Publications

Well drawdown data from an anisotropic aquifer in the Salinas alluvial fan were collected and analyzed with a computer program called TENSOR2D. The program uses ordinary and weighted least-squares optimization procedures to solve the system of simultaneous equations needed to define the theoretical transmissivity ellipse. Prediction of drawdown data was made by coupling the anisotropy ellipse with

No abstract available.

Chloride was injected as a conservative tracer with nitrate to examine nitrate retention (storage plus biotic uptake) and transport in a 327—m reach of a third—order stream draining a forested basin in northwestern California. Prior to injections, diel patterns of nutrient concentrations were measured under background conditions. Nitrate concentration of stream water increased downstream, indicati

Samples of Recent sediments, representing up to 1000 years of accumulation, were collected from three closed basin lakes (Mono Lake, CA, Walker Lake, NV, and Great Salt Lake, UT) to assess the effects of brine composition on the accumulation of total organic carbon, the concentration of dissolved organic carbon, humic acid structure and diagenesis, and trace metal complexation.The Great Salt Lake

Short-term variability of a conservative quantity (salinity) and two nonconservative quantities (chlorophyll a, suspended particulate matter) was measured across a sampling grid in the South San Francisco Bay estuary. Surface measurements were made every 2 h at each of 29 (or 38) sites, on four different dates representing a range of tidal current regimes over the neap-spring cycle. From the distr

Spatial distributions of copper (Cu), zinc (Zn) and cadmium (Cd) were followed along a longitudinal gradient of dissolved organic carbon (DOC) in South San Francisco Bay (herein referred to as the South Bay). Dissolved Cu, Zn and Cd concentrations ranged from 24 to 66 nM, from 20 to 107 nM and from 1·2 to 4·7 nM, respectively, in samples collected on five dates beginning with the spring phytoplank

The horizontal pattern of mesoscale (1–4 km) variability in salinity was a poor predictor of mesoscale patterns in chlorophyll a, suspended particulate matter, and daily primary productivity in the South San Francisco Bay estuary during spring 1987. The tidally-averaged salinity distribution varied over weekly time scales, reflecting inputs of freshwater as well as transport processes. Spatial dis

A semiquantitative X‐ray diffraction procedure has been developed that can be used to acquire reproducible mineralogic data from geographically unrelated stream‐sediment samples having similar mineralogy. Weight percentages for quartz, total‐feldspar, and total‐clay can be determined by direct comparison of intensities with standard‐mineral mixtures of known weight percent. Matrix effects and mass

Sediment samples from nearshore sites in south San Francisco Bay and from streams flowing into that section of the Bay have been characterized in terms of their content of biogenic and anthropogenic molecular marker compounds. The distributions, input sources, and applicability of these compounds in determining sediment movement are discussed. By means of inspection and multivariate analysis, the

As part of the U.S. Geological Survey Water Resources Division 's objective of presenting impartial, accurate data and scientific analyses equally to all interested parties, current activities in Pennsylvania are described by a listing of project location, cooperator(s), period of project, project chief, headquarters office, problem, objective, approach, progress and plans. The basic data programs

No abstract available.

Continuous and periodic measurements in 54 key wells and water-level measurements emplaced in Coastal Plain aquifers across North Carolina in 193 supplemental wells are presented in this report. Hydrographs of selected wells show changes in ground-water storage in the State. The water table in the shallow aquifers was higher throughout most of the State in 1987 than in 1986, indicating that rain h