ALBERT

Description / Table of Contents: Inhalt: Grußwort. - Zu diesem Buch. - Entdeckerlust und nationaler Ehrgeiz. - Anschluss-Suche: Die ersten Expeditionen. - Außen vor: Die Antarktis wird international. - Wachsende Eigenständigkeit: DDR-Forschung in der Antarktis. - Rohstoffe locken: Die Bundesrepublik Deutschland entdeckt die Antarktis. - Endlich dabei: Polarforschung wird nationale Aufgabe. - Eine Struktur wird geschaffen: Aufbau der neuen Instrumente. - Ordnung in der Vielfalt: Die Wissenschaft setzt Schwerpunkte. - Präzisionsarbeit: Beispielhaftes aus multinationalen Kooperationen. - Polarforschung in der Zukunft. - Abkürzungsverzeichnis. - Hinweise auf weiterführende Literatur. - Register. - Personenregister. - Verzeichnis der Polarstationen

Description / Table of Contents: Contents: Introduction to rock physics. Rock physics interpretation of texture, lithology and compaction. Statistical rock physics: combining rock physics, information theory, and statistics to reduce uncertainty. Common techniques for quantitative seismic interpretation. Case studies: lithology and pore fluid prediction from seismic data. Work flows and guide lines.

Description / Table of Contents: Contents: Introduction and previous research. - Seismology and neotectonics. - The gravity field. - Pre-Tertiary stratigraphy. - Granites. - Pre-Tertiary volcanic rocks. - Tertiary stratigraphy. - Tertiary volcanicity. - Quaternary volcanicity. - Fuel resources: oil and gas. - Fuel resources: coal. - Metallic mineral resources. - Structure and structural history. - Tectonic evolution. - Appendix: Radiometric age data for Sumatra.

Description / Table of Contents: The publication of this volume occurs at the one-hundredth anniversary of 1905, which has been called the annus mirabilus because it was the year of a number of enormous scientific advances. Among them are four papers by Albert Einstein explaining (among other things) Brownian motion, the photoelectric effect, the special theory of relativity, and the equation E = mc2. Also of significance in 1905 was the first application of another major advance in physics, which dramatically changed the fields of Earth and planetary science. In March of 1905 (and published the following year), Ernest Rutherford presented the following in the Silliman Lectures at Yale: "The helium observed in the radioactive minerals is almost certainly due to its production from the radium and other radioactive substances contained therein. If the rate of production of helium from known weights of the different radioelements were experimentally known, it should thus be possible to determine the interval required for the production of the amount of helium observed in radioactive minerals, or, in other words, to determine the age of the mineral." Rutherford E (1906) Radioactive Transformations. Charles Scriber's Sons, NY Thus radioisotopic geochronology was born, almost immediately shattering centuries of speculative conjectures and estimates and laying the foundation for establishment of the geologic timescale, the age of the Earth and meteorites, and a quantitative understanding of the rates of processes ranging from nebular condensation to Quaternary glaciations. There is an important subplot to the historical development of radioisotopic dating over the last hundred years, which, ironically, arises directly from the subsequent history of the U-He dating method Rutherford described in 1905. Almost as soon as radioisotopic dating was invented, it was recognized that the U-He [or later the (U-Th)/He method], provided ages that were often far younger than those allowed by stratigraphic correlations or other techniques such as U/Pb dating. Clearly, as R.J. Strutt noted in 1910, He ages only provided "minimum values, because helium leaks out from the mineral, to what extent it is impossible to say" (Strutt, 1910, Proc Roy Soc Lond, Ser A 84:379-388). For several decades most attention was diverted to U/Pb and other techniques better suited to measurement of crystallization ages and establishment of the geologic timescale. Gradually it became clear that other radioisotopic systems such as K/Ar and later fission-track also provided ages that were clearly younger than formation ages. In 1910 it may have been impossible to say the extent to which He (or most other elements) leaked out of minerals, but eventually a growing understanding of thermally-activated diffusion and annealing began to shed light on the significance of such ages. The recognition that some systems can provide cooling, rather than formation, ages, was gradual and diachronous across radioisotopic systems. Most of the heavy lifting in this regard was accomplished by researchers working on the interpretation of K/Ar and fission-track ages. Ironically, Rutherfordπs He-based radioisotopic system was one of the last to be quantitatively interpreted as a thermochronometer, and has been added to K/Ar (including 40Ar/39Ar) and fission-track methods as important for constraining the medium- to low-temperature thermal histories of rocks and minerals. Thermochronology has had a slow and sometimes fitful maturation from what were once troubling age discrepancies and poorly-understood open-system behaviors, into a powerful branch of geochronology applied by Earth scientists from diverse fields. Cooling ages, coupled with quantitative understanding of crystal-scale kinetic phenomena and crustal- or landscape-scale interpretational models now provide an enormous range of insights into tectonics, geomorphology, and subjects of other fields. At the same time, blossoming of lower temperature thermochronometric approaches has inspired new perspectives into the detailed behavior of higher temperature systems that previously may have been primarily used for establishing formation ages. Increased recognition of the importance of thermal histories, combined with improved analytical precision, has motivated progress in understanding the thermochronologic behavior of U/Pb, Sm/Nd, Lu/Hf, and other systems in a wide range of minerals, filling out the temperature range accessible by thermochronologic approaches. Thus the maturation of low- and medium-temperature thermochronology has led to a fuller understanding of the significance of radioisotopic ages in general, and to one degree or another has permeated most of geochronology. Except in rare cases, the goal of thermochronology is not thermal histories themselves, but rather the geologic processes responsible for them. Thermochronometers are now routinely used for quantifying exhumation histories (tectonic or erosional), magmatism, or landscape evolution. As thermochronology has matured, so have model and interpretational approaches used to convert thermal histories into these more useful geologic histories. Low-temperature thermochronology has been especially important in this regard, as knowledge of thermal processes in the uppermost few kilometers of the crust require consideration of coupled interactions of tectonic, geodynamic, and surface processes. Exciting new developments in these fields in turn drive improved thermochronologic methods and innovative sampling approaches. The chapters This volume presents 22 chapters covering many of the important modern aspects of thermochronology. The coverage of the chapters ranges widely, including historical perspective, analytical techniques, kinetics and calibrations, modeling approaches, and interpretational methods. In general, the chapters focus on intermediate- to low-temperature thermochronometry, though some chapters cover higher temperature methods such as monazite U/Pb closure profiles, and the same theory and approaches used in low-temperature thermochronometry are generally applicable to higher temperature systems. The widely used low- to medium-temperature thermochronometric systems are reviewed in detail in these chapters, but while there are numerous chapters reviewing various aspects of the apatite (U-Th)/He system, there is no chapter singularly devoted to it, partly because of several previous reviews recently published on this topic. Chapter 1 by Reiners, Ehlers, and Zeitler provides a perspective on the history of thermochronology, comments on modern work in this field and general lessons on the potential for noise to be turned into signal. This chapter also provides a summary of the current challenges, unresolved issues, and most exciting prospects in the field. Much of the modern understanding of kinetic controls on apparent ages, thermal histories, and sampling approaches comes from decades of progress in fission-track dating, a method that remains as essential as ever, partly because of the power of track-length measurements and the depth of (at least empirical) understanding of the kinetics of track annealing. Tagami, Donelick and OπSullivan review the fundamentals of modern fission-track dating (Chapter 2). Two of the most commonly dated, well-understood, and powerful minerals dated by fission-track methods are apatite and zircon, and the specifics of modern methods for these systems and their kinetics are reviewed by Donelick, OπSullivan, and Ketcham (Chapter 3), and Tagami (Chapter 4). Although 40Ar/39Ar and (U-Th)/He dating methods followed somewhat different paths to their modern thermochronologic incarnations, they have many features in common, especially in the kinetics of diffusion and closure. Zeitler and Harrison review the concepts underlying both 40Ar/39Ar and (U-Th)/He methods (Chapter 5). Zircon was one of the first minerals dated by the (U-Th)/He method, but has only just begun to be used for thermochronometry of both bedrock and detrital samples, as reviewed by Reiners (Chapter 6). Continuous time-temperature paths from intracrystalline variations of radiogenic Ar proven perhaps the most powerful of all thermochronologic approaches, and an innovative analogous approach in He dating (4He/3He thermochronometry) is revealing remarkably powerful constraints on the extreme low temperature end of thermal histories, as reviewed by Shuster and Farley (Chapter 7). Thermochronology of detrital minerals provides unique constraints on the long-term evolution of orogens, sediment provenance, and depositional age constraints, to name a few. Bernet and Garver (Chapter 8) review the essentials of detrital zircon fission-track dating, one of the most venerable and robust of detrital thermochronometers, and in Chapter 9, Hodges, Ruhl, Wobus, and Pringle review the use of 40Ar/39Ar dating of detrital minerals, demonstrating the power of detrital muscovite ages in illuminating variations in exhumation rates in catchments over broad landscapes. (U-Th)/He thermochronometry presents several unique interpretational challenges besides new kinetics and low temperature sensitivity. One of these is long-alpha stopping distances, and its coupling with diffusion and U-Th zonation in age corrections. Dunai reviews modeling approaches to deal with these issues in interpreting low-temperature thermal histories (Chapter 10). Ketcham (Chapter 11) reviews the theory and calibration of both forward and inverse models of thermal histories from fission-track and (U-Th)/He data, and makes some important points about the interpretations of such models. Translating thermal histories into exhumational histories and their tectonic or geomorphic significance across a landscape requires quantitative understanding of the thermal structure of the crust and how it is perturbed, a review of which is presented by Ehlers (Chapter 12). Braun (Chapter 13) illustrates the power of low-temperature thermochronometry to constrain topographic evolution of landscapes over time, using PECUBE. Gallagher, Stephenson, Brown, Holmes, and Ballester present a novel method of inverse modeling of fission-track and (U-Th)/He data for thermal histories over landscapes (Chapter 14). Continuous time-temperature paths from closure profiles or their step-heating-derived equivalents are, to some degree, the holy grail of thermochronology. Harrison, Zeitler, Grove, and Lovera (Chapter 15) provide a review of the theory, measurement, and interpretation of continuous thermal histories at both intermediate and high temperatures, derived from both K-feldspar 40Ar/39Ar and monazite U/Pb dating. Extensional orogens provide a special challenge and opportunity for thermochronometry because tectonic exhumation by footwall unroofing often outstrips erosional exhumation, and often occurs at high rates. As Stockli shows (Chapter 16) thermochronology in these setting provides opportunities to measure rates of a number of important processes, as well as obtain a snapshot of crustal thermal structure and its imprint on thermochronometers with varying closure temperatures. Spotila (Chapter 17) reviews the use of thermochronology applied to tectonic geomorphology in a wide range of orogenic settings, introducing the concept of denudational maturity. Thermochronology has found great utility in economic geology, and newly developed approaches pose great potential in this area, and shown by McInnes, Evans, Fu, and Garwin in their review of the use and modeling of thermochronology of hydrothermal ore deposits (Chapter 18). The thermal histories of sedimentary basins are also critical to understanding thermal maturation of hydrocarbons, but are also critical for understanding basin formation, erosional histories of source regions, fluid flow, and climate change and other temporal signals preserved in sedimentary rocks. Armstrong (Chapter 19) reviews these issues and the use of thermochronology in deducing the thermal histories of sedimentary basins. Drawing on large datasets of bedrock apatite fission-track dates, Kohn, Gleadow, Brown, Gallagher, Lorencak, and Noble demonstrate the power of modeling, and, importantly, effectively visualizing, integrated thermotectonic and denudational histories over large regions (Chapter 20). Thermal histories of meteorites provide constraints on a wide range of fundamentally important processes, including nebular condensation and early solar-system metamorphic histories, and the dynamics of interplanetary collisions and shock metamorphism. Min reviews thermochronologic approaches to understanding meteorite thermal histories (Chapter 21), including new methods and approaches. Finally, the importance of robust models with which to interpret thermochronologic data is underscored by the review of the Software for Interpretation and Analysis of Thermochronologic Data (Chapter 22), summarized and compiled by Ehlers, for programs associated with the work of authors in this volume and others.

Description / Table of Contents: Contents: Neutron Sources . Properties of the neutron, e1ementary scattering processes . E1astic Scattering from Many-Body Systems . Polarization analysis. Correlation Functions Measured By Scattering Experiments. Continuum description: Grazing Incidence Neutron Scattering. Diffractometer . Small-angle Scattering and Reflectometry . Crystal spectrometer: triple-axis and back-scattering spectrometer . Time-of-flight spectrometers . Neutron spin-echo spectrometer. Structure determination .lnelastic neutron scattering: phonons and magnons . Soft Matter: Structure D. . Polymer Dynamics . Magnetism . Translation and Rotation . Texture in Materials and Earth Sciences.

Description / Table of Contents: In the first edition of this book I tried to survey in brief compass the main ideas, methods, and discoveries of rational thermodynamics as it then stood, only five years after Messrs. COLEMAN & NOLL, while in Baltimore, had written the fundamental memoir that provided for the new science the one root theretofore wanting. A survey in the same style today would require an almost wholly new book, three or four times as long. As it was in 1968, again in 1983 a consecutive treatise restricted to the foundations would be premature, for at this moment they are under earnest discussion, probing analysis, and powerful attack by several students and from several directions. Because, although in the first edition I expressed some opinions I no longer hold and made some statements I should now recast or even re­ tract, it seems even yet to offer a simple introduction to some aspects of the field that remain current, I have chosen to reprint it unaltered except for emendation of slips and bettering of the English here and there.

Description / Table of Contents: An account of the results of the 2 March 1987 earthquake in the eastern Bay of Plenty and the aftermath's effects on the people and places on the Rangitaiki Plains

Description / Table of Contents: Orwell Lake, in west-central Minnesota, is a flood-control, water-management reservoir first impounded in 1953. Subsequent erosion of the shoreline and a lack of knowledge of slope erosion processes in this region prompted this study to identify and quantify the processes there. The processes were measured at selected sites between June 1980 and June 1983. Erosion of the banks is primarily caused by three processes: rain, frost thaw, and waves. The first two processes tend to move sediment to the base of the steep slopes, forming 4 relatively gentle surface of accumulation. Wave action then tends to move this sediment into the lake. Analysis of the data collected over three years has confirmed that wave action is the dominant erosion process, providing almost 77% of the erosion during the 1981-82 study year. During the 1981 high pool level, 2,089 Mg of sediment, mostly colluvium, was removed from the lower slopes by wave action striking the 1.62 km of eroding shoreline. More than 4,300 Mg was eroded by waves accompanying the higher pool levels of 1982., During years in which the pool level does not exceed 325.5 m in elevation, the colluvium slope builds up at the expense of the steeper slope. But during successive years with higher pool levels, the resulting thin colluvium is quickly eroded. Erosion of the primary sediment, a compact till, then occurs, forming the S typical nearly vertical banks. In winter the upland surface adjacent to the lake freezes to a depth of between 1 and 2 m, depending on the surface temperature, the mow cover, and the distance from exposed banks. In late winter soil aggregates, released by the sublimation of interstitial ice within the banks, begin to accumulate at the base of the slopes, often veneering snowbanks there. Once thaw begins, slab failure of bank sediment is followed by mudflows and earthflows. Thaw failure at Orwell Lake in the winter of 1981-82 accounted for over 20% of the erosion; in the spring of 1982, 824 Mg was eroded by this process and 746 Mg the following spring. Such slope failure is most intense along north-facing banks and considerably less intense on south-facing banks, where more effective desiccation and sublimation reduce the soil moisture content. Summer rainfall is responsible for the remaining 3% of the total erosion, amounting to 102 Mg in 1981 and 208 Mg in 1982. Because the banks are steep and relatively short, rainwash is infrequent; rainsplash is the most consistent process during the summer, but the infrequent storms during which rainwash occurscause greater total erosion. Erosion by rain has increased in each of the past three summers, largely because of increased precipitation. Infrequent massive slope failures (slumps) have occurred at the east end of the lake where a buried clay rich unit is stratigraphically and topographically positioned to favor such failures. Drought years followed by heavy spring rains probably will result in additional slope failures of this type at the east end. Unless changes are made, the banks at Orwell Lake will continue to recede. Restriction of the pool level to less than 325.5-m elevation is the least expensive solution to the problem.

Description / Table of Contents: Observations of shore ice pile-up and ride-up along the Alaska Beaufort Sea coast in 1983 and 1984 are presented. New information on historical accounts of onshore ice movement, uncovered since publication of Part I in this series, is reported. An account is given of ice overtopping a concrete caisson exploration island in the Canadian Beaufort Sea.

Description / Table of Contents: Investigations of the in situ complex dielectric constant of sea ice were made using time-domain spectroscopy. It was found that (1) for sea ice with a preferred horizontal crystal c-axis alignment, the anisotropy of polarizing properties of the ice increased with depth, (2) brine inclusion conductivity increased with decreasing temperature down to about -8 C, at which point the conductivity decreased with decreasing temperature, (3) the DC conductivity of sea ice increased with increasing brine volume, (4) the real part of the complex dielectric constant is strongly dependent upon brine volume but less dependent upon the brine inclusion orientation, (5) the imaginary part of the complex dielectric constant was strongly dependent upon brine inclusion orientation but much less dependent upon brine volume. Because the electromagnetic (EM) properties of sea ice are dependent upon the physical state of the ice, which is continually changing, it appears that only trends in the relationships between the EM properties of natural sea ice and its brine volume and brine inclusion microstructure can be established.

Description / Table of Contents: The results of resistance tests in level ice and broken ice channels are presented for two models of the WTGB 140-fticebreaker at scales of 1:10 and 1:24, respectively. No scale effect on the resistance in level ice could be detected between the two models. From the test results an empirical predictor equation for the full scale ice resistance is derived. Predicted resistance is compared against, and found to be 25 to 40% larger than, available full-scale values estimated from thrust measurements during full-scale trials of the Great Lakes icebreaker Katmai Bay.

Description / Table of Contents: Icing on stationary structures such as oil rigs is becoming an increasingly serious problem as offshore drilling operations in the subpolar regions become more common. Little information exists on this subject. Extensive observations have been made of icing on the upper structures of moving ships, but the complexity of this problem makes analysis of the results very difficult. Even the generation of water drops in this case involves many factors, such as windspeed, wave direction relative to the bearing of the ship, and size and free-board of the ship. On stationary structures, however, the problem is much simpler, since the major factor in drop generation is whitecaps produced by wind, and no motion of the structure is involved. In the present study, a theoretical calculation was made by combining the data available on the generation of drops by wind with data on the proportion of ice frozen from the collected water. The rate of ice accumulation on stationary structures was calculated using published data. The results were compared with icing measured on board ships. Although the general trend of this calculation indicated parallelism with the onboard measurements, the measured ice accumulation rate on ships needed a 5 to 8 m/s higher windspeed to correspond with the calculated rate for stationary structures.

Description / Table of Contents: Data obtained from two sets of data buoys either air-dropped or deployed by ship onto the Weddell Sea pack ice during the period from Dec 1978 to Nov 1980 are presented. The buoy data include position, pressure and temperature information and to date represent the most complete combined weather and pack ice drift records for the ice-covered Southern Ocean regions. The buoys tended to drift north initially and then to turn east generally between latitudes 62°S and 64°S. Buoy 1433 turned east farther south at approximately 67°S but at about the same time as buoy 0527, implying that the westerly wind belt was farther south than usual in 1979. The range of air pressures-from about 950 mb to about 1020 mb is typical of the circumpolar low pressure trough in the Southern Hemisphere. All buoys were equipped with an internal or compartment temperature sensor. The 1980 buoys also contained an external air temperature sensor in a ventilated, shielded can at 1-m height. Although differences of 10°C or more between recorded air and compartment temperatures are common, the correlation between the two measured temperatures is generally very good. The compartment temperatures are higher probably because the buoy is radiationally heated. We found that subtracting 3°C from the average daily compartment temperature yielded a good estimate of the average air temperature for any given day. This technique can be used to construct average daily air temperature records for the 1979 buoys which only contained the internal or compartment temperature sensor.

Description / Table of Contents: This report presents the results of the first phase of a test program designed to obtain a comprehensive understanding of the mechanical properties of multi-year sea ice from the Alaskan Beaufort Sea. In Phase I, 222 constant-strain-rate uni-axial compression tests were performed on ice samples from ten multi-year pressure ridges to examine the magnitude and variation of ice strength within and between pressure ridges. A limited number of constant-strain-rate compression and tension tests, constant-load compression tests, and conventional triaxial tests were also performed on ice samples from a multi-year floe to provide preliminary data for developing ice yield criteria and constitutive laws for multi-year sea ice. Data are presented on the strength, failure strain, and modulus of multi-year sea ice under different loading conditions. The statistical variation of ice strength within and between pressure ridges is examined, as well as the effects of ice temperature, porosity, structure, strain rate and confining pressure on the mechanical properties of multi-year sea ice.