Conference Papers

As the nation's primary Federal earth-science, factfinding and research agency, the U. S. Geological Survey (USGS) provides cartographic and natural resource information to many users to aid in planning and decision-making. Users of the data, both inside and outside the USGS, have become more and more sophisticated in their applications. As a consequence, scientists at the USGS are embracing compu

Artificial-recharge experiments were conducted at East Meadow in central Nassau County, Long Island, N. Y. , from October 1982 through January 1984, to evaluate the degree of ground-water mounding and chemical effects of artificially replenishing the ground-water system with tertiary-treated wastewater. Reclaimed water was provided by the Cedar Creek wastewater-treatment plant in Wantagh. Recharge

A field study was conducted to determine the effect of fabric wrap envelope and drain slope on the performance of a combination drainage and subirrigation system. Data were analyzed by examining relationships between flow rate and midpoint water table elevations. An entry resistance was defined and its value for each pair of 9,100 data points for drain flow rate versus water table elevation midway

The United States was divided into three regions, on the basis of mean annual rainfall, to decrease the variability in storm-runoff constituent loads and to improve regression relations with basin and climatic characteristics. Multiple-regression analyses, in progress, are being refined to determine the best regression models for each of the storm-runoff constituent loads in each of the three regi

Few studies have focused specifically on use of Alaskan wetlands by waterfowl. However, substantial information on the values of wetlands is available from studies on individual species or that were conducted for other purposes. Most investigators have found it most effective to classify habitat use on the basis of observed distribution patterns of waterfowl in relation to local physiographic feat

Earthquake-induced liquefaction features (sand blows), found near Hollywood, S. C. , have yielded abundant clasts of humate-impregnated sand and sparse pieces of wood. Radiocarbon ages for the humate and wood provide sufficient control on the timing of the earthquakes that produced the sand blows to indicate that at least three prehistoric liquefaction-producing earthquakes (m//b approximately 5.

This paper presents results of site-response experiments performed five months after the M//s equals 7. 8 Central Chile Earthquake of 3 March 1985. The objectives of the experiments performed are to identify amplification due to topography and geology. Topographical amplification at Canal Beagle, a subdivision of Vina del Mar, was hypothesized immediately after the main event, when extensive damag

No abstract available at this time

Two tropical weather systems, Hurricane Donna (1960) and Tropical Storm Dennis (1981), produced nearly equivalent amounts of rainfall in a 48-hour period south of the Miami (Florida) area. These two systems caused extensive flooding over a 600-square mile area, which is primarily agricultural and low density residential. The 1960 and 1981 storms caused the highest water levels recorded in south Da

The magnitude 6. 1 Morgan Hill, California, earthquake of April 24, 1984, produced a set of acceleration records at the freeway overpass in San Jose carrying I-280/I-680 across U. S. 101, 12 km from the epicenter. Peak accelerations reached 0. 10 g at ground level and 0. 16 g in the box girder. The integrated displacements at frequencies higher than 3 Hz permit the identification of the fundamenta

Multiple generations of prehistoric sand blows, interpreted as earthquake induced, have been discovered throughout coastal South Carolina. These sand blows extend far beyond 1886 earthquake induced sand blows, in sediments having approximately the same liquefaction susceptibility. The seismic source zone for the prehistoric sand blows is unknown. The different distributions of prehistoric and 1886

Hydrodynamics of the upper extent of the Potomac Estuary between Indian Head and Morgantown, Md. , are simulated using a two-dimensional model. The model computes water-surface elevations and depth-averaged velocities by numerically integrating finite-difference forms of the equations of mass and momentum conservation using the alternating direction implicit method. The fundamental, non-linear, un