On the basis of work by several authors (Maurin and Lathram, 1977), (Fischer and Lathram, 1973) plans are now being made (Gryc, written communication, 1977) to drill a Lands at-detected apparent geologic structure in northern Alaska to a depth of approximately 19,775 feet this coming year. The results, if favorable, will help establish Landsat as an important exploration tool. Over 600 representatives from a number of petroleum and petroleum exploration companies attended the most recent William T. Pecora Symposium in Sioux Falls, s. D., in October of 1977. Both in presented papers and in private discussions, it became apparent that the petroleum industry 18 not only the largest single customer of data from Landsat, but that they are now using the data routinely to improve their total exploration and planning programs. Many companies have established their own computerized data listings, and several are routinely using computer analysis methods in addition to conventional interpretation procedures. One company representative stated that the characteristics of broad overview and low sun angle perspective provided by Landsat images have enabled his company to select targets for detailed geological and geophysical exploration. Another representative stated that Landsat Images of the United States are being used extensively and are providing new structural information that will extend known oil fields in the United States. Miller (1977) demonstrated how Landsat data have assisted in exploration in Kenya. He states that "ERTS (Landsat) studies have the advantage of very quick Interpretation over new areas and regions. Such work saves time and money and gives a substantial basis for new ideas." In 1977 he reported the discovery of a large and thick sequence of sedimentary rocks in southern Sudan that provide a new target for oil exploration, which is now underway (Miller and Vandenakker, 1977). Mosaics of the conterminous United States compiled by the Soil Conservation Service for NASA have been analyzed by U.S. Geological Survey geologists interested in linear features that may be of tectonic significance. Mosaics at scales of 1:5,000,000 and 1:1,000,000 were used to identify and evaluate new features and to re-evaluate previously known geologic features. Field work in northern Sonora, Mexico, has confirmed early interpretations by Salas (1977) that the occurrence of major mineral deposits are closely related to the intersection of linear features that are major fracture systems. This confirmation is supported by geochemical and geophysical evidence (Raines, 1977, and Kleinkopf and others, 1977). Rowan and others (1974) demonstrated that the combination of digital computer processing of band ratios and color compositing of Landsat Multispectral Scanner (MSS) images could be used to detect and map areas of hydrothermally altered rocks associated with ore deposits and to discriminate most major rock types in south-central Nevada. Schmidt (1976) used computer enhanced Landsat imagery to examine the characteristics of known copper deposits in Pakistan. He then examined the imagery to find areas that have similar spectral and textural characteristics. He found 19 areas that he considered to be potential sites for the presence of mineralized rock and was able to confirm surface mineralization by field inspection at seven of these. Using similar methods, Dykstra and Bimic (1977) have extended the geologic Information of the area to the east and confirmed many of the early findings. Use of Landsat to observe water-quality conditions Landsat data have been successfully used in water-quality and environmental applications. The Program of the International Hydrological Decade (IHD) had as a major objective the monitoring of water-quality conditions in the Great Lakes. As an adjunct exercise to the IHD, the EROS Program collaborated with the National Oceanic and Atmospheric Administration (NOAA), NASA, the Canada Centre for Inland Waters, and Guelph and McMaster Universities in studying the applicability of Landsat data. Falconer and others (1975) used photo-optical techniques to enhance water features recorded in the data and clearly showed turbidity plumes from the Welland Canal and Niagara River. They also showed turbidity pattems interrupted by offshore bars, and steel mill and municipal effluents in Hamilton Harbour. Tonal differences extending into the lake from the Humber River at Toronto were clearly depicted as well as additional unidentified effluent discharges. The study demonstrated the capability of Landsat to detect sources and movement of natural pollutants and municipal and industrial wastes into major water bodies. Linear features, presumably Internal waves, which are indicative of lake dynamics, were also depicted on the enhanced imagery. Concentrations of floating or near-surface biotic materials were detected, illustrating the suitability of the data for certain types of ecological analyses. Allan Strong of NOAA, in cooperation with the EROS Program, prepared & water-quality classification of eastern Lake Ontario using digital analysis techniques and color codings to distinguish carbonate precipitates, chlorophylls, algae, and floating oil slicks. |