Imágenes de páginas

The next few years will see a rapid expansion of our knowledge of

the solar system. The major events anticipated are as follows:


In addition to the Viking missions previously cited, high public interest in Viking has stimulated recommendations for another Mars mission in 1984. Rovers with a 100 km roam radius and an orbiter equipped mainly with geochemical sensors and penetrators, and possibly a sample return, are being considered.


A Venus orbiter imaging radar (VOIR) is needed to study the surface features of this planet. This radar has been given the highest ranking by most science advisory groups and will return high resolution images (less than 1 km) of most of the planet. Because Venus is closest to the Earth in size and composition, this mission, and the 1978 radar mission to measure mechanical properties of the Venusian surface, have particular interest to terrestrial geologists.

are members of the science team.

Two GS scientists


Two Voyager spacecraft are presently on their way to Jupiter and Saturn. The satellites of those planets range widely in density and surface properties, and considerable variations in the geology are anticipated. Voyager will return several thousand pictures for study and analysis. A subsequent mission to orbit Jupiter would provide a more systematic set of observations than will be possible from Voyager.


The Voyagers, launched in 1977 for an encounter with Jupiter, will continue on for an encounter with Saturn in 1983.

Moore, G. K., and Deutsch, Morris, 1975, ERTS Imagery for Ground-Water Ground Water, v. 13, no. 2, p. 214-226.


Moore, G. K., 1976, Recommended procedures and keys for detection of aquifers on Landsat images: U.S. Geol. Survey Water Resources Division Bull., p. 15-20, October.

Moore, G. K., 1977, Prospecting for ground water with Landsat imagery: Proc. Technical Session on Hydrologic Applications of Remote Sensors, U.N. World Water Conf. Mar del Plata, Argentina, March.

National Research Council, 1977, Microwave remote sensing from space for earth resource surveys: National Academy of Sciences, Wash. D.C., 139 p.

Parashar, S. K., Bigg, A. W., Fung, A. K., and Moore, R. K., 1974,
Investigation of radar discrimination of sea ice: Internat.
Symposium on Remote Sensing of Environment, 9th, Ann Arbor,
Mich. 1974, Proc., p. 323-332.

Projecto RADAM, 1973, Levantamento de recursos naturais geologia,
geomorfologia, solos, vegetaco, uso potential da terra:

Rio de Janiero, Brasil, Ministerio das Minas e Energia,
Departamento Nacional de Producão Mineral, v. 1, 2, and 3.

Raines, G. L., 1977, Maps of Lineament Intersections and of Hydrothermal Alteration, Northern Sonora, Mexico: U.S. Geol. Survey Open File Report No. 77-78, 12 maps, 5 p.

Regan, R. C., Cain, J. C., and Davis, W. M., 1975, A global magnetic anomaly map: Jour. Geophys. Research, v. 80, no. 5, P. 794-802.

Rinkenberger, R. K., 1977, Implementing remote sensing techniques for

evaluating mine ground stability, Mining Enforcement and Safety

Administration information report 1057,

36 P.

Robinove, C. J., 1977, Experimental land systems mapping with digital Landsat images. Proceedings of the Eleventh International Symposium on Remote Sensing of Environment, 25-29 April, 1977, Center for Remote Sensing Information and Analysis, Environmental Research Institute of Mich., Ann Arbor, Mich., v. II, p. 1241.

Rowan, L. C., Wetlaufer, P. H., Goetz, A. F. H., Billingsley, F. C. and Stewart, J. H., 1974, Discrimination of rock types and detection of hydrothermally altered areas in south-central Nevada by use of computer-enhanced ERTS images: U.S. Geol. Survey Prof. Paper 883,

35 p.

Salas, Guillermo P., 1977, Relationship of Mineral resources to linear features in Mexico as determined from Landsat data: U.S. Geol. Survey Prof. Paper 1015, p. 61-74.

Schmidt, R. G., 1976, Detection of hydrothermal sulfide deposits, Saindak area, Western Pakistan, in ERTS-1, A new window on our planet: U.S. Geol. Survey Prof. Paper 929, P. 89-91.

Schmugge, T., Wilheit, T., Webster, W., and Gloering, P., 1976, Remote

sensing of soil moisture with microwave radiometers-II:

Technical Note TND-8321, NASA, Wash. D.C.


Energy resources in evaporite basins

Future energy requirements and current estimates of world oil and

gas reserves indicate that other energy sources must be found to replace conventional sources that are rapidly being depleted.

While coal remains

Nuclear and hydroelectric

relatively abundant, industrial conversion to coal is often costly and creates concommitant environmental problems. power sources have been well established but caution must be used in certain areas of high seismic risk. Solar, wind, and tidal power must also be explored. Another alternate source of energy employing fusion reactors is receiving greater attention and depends heavily on lithium to produce tritium. Lithium, an alkaline metal used in storage batteries, was previously thought to be very limited in distribution and restricted to small igneous bodies known as pegmatites. In recent years, however,

it has been found and is mined from the salt evaporite basin at Clayton Valley, Nevada, by the Foote Mineral Company. More recently, lithium has been found in salt brines of evaporite basins of the Atacama desert of northern Chile and in the Salar de Uyuni of southern Bolivia.

Research studies of Landsat images covering these two salars have demonstrated that the salt surfaces are highly dynamic features subjected to seasonal flooding (Carter and others, in press). Spectral signatures of mapped units of the salt surface were found to be based on roughness and moisture content. Repetitive images show that surface water tends

to accumulate in the same areas. Lithium has been found both in surface brine ponds and brine layers below the salt crust (Ericksen and others, 1977). While research has not yet defined a spectral signature for

Monitoring dynamic marine phenomena

Landsat may be uniquely configured, both in terms of spatial resolution and in spectral sensitivity of its sensors to obtain images

of dynamic marine phenomena. On June 19, 1976, an unusual Landsat
band 4 image (2514-12021) was acquired off the southwest coast of
Iceland, which recorded some peculiar near-surface, large-scale marine
current patterns (Williams, 1977).

Within the area of the image, at least eight well defined eddies are visible, and at least three well developed double eddies (one turning clockwise, the other counterclockwise) can be delineated in the

near-surface waters.

Individual eddies associated with the double

eddies have diameters of 12 to 19 mi. The area of the image is a region of high productivity of phytoplankton and zooplankton which support a large and economically important fish population. Although the light-toned water spectrally resembles sediment-laden water, the distance from the Icelandic coast (77 mi. to the center of the image) makes it more probable that the light tone of the water is the result of concentrations of phytoplankton. The variation in light- and dark-toned water is caused

by extensive mixing of coastal currents, possibly modified by upwelling. MSS band 4 Landsat images may represent an important new source of data about the dynamic marine environment of coastal shelf-slope areas.

« AnteriorContinuar »