Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Eastern”

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 739 records · Page 41

Volcanism of the Eastern Snake River Plain, Idaho: A comparative planetary geology-guidebook

The Planetary Geology Field Conference on the central Snake River Plain was conceived and developed to accomplish several objectives. Primarily, field conferences are sponsored by the National Aeronautics and Space Administration to draw attention to aspects of terrestrial geology that appear to be important in interpreting the origin and evolution of extraterrestrial planetary surfaces. Another aspect is to present results of recent research in a region. A final objective of this conference is to bring together investigators of diverse backgrounds who share a common interest in the Snake River Plain. The Snake River Plain appears to be similar in surface morphology to many volcanic regions on the Moon, Mars, and possibly Mercury. Therefore, the Snake River Plain, in combination with the relatively good state of preservation, the lack of forests or other heavy vegetation, and the good network of jeep trails, is an area nearly ideal for analog studies.

Greeley, R.↗

Summary of airborne chlorine and hydrogen chloride gas measurements for August 20 and September 5, 1977 Voyager launches at Air Force Eastern Test Range, Florida

Airborne chlorine and hydrogen chloride measurements were made in the tropospheric ground cloud following the Voyager launches of August 20 and September 5, 1977. The maximum observed hydrogen chloride concentration for both launches was about 25 to 30 parts per million (ppm) occurring typically 2 to 6 minutes after launch. By completion of the sampling mission (1-1/2 hours for August, 4-1/2 hours for September), the maximum in-cloud concentration decayed to about 1 to 2 ppm. Maximum observed chlorine concentrations were about 40 to 55 parts per billion (ppb) about 2 to 8 minutes after launch; by about 15 minutes after launch, chlorine concentrations were less than 10 ppb (detection limit). In-cloud chlorine concentrations were well below 1 percent of hydrogen chloride concentrations. The appendix of the report discusses the chlorine instrument and the laboratory evaluation of the detector.

Gregory, G. L.↗

A model for eruption behavior of a volcanic vent in eastern Mare Serenitatis

The origin is considered of droplets of ultramafic composition which are present in all soils collected from the mare surface at the Apollo 17 landing site. The droplets consist of homogeneous orange glass or their partially crystallized equivalent, the black droplets. These clastic deposits have a mean grain size of 40 micrometers. The droplet formation ages range from 3.5 to 3.83 b.y. It has been proposed that the droplets formed as a spray of low viscosity melt during lava fountaining. Based upon the thermal history as determined by studying olivine and particle shapes, two models for the formation of the sequence of droplets represented by samples 74001 and 74220 are presented. Both models assume, as proposed by Heiken et al. (1974), that the droplets were formed as a spray from a lava fountain and the compound forms were evidence for 'recycling' of solid, cooler droplets back into the fountain, encountering molten droplets before being deposited.

Heiken, G.↗

Effluent monitoring of the December 10, 1974, Titan 3-E launch at Air Force Eastern Test Range, Florida

Surface and airborne field measurements of the cloud behavior and effluent dispersion from a solid rocket motor launch vehicle are presented. The measurements were obtained as part of a continuing launch vehicle effluent monitoring program to obtain experimental field measurements in order to evaluate a model used to predict launch vehicle environmental impact. Results show that the model tends to overpredict effluent levels.

Wornom, D. E.↗

Launch vehicle effluent measurements during the August 20, 1977, Titan 3 launch at Air Force Eastern Test Range

Airborne effluent measurements within the launch cloud and visible and infrared measurements of cloud physical behavior are discussed. Airborne effluent measurements include concentrations of HCl, Cl2, NO, NOX, and particulates as a function of time during each sampling pass through the exhaust cloud. The particle size distribution was measured for each pass through the cloud. Mass concentration as a function of particle diameter was measured over the size range of 0.05- to 25 micron diameter, and particle number density was measured as a function of diameter over a size range of 0.5 to 7.5 micron. Effluent concentrations in the cloud ranged from about 30 ppm several minutes after launch to about 1 to 2 ppm at 100 minutes. Maximum Cl2 concentrations were about 40 to 55 ppb and by 20 minutes were less than 1.0 ppb. A tabulated listing of the airborne data is given in the appendix. Usable cloud imaging data were limited to the first 16 minutes after launch.

Woods, D. C.↗

Launch vehicle effluent measurements during the September 5, 1977, Titan 3 launch at Air Force eastern test range

Airborne effluent measurements and cloud physical behavior data are presented. The monitoring program included airborne effluent measurements in situ in the launch cloud, visible and infrared photography of cloud growth and physical behavior, and limited surface collection of rain samples. Effluent measurements included concentrations of HCl, Cl2, NO, nitric oxide, and particles as a function of time in the exhaust cloud. In situ particle mass concentration and number density were measured as a function of time and size in the range of 0.05 micron m to 30 micron m diameter. Measurement results were similar to those of previous launch monitorings. Maximum HCl and nitric oxide concentrations of Cl2 were maximum about 2 minutes after launch and by 10 to 15 minutes had decayed to less than 10 ppb (detection limit). Particle measurements showed most of the particles present to be below about 3-micron m diameter. Postlaunch analyses of collected particle samples showed significant amounts of Al (some cases Cl) from about 3-micron m to 0.04-micron m diameter.

Wornom, D. E.↗

Investigations of medium wavelength magnetic anomalies in the eastern Pacific using Magsat data

The author has identified the following significant results. Three long total magnetic field profiles taken over ocean basins were analyzed. It is found that there is a significant signal in the wavelength range of 1500 to 150 km. This is too short a wavelength to be caused by the core field, which becomes insignificant at about a wavelength of 1500 km; this intermediate wavelength signal is not caused by a typical sea floor spreading process, which should give maximum power in the wavelength region about 50 km. It is shown that the external magnetic field contributes very little to this intermediate wavelength signal. Efforts to explain the cause of this signal have failed.

Harrison, C. G. A.↗

Subsidence and eustasy at the continental margin of eastern North America

Biostratigraphic data from the COST B-2 well off New York and four deep commercial wells off Nova Scotia have been used to remove the effect of sediment loading at the Atlantic-type continental margin off the East Coast of North America. The resulting subsidence contains terms due to both 'tectonic' and 'eustatic' effects. By assuming the tectonic subsidence is thermal in origin these effects can be separated. The 'eustatic' effects have been isolated by least squares fitting an exponential curve to the subsidence data. The resulting sea-level curve shows a maximum rise in sea level during the Late Cretaceous era which probably does not exceed 150 m. The tectonic subsidence has been interpreted in terms of a simple thermal model for the cooling lithosphere. Based on this model the thermal thickness of the lithosphere and the total amount of crustal thinning are estimated. These estimates which are consistent with surface ship gravity and GEOS-3 altimeter measurements are used to define the structural elements which control the tectonic evolution of the margin.

Watts, A. B.↗

Investigations of medium wavelength magnetic anomalies in the eastern Pacific using MAGSAT data

The suitability of using magnetic field measurements obtained by MAGSAT is discussed with regard to resolving the medium wavelength anomaly problem. A procedure for removing the external field component from the measured field is outlined. Various methods of determining crustal magnetizations are examined in light of satellite orbital parameters resulting in the selection of the equivalent source technique for evaluating scalar measurements. A matrix inversion of the vector components is suggested as a method for arriving at a scalar potential representation of the field.

Harrison, C. G. A.↗

Investigations of medium wavelength magnetic anomalies in the eastern Pacific using MAGSAT data

The computer program package for dealing with MAGSAT data was refined and a program listing and deck of cards was forwarded for use by interested investigators. Instead of doing equivalent source calculations, it is proposed to use spherical harmonics to model the observed data since spherical harmonic functions are orthogonal and addition of higher degree and order harmonics can be done without recalculation of the harmonics of lower degree and order already calculated. These functions are much more easy to manipulate in that the height of the term of the observation can be taken care of with great facility. Downward calculation (after suitable filtering) can also be performed very simply.

Harrison, C. G. A.↗

Compatibility study of the Magsat data and aeromagnetic data in the eastern Piedmont of US

Data from a 2 day period recorded by Magsat were used to produce world magnetic maps of the scalar total field and three vector component total fields. Subtracting the reference field of Magsat 6/80, a scalar anomalous field and three vector component anomalous fields were also mapped. After removing 718 bad points from the original data, every fifth point was picked for contouring. While the main geomagnetic field of the Earth is surprisingly well mapped considering the short data period, the anomaly maps suffer from data sparseness. The entire Magsat file collected at altitudes of 500-700 m in nonmountainous terrain and at 900-1,000 m in mountainous terrain was averaged to reduce the total data to 6,500 measurements, yielding a 0.1 deg sampling interval along the flight path. A U.S. aeromagnetic anomaly surface map was produced and the field was upward continued to a 300 km altitude. Differences in anomaly structure between the POGO data and the map produced were attributed to insufficient removal of the reference field. Reprocessing of the data using the GSFC reference field (9/80-2) should remove the low harmonic field and improve the anomalous field structure.

Won, I. J.↗

Investigations of medium wavelength magnetic anomalies in the Eastern Pacific using Magsat data

Processing continued on the data set covering the first three months of the mission. Orbits were selected over a specified range of longitude and latitude and those orbits falling within the geographical boundaries were stored on a disk and a listing made. To verify the quality of the data, plots were made showing altitude vs latitude, anomalous field vs latitude, and corrected anomalous field vs latitude. Results of the plotting showed that: (1) data from the first day of the mission are not usable because they are too noisy; (2) some orbits contain spikes, no doubt a processing error on the tape; (3) some orbits contain a 20 deg region in latitude, offset roughly 30 nT from the rest of the anomalous field profiles; and (4) the correlation between the adjacent orbits is poor. Even the new ring current coefficients provided with a later, corrected set of data tapes did not not yield the desired correlations.

Harrison, C. G. A.↗

Crustal structures under the active volcanic areas of central and eastern Mediterranean (M-44)

Programs are being adapted to the UNIVAC 1000 computer and others are being developed for immediate utilization in processing MAGSAT data. stability intermediate for lower continental crust and to upper manele conditions. Attempts to residuate crustal anomalies from one selected profile passing through western mediterranean using procedures commonly used at NASA yielded dubious results because of uncertainties in the adoption of coefficients in the expression accounting for the effect of equatorial ring currents and the empirical approach used for other corrections. Instead, filtering techniques are to be applied to each profile once investigator B tapes relative to the whole planet are received.

Gasparini, P.↗

Investigations of medium wavelength magnetic anomalies in the eastern Pacific using MAGSAT data

Efforts concerning spherical harmonic modeling of the Earth's magnetic field and the use of such models in removing core produced magnetic fields from magnetic fields of crustal origin are discussed. Results indicate that the terms of a spherical harmonic expansion do not uniquely determine a given wavelength of signal as the terms in a Fourier series do. Addition of terms of higher degree and order to a spherical harmonic expansion tend to fine tune the amplitude of the terms of lower degree and order. As a result, removal of such a model from a regional data set will not remove long wavelengths completely.

Harrison, C. G. A.↗