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Beginning in October 1976, a program of water-level monitoring of abandoned water wells was initiated in the Palmdale area with the purpose of identifying possible water-level changes premonitory to a major earthquake on the San Andreas fault. In October 1977, the program was extended southeastward along the rift zone to...

The hydrology and geology of Williams Lake watershed was studied to evaluate the accuracy of various methods used to determine precipitation and evaporation in lake water-balance studies and to define a lake and ground-water system according to approaches suggested by theoretical modeling studies. Regression analysis between estimated and measured precipitation...

PART A: A model of the discovery process can be used to predict the size distribution of future petroleum discoveries in partially explored basins. The parameters of the model are estimated directly from the historical drilling record, rather than being determined by assumptions or analogies. The model is based on...

The Boulder Creek batholith is the best known of several large Precambrian batholiths of similar rock composition that crop out across central Colorado. The rocks in the batholith belong to the calc-alkaline series and range in composition from granodiorite through quartz diorite (tonalite) to gneissic aplite. Two rock types dominate':...

Work in the Seismology Branch on the problem of earthquake prediction is based primarily on the recording and analysis of seismic (elastic) waves in the Earth generated either by earthquakes themselves or by artificial sources such as quarry blasts or explosions detonated in drill holes. At the present time this...

A three-dimensional digital model of ground-water flow was constructed to represent the dipping anisotropic beds of the Tesuque aquifer system underlying the Pojoaque River basin and vicinity, New Mexico. Simulations of steady-state conditions and historical ground-water withdrawals were consistent with observed data. The model was used to simulate the response...

Detailed flow and cross-section data for a 17-mile reach of the Chattahoochee River in northeast Georgia are described and summarized. Flow data include measurements of highly dynamic stage and discharge at five stations during the period March 21-23, 1976. Flow data were collected at 5-minute intervals and are listed accordingly....

An analytical plan is presented for a study of the effects of land-use changes on the magnitude and frequency of flood-peak flows and on sediment characteristics of the Tug Fork in Kentucky, Virginia, and West Virginia. The plan includes compilation and analysis of available data, collection of new data on...

The objective of this study is to develop a probabilistic model for earthquake occurrences with temporal and spatial memory. Stochastic processes are used to characterize both the spatial and temporal dependencies of seismic occurrences along a fault. Currently, only homogeneous space and time transitions are considered. The resulting process however...

Two hundred twenty-four kilometers of closely spaced side-scan sono­graph data have been collected from eastern Rhode Island Sound and Vineyard Sound, Mass., by the U.S. Geological Survey in cooperation with the New England Division of the U.S. Army Corps of Engineers. These data were obtained during the August 1976 cruise...

A digital model of two-dimensional ground-water flow was used to predict changes in the potentiometric surface of the Floridan aquifer, 1976-2000, in a 5,938-square-mile area of west-central Florida. In 1975, ground water withdrawn from the Floridan aquifer for irrigation, phosphate mines, other industries, and municipal supplies averaged about 649 million...

North-central Santa Cruz County is underlain mainly by folded sedimentary rocks of Tertiary and Cretaceous age that have been highly fractured by movements in the San Andreas fault system. Ground water is stored in fractures within shale and mudstone formations and in intergranular pore spaces within fine- to very fine-grained...

This report contains rainfall and runoff data collected during the 1978 water year for drainage basins in the Houston, Tex., metropolitan area. The information will be useful in determining the extent to which progressive urbanization will affect the yield and mode of occurrence of storm runoff. Rainfall-runoff computations are presented...

The magnitude 5.2 (mb) northern Kentucky earthquake of July 27, 1980, at 18:52:21.8 UTC, located at 38.17N, 83.91W with a depth of 8 km (as determined by the National Earthquake Information Service), was particularly notable for the widespread damage it did, especially to older chimneys. Investigators from several different organizations...

A subdivision developer encountered water while digging trenches associated with developing property at Spring Acres Subdivision, Anchorage, Alaska, during the summer of 1975. He reported encountering water at a depth of about 8 feet in June 1975 and also reported a rise in water level to approximately land surface by...

A computer program for simulating one-dimensional, unsteady temperature and solute transport in a river has been developed and documented for general use. The solution approach to the convective-diffusion equation uses a moving reference frame (Lagrangian) which greatly simplifies the mathematics of the solution procedure and dramatically reduces errors caused by...

The model developed in this study simulates .recharge to, flow through, and discharge from the water-table aquifer in the upper Pickering Creek basin, a 5.98-square-mile basin representative of most of Chester County, Pennsylvania. The two-dimensional finite-difference model of Trescott, Pinder, and Larson was used with slight modification. The way ground-water...

The water quality in carbonate aquifers can be determined by analysis of resistivity and porosity logs. When supporting data from water analyses are available, the value of the cementation exponent m can be determined more precisely. Data for this study were taken from logs of oil-test wells, Amstrat sample studies,...

An aquifer test was designed and conducted in the anisotropic dipping beds of the Tesuque Formation on the Tesuque Pueblo Grant, N.M. The three-dimensional digital model used to analyze the test approximated the response to the test. The analysis of the geohydrology of the test site in combination with the...

Procedures are defined for estimating the magnitude and frequency of future flood peaks and flood volumes and for estimating the expected hydrograph shape of rainfall-induced runoff of small streams in South Dakota. The procedures are applicable to flood flows that are not significantly affected by artificial storage or other manmade...

Modification of sampling programs at some water-quality stations in the Missouri River basin in Montana has eliminated the means by which solute loads have been directly obtained in past years. To compensate for this loss, water-quality and streamflow data were statistically analyzed and solute loads were simulated using computer techniques.Functional...

Four modified nonradioactive-tracer methods and 20 predictive equations for determination of stream-reaeration coefficients in three small Wisconsin streams were compared with the radioactive-tracer method developed by Tsivoglou. Of the four modified-tracer techniques, the propane-area technique, which measures the total weight of propane gas passing stream-sampling stations, yielded the least mean absolute...