Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “GROUND WATER”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Introduction: Historical perspective on the HCMM program

When some thermal radiation sensitive devices on U.S. meteorological satellites generated low resolution images showing temperature variations on Earth's land and sea surfaces during the middle 1960's, interest was aroused in the potential of thermal sensing in geology, agriculture, soil moisture, ground water, water temperature, and vegetation applications. The concept of using the property of thermal inertia to identify materials, particularly those of a geologic nature can be traced to the same time period that marks the flight of the first LANDSAT - Spacecraft systems and their performance, and capabilities are reviewed as well as achievements in hydrology, geology, agriculture, pedology, and urban climate effects applications.

Source record↗
NASA NTRS1983

Substance geology of the western desert in Egypt and Sudan revealed by Shuttle Imaging Radar (SIR-A)

A correlation of known archaeologic sites with the mapped locations of the streamcourses is expected and may lead to new interpretations of early human history in the Sahara. The valley networks, faults, and other subjacent bedrock features mapped on the SIR-A images are promising areas for ground water and mineral exploration. Additionally, the analogies between the interplay of wind and running water in the geologic history of the Sahara and of Mars are strengthened by the SIR-A discoveries of relict drainage systems beneath the eolian veneer of Egypt and Sudan.

Breed, C. S.↗
NASA NTRS1984

Wind Erosion and Dune Formation on High Frozen Bluffs

Frost penetration increases upslope on barren, windswept bluffs in cold environments. Along the south shore of Lake Superior, near the brow of 100 m high bluffs it typically exceeds 5 m. Frost increases the shear strength of damp sand to a level comparable to that of concrete, making winter slopes highly stable despite undercutting by waves and ground-water sapping along the footslope. Sublimation of interparticle ice in the slope face increases with wind speed and lower vapor pressures. The cold and dry winter winds of Lake Superior ablate these slopes through loss of binding ice. Wind erosion rates, based on measurements of sand accumulation on the forest floor downwind of the brow, show most airborne sand falls out within several meters of the brow, forming a berm 1 to 3 m high after many years. The spatial pattern of sand deposition, however, varies considerably over distances of several hundred meters along the top bluffs in response to frost conditions and the build-up of gravel lag on the slope face, sand exposure from mass movements, and local aerodynamics of the crest slope. The formation of perched sand dunes in the Great Lakes region is clearly related to wind erosion of sand from high bluffs in winter. Broadly similar processes may operate on Mars.

Marsh, W. M.↗
NASA NTRS1984

Application of SIR-B data for groundwater exploration in the Arabian shield and sand-drift monitoring in the AN Nafud and Al Jafurah fringe areas, Kingdom of Saudi Arabia

The primary objectives of the investigation are to determine fully the utility of Shuttle Imaging Radar-B (SIR-B) images for providing valuable surface indicators for ground-water prospecting in the Arabian shield and to identify and assess defining characteristics of sand sheets, sand streaks, and sand dunes in the fringe areas of An Nafud and Al Jafurah. Specific objectives include the determination of the incremental contribution of incidence angle to the total information that can be extracted from SIR-B standard and digitally-enhanced images in the AL Jafurah fringe area; the determination of the incremental contribution of digitally-registered multisensor images; and the development of a groundwater exploration plan for the Ha'il test area in the Arabian Shield.

Berlin, G. L.↗
NASA NTRS1985

A method for estimating soil moisture availability

A method for estimating values of soil moisture based on measurements of infrared surface temperature is discussed. A central element in the method is a boundary layer model. Although it has been shown that soil moistures determined by this method using satellite measurements do correspond in a coarse fashion to the antecedent precipitation, the accuracy and exact physical interpretation (with respect to ground water amounts) are not well known. This area of ignorance, which currently impedes the practical application of the method to problems in hydrology, meteorology and agriculture, is largely due to the absence of corresponding surface measurements. Preliminary field measurements made over France have led to the development of a promising vegetation formulation (Taconet et al., 1985), which has been incorporated in the model. It is necessary, however, to test the vegetation component, and the entire method, over a wide variety of surface conditions and crop canopies.

Carlson, T. N.↗
NASA NTRS1986

Determination of CA-41, I-129 and OS-187 in the Rochester tandem accelerator and some applications of these isotopes

The measurement of Ca-41 and I-129 utilizing the Rochester Tanden Accelerator Mass Spectrometer (TAMS) is discussed. Ca-41, having a half-life of 100,000 yrs., is of potential use for the dating of ground water as well as of bones in the age range between 50,000 and 1 million yrs. A major problem for the measurement of Ca-41 with TAMS is the fact that calcium does not readily form negative atomic ions. It does, however, form negative molecular ions. The production of CaO ions from compounds such as CaO and CaCO3 and from free Ca molecules sprayed with oxygen gas was studied. A project to utilize I-129 as a tracer for hydrothermal convection in sediment-covered oceanic crust is also briefly described. Finally, plans to use the Os-187/Os-186 ratio for the determination of extraterrestrial material in the Ries crater in Germany are summarized.

Fehn, U.↗
NASA NTRS1987

Ring furrows - Inversion of topography in Martian highland terrains

Viking Orbiter images showing ring furrows (as defined by De Hon, 1984) and related structures on the Martian highlands are presented and analyzed. It is pointed out that ring furrows occur only on modified or dissected plains and plains within hilly or cratered terrain, that all ring furrows are breached in some way, and that they appear to arise at the same time as nearby valley systems (although they do not contain small valleys themselves). A number of features with some similarities to ring furrows are discussed, and it is suggested that the furrows arise as a result of a sequence of processes including crater formation on a plains surface, partial burial by plains-forming materials, and preferential water/ice erosion of the exposed rim. The presence of significant ground-water/ice storage systems near ring furrows is inferred.

De Hon, Rene A.↗
NASA NTRS1991

New evidence for a dramatic rise in atmosphere oxygen ca. 1,900 m.y. ago

Several lines of geologic evidence have pointed to a significant increase in P sub O2 about 2,000 m.y. ago, but the magnitude of P sub O2 before and after that time has been quite uncertain. The data that we have recently accumulated suggest that P sub O2 was approximately less than 2 x 10 (exp -3) atm more than 2,000 m.y. ago, and approximately greater than 0.03 atm more recently than ca. 1,900 m.y. ago. These estimates are based on the behavior of iron in Precambrian weathering horizons. More than ca. 2,000 m.y. ago, Fe(+2), released during the weathering of basalts was not oxidized to Fe(+3), and was removed in ground water from the upper layers of soil horizons. More recently than ca. 1,850 m.y. ago, Fe(+2) was oxidized to Fe(+3) and precipitated as iron oxides and hydroxides in such soil horizons and in the weathering products of a carbonate facies banded iron formation in Griqualand West, South Africa. The O2 content of the atmosphere must have increased dramatically about 1,900 m.y. ago to explain these observations. The reasons for the increase are still obscure, but are probably related to changes in the biologic productivity of the oceans. Eukaryotes appear to have developed shortly after the increase in P sub O2, perhaps in response to the subsequent increase in the supply of nitrate from the atmosphere to the oceans.

Holland, H. D.↗
NASA NTRS1991

Applications of the Strategic Defense Initiative's compact accelerators

The Strategic Defense Initiative's (SDI) investment in particle accelerator technology for its directed energy weapons program has produced breakthroughs in the size and power of new accelerators. These accelerators, in turn, have produced spinoffs in several areas: the radio frequency quadrupole linear accelerator (RFQ linac) was recently incorporated into the design of a cancer therapy unit at the Loma Linda University Medical Center, an SDI-sponsored compact induction linear accelerator may replace Cobalt-60 radiation and hazardous ethylene-oxide as a method for sterilizing medical products, and other SDIO-funded accelerators may be used to produce the radioactive isotopes oxygen-15, nitrogen-13, carbon-11, and fluorine-18 for positron emission tomography (PET). Other applications of these accelerators include bomb detection, non-destructive inspection, decomposing toxic substances in contaminated ground water, and eliminating nuclear waste.

Montanarelli, Nick↗
NASA NTRS1992

Valley systems on Tyrrhena Patera, Mars - Earth-based radar measurements of slopes

The presently treated eight topographic profiles across the Martian volcano Tyrrhena Patera indicate that the vocano rises about 1.5 km above the plains of Hesperia Planum to the east, and exhibit an average height/diameter ratio of about 1:340. The slopes of the northern flank of Tyrrhena Patera bear little correlation with the width or depth of valley systems in that area, suggesting that erosion by gravity-driven flows was not responsible for valley formation. Attention is given to such other valley geometry and location controlling factors as ground-water release variations and volcano surface unit materials' strength differences.

Zisk, S. H.↗
NASA NTRS1993

Space Life Support Technology Applications to Terrestrial Environmental Problems

Many of the problems now facing the human race on Earth are, in fact, life support issues. Decline of air Quality as a result of industrial and automotive emissions, pollution of ground water by organic pesticides or solvents, and the disposal of solid wastes are all examples of environmental problems that we must solve to sustain human life. The technologies currently under development to solve the problems of supporting human life for advanced space missions are extraordinarily synergistic with these environmental problems. The development of these technologies (including both physicochemical and bioregenerative types) is increasingly focused on closing the life support loop by removing and recycling contaminants and wastes to produce the materials necessary to sustain human life. By so doing, this technology development effort also focuses automatically on reducing resupply logistics requirements and increasing crew safety through increased self-sufficiency. This paper describes several technologies that have been developed to support human life in space and illustrates the applicability of the technologies to environmental problems including environmental remediation and pollution prevention.

Schwartzkopf, Steven H.↗
NASA NTRS1993

Post-eruptive alteration of silicic ignimbrites and lavas, Gran Canaria, Canary Islands - Strontium, neodymium, lead, and oxygen isotopic evidence

The isotopic composition of lavas from oceanic islands provides important information about the composition and evolution of the earth's mantle. Isotopic analyses of Miocene comenditic, pantelleritic, and trachyphonolitic ignimbrites and lavas from the Canary islands were performed. Results provide evidence for posteruptive mobility of Rb and Sr during low temperature postemplacement interaction with circulating ground water. Calculated Sr isotope ratios define a magmatic trend in the stratigraph section. 87Sr/86Sr ratios in hydrated vitrophyte and devitrified matrix separates indicate significant posteruptive interaction with meteoric water starting soon after deposition. This process extends patchily through the entire pyroclastic flow and may be ongoing. 87Sr/86Sr ratios determined by whole rock analysis of silicic rocks from oceanic islands are suspect and should not be incorporated into mantle tracer studies. Anorthoclase phenocrysts are resistant to these processes and may produce useful data.

Cousens, Brian L.↗
NASA NTRS1992

Channels and valley networks

Attention is given to Martian channels and valley networks, since they have become a principal element of evidence to the effect that the Martian atmosphere evolved from an early volatile-rich state to its present condition. The outflow channels are relatively young, later Hesperian or Amazonian in age. They formed by immense outbursts of fluid from subsurface sources. Complexity in outflow-channel morphology was generated by varying amounts of sediment and ice in the aqueous-fluid flow systems. The overall cataclysmic-flood morphology may thus be locally transitional to morphologies generated by ice and debris flowage. Although local areas of valley networks, such as on Alba Patera, formed coevally with outflow channel activity, regionally extensive networks dominate in the heavily cratered terrains. The morphology of many valleys suggests genesis by ground-water sapping; for some valleys, surface runoff may have been more important.

Baker, Victor R.↗
NASA NTRS1994

Liquid/Gas Flow Mixers

Improved devices mix gases and liquids into bubbly or foamy flows. Generates flowing, homogeneous foams or homogeneous dispersions of small, noncoalescing bubbles entrained in flowing liquids. Mixers useful in liquid-metal magnetohydrodynamic electric-power generator, froth flotation in mining industry, wastewater treatment, aerobic digestion, and stripping hydrocarbon contaminants from ground water.

Fabris, Gracio↗
NASA NTRS1993

Oxidation of dissolved iron under warmer, wetter conditions on Mars: Transitions to present-day arid environments

The copious deposits of ferric-iron assemblages littering the surface of bright regions of Mars indicate that efficient oxidative weathering reactions have taken place during the evolution of the planet. Because the kinetics of atmosphere-surface (gas-solid) reactions are considerably slower than chemical weathering reactions involving an aqueous medium, most of the oxidation products now present in the martian regolith probably formed when groundwater flowed near the surface. This paper examines how chemical weathering reactions were effected by climatic variations when warm, wet environments became arid on Mars. Analogies are drawn with hydrogeochemical and weathering environments on the Australian continent where present-day oxidation of iron is occurring in acidic ground water under arid conditions.

Burns, R. G.↗
NASA NTRS1994

Integration of remote sensing and hydrologic modeling through multi-disciplinary semiarid field campaigns: Moonsoon 1990, Walnut Gulch 1992, and SALSA-MEX

A research and modeling strategy is presented for development of distributed hydrologic models given by a combination of remotely sensed and ground based data. In support of this strategy, two experiments Moonsoon'90 and Walnut Gulch'92 were conducted in a semiarid rangeland southeast of Tucson, Arizona, (U.S.) and a third experiment, the SALSA-MEX (Semi Arid Land Surface Atmospheric Mountain Experiment) was proposed. Results from the Moonsoon'90 experiment substantially advanced the understanding of the hydrologic and atmospheric fluxes in an arid environment and provided insight into the use of remote sensing data for hydrologic modeling. The Walnut Gulch'92 experiment addressed the seasonal hydrologic dynamics of the region and the potential of combined optical microwave remote sensing for hydrologic applications. SALSA-MEX will combine measurements and modeling to study hydrologic processes influenced by surrounding mountains, such as enhanced precipitation, snowmelt and recharge to ground water aquifers. The results from these experiments, along with the extensive experimental data bases, should aid the research community in large scale modeling of mass and energy exchanges across the soil-plant-atmosphere interface.

Moran, M. S.↗
NASA NTRS1993

Surficial geology of the Chicxulub impact crater, Yucatan, Mexico

The Chicxulub impact crater in northwestern Yucatan, Mexico is the primary candidate for the proposed impact that caused mass extinctions at the end of the Cretaceous Period. The crater is buried by up to a kilometer of Tertiary sediment and the most prominent surface expression is a ring of sink holes, known locally as cenotes, mapped with Landsat imagery. This 165 +/- 5 km diameter Cenote Ring demarcates a boundary between unfractured limestones inside the ring, and fractured limestones outside. The boundary forms a barrier to lateral ground water migration, resulting in increased flows, dissolution, and collapse thus forming the cenotes. The subsurface geology indicates that the fracturing that created the Cenote Ring is related to slumping in the rim of the buried crater, differential thicknesses in the rocks overlying the crater, or solution collapse within porous impact deposits. The Cenote Ring provides the most accurate position of the Chicxulub crater's center, and the associated faults, fractures, and stratigraphy indicate that the crater may be approximately 240 km in diameter.

Pope, Kevin O.↗