Download or read book Ultrasonic Velocity Investigations of Crystal Anisotropy in Deep Ice Cores from Antarctica written by Heinz Kohnen and published by . This book was released on 1979 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultrasonic Velocity Investigations of Crystal Anisotropy in Deep Ice Cores from Antarctica written by Heinz Kohnen and published by . This book was released on 1979 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ice cores from Byrd Station and Little America V have been used to test an ultrasonic technique for evaluating crystal anisotropy in the Antarctic Ice Sheet. P-wave velocities measured parallel and perpendicular to the vertical axes of cores from the 2164-m-thick ice sheet at Byrd Station have yielded results in excellent agreement with the observed c-axis fabric profile and with the in-situ P-wave velocity profile measured parallel to the bore hole axis. Velocity differences in excess of 140 m/s for core samples from deeper than 1300 m attest to the strong single pole clustering of crystallographic c-axes about the vertical, especially in the zone from 1300-1800 m. Such oriented structure is compatible only with strong horizontal shearing in this zone. The existence in an ice sheet of widespread shearing several hundred meters above its bed raises serious questions as to the validity of current concepts of the flow of large ice masses that tend to gloss over or ignore crystal alignments of this magnitude.

Download or read book Measurements of Ultrasonic Wave Velocities in Ice Cores from Greenland and Antarctica written by Hugh Frederick Bennett and published by . This book was released on 1972 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed ultrasonic velocity measurements were made on snow and ice cores from Greenland and Antarctica in order to study velocity anisotropy and its relationship to the petrofabric analysis of these cores. In addition, ultrasonic velocities were measured in the near-surface snow layers at Byrd Station and South Pole Station, Antarctica, to provide a detailed velocity profile in the region of the ice sheet where the velocity is greatly influenced by the snow structure. The experimental arrangement, including the design of equipment, measurement errors, techniques, and problems encountered in the study, is discussed. The theory of wave propagation in a general anisotropic medium is reviewed and a detailed presentation of this theory, concerning transversely isotropic media, is given. A method is developed for calculating a theoretical velocity model from the petrofabric analysis of the ice cores, thus providing a means of testing the theory with field and laboratory observations. (Author).

Download or read book Technical Report written by Cold Regions Research and Engineering Laboratory (U.S.) and published by . This book was released on 1979 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Investigation Into Velocity Anisotropy Through Measurements of Ultrasonic Wave Velocities in Snow and Ice Cores from Greenland and Antarctica written by Hugh Frederick Bennett and published by . This book was released on 1988 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Report written by Cold Regions Research and Engineering Laboratory (U.S.) and published by . This book was released on 1979 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1982 with total page 1102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by United States. Superintendent of Documents and published by . This book was released on 1982 with total page 1710 pages. Available in PDF, EPUB and Kindle. Book excerpt: February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

Download or read book CRREL Technical Publications written by Cold Regions Research and Engineering Laboratory (U.S.) and published by . This book was released on 1981 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book About the Relevance of Snow Microstructure Study in Cryospheric Sciences written by Maurine Montagnat and published by Frontiers Media SA. This book was released on 2021-01-07 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Library Acquisitions written by United States. Department of Transportation and published by . This book was released on with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1980 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Earth Science Investigations in the United States Antarctic Research Program USARP written by and published by . This book was released on 1977 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Earth Science Investigations written by and published by National Academies. This book was released on 1974 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of Ultrasonic Wave Velocities in Ice Cores from Greenland and Antarctica written by Charles R. Bentley and published by . This book was released on 1965 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study to measure ultrasonic P and S wave velocities in the ice cores from Greenland and Antarctica was designed to overcome the limitations of the standard methods. The main object of the study was to determine whether the sonic velocity measurements were consistent with the petrofabrics of the ice cores and thereby establish a method of estimating gross crystal orientation by sonic means. In addition, it provided a means of checking the results determined by refraction seismic methods. The comparison of these results indicated the amount of anisotropy present. The determination of wave attenuation as a function of depth also gave a measure of the mechanical filtering properties of the upper layers in the ice sheet. (Author).

Download or read book Glaciological Data written by and published by . This book was released on 1977 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report documents most of the ice cores so far collected on a world-wide basis, as well as providing information on literature sources and on the currents status of research activities which may affect the types of data that can be archived."--Foreword.

Download or read book Greenland Ice Core written by Chester C. Langway and published by American Geophysical Union. This book was released on 1985 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: