Conference Papers

No abstract available.

No abstract available.

No abstract available.

No abstract available.

This paper briefly summarizes some recent developments in studies of seismic source parameter estimation, emphasizing the essential similarities between mining-induced seismogenic-failure and naturally occurring, tectonically driven earthquakes. The root-mean-square acceleration, a//r//m//s, shows much promise as an observational measure of high-frequency ground motion; it is very stable observati

An approach is given that develops spatial operators about the basic geometric elements common to spatial data structures. In this fashion, a single set of spatial operators may be accessed by any system that reduces its operands to such basic generic representations. Algorithms based on this premise have been formulated to perform operations such as separation, overlap, and intersection. Moreover

Data obtained from 59 Landsat scenes were used to estimate the areal extent of irrigated agriculture over the High Plains region of the United States for a ground-water flow model. This model provides information on current trends in the amount and distribution of water used for irrigation. The analysis and reduction process required that each Landsat scene be ratioed, interpreted, and aggregated.

Summary form only given. A classification error matrix typically contains tabulation results of an accuracy evaluation of a thematic classification, such as that of a land use and land cover map. The diagonal elements of the matrix represent the counts corrected, and the usual designation of classification accuracy has been the total percent correct. The nondiagonal elements of the matrix have usu

Geothermal exploration and development has been under way on Sao Miguel Island, Azores since 1975. This work had been restricted to the Fogo volcano, one of three dormant silicic volcanic centers on the island. The USGS in 1982 and 1983 conducted reconnaissance natural-source audio-magnetotelluric (AMT) surveys of all three silicic centers to evaluate the potential for geothermal systems at each a

The U. S. Geological Survey operates two water-quality laboratories. The quality of data produced by each laboratory is judged primarily from an evaluation of the data obtained from the analysis of reference samples. Quality-assurance reports that contain an analysis of the results obtained from chemical analysis of these reference materials by the two laboratories are prepared quarterly, and annu

Petroleum resource assessment procedures require the analysis of a large volume of spatial data. The US Geological Survey (USGS) has developed and applied spatial information handling procedures and digital cartographic techniques to a recent study involving the assessment of oil and gas resource potential for 74 million acres of designated and proposed wilderness lands in the western United State

Observations made from 1972 to 1976 with the Electrically Scanning Microwave Radiometer on board the Nimbus-5 satellite provide sequential synoptic information of the Arctic sea ice cover. This four-year data set was used to construct a fairly continuous series of three-day average 19-GHz passive microwave images which has become a valuable source of polar information, yielding many anticipated an