Plant succession at Skaftafellsjoekull
Investigating alluvial plain of Icelandic glacier for terrestrial and aquatic plant succession
Sheridan, R. P.↗
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Evaluate the application of ERTS-A data for detecting and mapping snow cover
The author has identified the following significant results. Preliminary results of the analysis of a limited sample of ERTS-1 data from the western United States and the Arctic indicate that snow cover can be detected in the MSS-4 and MSS-5 bands by its high reflectance compared to that of the surrounding snow-free terrain. Snow can generally be distinguished from clouds because of well-defined boundaries as compared with the less distinct cloud edges, the lack of shadows characteristic of clouds, and pattern configurations that fit closely with higher elevations and terrain features. At higher latitudes where repetitive ERTS-1 coverage occurs snow can also be identified by the day-to-day continuity of the patterns. In the longer wavelengths, particularly the MSS-7 band, the contrast between snow and snow-free terrain is much lower, and, thus, snow is more difficult to detect. ERTS-1 data from the Canadian Arctic shows the seasonal increase in snow cover in several areas. In other ERTS-1 data, considerable detail is evident in glaciers located along the east and west coasts of Greenland.
Barnes, J. C.↗
Identification of phenological stages and vegetative types for land use classification
The author has identified the following significant results. Two procedures for examining ERTS-1 imagery were investigated in cooperation with the photographic services section. Positive, 10X enlargements were produced of spectral bands 4, 6, and 7, for a portion of photo 1033-21020. Adequate detail remained to recognize physical features such as streams, glaciers, ice, and snow. Also the entire image was studied using transparencies produced by the 3M color-key process. A combination of three complementary color combinations produced visually recognizable shades apparently indicating vegetation differences. Also lakes and glacial streams of sufficient size, ice and snow, and drainage patterns can be recognized. A need is indicated for oblique low level color aerial photography in the vicinity of identifiable terrain features to assist in the positive location of vegetative communities appearing in the analysis process. In the primary areas of concern to this project identifiable manmade features are conspicuous by their absence. In image 1049-20505 band 7 produced distinct tonal differences on a mountain slope to river bottom gradient.
Branton, C. I.↗
Circulation of Prince William Sound
The author has identified the following significant results. Visual examination of the available ERTS-1 and NASA NP-3 aircraft imagery has suggested that sediment-laden plumes from rivers may be useful in tracking surface circulation over the regions where these plumes retain their visible identities. Plumes of ice derived from tidewater glaciers are highly visible on the ERTS-1 imagery, but are generally of too small an areal extent to be useful in tracing surface circulation. Shore-fast ice is also highly visible on the ERTS-1 data. Practical scientific results include a corroboration of the westward flow just offshore in the Gulf of Alaska with inflow through Hinchinbrook Entrance into Prince William Sound. The tracer in this case was the Copper River Plume, which originates at the mouth of the Copper River east of Prince William Sound. A single partial image of Port Valdez, in northeastern Prince William Sound, suggests by the visible suspended sediment distribution that surface circulation there was cyclonic, as deduced previously from oceanographic baseline data. Surf along the shoreline of the Gulf of Alaska is highly visible on ERTS-1 imagery.
Muench, R. D.↗
Investigation of the detection and monitoring of forest insect infestations in the Sierra Nevada Mountains of California
The author has identified the following significant results. The detection of insect infestations through the use of ERTS-1 imagery alone is very promising. In the field of features other than insect infestation, it is possible to detect: timber vs. non-timber; timber density in broad categories; lakes, major stream courses, rock outcrops and domes; riparian vegetation, cultivated fields, pasture land, and glaciers.
Hall, R. C.↗
Evaluate the application of ERTS-A data for detecting and mapping sea ice
The author has identified the following significant results. Sea ice is detectable in all of the ERTS-1 MSS bands and can be distinguished from clouds through a number of interpretive keys. Considerable information on ice type can be derived from the ERTS-1 data. Ice types that appear to be identifiable include: ice floes of various categories, pack ice of various concentrations, ice belts, brash ice, rotten ice, fast ice, leads, fractures, cracks, puddles, thaw holes, and flooded ice. Although larger icebergs can be seen, it is difficult to distinguish them from ice floes. Ice features as small as the small floe of 20 to 100 m across can be detected, and the sizes of features somewhat smaller than 100 m can be measured from enlarged ERTS-1 prints. The multispectral analysis of the ERTS-1 MSS-7 bands provides much information on ice type and ice surface features that cannot be derived from a single spectral band. For example, thaw holes can often be distinguished from puddles because of their different appearances in the two bands. These surface features can be indicative of ice age. Furthermore, snow lines on glaciers can be reliably mapped through the joint use of the MSS-4 and 7 data.
Barnes, J. C.↗
Remote sensing of permafrost and geological hazards in Alaska
The author has identified the following significant results. The study of the ERTS-1 imagery of Alaska indicates the following: that areas of different topographic expression affecting the distribution and character of permafrost can be distinguished clearly; that on the Arctic North Slope, regional differences in the distribution and character of permafrost-related oriented thaw lakes can be observed; that the distribution of certain types of geologic materials having a significant effect on the character of permafrost can be delineated on a regional scale; and that the resolution of the imagery is adequate to identify large scale geologic hazards such as landslides, glacier-dammed lakes, aufeis fields, etc. The information concerning the distribution and character of permafrost and geologic hazards to the gained in accomplishing the objectives of this project will be an invaluable aid in solving engineering-geologic and environmental problems related to route and site selection for structures such as roads, railroads, pipelines, and large installations; to distribution of natural construction materials; and to construction and maintenance.
Ferrians, O. J., Jr.↗
Geological and geophysical remote sensing of Iceland
The author has identified the following significant results. A binational, multidisciplinary research effort in Iceland is directed at an analysis of MSS imagery from ERTS-1 to study a variety of geologic, hydrologic, oceanographic, and agricultural phenomena. Initial findings are: (1) recent lava flows can be delineated from older ones; (2) ERTS-1 and NOAA-2 recorded volcanic eruptions on Heimaey, Vestmann Islands; (3) coastline changes are mappable; (4) areas covered with new or residual snow can be mapped, and dark appearance of newly fallen snow on band 7 appears to be related to melting; (5) sediment plumes from discharge of glacial rivers can be delineated; (6) the area encompassed by glacial ice can be mapped, including the new position of a surging glacier, Eyjabakkajokull, and related phenomena of nunataks and moraines; (7) changes in position of rivers, lake sizes, and new lakes can be mapped; (8) low sun angle imagery enhances the morphologic expression of constructional glacial and volcanic landforms; (9) MSS color composites permit regional mapping of distribution of vegetation; and (10) at least at 1:250, 000 map scale and smaller, ERTS-1 imagery provides a means of updating various types of maps of Iceland and will permit the compilation of maps specifically aimed at those dynamic environmental phenomena which impact on the Icelandic economy.
Williams, R. S., Jr.↗
ERTS-1 applications in hydrology and water resources
After having been in orbit for less than one year, the Earth Resources Technology Satellite (ERTS-1) has shown that it provides very applicable data for more effective monitoring and management of surface water features over the globe. Mapping flooded areas, snowcover, and wetlands and surveying the size, type, and response of glaciers to climate are among the specific areas where ERTS-1 data were applied. In addition the data collection system has proven to be a reliable tool for gathering hydrologic data from remote regions. Turbidity variations in lakes and rivers were also observed and related to shoreline erosion, industrial plant effluent, and overall water quality.
Salomonson, V. V.↗
Analysis of ERTS imagery using special electronic viewing/measuring equipment
An electronic satellite image analysis console (ESIAC) is being employed to process imagery for use by USGS investigators in several different disciplines studying dynamic hydrologic conditions. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. Quantitative measurements of distances, areas, and brightness profiles can be extracted digitally under operator supervision. Initial results are presented for the display and measurement of snowfield extent, glacier development, sediment plumes from estuary discharge, playa inventory, phreatophyte and other vegetative changes.
Evans, W. E.↗
Snow cover surveys in Alaska from ERTS-1 data
September and October ERTS scenes have been analyzed to delineate snow cover patterns in northern Alaska's Brooks Range and on Mt. Wrangell, and active volcano in South Central Alaska. ERTS images demonstrate that the snow on the northern foothills of the Brooks Range are significantly more affected by katabatic wind action than are the southern foothills. Aufeis deposits along arctic rivers also can be identified in late summer. A survey of such aufeis deposits could identify additional summertime sources of fresh water supplies. Images of Mt. Wrangell permit monitoring of the interaction between volcanic heat and the mass balance of glaciers that exist on active volcanoes. Temporal changes in the areas of bare rock on the rim of the caldera on the summit reveal significant melting of new snow from an extensive storm on August 18. Digital analysis of data from subsequent passes over the summit on September 7, 23 and 24 revealed considerable bare rock exposed by melting, which is virtually impossible from solar heating at this altitude and date.
Benson, C. S.↗
Water resources
The application of ERTS-1 imagery to the conservation and control of water resources is discussed. The effects of exisiting geology and land use in the water shed area on the hydrologic cycle and the general characteristics of runoff are described. The effects of floods, snowcover, and glaciers are analyzed. The use of ERTS-1 imagery to map surface water and wetland areas to provide rapid inventorying over large regions of water bodies is reported.
Salomonson, V. V.↗
Water Resources
Uses of ERTS-1 imagery and data for water resources surveys and management are summarized. Areas discussed are: (1) land use and geology; (2) flood plain and flood inundation mapping; (3) snow cover mapping; (4) glacier observations; (5) data collection systems; (6) surface waters; (7) wetlands mapping; (8) water quality; (9) soil mapping; (10) phreatophyte and riparian vegetation mapping; and (11) evapotranspiration.
Salomonson, V. V.↗
The cartographic application of ERTS/RBV imagery in polar regions
The author has identified the following significant results. Results of the SR-149 experiments demonstrated the feasibility of revising coastlines on maps of Antarctica, detected gross changes in the northern limits of the three largest ice shelves in the world, and led to the discovery of unmapped geographical features in Antarctica. Analyses of MSS imagery during the investigations show positive identification and obvious changes in size, shape, and position of such features as glaciers, ice tongues, ice shelves, and fast ice when compared to the existing USGS 1:250,000 scale maps. Investigations also pointed out that accurate and meaningful photoimage mosaics can be compiled at scales of 1:500,000 and 1:1,000,000 over the Polar Regions. With respect to the Antarctic region, many thousands of square miles can be image mapped for the very first time if cloud-free imagery becomes available and at a great reduction in cost of compilation. The international scientific community will benefit from such timely products. Current maps are a necessity for proper planning for field operations, especially over the treacherous terrain of the Antarctic.
Macdonald, W. R.↗
Interference patterns of a horizontal electric dipole over layered dielectric media.
Interference patterns for electromagnetic fields due to a subsurface reflector below a layered lossy dielectric are calculated with the geometrical optics approximation for use in interpreting data to be collected on the moon by Apollo 17 as well as data currently being obtained on terrestrial glaciers. The radiating antenna lies on the surface. All six field components are calculated and studied. For the endfire solutions, the peak of the first reflected wave is found to be different from that of the broadside ones. To facilitate a physical discussion, we plotted the radiation patterns due to the antenna on the surface.
Tsang, L.↗
Radio interferometry depth sounding. II.
Experimental results from an analog scale model and from field tests on two glaciers using radio-frequency interferometry (RFI) are interpreted on the basis of previously described theoretical results. The RFI technique is found to be a practical method with which to study layering in low-loss dielectrics. Three parameters of the upper layer can be estimated from the data: the dielectric constant, the loss tangent, and an estimate of the thickness to a reflector. The method is an inexpensive way to sound ice sheets less than a few hundred meters thick, and could be used to study low-loss layers on the moon.
Rossiter, J. R.↗
Microwave maps of the polar ice of the earth
Synoptic views of the entire polar regions of earth were obtained free of the usual persistent cloud cover using a scanning microwave radiometer operating at a wavelength of 1.55 cm on board the Nimbus-5 satellite. Three different views at each pole are presented utilizing data obtained at approximately one-month intervals during the winter of 1972-1973. The major discoveries resulting from an analysis of these data are as follows: (1) Large discrepancies exist between the climatic norm ice cover depicted in various atlases and the actual extent of the canopies. (2) The distribution of multiyear ice in the north polar region is markedly different from that predicted by existing ice dynamics models. (3) Irregularities in the edge of the Antarctic sea ice pack occur that have neither been observed previously nor anticipated. (4) The brightness temperatures of the Greenland and Antarctica glaciers show interesting contours probably related to the ice and snow morphologic structure.
Gloersen, P.↗
Satellite geological and geophysical remote sensing of Iceland
The author has identified the following significant results. Under a binational, multidisciplinary experiment ERTS-1 imagery is being used to measure and map dynamic natural phenomena in Iceland. A few of the initial results from the project are: (1) a large variety of geological and volcanic features can be studied, particularly on imagery acquired at low sun angle ( 10 deg), which have not been previously recognized; (2) under optimum snow cover conditions, geothermal areas can be discerned by their snowmelt pattern or by warm spring discharge into frozen lakes; (3) a variety of map types at scale of 1:1,000,000 and 1:500,000, can be compiled, made more accurate, or updated (changes in coastline, glaciers, lakes, etc.); (4) the persistence of snow in the highland areas, during the summer months, has important ramifications to rangeland management; (5) false color composites (MSS) permitted the mapping of four types of vegetation; forested, reclaimed, cultivated areas and grasslands, and the mapping of the seasonal change of the vegetation, all of high value to rangeland management when complete, repetitive coverage of Iceland becomes a reality with an operational satellite; and (6) the volcanic eruption on Heimaey was recorded.
Williams, R. S., Jr.↗