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LANDSAT imagery was used primarily to map geologic features such as lineaments, linears, faults, and other major geologic structures which affect site selection for a nuclear power plant. Areas studied include Pakistan, the South Carolina Piedmont, and Huelva, Spain.
The author has identified the following significant results. Sao Domingos Range, Pocos de Caldas, and Araguaia and Tocantins Rivers in Brazil were selected as test sites for LANDSAT imagery. The satellite images were analyzed using conventional photointerpretation techniques, and the results indicate the application of small scale image data in regional structural data analysis, geological mapping, and mineral exploration.
The author has identified the following significant results. The first part of the study resulted in photographic procedures for making multispectral positive images which greatly enhance the color differences in land detail using an additive color viewer. An additive color analysis of the geologic features near Willcox, Arizona using enhanced black and white multispectral positives allowed compilation of a significant number of unmapped geologic units which do not appear on geologic maps of the area. The second part demonstrated the feasibility of utilizing Skylab remote sensor data to monitor and manage the coastal environment by relating physical, chemical, and biological ship sampled data to S190A, S190B, and S192 image characteristics. Photographic reprocessing techniques were developed which greatly enhanced subtle low brightness water detail. Using these photographic contrast-stretch techniques, two water masses having an extinction coefficient difference of only 0.07 measured simultaneously with the acquisition of S190A data were readily differentiated.
The author has identified the following significant results. An enhanced enlargement of a S190B color image at a scale of 1/19,200 of the Bingham porphyry copper deposit has compared a geological map of the area with the space imagery map as fair for the intrusion boundaries and total lack of quality for mapping the sediments. Hydrothermal alteration is only slightly evident on space imagery at Bingham, but in the Tintic mining district and the volcanic piles of the Keg and Thomas ranges, Utah, hydrothermal alteration is readily mapped on color enlargements of S190B. Several sites of calderas were recognized and new ones located on space imagery. One of the tools developed is a mercury soil-gas analyzer that is becoming significant as an aid in locating hidden mineralized zones which were suggested from space imagery. In addition, this tool is a prime aid in locating and better delineating geothermal sites.
The author has identified the following significant results. Working from the S190A photography at a scale of 1:702,000 and comparing the results with existing geologic maps has suggested that the larger scale structural features can be mapped and related to regional trends which provide an overall view not available at lower altitudes. All S190B in-house coverage was in stereo. The stereo capability was helpful in resolving problems relating to elevations and attitude of bedding, etc., but the greatest single contribution was the resolution capability.
With geological data available for all inner planets except Venus, we are entering an era of true comparative planetary geology, when knowledge of the differences and similarities for classes of structures (e.g., shield volcanoes) will lead to a better understanding of general geological processes, regardless of planet. Thus, it is imperative that planetologists, particularly those involved in geological mapping and surface feature analysis for terrestrial planets, be familiar with volcanic terrain in terms of its origin, structure, and morphology. One means of gaining this experience is through field trips in volcanic terrains - hence, the Planetology Conference in Hawaii. In addition, discussions with volcanologists at the conference provide an important basis for establishing communications between the two fields that will facilitate comparative studies as more data become available.
Physiographic and surficial cover information were combined into unified surficial geology maps (30 quadrangles and 1 synoptic map). The surface of Mars is heterogeneous and is modified by wind, water, volcanism, tectonism, mass wasting and other processes. Surficial mapping identifies areas modified by these processes on a regional basis. Viking I mission results indicate that, at least in the landing site area, the surficial mapping based on Mariner data is fairly accurate. This area was mapped as a lightly cratered plain with thin or discontinuous eolian sediment. Analysis of lander images indicates that this interpretation is very close to actual surface conditions. These initial results do not imply that all surficial units are mapped correctly, but they do increase confidence in estimates based on photogeologic interpretations of orbital pictures.
NASA's remote sensing technology as exemplified by ERTS-1 and LANDSAT 2 developed far more rapidly than they could have been reasonably absorbed with proved results by geological industries. This under-utilization of available technology is due to the ingrown infrastructure of exploration and engineering programs and techniques, and the inherent indirectness and long term effectiveness of the application of remote sensing to geological needs. The value of four dimensional geologic maps and the capabilities of various sensors are discussed.
Areas in which LANDSAT satellite imagery were found most useful include regional interpretations of geological structure, updating verifying of geologic maps, mineral and petroleum exploration, and the monitoring of natural hazards such as large-scale erosion and seismicity. Investigations in these areas of application demonstrated the wide variety of uses presently undertaken or envisioned for the future.
Fifteen sites within the channeled scabland were selected as stops with the dual aim of visiting locations critical to the arguments for a catastrophic flood origin of the scablands, as well as permitting an examination of the variability in both erosional and depositional features. The stop locations are plotted on a generalized geologic map and their coordinates are given in table form.
Surface roughness spectra of nine radar backscatter units in the Askja caldera region of Iceland were predicted from computer-enhanced like- and cross-polarized radar images. A field survey of the caldera was then undertaken to check the accuracy of the preliminary analysis. There was good agreement between predicted surface roughness of backscatter units and surface roughness observed in the field. In some cases, variations in surface roughness could be correlated with previously mapped geologic units.
The application of radiometric analysis in the interpretation of Mariner 6 and 7 imagery is investigated and illustrated. The following types of problems were felt could be addressed using this imagery: (1) evaluation of local reflectivity changes; (2) augmentation of geological mapping; (3) discrimination of atmospheric phenomena; and (4) investigation of polar cap structure.
During the Viking mission, three broad areas of the northern plains were investigated as possible landing sites for Viking lander 2. We present a geological map of the area designated the B1 landing site in Cydonia centered on 45 deg N latitude, 4 deg W longitude. Viking imagery of this area has given detailed coverage, allowing the northern plains to be examined in more detail over wider areas than was possible from Mariner 9. Some plains areas with polygonal fracture patterns are considered to be pediments in ancient southern hemisphere rocks. The fracture patterns predate at least some of the younger northern plains material. Several northern plains units are distinguished as well as surface textures of unknown origin. Viking pictures provide good data for future studies of stratigraphy and surface process in this region and others like it in northern latitudes.
Comparison of the magnetic-field measurements of the Apollo subsatellite magnetometers with USGS geologic maps suggests that the ancient lunar field may have been greater during the Imbrian Period than the earlier Pre-Nectarian and Nectarian periods. Further, the field seems to have varied in direction. These data are consistent with a model in which the ancient lunar magnetizing field arises from a core dynamo which does not form until the Imbrian Period. Impacts during this period then result in magnetized crater melt and ejecta blankets. It is emphasized, however, that the area sampled by the subsatellite magnetometers is but a small fraction of the lunar surface. These results must be confirmed with studies of independent regions of the lunar surface before they can be considered conclusive.
A review of applications and results of Landsat projects is presented. Attention is given to the MSS bands, band ratios, and color composites noting the applications of each in agriculture, forestry and range, water resources, geology, land use, and marine resources. A series of Landsat images is presented noting forest regions, burn scars, vegetated areas, and flood regions. A geological map compiled from an analysis of Landsat imagery is presented along with a strip-mine map also constructed from the data of Landsat images. Landsat data is further discussed with reference to mineral exploration, earthquake-zone investigations, and geothermal surveys.
Observations of the earth from remote-sensing platforms are discussed noting the NASA Earth Resources Aircraft Program, Earth Resources Technology Satellite program, and the Earth Resources Experiments Package. Techniques for geological mapping are described including automatic mapping, visual interpretation, band selection, radar, band combination, and image enhancement.
LANDSAT imagery of the region were studied allowing the placement of the area of study in the regional geological context. A geological mapping of the 1.60.000 scale was done. A methodology was developed which consisted in a regional temperature mapping using trend surface analysis. Through the correlation of all these data, four different areas were localized with a high potential as thermomineral sources.
Synoptic, large-area radar images of the earth's land and ocean surface, obtained from the Seasat orbiting spacecraft, show the potential for geologic mapping and for monitoring of ocean surface patterns. Structural and topographic features such as lineaments, anticlines, folds and domes, drainage patterns, stratification, and roughness units can be mapped. Ocean surface waves, internal waves, current boundaries, and large-scale eddies have been observed in numerous images taken by the Seasat imaging radar. This article gives an illustrated overview of these applications.