Geology topics

S. E. Ingebritsen

Publications and source records attributed to S. E. Ingebritsen.

40 records · Page 3Linked to original sources

USGS1986

Shallow subsurface temperature surveys in the basin and range province-II. Ground temperatures in the Upsal Hogback geothermal area, west-central Nevada, U.S.A.

Numerous temperature surveys at a depth of 1 m were made in 1973–1985 in the Upsal Hogback and Soda Lakes geothermal areas in west-central Nevada. Whereas the surveys effectively delineated temperature at depth and heat flow within the relatively intense Soda Lakes thermal anomaly, they were not effective at the diffuse Upsal Hogback anomaly, where several perturbing factors that affect shallow subsurface temperatures are exceedingly variable. Albedo is the most important factor in the Upsal Hogback area, even at a depth of 30 m. All possible perturbing factors should be considered when designing a shallow temperature-based prospecting scheme.

Geothermics↗

USGS1986

Flow testing of the Newberry 2 research drillhole, Newberry volcano, Oregon

A 20 hour flow test of the Newberry 2 research drillhole at Newberry Volcano produced about 33,000 kilograms of fluid. The flow rate declined from about 0.8 kilograms per sec to less than 0.3 kilograms per sec during the course of the test. The mass ratio of liquid water to vapor was about 3:2 at the separator and stayed fairly constant throughout the test. The vapor phase was about half steam and half CO2 by weight. The average enthalpy of the steam/water mixture at the separator was about 1 ,200 kilojoules per kilogram. Because of the low flow rate and the large temperature gradient into the surrounding rocks, heat loss from the wellbore was high; a simple conductive model gives overall losses of about 1,200 kilojoules per kilogram of H2O produced. The actual heat loss may have been even higher due to convective effects, and it is likely that the fluid entering the bottom of the wellbore was largely or entirely steam and CO2. (Author 's abstract)

Water-Resources Investigations Report↗

USGS1984

Geohydrology, aqueous geochemistry, and thermal regime of the Soda Lakes and Upsal Hogback geothermal systems, Churchill County, Nevada

A flow-routing model of the upper Schoharie Creek basin, New York, was developed and used to simulate high flows at the inlet of the Blenheim-Gilboa Reservoir. The flows from Schoharie Creek at Prattsville, the primary source of flow data in the basin, and tributary flows from the six minor basins downstream, are combined and routed along the 9.7 mile reach of the Schoharie Creek between Prattsville and the reservoir inlet. Data from five historic floods were used for model calibration and four for verification. The accuracy of the model as measured by the difference between simulated and observed total flow volumes, is within 14 percent. Results indicate that inflows to the Blenheim-Gilboa Reservoir can be predicted approximately 2 hours in advance. One of the historical floods was chosen for additional model testing to assess a hypothetical real-time model application. Total flow-volume errors ranged from 30.2 percent to -9.2 percent. Alternative methods of obtaining hydrologic data for model input are presented for use in the event that standard forms of hydrologic data are unavailable. (USGS)

Water-Resources Investigations Report↗

USGS1984

Quantitative analysis of the hydrothermal system in Lassen Volcanic National Park and Lassen Known Geothermal Resource Area

The conceptual model of the Lassen system is termed a liquid-dominated hydrothermal system with a parasitic vapor-dominated zone. The essential feature of this model is that steam and steam-heated discharge at relatively high elevations in Lassen Volcanic National Park (LVNP) and liquid discharge with high chloride concentrations at relatively low elevations outside LVNP are both fed by an upflow of high-enthalpy two-phase fluid within the Park. Liquid flows laterally away from the upflow area towards the areas of high-chloride discharge, and steam rises through a vapor-dominated zone to feed the steam and steam-heated features. Numerical simulations show that several conditions are necessary for the development of this type of system, including (1) large-scale topographic relief, (2) an initial period of convective heating within an upflow zone followed by some change in hydrologic or geologic conditions that initiates drainage of liquid from portions of the upflow zone, and (3) low permeability barriers that inhibit the movement of cold water into the vapor zone. Simulations of thermal fluid withdrawal south of LVNP, carried out in order to determine the effects of such withdrawal on portions of the hydrothermal system within the Park, showed decreases in pressure and liquid saturation beneath the vapor zone which result in a temporary increase and subsequent decrease in the rate of upflow of steam.

California↗