371 research outputs found
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Depositional setting, structural style, and sandstone distribution in three geopressured geothermal areas, Texas Gulf Coast
Funded by the U.S. Department of Energy, Division of Geothermal Energy, under contract nos. DE-AS05-76ET28461 and DE-AC08-79ET27111.UT Librarie
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Geology and Geohydrology of the East Texas Basin
The investigations in the East Texas Basin are part of the broader salt dome studies underway in the Gulf Coast Interior Salt Basin of Texas, Louisiana, and Mississippi, constituting one regional element of the national Nuclear Waste Repository Program. The U.S. Department of Energy (DOE) aims to select one salt site for site-specific evaluation as a nuclear waste repository. This report focuses on the salt dome program in East Texas and outlines some preliminary conclusions reached on dome suitability during FY1980.
The 1980 program to investigate the tectonic, geologic, and hydrogeologic stability of salt domes in the East Texas Basin was divided into four subprograms:
1. Subsurface geology.
2. Surficial geology, remote sensing, and geomorphology.
3. Hydrogeology.
4. Salt dome characteristics.
Integration of the results from these four subprograms will determine the general suitability of salt domes in the East Texas Basin for further evaluation as a potential nuclear waste repository and will provide information on specific candidate domes in the East Texas Basin.Bureau of Economic Geolog
Calibration Technique for Polarization-Sensitive Lidars
Polarization-sensitive lidars have proven to be highly effective in discriminating between spherical and non-spherical particles in the atmosphere. These lidars use a linearly polarized laser and are equipped with a receiver that can separately measure the components of the return signal polarized parallel and perpendicular to the outgoing beam. In this work we describe a technique for calibrating polarization-sensitive lidars that was originally developed at NASA s Langley Research Center (LaRC) and has been used continually over the past fifteen years. The procedure uses a rotatable half-wave plate inserted into the optical path of the lidar receiver to introduce controlled amounts of polarization cross-talk into a sequence of atmospheric backscatter measurements. Solving the resulting system of nonlinear equations generates the system calibration constants (gain ratio, G, and offset angle, theta) required for deriving calibrated measurements of depolarization ratio from the lidar signals. In addition, this procedure also determines the mean depolarization ratio within the region of the atmosphere that is analyzed. Simulations and error propagation studies show the method to be both reliable and well behaved. Operational details of the technique are illustrated using measurements obtained as part of Langley Research Center s participation in the First ISCCP Regional Experiment (FIRE)
The 48-inch lidar aerosol measurements taken at the Langley Research Center
This report presents lidar data taken between July 1991 and December 1992 using a ground-based 48-inch lidar instrument at the Langley Research Center in Hampton, Virginia. Seventy lidar profiles (approximately one per week) were obtained during this period, which began less than 1 month after the eruption of the Mount Pinatubo volcano in the Philippines. Plots of backscattering ratio as a function of altitude are presented for each data set along with tables containing numerical values of the backscattering ratio and backscattering coefficient versus altitude. The enhanced aerosol backscattering seen in the profiles highlights the influence of the Mount Pinatubo eruption on the stratospheric aerosol loading over Hampton. The long-term record of the profiles gives a picture of the evolution of the aerosol cloud, which reached maximum loading approximately 8 months after the eruption and then started to decrease gradually. NASA RP-1209 discusses 48-inch lidar aerosol measurements taken at the Langley Research Center from May 1974 to December 1987
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Prospectus for a Design Well in the Blessing Area Matagorda County, Texas
In recent years, the Bureau of Economic Geology has conducted regional subsurface studies of the Wilcox Group and Frio Formation of Texas as part of the U. S. Department of Energy's assessment of deep geopressured geothermal resources along the Gulf Coast. These studies resulted in two reports (Bebout and others, 1978; 1979) that describe several areas in Texas where temperatures are greater than 300°F and where the geology and reservoir conditions are suitable for resource testing by a design well.
Throughout the Texas Coastal Plain, the 300°F isotherm generally occurs at depths ranging from 12,000 to 16,000 ft. The overlying geopressured sediments represent a substantial portion of the sedimentary column that contains significant quantities of entrained methane, making them a significant portion of the resource base (Gregory and others, 1980). The lower temperatures and pressures of these shallow geopressured sediments result in lower methane solubility, but drilling costs would be substantially lower, and perhaps reservoir quality would be better in comparison to the deep geopressured intervals. Although the latter condition has not been substantiated, several areas that are geologically favorable for testing shallow geopressured aquifers with temperatures less than 300°F were identified in a recently completed study (Weise and others, 1980) funded by the Gas Research Institute.
The Blessing Prospect (fig. 1), one of the shallow prospects in Matagorda County, Texas, is presented in this prospectus as a candidate for the DOE design well program. The prospectus focuses on the geological and engineering aspects of the test site. Although legal and environmental considerations are mentioned, they have not been studied in detail and additional work would necessarily follow if the prospect is approved for drilling and testing. Likewise, a drilling program and an economic analysis would be necessary before final approval of a design well.Bureau of Economic Geolog
Airborne dust distributions over the Tibetan Plateau and surrounding areas derived from the first year of CALIPSO lidar observations
International audienceAirborne dust is a major environmental hazard in Asia. Using an analysis of the first full year of CALIPSO lidar measurements, this paper derives unprecedented, altitude-resolved seasonal distributions of desert dust transported over the Tibetan Plateau (TP) and the surrounding areas. The CALIPSO lidar observations include numerous large dust plumes over the northern slope and eastern part of the TP, with the largest number of dust events occurring in the spring of 2007, and some layers being lofted to altitudes of 10 km and higher. Generation of the Tibetan airborne dusts appears to be largely associated with source regions to the north and on the eastern part of the plateau. Examination of the CALIPSO time history reveals an "airborne dust corridor" due to the eastward transport of dusts originating primarily in these source areas. This corridor extends from west to east and shows a seasonality largely modulated by the TP through its dynamical and thermal forcing on the atmospheric flows. On the southern side, desert dust particles originate predominately in North India and Pakistan. The dust transport occurs primarily in dry seasons around the TP western and southern slopes and dust particles become mixed with local polluted aerosols. No significant amount of dust appears to be transported over the Himalayas. Extensive forward trajectory simulations are also conducted to confirm the dust transport pattern from the nearby sources observed by the CALIPSO lidar
Title: will be set by the publisher Editors: will be set by the publisher EAS Publications Series, Vol.?, 2009 THE BEST SITE ON EARTH?
Abstract. We compare the merits of potential observatory sites on the Antarctic Plateau, in regard to the boundary layer, cloud cover, free atmosphere seeing, aurorae, airglow, and precipitable water vapour. We find that (a) all Antarctic sites are likely compromised for optical work by airglow and aurorae; (b) Dome A is the best existing site in almost all respects; (c) there is an even better site (‘Ridge A’) 150kms SW of Dome A; (d) Dome F is a remarkably good site except for aurorae; (e) Dome C probably has the least cloud cover of any of the sites, and might be able to use a predicted ‘OH hole ’ in the Spring. The Antarctic plateau probably contains the best astronomical sites on Earth, but none of the existing bases were situated with astronomy in mind. In Saunders et al.(2009), we use published data and models, and unpublished meteorological and other information, to try to compare the merits of the potential sites. Here, we summarise only the new findings and conclusions. We include boundary layer thickness, cloud cover, auroral emission, airglow, precipitable water vapour, an
Heuristic Optimization Methods for Dynamic Panel Data Model Selection: Application on the Russian Innovative Performance
Innovations, be they radical new products or technology improvements are widely recognized as a key factor of economic growth. To identify the factors triggering innovative activities is a main concern for economic theory and empirical analysis. As the number of hypotheses is large, the process of model selection becomes a crucial part of the empirical implementation. The problem is complicated by the fact that unobserved heterogeneity and possible endogeneity of regressors have to be taken into account. A new efficient solution to this problem is suggested, applying optimization heuristics, which exploits the inherent discrete nature of the problem. The model selection is based on information criteria and the Sargan test of overidentifying restrictions. The method is applied to Russian regional data within the framework of a log-linear dynamic panel data model. To illustrate the performance of the method, we also report the results of Monte-Carlo simulations
Learning from the peer review of ‘Estimating stock status from relative abundance and resilience’
This contribution presents the detailed responses to the peer-review of Froese et al. (2019) “Estimating stock status from relative abundance and resilience” (ICES J. Mar. Sci. 2019) which outlined a method called “AMSY” for inferring biomass trends for stocks for which only catch-per-unit-effort and limited ancillary (‘priors’) data are available. The responses emphasize that the required priors are legitimate and straightforward to obtain, thus, making AMSY a method of choice in data-sparse situations. This is also a good example of the role of peer-review in validating and improving science
Association of Antarctic polar stratospheric cloud formation on tropospheric cloud systems, Geophys
[1] The formation of polar stratospheric clouds (PSCs) is critical to the development of polar ozone loss. However, the mechanisms of PSC formation remain poorly understood, which affects ozone loss models. Here, based on observations by the NASA A-train satellites, we show that 66% ± 16% and 52% ± 17% of PSCs over west and east Antarctica during the period June -October 2006 were associated with deep tropospheric cloud systems, with maximum depths exceeding 7 km. The development of such deep tropospheric cloud systems should cool the lower stratosphere through adiabatic and radiative processes, favoring PSC development. These deep systems also transport lower tropospheric air into the upper troposphere and lower stratosphere. These new findings suggest that Antarctic PSC formation is closely connected to tropospheric meteorology and thus governed by synoptic scale dynamics, local topography, and large-scale circulation. More dedicated studies are still needed to better understand Antarctic PSC formation. Citation: Wang
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