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J.S. Booth

Publications and source records attributed to J.S. Booth.

11 recordsLinked to original sources
USGS1999

Formation of natural gas hydrates in marine sediments 1. Conceptual model of gas hydrate growth conditioned by host sediment properties

The stability of submarine gas hydrates is largely dictated by pressure and temperature, gas composition, and pore water salinity. However, the physical properties and surface chemistry of deep marine sediments may also affect the thermodynamic state, growth kinetics, spatial distributions, and growth forms of clathrates. Our conceptual model presumes that gas hydrate behaves in a way analogous to ice in a freezing soil. Hydrate growth is inhibited within fine-grained sediments by a combination of reduced pore water activity in the vicinity of hydrophilic mineral surfaces, and the excess internal energy of small crystals confined in pores. The excess energy can be thought of as a "capillary pressure" in the hydrate crystal, related to the pore size distribution and the state of stress in the sediment framework. The base of gas hydrate stability in a sequence of fine sediments is predicted by our model to occur at a lower temperature (nearer to the seabed) than would be calculated from bulk thermodynamic equilibrium. Capillary effects or a build up of salt in the system can expand the phase boundary between hydrate and free gas into a divariant field extending over a finite depth range dictated by total methane content and pore-size distribution. Hysteresis between the temperatures of crystallization and dissociation of the clathrate is also predicted. Growth forms commonly observed in hydrate samples recovered from marine sediments (nodules, and lenses in muds; cements in sands) can largely be explained by capillary effects, but kinetics of nucleation and growth are also important. The formation of concentrated gas hydrates in a partially closed system with respect to material transport, or where gas can flush through the system, may lead to water depletion in the host sediment. This "freeze-drying" may be detectable through physical changes to the sediment (low water content and overconsolidation) and/or chemical anomalies in the pore waters and metastable presence of free gas within the normal zone of hydrate stability.

Journal of Geophysical Research B: Solid Earth↗
USGS1998

Evidence for faulting related to dissociation of gas hydrate and release of methane off the southeastern United States

This paper is part of the special publication Gas hydrates: relevance to world margin stability and climatic change (eds J.P. Henriet and J. Mienert). An irregular, faulted, collapse depression about 38 x 18 km in extent is located on the crest of the Blake Ridge offshore from the south- eastern United States. Faults disrupt the sea floor and terminate or sole out about 40-500 m below the sea floor at the base of the gas hydrate stable zone, which is identified from the location of the bottom simulating reflection (BSR). Normal faults are common but reverse faults and folds also are widespread. Folds commonly convert upward into faults. Sediment diapirs and deposits of sediments that were erupted onto the sea floor are also present. Sea-floor depressions at faults may represent locations of liquid/gas vents. The collapse was probably caused by overpressures and by the decoupling of the overlying sediments by gassy muds that existed just beneath the zone of gas hydrate stability.

Blake Ridge↗
USGS1989

Geotechnical, geological, and selected radionuclide retention characteristics of the radioactive waste disposal site near the Farallon Islands

A geotechnical and geological investigation of the Farallon Islands low-level radioactive waste (LLW) disposal area was conducted to qualitatively assess the host sediments' relative effectiveness as a barrier to radionuclide migration, to estimate the portion of the barrier that is in contact with the waste packages at the three primary disposal sites, and to provide a basic physical description of the sediments. Box cores recovered from within the general disposal area at depths of 500, 1000, and 1500 m were subcored to provide samples (~30 cm in length) for detailed descriptions, textural and mineralogical analyses, and a suite of geotechnical tests (index property, CRS consolidation, and CIU triaxial compression). -from Authors

Marine Geotechnology↗
USGS1985

A nomogram for interpreting slope stability of fine-grained deposits in modern and ancient-marine environments.

Design of the nomogram is based on effective stress and combines consolidation theory as applicable to depositional environments with the infinite-slope model of slope-stability analysis. The link between the two combined theories is a term representing the effective overburden stress, which may be predicted from consolidation theory and a knowledge of sedimentation rate, time, and the coefficient of consolidation. In turn, if infinite-slope conditions are assumed to exist, the effective overburden stress can be used to derive a factor of safety against static slope failure by using the angle of internal friction and the slope angle. The nomogram applies to depostitional settings in which fine-grained sediment has accumulated at a relatively constant rate upon a base that is essentially impermeable. The model further assumes that the lateral extent of sediment affected by any mass movement will be great compared to its thickness and that no outside agents (e.g., cements, gas) are influencing the section. The nomogram is applicable to static conditions (inherent stability of the slope) and certain dynamic conditions (such as earthquakes). It may be used to investigate mass movements in the geologic past as well as those in modern environments.--Modified journal abstract.

Journal of Sedimentary Petrology↗
USGS1984

Creep behavior of submarine sediments

A series of experiments on drained creep of marine sediment indicates that strength degradation results from the creep process, which implies an associated reduction in slope stability. Furthermore, the highest creep potential of a sediment may be at its preconsolidation stress. Results from the experiments on samples from Georges Bank continental slope were also used in conjunction with a preliminary theoretical model to predict creep displacements. For the case illustrated in this report, steep slopes (>20??) and thick sections (>30 m) give rise to substantial creep and probable creep rupture; as angles or thicknesses decrease, displacements rapidly become negligible. Creep may be a significant geologic process on many marine slopes. Not only can it cause major displacements of surface sediment, but it may also be the precursor to numerous slope failures. ?? 1985 Springer-Verlag New York Inc.

Geo-Marine Letters↗
USGS1982

Determination and analysis of bearing capacity of calcarenites off the Florida Keys

A specially designed instrument was used to determine the in situ bearing capacity at 12 sites in the carbonate sand seaward of the Florida Keys. The resulting data set not only represents unique information in such an environment, but also provided an opportunity to determine whether bearing capacity is controlled by any specific property of the calcarenites, or, conversely, whether the bearing-capacity value could be used as an index of a particular substrate characteristic. The in sltu measurements were made in several subenvironments in order to bracket the variability of sediment properties throughout the area. Samples were collected at each bearing-capacity test site and w .ere analyzed for selected geological and geotechnical properties, including texture, grain shapes, and biological constituents. No relationship was found between bearing capacity and any of the analyzed properties of the sediment. Although many salient characteristics of calcarenites exist, at the stress levels used in this study their influence is either masked owing to the complex interaction of properties that leads to a specific bearing-capacity value or, at least in these sediments, is absent.

Open-File Report↗