Conference Papers

As with hydrothermal systems, the western U.S has higher HDR potential overall than the eastern U.S. because geothermal gradients on average are higher in the west. Nevertheless, some attractive exploration targets occur in the eastern U.S. The most favorable target in the eastern U.S. (defined here to include the Great Plains province) is one in which the heat flow from the basement rocks is high

This paper aims to assess the validity of the generalized viscoplastic fluid (GVF) model in the light of both the classical relative-viscosity versus concentration relation and the dimensionless stress versus shear-rate squared relations based on kinetic theory, thereby addressing how to evaluate the rheological parameters of the GVF model using Bagnold's data.

The Courant number C, the key to unsteady flow computation, is a ratio of physical wave velocity, ??, to computational signal-transmission velocity, ??, i.e., C = ??/??. In this way, it uniquely relates a physical quantity to a mathematical quantity. Because most unsteady open-channel flows are describable by a set of n characteristic equations along n characteristic paths, each represented by vel

A program based on the U.S. Geological Survey (USGS) methods for indirectly computing peak discharges through culverts allows users to employ input data formats used by the water surface profile program (WSPRO). The program can be used to compute discharge rating surfaces or curves that describe the behavior of flow through a particular culvert or to compute discharges from measurements of upstrea

Debris flows are recurrent sediment-transport processes in 525 tributaries of the Colorado River in Grand Canyon. Arizona. Initiated by slope failures in bedrock and (or) colluvium during intense rainfall, Grand Canyon debris flows are high-magnitude, short-duration floods. Debris flows in these tributaries transport very large boulders into the river where they accumulate on debris fans and form

The determination of in situ stresses along deep vertical profiles was declared a key issue for two scientific deep drilling projects:the German Continental Deep Drilling Project (KTB) situated in northeast Bavaria in an area of complex variscian thrust tectonics andthe CAJON PASS Project, located only about 4 km from the San Andreas Fault Zone In southern California.In the KTB project 7 successfu

Computerized three-dimensional geologic models of potential high-level nuclear waste repositories such as Yucca Moutain, Nevada, are important for visualizing the complex interplay of (1) thickness and facies variations in lithostratigraphic units and (2) the disruption of these units by faults. The concept of a 'model of confidence' in the lithostratigraphic model is introduced to show where data

Inspecting bridges and monitoring scour during high flow can improve public transportation safety by providing early identification of scour and stream stability problems at bridges. Most bridge-inspection data are collected during low flow, when scour holes may have refilled. More than 25 percent of the States that responded to a questionnaire identified lack of adequate methodology and/or equipm

Debris flows and flash floods are common geomorphic processes in the Colorado Rocky Mountain Front Range and foothills. Usually, debris flows and flash floods are associated with excess summer rainfall or snowmelt, in areas were unconsolidated surficial deposits are relatively thick and slopes are steep. In the Front Range and foothills, flash flooding is limited to areas below about 2300m whereas

Net transport of atmospheric gases into and out of soil systems is primarily controlled by diffusion along gas partial pressure gradients. Gas fluxes between soil and the atmosphere can therefore be estimated by a generalization of the equation for ordinary gaseous diffusion in porous unsaturated media. Consumption of CH4 by methylotrophic bacteria in the top several centimeters of soil causes the

Distribution of dissolved selenium in ground water of the irrigated Grand and Uncompahgre Valleys is affected by the aqueous geochemical environment of the shallow ground-water system composed of alluvium and shale residuum. Selenium concentrations are as high as 1,300 micrograms per liter in water from shallow wells. The highest concentrations of dissolved selenium were in water from wells comple

Since 1982, imported water originating in the Sierra Nevada has been used to recharge the Rialto-Colton ground-water basin, about 100 km east of Los Angeles. Stable isotopes of oxygen (oxygen-18) and hydrogen (deuterium) were used to determine the disposition of artificially recharged, imported water within the basin. Delta oxygen-18 ratios in water from wells sampled in spring and summer 1992 ran