new gravity reduction methodology removed vertical and horizontal accelerations, the Eötvös effect, and the theoretical gravity; unlike previous analyses, this reduction did not level individual lines, preserving the high frequency data and avoiding introduction of new errors. This reduction provided the free-air gravity disturbance over the area, which was then leveled and registered by the more regional extensive GOCE satellite gravity. The processing and reduction of the data improved the high frequency signal over previous work on the data, giving better definition of small scale, short wavelength features, which works well with satellite gravity data that emphasizes the large scale, long wavelength features. The leveled free-air gravity was then processed with a FORTRAN 90 program that calculates the Bouguer disturbance based on the free-air gravity and the topography. The topography was gathered concurrently with the gravity with ice penetrating radar during the airborne survey. The Bouguer disturbances provide a crustal model of the area. The final Bouguer disturbance was also corrected for the ice above sea level, which was calculated with a simple Bouguer slab correction. Finally, a power spectrum analysis was run on a profile in the Bouguer gravity disturbance in order to complete a spectral analysis. The spectral analysis provides crustal density boundaries for a density anomaly near the surface, a mid-crustal anomaly, and the Moho boundary. The improved the high frequency content of the data allows spectral analysis down to 4 km. The differing crustal thickness from spectral analysis also shows the character and extent of the West Antarctic Rift System, the northern flank of which extends out from Marie Byrd Land and into the survey area. Bindschadler Ice Stream is located on the WARS rift floor and MacAyeal Ice Stream sits on the rift flank. .

Download or read book Glaciology and Glacial Geology of Antarctica written by James P. Minard and published by . This book was released on 1961 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterizing the Subglacial Hydrology of Thwaites Glacier West Antarctica Using Airborne Radar Sounding written by Dustin Matthew Schroeder and published by . This book was released on 2014 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrologic, lithologic, and geothermal basal boundary conditions can exert strong, even dominating, control on the evolution, stability, and sea level contribution of ice sheets and glaciers. However, the scales at which the physical processes and observable signatures of this control occur are typically smaller than the spatial resolutions currently achievable using ice penetrating radar. Further, the strength of radar bed echo returns is affected by the material and geometric properties of the bed as well as englacial attenuation from unknown ice temperature and chemistry, making assessment of basal conditions from echo strengths difficult. To address these challenges in interpreting basal properties at glaciologically relevant scales, a new algorithmic approach is applied to measuring the radar scattering function of the bed in terms of the relative contribution of angularly narrow specular energy and isotropically scattered diffuse energy. This relative specularity content is insensitive to englacial attenuation and can be used to constrain the geometry of the bed down to the centimeter scale. This approach is applied to an airborne radar sounding survey of Thwaites Glacier, West Antarctica using the information in the along-track scattering function to assess the extent and geometry of water across the catchment and detect the transition of that water from distributed canals to concentrated channels. This information is also used to constrain the morphology of subglacial bedforms and infer that the distribution of deformable sediments and exposed bedrock is similar to deglaciated paleo ice streams that experienced meltwater intensive retreats. Finally, models of radar echo strength and subglacial water routing are compared to estimate a catchment-wide distribution of geothermal flux consistent with rift-associated magma migration and volcanism. These observations of basal conditions provide new context for the past, current, and future evolution of Thwaites Glacier, the West Antarctic Ice Sheet, and their contribution to global sea level.

Download or read book Geology and Seismic Stratigraphy of the Antarctic Margin written by Alan K. Cooper and published by American Geophysical Union. This book was released on 1997-01-23 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Antarctic Research Series, Volume 71. The Antarctic Ice Sheet has greatly affected global climate, sea level, ocean circulation, and southern hemisphere biota during Cenozoic times. Much of our understanding of the evolution of the ice sheet has been inferred from isotopic studies on distant deep-ocean sediments, because few Cenozoic rocks are exposed on the Antarctic continent. Yet, large differences occur between past ice volumes inferred from isotopic studies and those inferred from low-latitude sea-level variation. The massive quantities of glacially transported terrigenous sediments that lie beneath the Antarctic continental margin provide an additional, more direct record of the inferred ice sheet fluctuations. Volume 68 addresses the history of ice sheet fluctuations as recorded by geological and geophysical investigations of selected areas of the Antarctic continental margin. As described below, the volume gives data and results from on-going research by a major multinational project directed toward better understanding the impact of Antarctic Ice Sheet fluctuations on global sea levels and climates.

Download or read book Volcanism in Antarctica 200 Million Years of Subduction Rifting and Continental Break up written by J.L. Smellie and published by Geological Society of London. This book was released on 2021-06-09 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: This memoir is the first to review all of Antarctica’s volcanism between 200 million years ago and the Present. The region is still volcanically active. The volume is an amalgamation of in-depth syntheses, which are presented within distinctly different tectonic settings. Each is described in terms of (1) the volcanology and eruptive palaeoenvironments; (2) petrology and origin of magma; and (3) active volcanism, including tephrochronology. Important volcanic episodes include: astonishingly voluminous mafic and felsic volcanic deposits associated with the Jurassic break-up of Gondwana; the construction and progressive demise of a major Jurassic to Present continental arc, including back-arc alkaline basalts and volcanism in a young ensialic marginal basin; Miocene to Pleistocene mafic volcanism associated with post-subduction slab-window formation; numerous Neogene alkaline volcanoes, including the massive Erebus volcano and its persistent phonolitic lava lake, that are widely distributed within and adjacent to one of the world’s major zones of lithospheric extension (the West Antarctic Rift System); and very young ultrapotassic volcanism erupted subglacially and forming a world-wide type example (Gaussberg).

Download or read book Subglacial Geology of Ice Stream B West Antarctica written by Sean T. Rooney and published by . This book was released on 1988 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Gravity Study of West Antarctica written by Bruce Alan Kososki and published by . This book was released on 1972 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Crustal Structure in Western Lake Superior from the Integration of Seismic and Gravity Data written by Rodolfo Anzoleaga and published by . This book was released on 1971 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Antarctic Subglacial Lake Vostok written by Igor A. Zotikov and published by Springer Science & Business Media. This book was released on 2006-08-31 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book on the subject, this monograph examines the phenomenon of a huge sealed, freshwater lake, isolated from the rest of the world by kilometers' thick ice. The existence of melting ice at the bottom of the huge Vostok Lake has served as a model and inspired the team planning the Galileo space craft to gather data on the ice sheet of the Jupiterian moon Europa. The book provides interpretation of, and calculations for, stimulating factors for possible melting and a huge lake's existence at the bottom of the Martian ice sheets.

Download or read book First airborne gravity results over the Thwaites Glacier catchment West Antarctica written by T.M. DIEHL and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Some Aspects of Subglacial Geology and Glacial Mechanics Between the South Pole and the Horlick Mountains written by Edwin S. Robinson and published by . This book was released on 1964 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Part 1 A Regional Analysis of Crustal Structure in North America and Part 2 A Study of the Problems Associated with the Prediction of Gravity in Europe written by George Prior Woollard and published by . This book was released on 1969 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report is contained in two parts. Part I is an analysis of present gravity prediction procedures in the light of geophysical data concerning the crust and upper mantle. The assumptions on which these procedures are based (areas in isostatic equilibrium, relationship between Bouguer values and elevation, secondary control of Bouguer values, effects of near surface changes in geology) and their effects are discussed. Part II analyses the problems of predicting gravity in Europe. The geophysical factors related to these problems (a continental block bounded by deep water, intense tectonic deformation, acid and basic intrusives, lack of seismic measurements, glacial loading) are reviewed and the results tabulated. (Author).

Download or read book Structural Geology and Tectonics of the Orville Coast Region Southern Antarctic Peninsula Antarctica written by Karl S. Kellogg and published by . This book was released on 1989 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: