Distribution and movement of suspended sediment in the Gulf of Mexico off the Texas coast
Sediment transport in nearshore water off Texas coast in Gulf of Mexico
Hunter, R. E.↗
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Applicability of ERTS-1 imagery to the study of suspended sediment and aquatic fronts
Imagery from three successful ERTS-1 passes over the Delaware Bay and Atlantic Coastal Region have been evaluated to determine visibility of aquatic features. Data gathered from ground truth teams before and during the overflights, in conjunction with aerial photographs taken at various altitudes, were used to interpret the imagery. The overpasses took place on August 16, October 10, 1972, and January 26, 1973, with cloud cover ranging from about zero to twenty percent. (I.D. Nos. 1024-15073, 1079-15133, and 1187-15140). Visual inspection, density slicing and multispectral analysis of the imagery revealed strong suspended sediment patterns and several distinct types of aquatic interfaces or frontal systems.
Klemas, V.↗
ERTS-1 observations of sea surface circulation and sediment transport, Cook Inlet, Alaska
Cook Inlet is a large tide-dominated estuary in southern Alaska. Highly turbid streams enter the upper inlet, providing an excellent tracer for circulation in the lower inlet. MSS 4 and 5 images both can be used in this area to plot sediment and pollutant trajectories, areas of (probable) commercial fish concentration, and the entire circulation regime.
Wright, F. F.↗
Dynamics of suspended sediment plumes in Lake Ontario
The author has identified the following significant results. Enhancement of ERTS-1 imagery yielded excellent quality 35-mm color slides and prints of several prominent turbidity plumes in Lake Ontario. Selected ERTS-1 frames of the Welland Canal and Genesee River plumes will be used to develop time-lapse sequences showing the impact of wind stress on each plume. Unusually high lake levels during the spring resulted in extensive beach erosion along the entire Lake Ontario shoreline. The resulting high concentrations of suspended matter generated highly turbid (up to 420 JTU) nearshore conditions that appeared milky white in the imagery obtained April 12 and 29th, 1973. During the shipping season, both the Welland Canal and a diversion channel at Port Dalhousie, Ontario, produced readily identifiable turbidity plumes in Lake Ontario. However, in the winter neither plume was visible in the ERTS-1 imagery suggesting sharply lower sediment discharge into Lake Ontario from these sources.
Pluhowski, E. J.↗
On the manganese content of cosmic flakes from deep-sea sediments
Cosmic flakes belong to the category of cosmic microparticles. They occur together with cosmic spherules in sediments. These flakes appear to represent ablation products of iron meteorites burnt away during the passage of a meteorite through the atmosphere by friction against air molecules. Microprobe analyses of flakes from deep sea deposits proved the particles to consist of magnetite which in most cases had been altered into maghemite in the outer zones. This is in agreement with the assumption that they represent fragments of fusion crust of iron meteorites. Most of the flakes, however, contained a small percentage of manganese. This element is not a common constituent of iron meteorites. An attempt is made to explain the presence of manganese in flakes and its absence in cosmic spherules.
Utech, K.↗
Sediment transport and erosion in the Fourchon area of Lafourche parish
NASA aerial photography in the form of color infrared and color positive transparencies is used as an aid in evaluating the rate and effect of erosion and sediment transport in Bay Champagne Louisiana.
Whitehurst, C. A.↗
Extraction of amino acids from soils and sediments with superheated water
A method of extraction for amino acids from soils and sediments involving superheated water has been investigated. About 75-97 per cent of the amino acids contained in four soils of a soil profile from Illinois were extracted by this method. Deep penetration of water into soil aggregates and partial hydrolysis of peptide bonds during this extraction by water at high temperature are likely mechanisms responsible for the release of amino acids from samples. This extraction method does not require subsequent desalting treatments when analyses are carried out with an ion-exchange amino acid analyzer.
Cheng, C. N.↗
The role of ballistic erosion and sedimentation in lunar stratigraphy
Aspects of base surge transport are considered along with questions regarding the applicability of base surge transport to lunar sedimentation, the ballistic transport of crater and basin ejecta, Copernicus crater ballistics, and the effects of ejecta impact on preexisting lunar ground. An ejecta emplacement model is discussed and attention is given to the structure of the surface of continuous deposits of craters and basins, the thickness of crater and basin deposits, and the characteristics of impact melts.
Oberbeck, V. R.↗
Applications of ERTS imagery to mappings sediments of the Twin Cities Metropolitan area
ERTS images were compared to surficial geologic maps, prepared through traditional field studies. Lithologic boundaries, bedrock outcrops, bedrock structures, and geomorphologic features were examined. An area southeast of the Twin Cities, located chiefly in northern Dakota County was studied, as well as the New Brighton 15-minute quadrangle located in portions of Ramsey and Anoka Counties. Visual comparison of geologic maps and ERTS imagery demonstrated the limitations of this approach to geological investigations. Bedrock outcrops and bedrock structure in the metropolitan area do not appear on ERTS imagery. However, certain glacial sediments can be identified and are potentially mappable. Certain geomorphological features were also discernable.
Poppe, J. R.↗
Studies on the toxic elements and organic degradation products in aquatic bodies and sediments around Kennedy Space Center (KSC) Haulover Canal and Mosquito Lagoon
The work during the first year ending September, 1975, is reported. Indian River, Haulover Canal, Mosquito Lagoon, and other aquatic areas of discharge around Kennedy Space Center (KSC) were studied. The presentation and interpretation of data on water and sediment samples collected from Haulover Canal and Mosquito Lagoon are included. The field and laboratory data are presented and tentative conclusions were drawn in the various aspects of the study. An attempt was made to correlate the physical, chemical, and biological parameters.
Ghuman, G. S.↗
Studies of the inner shelf and coastal sedimentation environment of the Beaufort Sea from ERTS-A
The author has identified the following significant results. Shearing periodically occurs between the westward moving pack ice (3 to 10 km/d) within the Pacific Gyre and the fast ice along the coast, forming major grounded shear and pressure ridges between the 10 to 40 m isobaths. Ridges occur in patterns conforming to known shoals. The zone of grounded ridges, called stamukhi zone, protects the inner shelf and coast from marine energy and pack ice forces. Relatively undeformed fast ice grows inshore of the stamukhi zone. The boundary is explained in terms of pack ice drift and major promontories and shoals. Intense ice gaging, highly disrupted sediments, and landward migration of shoals suggest that much of the available marine energy is expended on the sea floor within the stamukhi zone. Naleds (products of river icings) on the North Slope are more abundant east than west of the Colville River. Their location, growth, and decay were studied from LANDSAT imagery.
Reimnitz, E.↗
Radiative transfer model for remote sensing of suspended sediments in water
A Monte Carlo simulation model of radiative transfer in turbid water is discussed. The model can be used to calculate characteristics of the backscattered signal from an illuminated body of water as a function of the turbidity level and spectral properties of the suspended particulates. The dependence of remote sensing applications on the concentration and spectral properties of sediments in the environmental waters is considered in terms of the model. Attention is directed to the effects of various inputs for the volume-scattering function on backscattered radiance from natural waters. The wavelength dependence of single scattering albedo is investigated.
Ghovanlou, A. H.↗
Stereochemistry of amino acids in surface samples of a marine sediment
In two surface samples of marine sediment, the percentages of D-alanine and D-aspartic acid are significantly higher than the other D-amino acids and are similar to the range found in soils. The percentage of D-glutamic acid is also higher than the other amino acids but less than D-alanine and D-aspartic acid. These D-amino acids may come mainly from bacteria.
Pollock, G. E.↗
Bay of Fundy verification of a system for multidate Landsat measurement of suspended sediment
A system for automated multidate Landsat CCT MSS measurement of suspended sediment concentration (S) has been implemented and verified on nine sets (108 points) of data from the Bay of Fundy, Canada. The system employs 'chromaticity analysis' to provide automatic pixel-by-pixel adjustment of atmospheric variations, permitting reference calibration data from one or several dates to be spatially and temporally extrapolated to other regions and to other dates. For verification, each data set was used in turn as test data against the remainder as a calibration set: the average absolute error was 44 percent of S over the range 1-1000 mg/l. The system can be used to measure chlorophyll (in the absence of atmospheric variations), Secchi disk depth, and turbidity.
Munday, J. C., Jr.↗
Marine sediment tolerances for remote sensing of atmospheric aerosols over water
In surveying the literature, it is pointed out that there is a need to quantify the turbidity below which reflectance from the water column is negligible in comparison with atmospheric effects to allow the monitoring of aerosol optical depth over water bodies. Data that partially satisfy this need are presented. Laboratory measurements of reflectance upwelled from the water column are given for mixtures with various types of sediment at wavelengths between 400 and 1600 nm. The results of the study described here are a quantitative endorsement of the recommendations of Morell and Gordon (1980).
Whitlock, C. H.↗
Present wind activity on Mars - Relation to large latitudinally zoned sediment deposits
The relation of present Martian winds to large latitudinally zoned sediment deposits has been investigated using global wind streak data and mapping of large sand and dust deposits. Dune sand deposits occur primarily in three latitude belts: north polar (74-85 degrees North), low latitude (5 degrees North-20 degrees South), and south polar (40-80 degrees South). Comparison with wind streak data shows the high-latitude dunes to be in areas of seasonally reversing winds. The present winds can form latitudinal dune belts from a variety of initial dune distributions, including uniform distribution and a polar source. The presence of dune sand within the polar layered deposits, the erosional state of the deposits, and the present surface wind flow away from the poles indicate that both polar dune concentrations have been derived from erosion of the layered deposits. The low-latitude dunes are topographically confined in canyons and craters; they are probably subject to long-term reversal of orientations with climate cycles.
Thomas, P.↗
Influence of suspended inorganic sediment on airborne laser fluorosensor measurements
The results of Poole and Esaias (1982) are presently extended to an examination of the influence of inorganic sediment on the water Raman normalization procedure, as well as an assessment of the potential for using the Raman signal to monitor surface water attenuation properties. An optically perfect lidar system is assumed which has geometric properties representative of the Airborne Oceanographic Lidar, and is mounted on an airborne platform flying at an altitude of 150 m above the water surface. The results obtained suggest that caution should be exercised in attempts to quantitatively monitor changes in optical attenuation by means of remote measurements of the Raman scattering signal.
Poole, L. R.↗
Biologically mediated isotope fractionations - Biochemistry, geochemical significance and preservation in the earth's oldest sediments
Preferential metabolization of isotopically light carbon and sulfur has resulted in a fractionation of the stable isotopes of these elements on a global scale, with the light species (C-12, S-32) markedly concentrated in biogenic materials. Since the biological effects are basically retained when carbon and sulfur are incorporated in sediments, the respective fractionations are propagated into the rock section of the geochemical cycle, this having consequently caused a characteristic bipartition of both elements between 'light' and 'heavy' crustal reservoirs. Preservation of the biological isotope effects in sedimentary rocks makes it possible to trace the underlying biochemical processes back over most of the geological record. According to the available evidence, biological (autotrophic) carbon fixation arose prior to 3.5(if not 3.8) billion years ago, while the emergence of dissimilatory sulfate reduction antedates the appearance of the oldest presumably bacteriogenic sulfur isotope patterns in rocks between 2.7 and 2.8 billion years old. Hence, biological control of the terrestrial carbon and sulfur cycles has been established very early in the earth's history.
Schidlowski, M.↗