Science.gov

Sample records for active geothermal areas

  1. Mono County geothermal activity

    SciTech Connect

    Lyster, D.L.

    1986-01-01

    Three geothermal projects have been proposed or are underway in Mono County, California. The Mammoth/Chance geothermal development project plans to construct a 10-MW geothermal binary power plant which will include 8 production and 3 injection wells. Pacific Lighting Energy Systems is also planning a 10-MW binary power plant consisting of 5 geothermal wells and up to 4 injection wells. A geothermal research project near Mammoth Lakes has spudded a well to provide a way to periodically measure temperature gradient, pressure, and chemistry of the thermal waters and to investigate the space-heating potential of the area in the vicinity of Mammoth Lakes. All three projects are briefly described.

  2. Geothermal resource evaluation of the Yuma area

    SciTech Connect

    Poluianov, E.W.; Mancini, F.P.

    1985-11-29

    This report presents an evaluation of the geothermal potential of the Yuma, Arizona area. A description of the study area and the Salton Trough area is followed by a geothermal analysis of the area, a discussion of the economics of geothermal exploration and exploitation, and recommendations for further testing. It was concluded economic considerations do not favor geothermal development at this time. (ACR)

  3. Mapping changes in Yellowstone's geothermal areas

    NASA Astrophysics Data System (ADS)

    Savage, Shannon Lea

    Yellowstone National Park (YNP) contains the world's largest concentration of geothermal features, and is legally mandated to protect and monitor these natural features. Remote sensing is a component of the current geothermal monitoring plan. Landsat satellite data have a substantial historical archive and will be collected into the future, making it the only available thermal imagery for historical analysis and long-term monitoring of geothermal areas in the entirety of YNP. Landsat imagery from Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) sensors was explored as a tool for mapping geothermal heat flux and geothermally active areas within YNP and to develop a change analysis technique for scientists to utilize with additional Landsat data available from 1978 through the foreseeable future. Terrestrial emittance and estimates of geothermal heat flux were calculated for the entirety of YNP with two Landsat images from 2007 (TM) and 2002 (ETM+). Terrestrial emittance for fourteen summer dates from 1986 to 2007 was calculated for defined geothermal areas and utilized in a change analysis. Spatial and temporal change trajectories of terrestrial emittance were examined. Trajectories of locations with known change events were also examined. Relationships between the temporal clusters and spatial groupings and several change vectors (distance to geologic faults, distance to large water bodies, and distance to earthquake swarms) were explored. Finally, TM data from 2007 were used to classify geothermally active areas inside the defined geothermal areas as well as throughout YNP and a 30-km buffer around YNP. Estimations of geothermal heat flux were inaccurate due to inherent limitations of Landsat data combined with complexities arising from the effects of solar radiation and spatial and temporal variation of vegetation, microbes, steam outflows, and other features at each geothermal area. Terrestrial emittance, however, was estimated with acceptable

  4. Earthquakes, active faults, and geothermal areas in the imperial valley, california.

    PubMed

    Hill, D P; Mowinckel, P; Peake, L G

    1975-06-27

    A dense seismograph network in the Imperial Valley recorded a series of earthquake swarms along the Imperial and Brawley faults and a diffuse pattern of earthquakes along the San Jacinto fault. Two known geothermal areas are closely associated with these earthquake swarms. This seismicity pattern demonstrates that seismic slip is occurring along both the Imperial-Brawley and San Jacinto fault systems.

  5. Hydrothermal fluids circulation and travertine deposition in an active tectonic setting: Insights from the Kamara geothermal area (western Anatolia, Turkey)

    NASA Astrophysics Data System (ADS)

    Brogi, Andrea; Alçiçek, M. Cihat; Yalçıner, Cahit Çağlar; Capezzuoli, Enrico; Liotta, Domenico; Meccheri, Marco; Rimondi, Valentina; Ruggieri, Giovanni; Gandin, Anna; Boschi, Chiara; Büyüksaraç, Aydin; Alçiçek, Hülya; Bülbül, Ali; Baykara, Mehmet Oruç; Shen, Chuan-Chou

    2016-06-01

    Coexistence of thermal springs, travertine deposits and tectonic activity is a recurring feature for most geothermal areas. Although such a certainty, their relationships are debated mainly addressing on the role of the tectonic activity in triggering and controlling fluids flow and travertine deposition. In this paper, we present the results of an integrated study carried out in a geothermal area located in western Anatolia (Turkey), nearby the well-known Pamukkale area (Denizli Basin). Our study focused on the relationships among hydrothermal fluids circulation, travertine deposition and tectonic activity, with particular emphasis on the role of faults in controlling fluids upwelling, thermal springs location and deposition of travertine masses. New field mapping and structural/kinematics analyses allowed us to recognize two main faults systems (NW- and NE-trending), framed in the Neogene-Quaternary extensional tectonic evolution of western Anatolia. A geo-radar (GPR) prospection was also provided in a key-area, permitting us to reconstruct a buried fault zone and its relationships with the development of a fissure-ridge travertine deposit (Kamara fissure-ridge). The integration among structural and geophysical studies, fluids inclusion, geochemical, isotopic data and 230 Th/238 U radiometric age determination on travertine deposits, depict the characteristics of the geothermal fluids and their pathway, up to the surface. Hydrological and seismological data have been also taken in account to investigate the relation between local seismicity and fluid upwelling. As a main conclusion we found strict relationships among tectonic activity, earthquakes occurrence, and variation of the physical/chemical features of the hydrothermal fluids, presently exploited at depth, or flowing out in thermal springs. In the same way, we underline the tectonic role in controlling the travertine deposition, making travertine (mainly banded travertine) a useful proxy to reconstruct the

  6. Monitoring of Acoustic Emissions Within Geothermal Areas in Iceland: A new Tool for Geothermal Exploration.

    NASA Astrophysics Data System (ADS)

    Brandsdóttir, B.; Gudmundsson, O.

    2007-12-01

    With increased emphasis on geothermal development new exploration methods are needed in order to improve general understanding of geothermal reservoirs, characterize their extent and assess the potential for sustainable power production. Monitoring of acoustic emissions within geothermal areas may provide a new tool to evaluate the spatial extent of geothermal fields and model rock-fluid interactions. Three-dimensional seismic data have been used to assess the spatial and temporal distribution of noise within several high-temperature geothermal fields in Iceland. Seismic noise in the 4-6 Hz range within the Svartsengi field can be attributed to steam hydraulics and pressure oscillations within the geothermal reservoirs. Seismic noise surveys compliment electrical resistivity soundings and TEM-surveys by providing information pertinent to the current geothermal activity and extent of steam fields within the uppermost crust of the geothermal reservoir. Information related to acoustic emissions can thus help define targets for future wells.

  7. Mapping Changes in Yellowstone's Geothermal Areas and Radiative Flux

    NASA Astrophysics Data System (ADS)

    Savage, S. L.; Lawrence, R. L.; Custer, S. G.

    2007-12-01

    Yellowstone National Park contains the world's largest concentration of geothermal features, with an estimated more than 10,000 features. The National Park Service is legally mandated to protect and monitor these natural features, and a geothermal monitoring plan including remote sensing has been approved. Inexpensive, accurate, and efficient geothermal mapping and change detection techniques are being developed to aid in monitoring geothermal features. Geothermal features are constantly changing in size, shape, distribution, and radiative flux. We are examining the change in geothermal activity in Yellowstone National Park and surrounding areas from up to 30 years ago to the present. Possible drivers of change include seismic activity, climate, geothermal energy development outside the park, and proximity to the caldera boundary. We are mapping and documenting changes in geothermally active areas and geothermal radiative flux using Landsat Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+), and potentially Multispectral Scanner (MSS) satellite imagery. We are using change vector analysis to study change in recent years starting with 2007 as our base year, as well as historic change possibly as far back as 1979. These maps will allow us to evaluate hypothesized drivers of change in geothermally active areas by determining whether observed spatial patterns are consistent with patterns expected from these drivers.

  8. Indoor radon concentration in geothermal areas of central Italy.

    PubMed

    Ciolini, R; Mazed, D

    2010-09-01

    The indoor radon ((222)Rn) activity concentration was measured between January and June in the schools of two geothermal areas in Tuscany, central Italy. One of these areas (the Larderello area) is characterized by a large number of geothermal power plants, covering about 9% of the world's geothermal power production. In contrast, the other area, Monte Pisano, has not any such facilities. About 250 measurements were made using track etch detectors. Only a slight difference in the concentrations between the two major sampling areas (98 Bq m(-3) for Larderello area and 43 Bq m(-3) for Monte Pisano area) was found, and this was related to different geological characteristics of the ground and not the presence of the geothermal plants. The measured radon concentrations were always well below the intervention levels in both areas, and health risks for students and personnel in the examined schools were excluded.

  9. Geology of Platanares geothermal area, Copan, Honduras

    SciTech Connect

    Heiken, G.; Duffield, W.; Wohletz, K.; Priest, S.; Ramos, N.; Flores, W.; Eppler, D.; Ritchie, A.; Escobar, C.

    1987-05-01

    The Platanares, Copan (Honduras) geothermal area is located in a highly faulted terrain of Paleozoic(.) metamorphic rocks, Cretaceous clastic sedimentary rocks, and Tertiary volcanic rocks. All thermal manifestations are located along faults. The volcanic rocks are probably too old to represent the surface expression of an active crustal magma body. Thus, the thermal water is interpreted to be heated during deep circulation in a regime of elevated heat flow. The water chemistry suggests that the geothermal reservoir originates within the Cretaceous sedimentary sequence and that the reservoir temperature may be as high as 240/sup 0/ C. Two exploration coreholes penetrated the volcanic sequence and bottomed within Cretaceous redbeds. Well PLTG-1 is 650 m deep and flows at 3 Mw thermal from a 160/sup 0/ C permeable zone. Well PLTG-2 is 401 m deep and has a thermal gradient of 139/sup 0/ C/km. Exploration drilling is continuing, with a third corehole to be drilled in May, 1987.

  10. Geothermal activity near Clearlake, California

    NASA Astrophysics Data System (ADS)

    Burns, K. L.; Potter, R. M.

    Geothermal activity in the region of high heat flow near the city of Clearlake includes hot springs, fumeroles, vents, and areas of hydrothermal alteration. Onshore, the location is controlled by Quaternary longitudinal NNW-trending faults of the San Andreas systems, and the transverse Burns Valley fault. Offshore, an additional control is arcuate graben-forming faults. The city is bracketed by three hydrothermal 'hot spots,' which are Sulphur Bank hot spring, resurgences in Burns Valley, and the Oak Cove hot spot. All three are associated with sharp 'spikes' in the isotherms and locally enhanced heat flow.

  11. Heat‐tolerant Flowering Plants of Active Geothermal Areas in Yellowstone National Park

    PubMed Central

    STOUT, RICHARD G.; AL‐NIEMI, THAMIR S.

    2002-01-01

    A broad survey of most of the major geyser basins within Yellowstone National Park (Wyoming, USA) was conducted to identify the flowering plants which tolerate high rhizosphere temperatures (≥40 °C) in geothermally heated environments. Under such conditions, five species of monocots and four species of dicots were repeatedly found. The predominant flowering plants in hot soils (>40 °C at 2–5 cm depth) were grasses, primarily Dichanthelium lanuginosum. Long‐term (weeks to months) rhizosphere temperatures of individual D. lanuginosum above 40 °C were recorded at several different locations, both in the summer and winter. The potential role of heat shock proteins (HSPs) in the apparent adaptation of these plants to chronically high rhizosphere temperatures was examined. Antibodies to cytoplasmic class I small heat shock proteins (sHSPs) and to HSP101 were used in Western immunoblot analyses of protein extracts from plants collected from geothermally heated soils. Relatively high levels of proteins reacting with anti‐sHSP antibodies were consistently detected in root extracts from plants experiencing rhizosphere temperatures above 40 °C, though these proteins were usually not highly expressed in leaf extracts from the same plants. Proteins reacting with antibodies to HSP101 were also present both in leaf and root extracts from plants collected from geothermal soils, but their levels of expression were not as closely related to the degree of heat exposure as those of sHSPs. PMID:12197524

  12. Heat-tolerant flowering plants of active geothermal areas in Yellowstone National Park.

    PubMed

    Stout, Richard G; Al-Niemi, Thamir S

    2002-08-01

    A broad survey of most of the major geyser basins within Yellowstone National Park (Wyoming, USA) was conducted to identify the flowering plants which tolerate high rhizosphere temperatures (> or = 40 degrees C) in geothermally heated environments. Under such conditions, five species of monocots and four species of dicots were repeatedly found. The predominant flowering plants in hot soils (>40 degrees C at 2-5 cm depth) were grasses, primarily Dichanthelium lanuginosum. Long-term (weeks to months) rhizosphere temperatures of individual D. lanuginosum above 40 degrees C were recorded at several different locations, both in the summer and winter. The potential role of heat shock proteins (HSPs) in the apparent adaptation of these plants to chronically high rhizosphere temperatures was examined. Antibodies to cytoplasmic class I small heat shock proteins (sHSPs) and to HSP101 were used in Western immunoblot analyses of protein extracts from plants collected from geothermally heated soils. Relatively high levels of proteins reacting with anti-sHSP antibodies were consistently detected in root extracts from plants experiencing rhizosphere temperatures above 40 degrees C, though these proteins were usually not highly expressed in leaf extracts from the same plants. Proteins reacting with antibodies to HSP101 were also present both in leaf and root extracts from plants collected from geothermal soils, but their levels of expression were not as closely related to the degree of heat exposure as those of sHSPs.

  13. Recent drilling activities at the earth power resources Tuscarora geothermal power project's hot sulphur springs lease area.

    SciTech Connect

    Goranson, Colin

    2005-03-01

    Earth Power Resources, Inc. recently completed a combined rotary/core hole to a depth of 3,813 feet at it's Hot Sulphur Springs Tuscarora Geothermal Power Project Lease Area located 70-miles north of Elko, Nevada. Previous geothermal exploration data were combined with geologic mapping and newly acquired seismic-reflection data to identify a northerly tending horst-graben structure approximately 2,000 feet wide by at least 6,000 feet long with up to 1,700 feet of vertical offset. The well (HSS-2) was successfully drilled through a shallow thick sequence of altered Tertiary Volcanic where previous exploration wells had severe hole-caving problems. The ''tight-hole'' drilling problems were reduced using drilling fluids consisting of Polymer-based mud mixed with 2% Potassium Chloride (KCl) to reduce Smectite-type clay swelling problems. Core from the 330 F fractured geothermal reservoir system at depths of 2,950 feet indicated 30% Smectite type clays existed in a fault-gouge zone where total loss of circulation occurred during coring. Smectite-type clays are not typically expected at temperatures above 300 F. The fracture zone at 2,950 feet exhibited a skin-damage during injection testing suggesting that the drilling fluids may have caused clay swelling and subsequent geothermal reservoir formation damage. The recent well drilling experiences indicate that drilling problems in the shallow clays at Hot Sulphur Springs can be reduced. In addition, average penetration rates through the caprock system can be on the order of 25 to 35 feet per hour. This information has greatly reduced the original estimated well costs that were based on previous exploration drilling efforts. Successful production formation drilling will depend on finding drilling fluids that will not cause formation damage in the Smectite-rich fractured geothermal reservoir system. Information obtained at Hot Sulphur Springs may apply to other geothermal systems developed in volcanic settings.

  14. The Coso geothermal area: A laboratory for advanced MEQ studies for geothermal monitoring

    USGS Publications Warehouse

    Julian, B.R.; Foulger, G.R.; Richards-Dinger, K.

    2004-01-01

    The permanent 16-station network of three-component digital seismometers at the Coso geothermal area, California, supplemented by 14 temporary instruments deployed in connection with the DOE Enhanced Geothermal Systems (EGS) Project, provides high-quality microearthquake (MEQ) recordings that are well suited to monitoring a producing geothermal area. We are currently using these data to investigate structure and active processes within the geothermal reservoir by applying three advanced methods: a) high-precision MEQ hypocenter location; b) time-dependent tomography; c) complete (moment tensor) MEQ source mechanism determination. Preliminary results to date resolve seismogenic structures in the producing field more clearly than is possible with conventional earthquake-location techniques. A shallow part of the producing field shows clear changes in the ratio of the seismic wave speeds, Vp/V s, between 1996 and 2002, which are probably related to physical changes in the reservoir caused by fluid extraction.

  15. Geopressured-geothermal well activities in Louisiana

    SciTech Connect

    John, C.J.

    1992-10-01

    Since September 1978, microseismic networks have operated continuously around US Department of Energy (DOE) geopressured-geothermal well sites to monitor any microearthquake activity in the well vicinity. Microseismic monitoring is necessary before flow testing at a well site to establish the level of local background seismicity. Once flow testing has begun, well development may affect ground elevations and/or may activate growth faults, which are characteristic of the coastal region of southern Louisiana and southeastern Texas where these geopressured-geothermal wells are located. The microseismic networks are designed to detest small-scale local earthquakes indicative of such fault activation. Even after flow testing has ceased, monitoring continues to assess any microearthquake activity delayed by the time dependence of stress migration within the earth. Current monitoring shows no microseismicity in the geopressured-geothermal prospect areas before, during, or after flow testing.

  16. Federal Interagency Geothermal Activities

    SciTech Connect

    Anderson, Arlene; Prencipe, Loretta; Todaro, Richard M.; Cuyler, David; Eide, Elizabeth

    2011-06-01

    This collaborative document describes the roles and responsibilities of key Federal agencies in the development of geothermal technologies including the U.S. Department of Energy (DOE); the U.S. Department of Agriculture (USDA), including the U.S. Forest Service; the U.S. Department of Interior (DOI), including the United States Geological Survey (USGS) and Bureau of Land Management (BLM); the Environmental Protection Agency (EPA); and the Department of Defense (DOD).

  17. Geothermal activity in Italy: present status and future prospects

    SciTech Connect

    Carella, R.; Palmerini, C.G.; Stefani, G.C.; Verdiani, G.

    1985-01-01

    In the Italian Peninsula the Apennines separate a relatively cold Po-Adriatic-Ionian ''foredeep'' external belt from a warmer Tyrrhenian ''back-arc'' internal tensional belt. The latter i characterized by high geothermal heat flow together with conspicuous recent or present-day volcani phenomena. In this area, extending from Tuscany to Campania, lie the known steam- and waterdominated fields. Other ''warm'' areas are located on some Tyrrhenian islands. Within the ''cold'' external belt, interesting locations for low enthalpy utilizations can be found in the Po river valley, particularly in the eastern part near Ferrara and Abano. Since 1977 ENEL (National Electri Energy Agency) and AGIP (State Oil Company) have been jointly conducting geothermal activities in Italy, with the exception of the Tuscan geothermal area where ENEL operates on an exclusive basis. At present the areas surveyed cover about 8250 kmS. As of December 1983 the geothermal installed capacity was 456.2 MW (net capacity 340 MW) and low-temperature geothermal resources equivalent to 100,000 OET /yr were being used. The National Energy Plant (PEN), issued on 4 December 1981, forecast for the year 1990 a geothermal power increment of 200 MW /SUB e/ above the 449.1 MW /SUB e/ already installed. The target in the low enthalpy non-electric sector is to save 300,000 OET/yr by 1990. This paper describes the activities carried out from March 1975 to December 1983 and the main projects in progress.

  18. Representative well models for eight geothermal-resource areas

    SciTech Connect

    Carson, C.C.; Lin, Y.T.; Livesay, B.J.

    1983-02-01

    Representative well models have been constructed for eight major geothermal-resource areas. The models define representative times and costs associated with the individual operations that can be expected during drilling and completion of geothermal wells. The models were made for and have been used to evaluate the impacts of potential new technologies. The nature, construction, and validation of the models are presented.

  19. Monitoring Biological Activity at Geothermal Power Plants

    SciTech Connect

    Peter Pryfogle

    2005-09-01

    The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has been evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.

  20. Geothermal activity helps life survive glacial cycles.

    PubMed

    Fraser, Ceridwen I; Terauds, Aleks; Smellie, John; Convey, Peter; Chown, Steven L

    2014-04-15

    Climate change has played a critical role in the evolution and structure of Earth's biodiversity. Geothermal activity, which can maintain ice-free terrain in glaciated regions, provides a tantalizing solution to the question of how diverse life can survive glaciations. No comprehensive assessment of this "geothermal glacial refugia" hypothesis has yet been undertaken, but Antarctica provides a unique setting for doing so. The continent has experienced repeated glaciations that most models indicate blanketed the continent in ice, yet many Antarctic species appear to have evolved in almost total isolation for millions of years, and hence must have persisted in situ throughout. How could terrestrial species have survived extreme glaciation events on the continent? Under a hypothesis of geothermal glacial refugia and subsequent recolonization of nongeothermal regions, we would expect to find greater contemporary diversity close to geothermal sites than in nongeothermal regions, and significant nestedness by distance of this diversity. We used spatial modeling approaches and the most comprehensive, validated terrestrial biodiversity dataset yet created for Antarctica to assess spatial patterns of diversity on the continent. Models clearly support our hypothesis, indicating that geothermally active regions have played a key role in structuring biodiversity patterns in Antarctica. These results provide critical insights into the evolutionary importance of geothermal refugia and the history of Antarctic species.

  1. Geothermal activity helps life survive glacial cycles

    PubMed Central

    Fraser, Ceridwen I.; Terauds, Aleks; Smellie, John; Convey, Peter; Chown, Steven L.

    2014-01-01

    Climate change has played a critical role in the evolution and structure of Earth’s biodiversity. Geothermal activity, which can maintain ice-free terrain in glaciated regions, provides a tantalizing solution to the question of how diverse life can survive glaciations. No comprehensive assessment of this “geothermal glacial refugia” hypothesis has yet been undertaken, but Antarctica provides a unique setting for doing so. The continent has experienced repeated glaciations that most models indicate blanketed the continent in ice, yet many Antarctic species appear to have evolved in almost total isolation for millions of years, and hence must have persisted in situ throughout. How could terrestrial species have survived extreme glaciation events on the continent? Under a hypothesis of geothermal glacial refugia and subsequent recolonization of nongeothermal regions, we would expect to find greater contemporary diversity close to geothermal sites than in nongeothermal regions, and significant nestedness by distance of this diversity. We used spatial modeling approaches and the most comprehensive, validated terrestrial biodiversity dataset yet created for Antarctica to assess spatial patterns of diversity on the continent. Models clearly support our hypothesis, indicating that geothermally active regions have played a key role in structuring biodiversity patterns in Antarctica. These results provide critical insights into the evolutionary importance of geothermal refugia and the history of Antarctic species. PMID:24616489

  2. Comparison of airborne and spaceborne TIR data for studying volcanic geothermal areas

    NASA Astrophysics Data System (ADS)

    Vaughan, R. G.; Heasler, H.; Jaworowski, C.; Bergfeld, D.; Evans, W.

    2015-12-01

    Mapping and quantifying the surface expression of geothermal heat flux in volcanic geothermal areas is important for establishing baseline thermal activity to better detect and understand any future changes that may be related to hydrothermal or volcanic processes, or human activities. Volcanic geothermal areas are often too large and inaccessible for only field-based thermal monitoring, so thermal infrared (TIR) remote sensing tools are also used. High resolution (sub-meter) airborne TIR imagery can be used for detailed, quantitative analyses of small, subtle geothermal features. Airborne data acquisitions have the advantage of being able to be acquired under ideal conditions (e.g., predawn, cloud-free), but the disadvantage of high costs - thus precluding high-frequency monitoring. Satellite-based TIR data from the Landsat 8 platform are freely available and can be acquired regularly for change detection, but are acquired with coarser spatial resolution (e.g., 100-m pixels), and thus are not as sensitive to subtle thermal characteristics. Two geothermal areas with clear, nighttime TIR data from nearly concurrent (within days) airborne and spaceborne instruments were investigated: Norris Geyser Basin in Yellowstone National Park, WY; and the Casa Diablo geothermal field, near Mammoth Lakes, CA. At Norris Geyser Basin, the area covered by high-resolution airborne TIR imagery is almost entirely geothermally heated ground, with hundreds of fumaroles, hot springs, and thermal drainages - although some non-geothermal background is exposed. With the coarser resolution Landsat 8 data, there are thermal variations within the smaller area covered by the airborne data, but the entire area appears to be thermally anomalous with respect to the non-geothermal background outside the basin. In the geothermal field around the Casa Diablo geothermal site, there are numerous, small areas of geothermal heating that are clearly distinguishable above the background by the high

  3. The Geyser Bight geothermal area, Umnak Island, Alaska

    SciTech Connect

    Motyka, R.J. ); Nye, C.J. Univ. of Alaska, Fairbanks, AK . Geophysical Inst.); Turner, D.L. . Geophysical Inst.); Liss, S.A. )

    1993-08-01

    The Geyser Bight geothermal area contains one of the hottest and most extensive areas of thermal springs in Alaska, and is the only site in the state with geysers. Heat for the geothermal system is derived from crustal magma associated with Mt. Recheshnoi volcano. Successive injections of magma have probably heated the crust to near its minimum melting point and produced the only high-SiO[sub 2] rhyolites in the oceanic part of the Aleutian arc. At least two hydrothermal reservoirs are postulated to underlie the geothermal area and have temperatures of 165 and 200 C, respectively, as estimated by geothermometry. Sulfate-water isotope geothermometers suggest a deeper reservoir with a temperature of 265 C. The thermal spring waters have relatively low concentrations of Cl (600 ppm) but are rich in B (60 ppm) and As (6 ppm). The As/Cl ratio is among the highest reported for geothermal waters. 41 refs., 12 figs., 8 tabs.

  4. Soil mercury levels in the area surrounding the Cerro Prieto geothermal complex, MEXICO.

    PubMed

    Pastrana-Corral, M A; Wakida, F T; García-Flores, E; Rodriguez-Mendivil, D D; Quiñonez-Plaza, A; Piñon-Colin, T D J

    2016-08-01

    Even though geothermal energy is a renewable energy source that is seen as cost-effective and environmentally friendly, emissions from geothermal plants can impact air, soil, and water in the vicinity of geothermal power plants. The Cerro Prieto geothermal complex is located 30 km southeast of the city of Mexicali in the Mexican state of Baja California. Its installed electricity generation capacity is 720 MW, being the largest geothermal complex in Mexico. The objective of this study was to evaluate whether the emissions generated by the geothermal complex have increased the soil mercury concentration in the surrounding areas. Fifty-four surface soil samples were collected from the perimeter up to an approximate distance of 7660 m from the complex. Additionally, four soil depth profiles were performed in the vicinity of the complex. Mercury concentration in 69 % of the samples was higher than the mercury concentration found at the baseline sites. The mercury concentration ranged from 0.01 to 0.26 mg/kg. Our results show that the activities of the geothermal complex have led to an accumulation of mercury in the soil of the surrounding area. More studies are needed to determine the risk to human health and the ecosystems in the study area.

  5. A brief description of geological and geophysical exploration of the Marysville geothermal area

    NASA Technical Reports Server (NTRS)

    Blackwell, D. D.; Brott, C. A.; Goforth, T. T.; Holdaway, M. J.; Morgan, P.; Petefish, D.; Rape, T.; Steele, J. L.; Spafford, R. E.; Waibel, A. F.

    1974-01-01

    Extensive geological and geophysical surveys were carried out at the Marysville geothermal area during 1973 and 1974. The area has high heat flow (up to microcalories per square centimeter-second, a negative gravity anomaly, high electrical resistivity, low seismic ground noise, and nearby microseismic activity. Significant magnetic and infrared anomalies are not associated with the geothermal area. The geothermal anomaly occupies the axial portion of a dome in Precambrian sedimentary rocks intruded by Cretaceous and Cenozoic granitic rocks. The results from a 2.4-km-deep test well indicate that the cause of the geothermal anomaly is hydrothermal convection in a Cenozoic intrusive. A maximum temperature of 95 C was measured at a depth of 500 m in the test well.

  6. The detection of geothermal areas from Skylab thermal data

    NASA Technical Reports Server (NTRS)

    Siegal, B. S.; Kahle, A. B.; Goetz, A. F. H.; Gillespie, A. R.; Abrams, M. J.; Pohn, H. A.

    1975-01-01

    Skylab-4 X-5 thermal data of the geysers area was analyzed to determine the feasibility of using midday Skylab images to detect geothermal areas. The hottest ground areas indicated on the Skylab image corresponded to south-facing barren or sparsely vegetated slopes. A geothermal area approximately 15 by 30 m coincided with one of the hottest areas indicated by Skylab. This area could not be unambiguously distinguished from the other areas which are believed to be hotter than their surroundings as a result of their topography, and micrometeorological conditions. A simple modification of a previous thermal model was performed and the predicted temperatures for the hottest slopes using representative values was in general agreement with the observed data. It is concluded that data from a single midday Skylab pass cannot be used to locate geothermal areas.

  7. Conceptual model of the Klamath Falls, Oregon geothermal area

    SciTech Connect

    Prucha, R.H.; Benson, S.M.; Witherspoon, P.A.

    1987-01-01

    Over the last 50 years significant amounts of data have been obtained from the Klamath Falls geothermal resource. To date, the complexity of the system has stymied researchers, leading to the development of only very generalized hydrogeologic and geothermal models of the area. Recently, the large quantity of available temperature data have been re-evaluated, revealing new information on subsurface heat flow and locations of faults in the system. These inferences are supported by borehole, geochemical, geophysical, and hydrologic data. Based on re-evaluation of all available data, a detailed conceptual model for the Klamath Falls geothermal resource is proposed.

  8. Conceptual Model of the Klamath Falls, Oregon Geothermal Area

    SciTech Connect

    Prucha, R.H.; Benson, S.M.; Witherspoon, P.A.

    1987-01-20

    Over the last 50 years significant amounts of data have been obtained from the Klamath Falls geothermal resource. To date, the complexity of the system has stymied researchers, leading to the development of only very generalized hydrogeologic and geothermal models of the area. Recently, the large quantity of available temperature data have been re-evaluated, revealing new information on subsurface heat flow and locations of faults in the system. These inferences are supported by borehole, geochemical, geophysical, and hydrologic data. Based on re-evaluation of all available data, a detailed conceptual model for the Klamath Falls geothermal resource is proposed. 1 tab., 8 figs., 21 refs.

  9. San Diego Gas and Electric Company Imperial Valley geothermal activities

    NASA Technical Reports Server (NTRS)

    Hinrichs, T. C.

    1974-01-01

    San Diego Gas and Electric and its wholly owned subsidiary New Albion Resources Co. have been affiliated with Magma Power Company, Magma Energy Inc. and Chevron Oil Company for the last 2-1/2 years in carrying out geothermal research and development in the private lands of the Imperial Valley. The steps undertaken in the program are reviewed and the sequence that must be considered by companies considering geothermal research and development is emphasized. Activities at the south end of the Salton Sea and in the Heber area of Imperial Valley are leading toward development of demonstration facilities within the near future. The current status of the project is reported.

  10. European Geothermal Drilling Experience-Problem Areas and Case Studies

    SciTech Connect

    Baron, G.; Ungemach, P.

    1981-01-01

    Geothermal drilling has long been restricted in Western Europe to the sole dry steam field of Larderello in Italy. In the last few years, a wider experience is building up as a consequence of intensified exploration and development programs carried out for evaluation and production of both low- and high-enthalpy geothermal resources. A sample of some 40 boreholes indicates the problem areas which are given.

  11. Detectability of geothermal areas using Skylab X-5 data

    NASA Technical Reports Server (NTRS)

    Siegal, B. S.; Kahle, A. B.; Goetz, A. F. H.; Gillespie, A. R.; Abrams, M. J.

    1975-01-01

    The results are presented of a study which was undertaken to determine if data from a single near-noon pass of Skylab could be used to detect geothermal areas. The size and temperature requirements for a geothermally heated area to be seen by Skylab S-192 MSS X-5 thermal sensor were calculated. This sensor obtained thermal data with the highest spatial resolution of any nonmilitary satellite system. Only very large hot areas could be expected to be unambiguously recognized with a single data set from this instrument. The study area chosen was The Geysers geothermal field in Sonoma County, California, the only geothermal area of significant size scanned by Skylab. Unfortunately, 95% of the Skylab thermal channel data was acquired within 3 hours of local noon. For The Geysers area only daytime X-5 data were available. An analysis of the thermal channel data (10.2 to 12.5 um) revealed that ground temperatures determined by Skylab were normally distributed. No anomalous hot spots were apparent. Computer enhancement techniques were used to delineate the hottest 100 and 300 ground areas (pixel, 75 m by 75 m) within the study region. It was found that the Skylab MSS with the X-5 thermal detector does not have sufficient spatial resolution to locate unambiguously from daytime data any but the largest and hottest convectively created geothermal features, which in general are prominent enough to have been previously recognized.

  12. Mantle helium and carbon isotopes in Separation Creek Geothermal Springs, Three Sisters area, Central Oregon: Evidence for renewed volcanic activity or a long term steady state system?

    SciTech Connect

    van Soest, M.C.; Kennedy, B.M.; Evans, W.C.; Mariner, R.H.

    2002-04-30

    Cold bubbling springs in the Separation Creek area, the locus of current uplift at South Sister volcano show strong mantle signatures in helium and carbon isotopes and CO{sub 2}/{sup 3}He. This suggests the presence of fresh basaltic magma in the volcanic plumbing system. Currently there is no evidence to link this system directly to the uplift, which started in 1998. To the contrary, all geochemical evidence suggests that there is a long-lived geothermal system in the Separation Creek area, which has not significantly changed since the early 1990s. There was no archived helium and carbon data, so a definite conclusion regarding the strong mantle signature observed in these tracers cannot yet be drawn. There is a distinct discrepancy between the yearly magma supply required to explain the current uplift (0.006 km{sup 3}/yr) and that required to explain the discharge of CO{sub 2} from the system (0.0005 km{sup 3}/yr). This discrepancy may imply that the chemical signal associated with the increase in magma supply has not reached the surface yet. With respect to this the small changes observed at upper Mesa Creek require further attention, due to the recent volcanic vent in that area it may be the location were the chemical signal related to the uplift can most quickly reach the surface. Occurrence of such strong mantle signals in cold/diffuse geothermal systems suggests that these systems should not be ignored during volcano monitoring or geothermal evaluation studies. Although the surface-expression of these springs in terms of heat is minimal, the chemistry carries important information concerning the size and nature of the underlying high-temperature system and any changes taking place in it.

  13. Assessment of the Geothermal Potential Within the BPA Marketing Area.

    SciTech Connect

    Lund, John W.; Allen, Eliot D.

    1980-07-01

    The potential of geothermal energy is estimated that can be used for direct heat applications and electrical power generation within the Bonneville Power Administration (BPA) marketing area. The BPA marketing area includes three principal states of Oregon, Washington, and Idaho and portions of California, Montana, Wyoming, Nevada, and Utah bordering on these three states. This area covers approximately 384,000 square miles and has an estimated population of 6,760,000. The total electrical geothermal potential within this marketing area is 4077 MW/sub e/ from hydrothermal resources and 16,000 MW/sub e/ from igneous systems, whereas the total thermal (wellhead) potential is 16.15 x 10/sup 15/ Btu/y. Approximately 200 geothermal resource sites were initially identified within the BPA marketing area. This number was then reduced to about 100 sites thought to be the most promising for development by the year 2000. These 100 sites, due to load area overlap, were grouped into 53 composite sites; 21-3/4 within BPA preference customer areas and 31-1/4 within nonpreference customer areas. The geothermal resource potential was then estimated for high-temperature (> 302/sup 0/F = 150/sup 0/C), intermediate-temperature (194 to 302/sup 0/F = 90 to 150/sup 0/C), and low-temperature (< 194/sup 0/F = 90/sup 0/C) resources.

  14. Ground radan survey of a geothermal area in Hawaii

    SciTech Connect

    Cox, M.E.

    1980-04-01

    Rates of ground radon emanation, in the Puna geothermal area on the lower east rift of Kilauea volcano, were measured by alpha particle sensitive cellulose nitrate films. The survey successfully defined an area of thermal significance associated with the rift structure, and suggests that a thermally driven ground gas convection system exists within, and peripheral to, the rift. This type of survey was found suitable for the basaltic island environmnet characteristic of Hawaii and is now used in Hawaii as a routine geothermal exploration technique.

  15. Mantle Helium and Carbon Isotopes in Separation Creek Geothermal Springs, Three Sisters Area, Central Oregon: Evidence for Renewed Volcanic Activity or a Long Term Steady State System?

    USGS Publications Warehouse

    Van Soest, M. C.; Kennedy, B.M.; Evans, William C.; Mariner, R.H.

    2002-01-01

    Here we present the helium and carbon isotope results from the initial study of a fluid chemistry-monitoring program started in the summer of 2001 near the South Sister volcano in central Oregon. The Separation Creek area which is several miles due west of the volcano is the locus of strong crustal uplift currently occurring at a rate of 4-5 cm/yr (Wicks, et. al., 2001).Helium [RC/RA = 7.44 and 8.61 RA (RC/R A = (3He/4He)sample-. air corrected/(3He/4He)air))] and carbon (??13C = -11.59 to -9.03??? vs PDB) isotope data and CO2/3He (5 and 9 ?? 109) show that bubbling cold springs in the Separation Creek area near South Sister volcano carry a strong mantle signal, indicating the presence of fresh basaltic magma in the volcanic plumbing system. There is no evidence though, to directly relate this signal to the crustal uplift that is currently taking place in the area, which started in 1998. The geothermal system in the area is apparently much longer lived and shows no significant changes in chemistry compared to data from the early 1990s. Hot springs in the area, which are relatively far removed from the volcanic edifice, do not carry a strong mantle signal in helium isotope ratios (2.79 to 5.08 RA), unlike the cold springs, and also do not show any significant changes in helium isotope ratios compared to literature data for the same springs of over two decades ago. The cold springs of the Separation Creek area form a very diffuse but significant low temperature geothermal system, that should, due to its close vicinity to the center of up uplift, be more sensitive to changes in the deeper volcanic plumbing system than the far removed hot springs and therefore require much more study and consideration when dealing with volcano monitoring in the Cascade range or possibly with geothermal exploration in general.

  16. Beowawe Geothermal Area evaluation program. Final report

    SciTech Connect

    Iovenitti, J. L

    1981-03-01

    Several exploration programs were conducted at the Beowawe Geothermal Prospect, Lander and Eureka County, Nevada. Part I, consisting of a shallow temperature hole program, a mercury soil sampling survey, and a self-potential survey were conducted in order to select the optimum site for an exploratory well. Part II consisted of drilling a 5927-foot exploratory well, running geophysical logs, conducting a drill stem test (2937-3208 feet), and a short-term (3-day) flow test (1655-2188 feet). All basic data collected is summarized.

  17. Absence of Remote Triggering in Geothermal Fields Due to Human Activity

    NASA Astrophysics Data System (ADS)

    Ge, S.; Zhang, Q.; Lin, G.

    2014-12-01

    Operational geothermal fields typically have high seismicity rates, which could be caused by both tectonic and anthropogenic activities. Due to the high background seismicity and possible interaction between fluid and seismic waves, geothermal areas have been recognized to be susceptible to large remote earthquakes. However, whether human activity (geothermal production) affects remote earthquake triggering by changing the stress state is unclear. Here we choose two geothermal fields, Coso and Salton Sea in southern California, to study the spatiotemporal distributions of the triggered earthquakes following the 1992 Mw 7.3 Landers and 1999 Mw 7.1 Hector Mine earthquakes. These two geothermal fields have been in operation since 1980s with comparable net capacity, and have long-term geothermal fluid loss. By analyzing the regional catalog recorded by the Southern California Seismic Network, we find that these two operational geothermal areas remain unaffected by the remote mainshocks, whereas the surrounding areas show vigorous triggered responses. We interpret this phenomenon as a result of human activity, which presumably has brought the stress state away from failure by reducing pore pressure. To further understand how much the human activity can affect the stress state, we also conduct a systematic study on Long Valley Caldera in northern California as a comparison site. Long Valley Caldera hosts an active geothermal field with net capacity about one sixth of that in Coso or Salton Sea geothermal field, and the extraction volume is not constantly larger than the injection. We will show comparisons of the triggered response in Long Valley with the two geothermal fields in southern California.

  18. Measuring ground movement in geothermal areas of Imperial Valley, California

    NASA Technical Reports Server (NTRS)

    Lofgren, B. E.

    1974-01-01

    Significant ground movement may accompany the extraction of large quantities of fluids from the subsurface. In Imperial Valley, California, one of the potential hazards of geothermal development is the threat of both subsidence and horizontal movement of the land surface. Regional and local survey nets are being monitored to detect and measure possible ground movement caused by future geothermal developments. Precise measurement of surface and subsurface changes will be required to differentiate man-induced changes from natural processes in this tectonically active region.

  19. Changes in thermal activity in the Rotorua geothermal field

    SciTech Connect

    Cody, A.D. ); Lumb, J.T. )

    1992-04-01

    During a period when geothermal fluid was being withdrawn for energy use at an increasing rate, the level of natural hydrothermal activity in the Rotorua geothermal field declined in an all-time low in the mid 1980s. total heatflow from a major hot-spring area fell by almost 50 percent, springs ceased their flow, and geysers displayed abnormal behavior consistent with a low aquifer pressure. since the enforced closure of bores within 1.5 km of Pohutu Geyser, sings of recovery, including a return to normal behavior of Pohutu and Waikorohihi Geysers, a resumption of activity at Kereru Geyser, and an increase in water flow from some springs are presented in this paper.

  20. Geology and geothermal potential of the tecuamburro volcano area, Guatemala

    USGS Publications Warehouse

    Duffield, W.A.; Heiken, G.H.; Wohletz, K.H.; Maassen, L.W.; Dengo, G.; McKee, E.H.; Castaneda, O.

    1992-01-01

    Tecuamburro, an andesitic stratovolcano in southeastern Guatemala, is within the chain of active volcanoes of Central America. Though Tecuamburro has no record of historic eruptions, radiocarbon ages indicate that eruption of this and three other adjacent volcanoes occurred within the past 38,300 years. The youngest eruption produced a dacite dome. Moreover, powerful steam explosions formed a 250 m wide crater about 2900 years ago near the base of this dome. The phreatic crater contains a pH-3 thermal lake. Fumaroles are common along the lake shore, and several other fumaroles are located nearby. Neutral-chloride hot springs are at lower elevations a few kilometers away. All thermal manifestations are within an area of about 400 km2 roughly centered on Tecuamburro Volcano. Thermal implications of the volume, age, and composition of the post-38.3 ka volcanic rocks suggest that magma, or recently solidified hot plutons, or both are in the crust beneath these lavas. Chemical geothermometry carried out by other workers suggests that a hydrothermal-convection system is centered over this crustal heat source. Maximum temperatures of about 300??C are calculated for samples collected in the area of youngest volcanism, whereas samples from outlying thermal manifestations yield calculated temperatures <- 165??C. An 808 m deep drill hole completed in 1990 to partly test the geothermal model developed from surface studies attained a maximum temperature of almost 240??C. Thus, the possibility of a commercial-grade hydrothermal resource in the area seems high. ?? 1992.

  1. Repeat Measurements of Seismic Noise at the Waiotapu Geothermal Area, North Island, NZ

    SciTech Connect

    Whiteford, P.C.

    1995-01-01

    The amplitudes of seismic ground noise were remeasured at 66 sites in the Waiotapu and Reporoa geothermal areas in 1995 to determine whether amplitudes had changed since the first survey in 1970. In both 1995 and 1970 high levels of seismic noise occurred in two localities, one at Waiotapu and one at Reporoa. The elevated levels of seismic noise at most sites are thought to be caused by surface or near-surface geothermal activity. At seven sites in the Waiotapu area seismic noise levels were almost the same in 1995 as in 1970, indicating no change in the intensity of the source of the geothermal seismic noise. At most other sites the 1995 seismic noise levels were different to those measured in 1970, although at sites with high levels of seismic noise the differences were usually less than at sites with low levels of seismic noise.

  2. Three dimensional images of geothermal systems: local earthquake P-wave velocity tomography at the Hengill and Krafla geothermal areas, Iceland, and The Geysers, California

    USGS Publications Warehouse

    Julian, B.R.; Prisk, A.; Foulger, G.R.; Evans, J.R.; ,

    1993-01-01

    Local earthquake tomography - the use of earthquake signals to form a 3-dimensional structural image - is now a mature geophysical analysis method, particularly suited to the study of geothermal reservoirs, which are often seismically active and severely laterally inhomogeneous. Studies have been conducted of the Hengill (Iceland), Krafla (Iceland) and The Geysers (California) geothermal areas. All three systems are exploited for electricity and/or heat production, and all are highly seismically active. Tomographic studies of volumes a few km in dimension were conducted for each area using the method of Thurber (1983).

  3. Geothermal wells: a forecast of drilling activity

    SciTech Connect

    Brown, G.L.; Mansure, A.J.; Miewald, J.N.

    1981-07-01

    Numbers and problems for geothermal wells expected to be drilled in the United States between 1981 and 2000 AD are forecasted. The 3800 wells forecasted for major electric power projects (totaling 6 GWe of capacity) are categorized by type (production, etc.), and by location (The Geysers, etc.). 6000 wells are forecasted for direct heat projects (totaling 0.02 Quads per year). Equations are developed for forecasting the number of wells, and data is presented. Drilling and completion problems in The Geysers, The Imperial Valley, Roosevelt Hot Springs, the Valles Caldera, northern Nevada, Klamath Falls, Reno, Alaska, and Pagosa Springs are discussed. Likely areas for near term direct heat projects are identified.

  4. Time-dependent seismic tomography of the Coso geothermal area, 1996-2004

    USGS Publications Warehouse

    Julian, B.R.; Foulger, G.R.

    2005-01-01

    The permanent 18-station network of three-component digital seismometers at the seismically active Coso geothermal area, California, provides high-quality microearthquake (MEQ) data that are well suited to investigating temporal variations in structure related to processes within the geothermal reservoir. A preliminary study [Julian, et al., 2003; Julian, et al., 2004] comparing data from 1996 and 2003 found significant variations in the ratio of the seismic wave-speeds, Vp/Vs, at shallow depths over this time interval. This report describes results of a more detailed study of each year from 1996 through 2004.

  5. Summary of geothermal exploration activity in the State of Washington from 1978 to 1983. Final report

    SciTech Connect

    Korosec, M.A.

    1984-01-01

    Project activity is summarized with references to the publications produced. Project findings are reported as they relate to specific geothermal resource target areas. Some major projects of the goethermal exploration program are: thermal and mineral spring chemistry, heat flow drilling, temperature gradient measurements, Cascade Range regional gravity, geohydrology study of the Yakima area, low temperature geothermal resources, geology, geochemistry of Cascade Mountains volcanic rocks, and soil mercury studies. (MHR)

  6. Continued seismic monitoring of the Geysers, California geothermal area

    SciTech Connect

    Ludwin, R.S.; Bufe, C.G.

    1980-01-01

    Probable effects of geothermal development on seismicity at the Geysers are shown by the spatial coherence of decreases in gravity and pressure with maximum geodetic deformation and seismic moment sum along a line through the most developed area of the geothermal field. Increases in the mean number of events per day and in the magnitude of largest annual event correlate with increases in steam production. The two largest earthquakes in the steam field occurred near the two injection wells most distant from production wells, and large events (M/sub c greater than or equal to 2.5) occurred most frequently during months of peak injection. Spatial seismic clusters in proximity to injection wells have occurred soon after injection began. Preliminary data also indicate an increase in seismicity in a previously aseismic area near plant 15 following the beginning of power production at that plant in 1979.

  7. Anthropogenic and natural ground deformation in the Hengill geothermal area, Iceland

    NASA Astrophysics Data System (ADS)

    Juncu, D.; Árnadóttir, Th.; Hooper, A.; Gunnarsson, G.

    2017-01-01

    We investigate crustal deformation due to the extraction of water and steam from a high-enthalpy geothermal reservoir; a common occurrence, yet not well understood. The cause of this deformation can be a change in pressure or in temperature in the reservoir, both of which can be caused by extraction or injection of geothermal fluids. Our study area, the Hengill mountains in SW Iceland, is an active volcanic center and a plate triple junction that hosts two power plants producing geothermal energy. This combination of natural and anthropogenic processes causes a complex displacement field at the surface. We analyze geodetic data—Global Navigation Satellite System and Interferometric Synthetic Aperture Radar—to obtain the surface velocity field, which we then simulate using an inverse modeling approach. We focus on the deformation around the geothermal power plants but need to model the regional tectonic and volcanic deformation as well, because the signals are overlapping. We find that plate motion and a deep contracting body can explain the broad scale signal in the area. Local deformation near the two power plants, Hellisheidi and Nesjavellir, can be explained by extraction of geothermal fluids. We estimate reservoirs extending from 0.6 to 3.0 km depth at Hellisheidi, and 1.0 to 3.0 km depth at Nesjavellir for observed pressure decrease rates of 0.25 MPa/yr and 0.1 MPa/yr, respectively. We find that the main cause for the subsidence in the geothermal area is the observed pressure drawdown.

  8. In-situ grown silica sinters in Icelandic geothermal areas.

    PubMed

    Tobler, Dominique J; Stefánsson, Andri; Benning, Liane G

    2008-12-01

    Field in-situ sinter growth studies have been carried out in five geochemically very different Icelandic geothermal areas with the aim to quantify the effects of water chemistry, (e.g. silica content (250 to 695 p.p.m. SiO(2)), salinity (meteoric to seawater), pH (7.5 to 10)), temperature (42-96 degrees C) and microbial abundance (prevalence, density) on the growth rates, textures and structures of sinters forming within and around geothermal waters. At each location, sinter growth was monitored over time periods between 30 min and 25 months using glass slides that acted as precipitation substrates from which sinter growth rates were derived. In geothermal areas like Svartsengi and Reykjanes, subaqueous sinters developed rapidly with growth rates of 10 and 304 kg year(-1 )m(-2), respectively, and this was attributed primarily to the near neutral pH, high salinity and medium to high silica content within these geothermal waters. The porous and homogeneous precipitates that formed at these sites were dominated by aggregates of amorphous silica and they contained few if any microorganisms. At Hveragerdi and Geysir, the geothermal waters were characterized by slightly alkaline pH, low salinity and moderate silica contents, resulting in substantially lower rates of sinter growth (0.2-1.4 kg year(-1 )m(-2)). At these sites sinter formation was restricted to the vicinity of the air-water interface (AWI) where evaporation and condensation processes predominated, with sinter textures being governed by the formation of dense and heterogeneous crusts with well-defined spicules and silica terraces. In contrast, the subaqueous sinters at these sites were characterized by extensive biofilms, which, with time, became fully silicified and thus well preserved within the sinter edifices. Finally, at Krafla, the geothermal waters exhibited high sinter growth rates (19.5 kg year(-1 )m(-2)) despite being considerably undersaturated with respect to amorphous silica. However, the bulk of

  9. The Preston Geothermal Resources; Renewed Interest in a Known Geothermal Resource Area

    SciTech Connect

    Wood, Thomas R.; Worthing, Wade; Cannon, Cody; Palmer, Carl; Neupane, Ghanashyam; McLing, Travis L; Mattson, Earl; Dobson, Patric; Conrad, Mark

    2015-01-01

    The Preston Geothermal prospect is located in northern Cache Valley approximately 8 kilometers north of the city of Preston, in southeast Idaho. The Cache Valley is a structural graben of the northern portion of the Basin and Range Province, just south of the border with the Eastern Snake River Plain (ESRP). This is a known geothermal resource area (KGRA) that was evaluated in the 1970's by the State of Idaho Department of Water Resources (IDWR) and by exploratory wells drilled by Sunedco Energy Development. The resource is poorly defined but current interpretations suggest that it is associated with the Cache Valley structural graben. Thermal waters moving upward along steeply dipping northwest trending basin and range faults emanate in numerous hot springs in the area. Springs reach temperatures as hot as 84° C. Traditional geothermometry models estimated reservoir temperatures of approximately 125° C in the 1970’s study. In January of 2014, interest was renewed in the areas when a water well drilled to 79 m (260 ft) yielded a bottom hole temperature of 104° C (217° F). The well was sampled in June of 2014 to investigate the chemical composition of the water for modeling geothermometry reservoir temperature. Traditional magnesium corrected Na-K-Ca geothermometry estimates this new well to be tapping water from a thermal reservoir of 227° C (440° F). Even without the application of improved predictive methods, the results indicate much higher temperatures present at much shallower depths than previously thought. This new data provides strong support for further investigation and sampling of wells and springs in the Northern Cache Valley, proposed for the summer of 2015. The results of the water will be analyzed utilizing a new multicomponent equilibrium geothermometry (MEG) tool called Reservoir Temperature Estimate (RTEst) to obtain an improved estimate of the reservoir temperature. The new data suggest that other KGRAs and overlooked areas may need to be

  10. Northwest Geothermal Corp. 's (NGC) plan of exploration, Mt. Hood Area, Clackamas County, Oregon

    SciTech Connect

    Not Available

    1980-05-01

    The Area Geothermal Supervisor (AGS) received a Plan of Operations (POO) from Northwest Geothermal Corporation (NGC) on 2/12/80. In the POO, NGC proposed two operations: testing and abandoning an existing 1219 meter (m) geothermal temperature gradient hole, designated as OMF No. 1, and drilling and testing a new 1524 m geothermal exploratory hole, to be designated as OMF No. 7A. The POO was amended on 5/6/80, to provide for the use of an imp

  11. Utah State Prison Space Heating with Geothermal Heat - Resource Assessment Report Crystal Hot Springs Geothermal Area

    SciTech Connect

    1981-12-01

    Reported herein is a summary of work conducted under the Resource Assessment Program-Task 2, for the Utah State Prison Geothermal Space Heating Project at Crystal Hot Springs, Draper, Utah. Assessment of the geothermal resource in and around the Utah State Prison property began in october of 1979 with an aeromagnetic and gravity survey. These tasks were designed to provide detailed subsurface structural information in the vicinity of the thermal springs so that an informed decision as to the locations of test and production holes could be made. The geophysical reconnaissance program provided the structural details needed to focus the test drilling program on the most promising production targets available to the State Prison. The subsequent drilling and well testing program was conducted to provide information to aid fin the siting and design of a production well and preliminary design activities. As part of the resource assessment portion of the Utah State Prison Geothermal Project, a program for periodic geophysical monitoring of the Crystal Hot Springs resource was developed. The program was designed to enable determination of baseline thermal, hydraulic, and chemical characteristics in the vicinity of Crystal Hot Springs prior to production and to provide a history of these characteristics during resource development.

  12. Geology of the Colado Geothermal Area, Pershing County, Nevada

    SciTech Connect

    Sibbett, B.S.; Bullett, M.J.

    1980-07-01

    The Colado geothermal area in south-central Pershing County, Nevada is defined by hot water wells in alluvium just west of the West Humboldt Range. Geothermal gradient holes have encountered temperatures up to 113.5/sup 0/C at a depth of 76 m (250 ft) with a gradient reversal in the alluvium below this depth. The West Humboldt Range consists mainly of Triassic to Jurassic slaty shale to quartzite of the Auld Lang Syne Group. Carbonate rocks of the Jurassic Lovelock Formation have been thrust over pelitic rocks on the south end of the area. Erosional remnants of Tertiary tuffs and sediments overlay the metasediments in the West Humboldt Range. The principal structures are high-angle faults striking north-northwest, northeast and north-south. The horst-to-graben transition along the range front consists of several step faults trending irregularly north. The structural pattern in the west edge of the range probably continues to the west under the Quaterary alluvium where the source of the hot water is located. Thermal waters probably rise along a major fault intersection in the Mesozoic rocks then spread out in an aquifer in the alluvium. Several thrust faults are exposed south of Coal Canyon, and a structural break in the Mesozoic rock exists under the canyon. Several low-angle faults are present north of Coal Canyon but their effect, if any, on the geothermal occurrence is not known.

  13. 3D Model of the San Emidio Geothermal Area

    DOE Data Explorer

    James E. Faulds

    2013-12-31

    The San Emidio geothermal system is characterized by a left-step in a west-dipping normal fault system that bounds the western side of the Lake Range. The 3D geologic model consists of 5 geologic units and 55 faults. Overlying Jurrassic-Triassic metasedimentary basement is a ~500 m-1000 m thick section of the Miocene lower Pyramid sequence, pre- syn-extensional Quaternary sedimentary rocks and post-extensional Quaternary rocks. 15-30º eastward dip of the stratigraphy is controlled by the predominant west-dipping fault set. Both geothermal production and injection are concentrated north of the step over in an area of closely spaced west dipping normal faults.

  14. Regional and local networks of horizontal control, Cerro Prieto geothermal area

    USGS Publications Warehouse

    Massey, B.L.

    1979-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley 30 km southeast of Mexicali, Baja California, is probably deforming due to (1) the extraction of large volumes of steam and hot water, and (2) active tectonism. Two networks of precise horizontal control were established in Mexicali Valley by the U.S. Geological Survey in 1977 - 1978 to measure both types of movement as they occur. These networks consisted of (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from survey stations on an existing U.S. Geological Survey crustal-strain network north of the international border, and (2) a local net tied to stations in the regional net and encompassing the area of present and planned geothermal production. Survey lines in this net were selected to span areas of probable ground-surface movements in and around the geothermal area. Electronic distance measuring (EDM) instruments, operating with a modulated laser beam, were used to measure the distances between stations in both networks. The regional net was run using a highly precise long-range EDM instrument, helicopters for transportation of men and equipment to inaccessible stations on mountain peaks, and a fixed wing airplane flying along the line of sight. Precision of measurements with this complex long-range system approached 0-2 ppm of line length. The local net was measured with a medium-range EDM instrument requiring minimal ancillary equipment. Precision of measurements with this less complex system approached 3 ppm for the shorter line lengths. The detection and analysis of ground-surface movements resulting from tectonic strains or induced by geothermal fluid withdrawal is dependent on subsequent resurveys of these networks. ?? 1979.

  15. Natural radioactivity levels of geothermal waters and their influence on soil and agricultural activities.

    PubMed

    Murat Saç, Müslim; Aydemir, Sercan; Içhedef, Mutlu; Kumru, Mehmet N; Bolca, Mustafa; Ozen, Fulsen

    2014-01-01

    All over the world geothermal sources are used for different purposes. The contents of these waters are important to understand positive/negative effects on human life. In this study, natural radioactivity concentrations of geothermal waters were investigated to evaluate the effect on soils and agricultural activities. Geothermal water samples were collected from the Seferihisar Geothermal Region, and the radon and radium concentrations of these waters were analysed using a collector chamber method. Also soil samples, which are irrigated with geothermal waters, were collected from the surroundings of geothermal areas, and natural radioactivity concentrations of collected samples (U, Th and K) were determined using an NaI(Tl) detector system. The activity concentrations of radon and radium were found to be 0.6-6.0 and 0.1-1.0 Bq l(-1), respectively. Generally, the obtained results are not higher compared with the geothermal waters of the world. The activity concentrations in soils were found to be in the range of 3.3-120.3 Bq kg(-1) for (226)Ra (eU), 0.3-108.5 Bq kg(-1) for (232)Th (eTh), 116.0-850.0 Bq kg(-1) for (40)K (% K).

  16. Resource investigation of low- and moderate-temperature geothermal areas in San Bernardino, California

    SciTech Connect

    Youngs, Leslie G.

    1982-07-01

    The California Division of Mines and Geology (CDMG) selected the San Bernardino area for detailed geothermal resource investigation because the area was known to contain promising geothermal resource sites, the area contained a large population center, and the City of San Bernardino had expressed serious interest in developing the area's geothermal resource. Ninety-seven geothermal wells and springs were identified and plotted on a compiled geologic map of the 40-square-mile study area. These wells and springs were concentrated in three distinguishable resource areas: Arrowhead Hot Springs, South San Bernardino, and Harlem Hot Springs--in each of which detailed geophysical, geochemical, and geological surveys were conducted. The Arrowhead Hot Springs geothermal area lies just north of the City of San Bernardino in the San Bernardino Mountains astride a shear zone (offshoot of the San Andreas fault) in pre-Cambrian gneiss and schist. The Harlem Hot Springs geothermal area, on the east side of the City, and the South San Bernardino geothermal area, on the south side, have geothermal reservoirs in Quaternary alluvial material which overlies a moderately deep sedimentary basin bound on the southwest by the San Jacinto fault (a ground water barrier). Geothermometry calculations suggest that the Arrowhead Hot Springs geothermal area, with a maximum reservoir temperature of 142 C, may have the highest maximum reservoir temperature of the three geothermal areas. The maximum temperature recorded by CDMG in the South San Bernardino geothermal area was 56 C from an artesian well, while the maximum temperature recorded in the Harlem Hot Springs geothermal areas was 49.5 C at 174 meters (570 feet) in an abandoned water well.

  17. Geothermal reservoir characterization through active thermal testing

    NASA Astrophysics Data System (ADS)

    Jung, Martin; Klepikova, Maria; Jalali, Mohammadreza; Fisch, Hansruedi; Loew, Simon; Amann, Florian

    2016-04-01

    Development and deployment of Enhanced Geothermal Systems (EGS) as renewable energy resources are part of the Swiss Energy Strategy 2050. To pioneer further EGS projects in Switzerland, a decameter-scale in-situ hydraulic stimulation and circulation (ISC) experiment has been launched at the Grimsel Test Site (GTS). The experiments are hosted in a low fracture density volume of the Grimsel granodiorite, similar to those expected at the potential enhanced geothermal system sites in the deep basement rocks of Northern Switzerland. One of the key goals of this multi-disciplinary experiment is to provide a pre- and post-stimulation characterization of the hydraulic and thermal properties of the stimulated fracture network with high resolution and to determine natural structures controlling the fluid flow and heat transport. Active thermal tests including thermal dilution tests and heat tracer tests allow for investigation of groundwater fluid flow and heat transport. Moreover, the spatial and temporal integrity of distributed temperature sensing (DTS) monitoring upgrades the potential and applicability of thermal tests in boreholes (e.g. Read et al., 2013). Here, we present active thermal test results and discuss the advantages and limitations of this method compared to classical approaches (hydraulic packer tests, solute tracer tests, flowing fluid electrical conductivity logging). The experimental tests were conducted in two boreholes intersected by a few low to moderately transmissive fault zones (fracture transmissivity of about 1E-9 m2/s - 1E-7 m2/s). Our preliminary results show that even in low-permeable environments active thermal testing may provide valuable insights into groundwater and heat transport pathways. Read T., O. Bour, V. Bense, T. Le Borgne, P. Goderniaux, M.V. Klepikova, R. Hochreutener, N. Lavenant, and V. Boschero (2013), Characterizing groundwater flow and heat transport in fractured rock using Fiber-Optic Distributed Temperature Sensing

  18. Tables of co-located geothermal-resource sites and BLM Wilderness Study Areas

    SciTech Connect

    Foley, D.; Dorscher, M.

    1982-11-01

    Matched pairs of known geothermal wells and springs with BLM proposed Wilderness Study Areas (WSAs) were identified by inspection of WSA and Geothermal resource maps for the states of Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. A total of 3952 matches, for geothermal sites within 25 miles of a WSA, were identified. Of these, only 71 (1.8%) of the geothermal sites are within one mile of a WSA, and only an additional 100 (2.5%) are within one to three miles. Approximately three-fourths of the matches are at distances greater than ten miles. Only 12 of the geothermal sites within one mile of a WSA have surface temperatures reported above 50/sup 0/C. It thus appears that the geothermal potential of WSAs overall is minimal, but that evaluation of geothermal resources should be considered in more detail for some areas prior to their designation as Wilderness.

  19. Forecast of geothermal-drilling activity

    SciTech Connect

    Mansure, A.J.; Brown, G.L.

    1982-07-01

    The number of geothermal wells that will be drilled to support electric power production in the United States through 2000 A.D. are forecasted. Results of the forecast are presented by 5-year periods for the five most significant geothermal resources.

  20. Reflection seismic imaging in the volcanic area of the geothermal field Wayang Windu, Indonesia

    NASA Astrophysics Data System (ADS)

    Polom, Ulrich; Wiyono, Wiyono; Pramono, Bambang; Krawczyk, CharLotte M.

    2014-05-01

    Reflection seismic exploration in volcanic areas is still a scientific challenge and requires major efforts to develop imaging workflows capable of an economic utilization, e.g., for geothermal exploration. The SESaR (Seismic Exploration and Safety Risk study for decentral geothermal plants in Indonesia) project therefore tackles still not well resolved issues concerning wave propagation or energy absorption in areas covered by pyroclastic sediments using both active P-wave and S-wave seismics. Site-specific exploration procedures were tested in different tectonic and lithological regimes to compare imaging conditions. Based on the results of a small-scale, active seismic pre-site survey in the area of the Wayang Windu geothermal field in November 2012, an additional medium-scale active seismic experiment using P-waves was carried out in August 2013. The latter experiment was designed to investigate local changes of seismic subsurface response, to expand the knowledge about capabilities of the vibroseis method for seismic surveying in regions covered by pyroclastic material, and to achieve higher depth penetration. Thus, for the first time in the Wayang Windu geothermal area, a powerful, hydraulically driven seismic mini-vibrator device of 27 kN peak force (LIAG's mini-vibrator MHV2.7) was used as seismic source instead of the weaker hammer blow applied in former field surveys. Aiming at acquiring parameter test and production data southeast of the Wayang Windu geothermal power plant, a 48-channel GEODE recording instrument of the Badan Geologi was used in a high-resolution configuration, with receiver group intervals of 5 m and source intervals of 10 m. Thereby, the LIAG field crew, Star Energy, GFZ Potsdam, and ITB Bandung acquired a nearly 600 m long profile. In general, we observe the successful applicability of the vibroseis method for such a difficult seismic acquisition environment. Taking into account the local conditions at Wayang Windu, the method is

  1. Transportation study for the Geysers Geothermal Resource Area

    SciTech Connect

    Not Available

    1981-12-01

    Potential cumulative impacts on the transportation system are assessed and recommendations are made as to options for handling future transportation development. The area is served by state highways, county roads, and an internal network of private roads. Access into the area is limited, and the roads must handle a variety of traffic including an unusually high percentage of heavy trucks transporting construction equipment and materials, hazardous chemicals, and toxic wastes. In conducting the transportation study public documents on geothermal power plant developments were researched and field trips to inspect the transportation facilities were made. People who have a special interest in the transportation system were also interviewed. In addition, traffic, accident, and road data were analyzed. Traffic forecasts based on projected geothermal resource develpoment were made. All access roads are of substandard design and efficient in structural adequacy. With projected traffic at 40% above the current level for most of the next six years, it is expected that cumulative impacts will cause accelerated degradation of the existing roads.

  2. High Resolution Aircraft Scanner Mapping of Geothermal and Volcanic Areas

    SciTech Connect

    Mongillo, M.A.; Cochrane, G.R.; Wood, C.P.; Shibata, Y.

    1995-01-01

    High spectral resolution GEOSCAN Mkll multispectral aircraft scanner imagery has been acquired, at 3-6 m spatial resolutions, over much of the Taupo Volcanic Zone as part of continuing investigations aimed at developing remote sensing techniques for exploring and mapping geothermal and volcanic areas. This study examined the 24-band: visible, near-IR (NIR), mid-IR (MIR) and thermal-IR (TIR) imagery acquired over Waiotapu geothermal area (3 m spatial resolution) and White Island volcano (6 m resolution). Results show that color composite images composed of visible and NIR wavelengths that correspond to color infrared (CIR) photographic wavelengths can be useful for distinguishing among bare ground, water and vegetation features and, in certain cases, for mapping various vegetation types. However, combinations which include an MIR band ({approx} 2.2 {micro}m) with either visible and NIR bands, or two NIR bands, are the most powerful for mapping vegetation types, water bodies, and bare and hydrothermally altered ground. Combinations incorporating a daytime TIR band with NIR and MIR bands are also valuable for locating anomalously hot features and distinguishing among different types of surface hydrothermal alteration.

  3. GEOTHERM Data Set

    DOE Data Explorer

    DeAngelo, Jacob

    1983-01-01

    GEOTHERM is a comprehensive system of public databases and software used to store, locate, and evaluate information on the geology, geochemistry, and hydrology of geothermal systems. Three main databases address the general characteristics of geothermal wells and fields, and the chemical properties of geothermal fluids; the last database is currently the most active. System tasks are divided into four areas: (1) data acquisition and entry, involving data entry via word processors and magnetic tape; (2) quality assurance, including the criteria and standards handbook and front-end data-screening programs; (3) operation, involving database backups and information extraction; and (4) user assistance, preparation of such items as application programs, and a quarterly newsletter. The principal task of GEOTHERM is to provide information and research support for the conduct of national geothermal-resource assessments. The principal users of GEOTHERM are those involved with the Geothermal Research Program of the U.S. Geological Survey.

  4. Air pollution and mortality in the Rotorua geothermal area.

    PubMed

    Bates, M N; Garrett, N; Graham, B; Read, D

    1997-10-01

    The effects on human health of geothermal emissions in the Rotorua area have been little studied. We calculated standardised mortality ratios (SMRs), comparing residents domiciled in the Rotorua territorial local authority area with those living in the rest of New Zealand, using mortality data for the decade 1981-1990. The SMRs were adjusted for age, calendar year, sex, and ethnicity. Diagnostic categories examined were based on known target-organ systems of hydrogen sulphide toxicity. Mortality causes examined were diseases of the nervous system and sense organs, diseases of the circulatory system, diseases of the respiratory system, and birth defects. Of these, notably elevated SMRs were found only for diseases of the respiratory system, particularly in Maori women (SMR = 1.61, 95 per cent confidence interval 1.19 to 2.12). A major concern was the possibility of confounding by ethnicity. This is because ethnicity in census data is based on self-identification, whereas ethnicity on death certificates is often based on funeral directors' impressions. This leads to serious underreporting of Maori mortality statistics. For the purposes of this study, this situation was further complicated by indications that ethnicity recording for Maori may be more accurate in the Rotorua area than in the rest of New Zealand. Our analysis suggested that, in general, SMRs based on ethnicity are likely to be spuriously high. Although this study found no clear indications of excess mortality in the Rotorua area likely to have been associated with geothermal emissions, there were limitations in the data that could have prevented the recognition of causal associations.

  5. Recent geothermal reservoir engineering activities at Lawrence Berkeley Laboratory

    SciTech Connect

    Lippmann, M.J.; Bodvarsson, G.S.; Benson, S.M.; Pruess, K.

    1987-09-01

    This paper briefly describes the most recent activities in reservoir engineering for the geothermal group of Lawrence Berkeley Laboratory (LBL). The primary emphasis of the geothermal program of LBL is dedicated to reservoir engineering including theoretical investigations, the development and application of mathematical models, and field studies. The objectives of these activities are to develop and validate methods and instruments which will be utilized in the determination of the parameters of geothermal systems, and the identification and evaluation of the importance of the distinct processes which occur in reservoirs. The ultimate goal of the program is the development of state of the art technologies which characterize geothermal reservoirs and evaluate their productive capacity and longevity.

  6. Campi Flegrei Deep Drilling Project and geothermal activities in Campania Region (Southern Italy)

    NASA Astrophysics Data System (ADS)

    De Natale, Giuseppe; Troise, Claudia; Troiano, Antonio; Giulia Di Giuseppe, Maria; Mormone, Angela; Carlino, Stefano; Somma, Renato; Tramelli, Anna; Vertechi, Enrico; Sangianantoni, Agata; Piochi, Monica

    2013-04-01

    The Campanian volcanic area has a huge geothermal potential (Carlino et al., 2012), similar to the Larderello-Radicondoli-Amiata region, in Tuscany (Italy), which has been the first site in the World exploited for electric production. Recently, the Campi Flegrei Deep Drilling Project (CFDDP), sponsored by ICDP and devoted to understand and mitigate the extreme volcanic risk in the area, has also risen new interest for geothermal exploration in several areas of Italy. Following the new Italian regulations which favour and incentivise innovative pilot power plants with zero emission, several geothermal projects have started in the Campania Region, characterized by strict cooperation among large to small industries, Universities and public Research Centers. INGV department of Naples (Osservatorio Vesuviano) has the technical/scientific leadership of such initiatives. Most of such projects are coordinated in the framework of the Regional District for Energy, in which a large part is represented by geothermal resource. Leading geothermal projects in the area include 'FORIO' pilot plant project, aimed to build two small (5 MWe each one) power plants in the Ischia island and two projects aimed to build pilot power plants in the Agnano-Fuorigrotta area in the city of Naples, at the easternmost part of Campi Flegrei caldera. One of the Campi Flegrei projects, 'SCARFOGLIO', is aimed to build a 5 MWe geothermal power plant in the Agnano area, whereas the 'START' project has the goal to build a tri-generation power plant in the Fuorigrotta area, fed mainly by geothermal source improved by solar termodynamic and bio-mass. Meanwhile such projects enter the field work operational phase, the pilot hole drilling of the CFDDP project, recently completed, represents an important experience for several operational aspects, which should contitute an example to be followed by the next geothermal activities in the area. It has been furthermore a source of valuable data for geothermal

  7. Fort Bliss Geothermal Area Data: Temperature profile, logs, schematic model and cross section

    SciTech Connect

    Adam Brandt

    2015-11-15

    This dataset contains a variety of data about the Fort Bliss geothermal area, part of the southern portion of the Tularosa Basin, New Mexico. The dataset contains schematic models for the McGregor Geothermal System, a shallow temperature survey of the Fort Bliss geothermal area. The dataset also contains Century OH logs, a full temperature profile, and complete logs from well RMI 56-5, including resistivity and porosity data, drill logs with drill rate, depth, lithology, mineralogy, fractures, temperature, pit total, gases, and descriptions among other measurements as well as CDL, CNL, DIL, GR Caliper and Temperature files. A shallow (2 meter depth) temperature survey of the Fort Bliss geothermal area with 63 data points is also included. Two cross sections through the Fort Bliss area, also included, show well position and depth. The surface map included shows faults and well spatial distribution. Inferred and observed fault distributions from gravity surveys around the Fort Bliss geothermal area.

  8. Research in the Geysers-Clear Lake geothermal area, Northern California

    USGS Publications Warehouse

    McLaughlin, Robert J.; Donnelly-Nolan, Julie M.

    1981-01-01

    The Geysers-Clear Lake area is one of two places in the world where major vapor-dominated hydrothermal reservoirs are commercially exploited for electric power production. Because energy can be extracted more efficiently from steam than from hot water, vapor-dominated systems are preferable for electric power generation, although most geothermal electric power facilities tap water-dominated systems. The Geysers- Clear Lake geothermal system has therefore been of great interest to the geothermal industry.

  9. Fracture Surface Area Effects on Fluid Extraction and the Electrical Resistivity of Geothermal Reservoir Rocks

    SciTech Connect

    Roberts, J J; Detwiler, R L; Ralph, W; Bonner, B

    2002-05-09

    Laboratory measurements of the electrical resistivity of fractured analogue geothermal reservoir rocks were performed to investigate the resistivity contrast caused by active boiling and to determine the effects of variable fracture dimensions and surface area on water extraction. Experiments were performed at confining pressures up to 10 h4Pa (100 bars) and temperatures to 170 C. Fractured samples show a larger resistivity change at the onset of boiling than intact samples. Monitoring the resistivity of fractured samples as they equilibrate to imposed pressure and temperature conditions provides an estimate of fluid migration into and out of the matrix. Measurements presented are an important step toward using field electrical methods to quantitatively search for fractures, infer saturation, and track fluid migration in geothermal reservoirs.

  10. Structural Data for the Columbus Salt Marsh Geothermal Area - GIS Data

    DOE Data Explorer

    Faulds, James E.

    2011-12-31

    Shapefiles and spreadsheets of structural data, including attitudes of faults and strata and slip orientations of faults. - Detailed geologic mapping of ~30 km2 was completed in the vicinity of the Columbus Marsh geothermal field to obtain critical structural data that would elucidate the structural controls of this field. - Documenting E‐ to ENE‐striking left lateral faults and N‐ to NNE‐striking normal faults. - Some faults cut Quaternary basalts. - This field appears to occupy a displacement transfer zone near the eastern end of a system of left‐lateral faults. ENE‐striking sinistral faults diffuse into a system of N‐ to NNE‐striking normal faults within the displacement transfer zone. - Columbus Marsh therefore corresponds to an area of enhanced extension and contains a nexus of fault intersections, both conducive for geothermal activity.

  11. Hydrologic reconnaissance of the geothermal area near Klamath Falls, Oregon

    USGS Publications Warehouse

    Sammel, E.A.; Peterson, D.L.

    1976-01-01

    Geothermal phenomena observed in the vicinity of Klamath Falls include hot springs with temperatures that approach 204°F (96 o C) (the approximate boiling temperature for the altitude), steam and water wells with temperatures that exceed 212°F (100°C), and hundreds of warm-water wells with temperatures mostly ranging from 68° to 95°F (20° to 35°C). Although warm waters are encountered by wells throughout much of the 350 square miles (900 square kilometers) of the area studied, waters with temperatures exceeding 140°F (60°C) are confined to three relatively restricted areas, the northeast part of the City of Klamath Falls, Olene Gap, and the southwest flank of the Klamath Hills.The hot waters are located near, and are presumably related to, major fault and fracture zones of the Basin and Range type. The displaced crustal blocks are composed of basaltic flow rocks and pyroclastics of Miocene to Pleistocene age, and of sediments and basalt flows of the Yonna Formation of Pliocene age. Dip-slip movement along the high-angle faults may be as much as 6,000 feet (1,800 meters) at places.Shallow ground water of local meteoric origin moves through the upper 1,000 to 1,500 feet (300 to 450 meters) of sediments and volcanic rocks at relatively slow rates. A small amount of ground water, perhaps 100,000 acre feet (1.2 x 108 cubic meters) per year, leaves the area in flow toward the southwest, but much of the ground water is discharged as evapotranspiration within the basin. Average annual precipitation on 7,317 square miles (18,951 square kilometers) of land surface near Klamath Falls is estimated to be 18.16 inches (461 millimeters), of which between 12 and 14 inches (305 and 356 millimeters) is estimated to be lost through evapotranspiration.Within the older basaltic rocks of the area, hydraulic conductivities are greater than in the shallow sediments, and ground water may move relatively freely parallel to the northwest-southeast structural trend. Recharge to the

  12. Geothermal resource assessment of Canon City, Colorado Area

    SciTech Connect

    Zacharakis, Ted G.; Pearl, Richard Howard

    1982-01-01

    In 1979 a program was initiated to fully define the geothermal conditions of an area east of Canon City, bounded by the mountains on the north and west, the Arkansas River on the south and Colorado Highway 115 on the east. Within this area are a number of thermal springs and wells in two distinct groups. The eastern group consists of 5 thermal artesian wells located within one mile of Colorado Highway 115 from Penrose on the north to the Arkansas river on the south. The western group, located in and adjacent to Canon City, consists of one thermal spring on the south bank of the Arkansas River on the west side of Canon City, a thermal well in the northeast corner of Canon City, another well along the banks of Four Mile Creek east of Canon City and a well north of Canon City on Four Mile Creek. All the thermal waters in the Canon City Embayment, of which the study area is part of, are found in the study area. The thermal waters unlike the cold ground waters of the Canon City Embayment, are a calcium-bicarbonate type and range in temperature from 79 F (26 C) to a high of 108 F (42 C). The total combined surface discharge o fall the thermal water in the study area is in excess of 532 acre feet (A.F.) per year.

  13. Association of Cancer Incidence and Duration of Residence in Geothermal Heating Area in Iceland: An Extended Follow-Up

    PubMed Central

    Kristbjornsdottir, Adalbjorg; Aspelund, Thor; Rafnsson, Vilhjalmur

    2016-01-01

    Background Residents of geothermal areas have higher incidence of non-Hodgkin’s lymphoma, breast cancer, prostate cancer, and kidney cancers than others. These populations are exposed to chronic low-level ground gas emissions and various pollutants from geothermal water. The aim was to assess whether habitation in geothermal areas and utilisation of geothermal water is associated with risk of cancer according to duration of residence. Methods The cohort obtained from the census 1981 was followed to the end of 2013. Personal identifier was used in record linkage with nation-wide emigration, death, and cancer registries. The exposed population, defined by community codes, was located on young bedrock and had utilised geothermal water supply systems since 1972. Two reference populations were located by community codes on older bedrock or had not utilised geothermal water supply systems for as long a period as had the exposed population. Adjusted hazard ratio (HR), 95% confidence intervals (CI) non-stratified and stratified on cumulative years of residence were estimated in Cox-model. Results The HR for all cancer was 1.21 (95% CI 1.12–1.30) as compared with the first reference area. The HR for pancreatic cancer was 1.93 (1.22–3.06), breast cancer, 1.48 (1.23–1.80), prostate cancer 1.47 (1.22–1.77), kidney cancer 1.46 (1.03–2.05), lymphoid and haematopoietic tissue 1.54 (1.21–1.97), non-Hodgkin´s lymphoma 2.08 (1.38–3.15) and basal cell carcinoma of the skin 1.62 (1.35–1.94). Positive dose-response relationship was observed between incidence of cancers and duration of residence, and between incidence of cancer and degree of geothermal/volcanic activity in the comparison areas. Conclusions The higher cancer incidence in geothermal areas than in reference areas is consistent with previous findings. As the dose-response relationships were positive between incidence of cancers and duration of residence, it is now more urgent than before to investigate

  14. Active and Fossil Geothermal Activity at Lake Chapala, Mexico

    NASA Astrophysics Data System (ADS)

    Zârate-del Vall, P.

    2002-12-01

    Geothermal systems are very abundant in the tectonically active zones of the earth's crust and the Citala rift, where Lake Chapala is located, is not the exception. The Lake Chapala basin is characterized by its paleo- and actual geothermal activity that includes: thermal springs, fossil sinter deposits and hydrothermal petroleum manifestations. Thermal springs occur both inside and outside the lake. The spring water in out-shore thermal springs around Lake Chapala is carbonate (Medina-Heredia A, 1986). To the NE area is San Luis Agua Caliente (69°C; ~ 240 mg L-1 [HCO3]1) in the NW at Jocotepec (36°C; ~263mg L-1 [HCO3]-); in the South we find Tuxcueca and Tizap n El Alto (30°C; 193 mg L-1 [HCO3]-). However, there is an exception, the spring water at the San Juan Cosal sector (North), which is sulfate (64-83°C; ~479 mg L-1, [SO4]-2). Examples of in-shore thermal springs are "Los Gorgos" (near South shore) and "El Fuerte" (near East shore and temporary "out-shore" because of actual severe drought); the characterisation of water of this in-shore sites is in progress. On the SE shore and five km NW from Regules village, outcrops a carbonate deposit named "La Calera". This carbonate fossil sinter outcrops 2 km in E-W direction and 600 m in N-S direction and overlays andesitic rock. With a thickness of approximately 5m and a roughly horizontal attitude, the carbonated sinter material is characterized by both massive and banded structure. When massive, it is colored in yellow brownish and grey and elsewhere it shows a pseudo-brecciated structure and when banded, alternated of yellow and dark millimetre bands can be seen; is characterized by vuggy porosity and silica (quartz and chalcedony) vein lets. Under microscope a pseudo-micritic texture is observed; vugs coated by iron oxides, are filled with calcite, and/or quartz, chalcedony and clay minerals. Six samples of carbonate of "La Calera" deposit were analysed for their stable isotopes (LODC-UParis VI). From δ 13

  15. Hydrochemistry and noble gas origin of geothermal waters of Icheon and Pocheon area in South Korea

    NASA Astrophysics Data System (ADS)

    Jeong, Chan Ho; Shin, Seon Ho; Nagao, Keisuke; Kim, Kyu Han; Koh, Yung Kwon; Kim, Gun Young

    2010-05-01

    Hydrochemical, stable isotopic (δ18O and δD) and noble gas isotopic analyses of seven geothermal water samples, eleven groundwater samples and six surface water samples collected from the Icheon and Pocheon area were carried out to find out hydrochemical characteristics, and to interpret the source of noble gases and the geochemical evolution of the geothermal waters. The geothermal waters show low temperature type ranging from 21.5 to 31.4 ℃ and the pH value between 6.69 and 9.21. Electrical conductivity of geothermal waters has the range from 310 to 735 μS/cm. Whereas the geothermal in the Icheon area shows the geochemical characteristics of neutral pH, the Ca-HCO3(or Ca(Na)-HCO3) chemical type and a high uranium content, the geothermal water in the Pocheon area shows the characteristics of alkaline pH, the Na-HCO3 chemical type and a high fluorine content. These characteristics indicate that the geothermal water in the Icheon area is under the early stage in the geochemical evolution, and that geothermal water in the Pocheon area has been geochemically evolved. The δ18O and δD values of geothermal waters show the range of -10.1˜-8.69‰ and from -72.2˜-60.8‰, respectively, and these values supply the information of the recharge area of geothermal waters. The 3He/4He ratios of the geothermal waters range from 0.09×10-6 to 0.65×10-6 which are plotted above the mixing line between air and crustal components. Whereas the helium gas in the Icheon geothermal water was mainly provided from the atmospheric source mixing with the mantle(or magma) origin, the origin of helium gas in the Pocheon geothermal water shows a dominant crustal source. 40Ar/36Ar ratios of geothermal water are in the range of an atmosphere source. Key words: hot spring water, hydrochemical composition, low temperature type, 3He/4He ratios, crustal source

  16. Final Scientific / Technical Report, Geothermal Resource Exploration Program, Truckhaven Area, Imperial County, California

    SciTech Connect

    Layman Energy Associates, Inc.

    2006-08-15

    With financial support from the U.S. Department of Energy (DOE), Layman Energy Associates, Inc. (LEA) has completed a program of geothermal exploration at the Truckhaven area in Imperial County, California. The exploratory work conducted by LEA included the following activities: compilation of public domain resource data (wells, seismic data, geologic maps); detailed field geologic mapping at the project site; acquisition and interpretation of remote sensing imagery such as aerial and satellite photographs; acquisition, quality control and interpretation of gravity data; and acquisition, quality control and interpretation of resistivity data using state of the art magnetotelluric (MT) methods. The results of this exploratory program have allowed LEA to develop a structural and hydrologic interpretation of the Truckhaven geothermal resource which can be used to guide subsequent exploratory drilling and resource development. Of primary significance, is the identification of an 8 kilometer-long, WNW-trending zone of low resistivity associated with geothermal activity in nearby wells. The long axis of this low resistivity zone is inferred to mark a zone of faulting which likely provides the primary control on the distribution of geothermal resources in the Truckhaven area. Abundant cross-faults cutting the main WNW-trending zone in its western half may indicate elevated fracture permeability in this region, possibly associated with thermal upwelling and higher resource temperatures. Regional groundwater flow is inferred to push thermal fluids from west to east along the trend of the main low resistivity zone, with resource temperatures likely declining from west to east away from the inferred upwelling zone. Resistivity mapping and well data have also shown that within the WNW-trending low resistivity zone, the thickness of the Plio-Pleistocene sedimentary section above granite basement ranges from 1,900–2,600 meters. Well data indicates the lower part of this

  17. Static chamber methane flux measurements in volcanic/geothermal areas: preliminary data from Sousaki and Nisyros (Greece)

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Walter; Fiebig, Jens; Konstantinos, Kyriakopoulos; Brusca, Lorenzo; Maneta, Victoria; Michas, Giorgios; Papadakis, Giorgios

    2010-05-01

    Methane plays an important role in the Earth's atmospheric chemistry and radiative balance being the second most important greenhouse gas after carbon dioxide. Methane is released to the atmosphere by a wide number of sources, both natural and anthropogenic, with the latter being twice as large as the former (IPCC, 2007). It has recently been established that significant amounts of geological methane, produced within the Earth's crust, are currently released naturally into the atmosphere (Etiope, 2004). Active or recent volcanic/geothermal areas represent one of these sources of geological methane. But due to the fact that methane flux measurements are laboratory intensive, very few data have been collected until now and the contribution of this source has been generally indirectly estimated (Etiope et al., 2007). The Greek territory is geodynamically very active and has many volcanic and geothermal areas. Here we report on methane flux measurements made at two volcanic/geothermal systems along the South Aegean volcanic arc: Sousaki and Nisyros. The former is an extinct volcanic area of Plio-Pleistocene age hosting nowadays a low enthalpy geothermal field. The latter is a currently quiescent active volcanic system with strong fumarolic activity due to the presence of a high enthalpy geothermal system. Both systems have gas manifestations that emit significant amounts of hydrothermal methane and display important diffuse carbon dioxide emissions from the soils. New data on methane isotopic composition and higher hydrocarbon contents point to an abiogenic origin of the hydrothermal methane in the studied systems. Measured methane flux values range from -48 to 29,000 (38 sites) and from -20 to 1100 mg/m^2/d (35 sites) at Sousaki and Nisyros respectively. At Sousaki measurement sites covered almost all the degassing area and the diffuse methane output can be estimated in about 20 t/a from a surface of about 10,000 m^2. At Nisyros measurements covered the Stephanos and

  18. Tectonic and stratigraphic evolution of the Sarulla graben geothermal area, North Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Hickman, R. G.; Dobson, P. F.; van Gerven, M.; Sagala, B. D.; Gunderson, R. P.

    2004-07-01

    The Sarulla graben is a composite Plio-Pleistocene basin developed along the northwest striking, dextral-slip Sumatra fault in a region where the fault coincides with the Sumatra volcanic arc. Offset of the 0.27±0.03 Ma Tor Sibohi rhyodacite dome by an active strand of the Sumatra fault, the Tor Sibohi fault (TSF), indicates a slip rate of about 9 mm/y. This value is lower than previous regional estimates of ˜25-30 mm/y for Holocene slip on the Sumatra fault determined from stream offsets in the Taratung region. This discrepancy may be due to (1) a difference between Holocene and late Quaternary rates of slip and (2) additional slip on other faults in the Sarulla area. Since the magnitude of undated stream offsets along the TSF in the Sarulla area is similar to those in the Taratung area, the discrepancy is likely to be due largely to a change in slip rate over time. Within the Sarulla area, major volcanic centers include the Sibualbuali stratavolcano (˜0.7-0.3 Ma), the Hopong caldera (˜1.5 Ma), and the Namora-I-Langit dacitic dome field (0.8-0.1 Ma). These centers generated the majority of the ash-flow tuffs and tuffaceous sediments filling the Sarulla graben, and appear to have been localized by structural features related to the Sumatra fault zone. Four geothermal systems within the Sarulla area are closely linked to major faults and volcanic centers. In three of the systems, reservoir permeability is clearly dominated by specific structures within the Sumatra fault system. In the fourth geothermal system, Namora-I-Langit geothermal field, permeability may be locally influenced by faults, but highly permeable fractures are widely distributed.

  19. United Nations geothermal activities in developing countries

    SciTech Connect

    Beredjick, N.

    1987-07-01

    The United Nations implements technical cooperation projects in developing countries through its Department of Technical Cooperation for Development (DTCD). The DTCD is mandated to explore for and develop natural resources (water, minerals, and relevant infrastructure) and energy - both conventional and new and renewable energy sources. To date, the United Nations has been involved in over 30 geothermal exploration projects (completed or underway) in 20 developing countries: 8 in Africa (Djibouti, Ethiopia, Kenya, Madagascar); 8 in Asia (China, India, Jordan, Philippines, Thailand); 9 in Latin America (Bolivia, Chile, El Salvador, Honduras, Mexico, Nicaragua, Panama) and 6 in Europe (Greece, Romania, Turkey, Yugoslavia). Today, the DTCD has seven UNDP geothermal projects in 6 developing countries. Four of these (Bolivia, China, Honduras, and Kenya) are major exploration projects whose formulation and execution has been possible thanks to the generous contributions under cost-sharing arrangements from the government of Italy. These four projects are summarized.

  20. Preliminary assessment of the geothermal resource potential of the Yuma area, Arizona

    SciTech Connect

    Stone, C.

    1981-01-01

    The Yuma area has had a long and complex tectonic history. The most southwesterly corner of the area presently comprises a small segment of the Salton Trough, a deep sediment-filled structural depression. Known geothermal anomalies in the Salton Trough make the Yuma area a favorable exploration target even though spreading-center heat sources are not expected to occur there. Geological and geophysical investigations reveal that the area is made up of low, rugged northwest-trending mountains separated by deep sediment-filled basins. Relief is a result of both erosional and structural activity. Northwest-trending en-echelon faults bound the range fronts and the basins, and have created several horst blocks (basement highs) that crop out at or near the surface. The Algodonnes fault is inferred to represent the northeast margin of the Salton Trough and apparently an inactive extension of the San Andreas fault system. Extensive well-pumping and applications of irrigation waters in recent years have created an unnatural state of flux in the hydrologic regime in the Yuma area. Gravity and aeromagnetic anomalies trend strongly northwest through the region as do lineaments derived from Landsat and Skylab photos. Electrical resistivity values in the Bouse Formation are exceptionally low, about 3 ohn-m. Heat flow appears to be normal for the Basin and Range province. Ground-water temperatures indicate zones of rising warm water, with one such warm anomaly confirmed by sparse geothermal-gradient data.

  1. Preliminary assessment of the geothermal system of the Tiris volcanic area, East Java, Indonesia.

    NASA Astrophysics Data System (ADS)

    Deon, F.; Moeck, I.; Sheytt, T.; Jaya, M. S.

    2012-04-01

    Indonesia, with 15 % of the world's active volcanoes, hosts a total estimated geothermal potential of 27000 MW of which 1197 MWe in 2011 have been installed. Exploration of magmatic remote areas is therefore important. Our investigation area is located at the volcano Lamongan, Tiris East Java, Indonesia, which is part of the modern Sunda Arc Region, characterized by extensional regime. The average ground water temperature in the area ranges between 27 and 29 ° C and the warm springs between 35 - 45 ° C, evidencing a geothermal potential of the area. Numerous maars and cindered cones have been located and studied here, some of them with a NW - SE lineament similar to the Tiris fault (only observed in satellite images). In this first exploration stage we characterized the geochemistry of the springs and investigated the petrology of the rocks. They were analyzed in terms of mineral composition (optical microscopy and electron microprobe) and major element composition (X-ray fluorescence). The samples have a typical basaltic - basaltic andesite composition, with abundant plagioclase with An65 up to An90, as well as olivine and pyroxene. The plagioclase crystals are several mm large, twinned and show no hydrothermal alteration. The fluid chemistry was determined in term of cation and anion concentration with Inductively Coupled Plasma Mass Spectrometry. The chemistry of geothermal waters provides specific information about the deep of the fluids in geothermal system and the discharge location. The concentrations of Na+, Ca2+, Li+, B3+ and Cl- suggest that the water of the Lamongan area derive from sea water intrusions. The high permeable pyroclastites, overlain by lower permeable basalt - andesitic basalt, observed in the field, may have channeled the sea water from the coast to the Tiris area. A structural lineament, NW - SE, may control the water intrusion, as the lineament of the springs confirms. The high HCO3-concentration in the fluid samples, as no carbonate

  2. Curie Point Depth, Geothermal Gradient and Heat-Flow Estimation and Geothermal Anomaly Exploration from Integrated Analysis of Aeromagnetic and Gravity Data on the Sabalan Area, NW Iran

    NASA Astrophysics Data System (ADS)

    Afshar, A.; Norouzi, G. H.; Moradzadeh, A.; Riahi, M. A.; Porkhial, S.

    2017-03-01

    Prospecting the geothermal resources in northwest of Iran, conducted in 1975, revealed several promising areas and introduced the Sabalan geothermal field as a priority for further studies. The Sabalan Mt., representing the Sabalan geothermal field, is a large stratovolcano which consists of an extensive central edifice built on a probable tectonic horst of underlying intrusive and effusive volcanic rocks. In this study, Curie point depth (CPD), geothermal gradient and heat-flow map were constituted from spectral analysis of the aeromagnetic data for the NW of Iran. The top of the geothermal resource (i.e., the thickness of the overburden) was evaluated by applying the Euler deconvolution method on the residual gravity data. The thickness of the geothermal resource was calculated by subtracting the Euler depths obtained from the CPDs in the geothermal anomalous region. The geothermal anomalous region was defined by the heat-flow value greater than 150 mW/m2. CPDs in the investigated area are found between 8.8 km in the Sabalan geothermal field and 14.1 in the northeast. The results showed that the geothermal gradient is higher than 62 °C/km and the heat-flow is higher than 152 mW/m2 for the geothermal manifestation region; the thickness of the geothermal resource was also estimated to vary between 5.4 and 9.1 km. These results are consistent with the drilling and other geological information. Findings indicate that the CDPs agree with earthquake distribution and the type of thermal spring is related to the depth of the top of the geothermal resource.

  3. Curie Point Depth, Geothermal Gradient and Heat-Flow Estimation and Geothermal Anomaly Exploration from Integrated Analysis of Aeromagnetic and Gravity Data on the Sabalan Area, NW Iran

    NASA Astrophysics Data System (ADS)

    Afshar, A.; Norouzi, G. H.; Moradzadeh, A.; Riahi, M. A.; Porkhial, S.

    2016-12-01

    Prospecting the geothermal resources in northwest of Iran, conducted in 1975, revealed several promising areas and introduced the Sabalan geothermal field as a priority for further studies. The Sabalan Mt., representing the Sabalan geothermal field, is a large stratovolcano which consists of an extensive central edifice built on a probable tectonic horst of underlying intrusive and effusive volcanic rocks. In this study, Curie point depth (CPD), geothermal gradient and heat-flow map were constituted from spectral analysis of the aeromagnetic data for the NW of Iran. The top of the geothermal resource (i.e., the thickness of the overburden) was evaluated by applying the Euler deconvolution method on the residual gravity data. The thickness of the geothermal resource was calculated by subtracting the Euler depths obtained from the CPDs in the geothermal anomalous region. The geothermal anomalous region was defined by the heat-flow value greater than 150 mW/m2. CPDs in the investigated area are found between 8.8 km in the Sabalan geothermal field and 14.1 in the northeast. The results showed that the geothermal gradient is higher than 62 °C/km and the heat-flow is higher than 152 mW/m2 for the geothermal manifestation region; the thickness of the geothermal resource was also estimated to vary between 5.4 and 9.1 km. These results are consistent with the drilling and other geological information. Findings indicate that the CDPs agree with earthquake distribution and the type of thermal spring is related to the depth of the top of the geothermal resource.

  4. Geophysical survey, Paso Robles geothermal area, California, part of the resource assessment of low- and moderate-temperature geothermal resource areas in California

    SciTech Connect

    Chapman, R.H.; Chase, G.W.; Youngs, L.G.

    1980-11-10

    Some general background information concerning the geology and geothermal occurrences in the Southern Coast Ranges is included, as well as the more detailed information dealing with the Paso Robles area proper. Results for two geophysical methods that have been used in the area: the ground magnetic and gravity surveys, are discussed and interpreted.

  5. Geothermal resource assessment of the Yucca Mountain Area, Nye County, Nevada. Final report

    SciTech Connect

    Flynn, T.; Buchanan, P.; Trexler, D.; Shevenell, L., Garside, L.

    1995-12-01

    An assessment of the geothermal resources within a fifty-mile radius of the Yucca Mountain Project area was conducted to determine the potential for commercial development. The assessment includes collection, evaluation, and quantification of existing geological, geochemical, hydrological, and geophysical data within the Yucca Mountain area as they pertain to geothermal phenomena. Selected geologic, geochemical, and geophysical data were reduced to a set of common-scale digital maps using Geographic Information Systems (GIS) for systematic analysis and evaluation. Available data from the Yucca Mountain area were compared to similar data from developed and undeveloped geothermal areas in other parts of the Great Basin to assess the resource potential for future geothermal development at Yucca Mountain. This information will be used in the Yucca Mountain Site Characterization Project to determine the potential suitability of the site as a permanent underground repository for high-level nuclear waste.

  6. Geologic map of the Sulphur Springs Area, Valles Caldera Geothermal System, New Mexico

    SciTech Connect

    Goff, F.E.; Gardner, J.N.

    1980-12-01

    The geologic and tectonic setting and geology of Sulphur Springs Area are described. Geologic faults, sheared or brecciated rock, volcanic vents, geothermal wells, hydrothermal alteration, springs, thermal springs, fumaroles, and geologic deposits are indicated on the map. (MHR)

  7. Induced seismicity caused by hydraulic fracturing in deep geothermal wells in Germany and adjacent areas

    NASA Astrophysics Data System (ADS)

    Plenefisch, Thomas; Brückner, Lisa; Ceranna, Lars; Gestermann, Nicolai; Houben, Georg; Tischner, Torsten; Wegler, Ulrich; Wellbrink, Matthias; Bönnemann, Christian; Bertram, Andreas; Kirschbaum, Bernd

    2016-04-01

    Recently, the BGR has worked out a study on the potential environmental impact caused by hydraulic fracturing or chemical stimulations in deep geothermal reservoirs in Germany and adjacent areas. The investigations and analyses are based on existing studies and information provided by operators. The two environmental impacts being essentially considered in the report are induced seismicity and possible contamination of the groundwater reservoirs which serve for drinking water supply. Altogether, in this study, information on 30 hydraulic frac operations and 26 chemical stimulations including information from neighboring countries were compiled and analyzed. Out of the hydraulic stimulations two thirds were carried out as waterfracs and one third as fracturing with proppants. Parameters used in the study to characterize the induced seismicity are maximum magnitude, number of seismic events, size of the seismically active volume, and the relation of this volume to fault zones and the cap rock, as well as, finally, the impacts at the Earth's surface. The response of the subsurface to hydraulic fracturing is variable: There are some activities, which cause perceptible seismic events, others, where no perceptible but instrumentally detected events occurred, and moreover activities without even any instrumentally detected events. A classification of seismic hazard with respect to tectonic region, geology, or depth of the layer is still difficult, since the number of hydraulic fracturing measures in deep geothermal wells is small making a statistically sound analysis impossible. However, there are some indications, that hydraulic fracturing in granite in tectonically active regions like the Upper Rhine Graben results in comparatively stronger, perceptible seismicity compared to hydraulic fracturing in the sedimentary rocks of the North German basin. The maximum magnitudes of induced earthquakes caused by hydraulic fracturing of deep geothermal wells in Germany are

  8. Geothermal Resource Area 5, Churchill, Douglas, Lyon and Storey Counties area development plan

    SciTech Connect

    Pugsley, M.

    1981-01-01

    Within this four county area there are many known geothermal resources ranging in temperature from 70 to over 350{sup 0}F. Thirteen of these resources are considered major and have been selected for evaluation. Various potential uses of the energy found were determined after evaluating the study area's physical characteristics, land ownership and land use patterns, existing population and projected growth rates, and transportation facilities. These factors were then compared with the site specific resource characteristics. The uses considered were divided into five main categories: electrical generation; space heating; recreation; industrial process heat; and agriculture.

  9. Geothermal resource areas database for monitoring the progress of development in the United States

    NASA Astrophysics Data System (ADS)

    Lawrence, J. D.; Lepman, S. R.; Leung, K. N.; Phillips, S. L.

    1981-01-01

    The Geothermal Resource Areas Database (GRAD) and associated data system provide broad coverage of information on the development of geothermal resources in the United States. The system is designed to serve the information requirements of the National Progress Monitoring System. GRAD covers development from the initial exploratory phase through plant construction and operation. Emphasis is on actual facts or events rather than projections and scenarios. The selection and organization of data are based on a model of geothermal development. Subjects in GRAD include: names and addresses, leases, area descriptions, geothermal wells, power plants, direct use facilities, and environmental and regulatory aspects of development. Data collected in the various subject areas are critically evaluated, and then entered into an on-line interactive computer system. The system is publically available for retrieval and use. The background of the project, conceptual development, software development, and data collection are described as well as the structure of the database.

  10. Geothermal resource areas database for monitoring the progress of development in the United States

    SciTech Connect

    Lawrence, J.D.; Lepman, S.R.; Leung, K.; Phillips, S.L.

    1981-01-01

    The Geothermal Resource Areas Database (GRAD) and associated data system provide broad coverage of information on the development of geothermal resources in the United States. The system is designed to serve the information requirements of the National Progress Monitoring System. GRAD covers development from the initial exploratory phase through plant construction and operation. Emphasis is on actual facts or events rather than projections and scenarios. The selection and organization of data are based on a model of geothermal development. Subjects in GRAD include: names and addresses, leases, area descriptions, geothermal wells, power plants, direct use facilities, and environmental and regulatory aspects of development. Data collected in the various subject areas are critically evaluated, and then entered into an on-line interactive computer system. The system is publically available for retrieval and use. The background of the project, conceptual development, software development, and data collection are described here. Appendices describe the structure of the database in detail.

  11. A gravity model for the Coso geothermal area, California

    SciTech Connect

    Feighner, M.A.; Goldstein, N.E.

    1990-08-01

    Two- and three-dimensional gravity modeling was done using gridded Bouguer gravity data covering a 45 {times} 45 km region over the Coso geothermal area in an effort to identify features related to the heat source and to seek possible evidence for an underlying magma chamber. Isostatic and terrain corrected Bouguer gravity data for about 1300 gravity stations were obtained from the US Geological Survey. After the data were checked, the gravity values were gridded at 1 km centers for the area of interest centered on the Coso volcanic field. Most of the gravity variations can be explained by two lithologic units: (1) low density wedges of Quarternary alluvium with interbedded thin basalts (2.4 g/cm{sup 3}) filling the Rose Valley and Coso Basin/Indian Wells Valley, and (2) low density cover of Tertiary volcanic rocks and intercalated Coso Formation (2.49 g/cm{sup 3}). A 3-D iterative approach was used to find the thicknesses of both units. The gravity anomaly remaining after effects from Units 1 and 2 are removed is a broad north-south-trending low whose major peak lies 5 km north of Sugarloaf Mountain, the largest of the less than 0.3 m.y. old rhyolite domes in the Coso Range. Most of this residual anomaly can be accounted for by a deep, low-density (2.47 g/cm{sup 3}) prismatic body extending from 8 to about 30 km below the surface. While some of this anomaly might be associated with fractured Sierran granitic rocks, its close correlation to a low-velocity zone with comparable geometry suggests that the residual anomaly is probably caused a large zone of partial melt underlying the rhyolite domes of the Coso Range. 12 refs., 9 figs.

  12. Slip and Dilation Tendency Analysis of the Tuscarora Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes

  13. Trampling Impacts on Thermotolerant Vegetation of Geothermal Areas in New Zealand

    NASA Astrophysics Data System (ADS)

    Burns, Bruce R.; Ward, Jonet; Downs, Theresa M.

    2013-12-01

    Geothermal features such as geysers, mud pools, sinter terraces, fumaroles, hot springs, and steaming ground are natural attractions often visited by tourists. Visitation rates for such areas in the Taupo Volcanic Zone of New Zealand are in the order of hundreds of thousands annually. These areas are also habitat for rare and specialized plant and microbial communities that live in the steam-heated soils of unusual chemical composition. We evaluated historical and current trampling impacts of tourists on the thermotolerant vegetation of the Waimangu and Waiotapu geothermal areas near Rotorua, and compared the results to experimental trampling at a third site (Taheke) not used by tourists. Historical tourism has removed vegetation and soil from around key features, and remaining subsoil is compacted into an impervious pavement on which vegetation recolonization is unlikely in the short term. Social tracks made by tourists were present at both tourist sites often leading them onto hotter soils than constructed tracks. Vegetation height and cover were lower on and adjacent to social tracks than further from them. Thermotolerant vegetation showed extremely low resistance to experimental trampling. This confirms and extends previous research that also shows that thallophytes and woody shrubs, life forms that dominate in thermotolerant vegetation, are vulnerable to trampling damage. Preservation of these vulnerable ecosystems must ensure that tourist traffic is confined to existing tracks or boardwalks, and active restoration of impacted sites may be warranted.

  14. Geology of the Pavana geothermal area, Departamento de Choluteca, Honduras, Central America: Field report

    SciTech Connect

    Eppler, D.B.; Heiken, G.; Wohletz, K.; Flores, W.; Paredes, J.R.; Duffield, W.A.

    1987-09-01

    The Pavana geothermal area is located in southern Honduras near the Gulf of Fonseca. This region is underlain by late Tertiary volcanic rocks. Within ranges near the geothermal manifestations, the rock sequences is characterized by intermediate to mafic laharic breccias and lavas overlain by silicic tuffs and lavas, which are in turn overlain by intermediate to mafic breccias, lavas, and tuffs. The nearest Quaternary volcanoes are about 40 km to the southwest, where the chain of active Central American volcanoes crosses the mouth of the Gulf of Fonseca. Structure of the Pavana area is dominated by generally northwest-trending, southwest-dipping normal faults. This structure is topographically expressed as northwest-trending escarpments that bound blocks of bedrock separated by asymmetric valleys that contain thin alluvial deposits. Thermal waters apparently issue from normal faults and are interpreted as having been heated during deep circulation along fault zones within a regional environment of elevated heat flow. Natural outflow from the main thermal area is about 3000 l/min of 60/sup 0/C water. Geothermometry of the thermal waters suggests a reservoir base temperature of about 150/sup 0/C.

  15. Trampling impacts on thermotolerant vegetation of geothermal areas in New Zealand.

    PubMed

    Burns, Bruce R; Ward, Jonet; Downs, Theresa M

    2013-12-01

    Geothermal features such as geysers, mud pools, sinter terraces, fumaroles, hot springs, and steaming ground are natural attractions often visited by tourists. Visitation rates for such areas in the Taupo Volcanic Zone of New Zealand are in the order of hundreds of thousands annually. These areas are also habitat for rare and specialized plant and microbial communities that live in the steam-heated soils of unusual chemical composition. We evaluated historical and current trampling impacts of tourists on the thermotolerant vegetation of the Waimangu and Waiotapu geothermal areas near Rotorua, and compared the results to experimental trampling at a third site (Taheke) not used by tourists. Historical tourism has removed vegetation and soil from around key features, and remaining subsoil is compacted into an impervious pavement on which vegetation recolonization is unlikely in the short term. Social tracks made by tourists were present at both tourist sites often leading them onto hotter soils than constructed tracks. Vegetation height and cover were lower on and adjacent to social tracks than further from them. Thermotolerant vegetation showed extremely low resistance to experimental trampling. This confirms and extends previous research that also shows that thallophytes and woody shrubs, life forms that dominate in thermotolerant vegetation, are vulnerable to trampling damage. Preservation of these vulnerable ecosystems must ensure that tourist traffic is confined to existing tracks or boardwalks, and active restoration of impacted sites may be warranted.

  16. Evaluation of the geothermal resource in the area of Albuquerque, New Mexico

    SciTech Connect

    Jiracek, G.R.; Swanberg, C.A.; Morgan, P.; Parker, M.D.

    1983-07-01

    Factors indicating a potential geothermal resource near Albuquerque are: (1) nearby volcanoes active as recently as 120,000 years ago, (2) gravity interpretation indicating a potential reservoir averaging 1.5 km thickness, (3) high heat flow near the city, (4) warm waters (>30/sup 0/C) in municipal wells, (5) recent seismicity indicating active faulting, thereby, allowing the possibility of deep hydrothermal circulation, (6) high shallow (<30 m) temperature gradients (>100/sup 0/C/km) discovered in our drillholes, (7) deeper (<500 m) gradients from water wells exceeding 80/sup 0/C/km, and (8) chemical analyses of 88 groundwater samples yielding estimated base reservoir temperatures as high as 190/sup 0/C. An area of elevated shallow temperature gradients (less than or equal to 140/sup 0/C/km) was discovered a few kilometers west of Albuquerque by our 69 hole drilling program. Resistivity, magnetic, and gravity measurements combined with computer modeling suggests that heated ground water is forced closer to the surface here by flow over a buried ridge. A well drilled nearby yielded the highest recorded temperature in the Albuquerque area at its maximum depth (32.8/sup 0/C at 364 m). The deep gradient is 35/sup 0/C/km. An oil test well close by reported large volumes of water at 1 km; therefore, the possibility of a low temperature (>50/sup 0/C) geothermal resource exists west of Albuquerque at less than 1 km depth.

  17. Slip and Dilation Tendency Analysis of the Patua Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes

  18. 3D Model of the Neal Hot Springs Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    The Neal Hot Springs geothermal system lies in a left-step in a north-striking, west-dipping normal fault system, consisting of the Neal Fault to the south and the Sugarloaf Butte Fault to the north (Edwards, 2013). The Neal Hot Springs 3D geologic model consists of 104 faults and 13 stratigraphic units. The stratigraphy is sub-horizontal to dipping <10 degrees and there is no predominant dip-direction. Geothermal production is exclusively from the Neal Fault south of, and within the step-over, while geothermal injection is into both the Neal Fault to the south of the step-over and faults within the step-over.

  19. Natural resource economic implications of geothermal area use

    SciTech Connect

    Darby, d'E Charles

    1993-01-28

    Large-scale use of geothermal energy is likely to result in depletion of natural resources that support both biodiversity and other human uses. Most of the problems could be averted with competent planning and adherence to agreed conditions, but they commonly develop because they are not perceived to be directly geothermal in origin and hence are not taken into account adequately. Some of the implications of such issues are discussed below, with particular reference to countries where all or most resources are held under traditional principals of custom ownership.

  20. Technical support for geopressured-geothermal well activities in Louisiana

    SciTech Connect

    Not Available

    1991-07-01

    Continuous recording microearthquake monitoring networks have been established around US Department of Energy (DOE) geopressured-geothermal design wells in southwestern Louisiana and southeastern Texas since summer 1980 to assess the effects well development may have had on subsidence and growth-fault activation. This monitoring has shown several unusual characteristics of Gulf Coast seismic activity. The observed activity is classified into two dominant types, one with identifiable body phases (type 1) and the other with only surface-wave signatures (type 2). During this reporting period no type 1 or body-wave events were reported. A total of 230 type 2 or surface-wave events were recorded. Origins of the type 2 events are still not positively understood; however, little or no evidence is available to connect them with geopressured-geothermal well activity. We continue to suspect sonic booms from military aircraft or some other human-induced source. 37 refs., 16 figs., 6 tabs.

  1. Geologic Map and GIS Data for the Patua Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2011-10-31

    Patua—ESRI Geodatabase (ArcGeology v1.3): - Contains all the geologic map data, including faults, contacts, folds, veins, dikes, unit polygons, and attitudes of strata and faults. - List of stratigraphic units. - Locations of geothermal wells. - Locations of 40Ar/39Ar and tephra samples.

  2. Mixing effects on geothermometric calculations of the Newdale geothermal area in the Eastern Snake River Plain, Idaho

    SciTech Connect

    Ghanashayam Neupane; Earl D. Mattson; Travis L. McLing; Cody J. Cannon; Thomas R. Wood; Trevor A. Atkinson; Patrick F. Dobson; Mark E. Conrad

    2016-02-01

    The Newdale geothermal area in Madison and Fremont Counties in Idaho is a known geothermal resource area whose thermal anomaly is expressed by high thermal gradients and numerous wells producing warm water (up to 51 °C). Geologically, the Newdale geothermal area is located within the Eastern Snake River Plain (ESRP) that has a time-transgressive history of sustained volcanic activities associated with the passage of Yellowstone Hotspot from the southwestern part of Idaho to its current position underneath Yellowstone National Park in Wyoming. Locally, the Newdale geothermal area is located within an area that was subjected to several overlapping and nested caldera complexes. The Tertiary caldera forming volcanic activities and associated rocks have been buried underneath Quaternary flood basalts and felsic volcanic rocks. Two southeast dipping young faults (Teton dam fault and an unnamed fault) in the area provide the structural control for this localized thermal anomaly zone. Geochemically, water samples from numerous wells in the area can be divided into two broad groups – Na-HCO3 and Ca-(Mg)-HCO3 type waters and are considered to be the product of water-rhyolite and water-basalt interactions, respectively. Each type of water can further be subdivided into two groups depending on their degree of mixing with other water types or interaction with other rocks. For example, some bivariate plots indicate that some Ca-(Mg)-HCO3 water samples have interacted only with basalts whereas some samples of this water type also show limited interaction with rhyolite or mixing with Na-HCO3 type water. Traditional geothermometers [e.g., silica variants, Na-K-Ca (Mg-corrected)] indicate lower temperatures for this area; however, a traditional silica-enthalpy mixing model results in higher reservoir temperatures. We applied a new multicomponent equilibrium geothermometry tool (e.g., Reservoir Temperature Estimator, RTEst) that is based on inverse geochemical modeling which

  3. Gold enrichment in active geothermal systems by accumulating colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Hannington, Mark; Harðardóttir, Vigdis; Garbe-Schönberg, Dieter; Brown, Kevin L.

    2016-04-01

    The origins of high-grade hydrothermal ore deposits are debated, but active geothermal systems provide important clues to their formation. The highest concentrations of gold are found in geothermal systems with direct links to island arc magmatism. Yet, similar concentrations have also been found in the absence of any input from arc magmas, for example, in the Reykjanes geothermal field, Iceland. Here we analyse brine samples taken from deep wells at Reykjanes and find that gold concentrations in the reservoir zone have increased over the past seven years from an average of 3 ppb to 14 ppb. The metal concentrations greatly exceed the maximum solubility of gold in the reservoir under saturated conditions and are now nearly two orders of magnitude higher than in mid-ocean ridge black smoker fluids--the direct analogues of Reykjanes deep liquids. We suggest that ongoing extraction of brine, the resulting pressure drop, and increased boiling have caused gold to drop out of solution and become trapped in the reservoir as a colloidal suspension. This process may explain how the stock of metal in the reservoirs of fossil geothermal systems could have increased over time and thus become available for the formation of gold-rich ore deposits.

  4. Investigation of Low-Temperature Geothermal Resources in the Sonoma Valley Area, California

    SciTech Connect

    Youngs, Leslie G.; Chapman, Rodger H.; Chase, Gordon W.; Bezore, Stephen P.; Majmundar, Hasu H.

    1983-01-01

    The Sonoma Valley area contains low-temperature geothermal resources (20 C {le} T {le} 90 C) having the potential for useful development. Sonoma Valley residents, local governments and institutions, private developers, and manufacturers may be able to utilize the geothermal resources as an alternate energy source. Historically, there have been at least six geothermal spring areas developed in the Sonoma Valley. Four of these (Boyes Hot Springs, Fetter's Hot Springs, Agua Caliente Springs, and the Sonoma State Hospital warm spring) lie on a linear trend extending northwestward from the City of Sonoma. Detailed geophysical surveys delineated a major fault trace along the east side of the Sonoma Valley in association with the historic geothermal areas. Other fault traces were also delineated revealing a general northwest-trending structural faulting fabric underlying the valley. Water wells located near the ''east side'' fault have relatively high boron concentrations. Geochemical evidence may suggest the ''east side'' fault presents a barrier to lateral fluid migration but is a conduit for ascending fluids. Fifteen of the twenty-nine geothermal wells or springs located from literature research or field surveys are located along or east of this major fault in a 10 km (6.2 miles) long, narrow zone. The highest recorded water temperature in the valley appears to be 62.7 C (145 F) at 137.2 meters (450 feet) in a well at Boyes Hot Springs. This is consistent with the geothermal reservoir temperature range of 52-77 C (126-171 F) indicated by geothermometry calculations performed on data from wells in the area. Interpretation of data indicates a low-temperature geothermal fluid upwelling or ''plume'', along the ''east side'' fault with subsequent migration into permeable aquifers predominantly within volcanic strata. It is quite likely other geothermal fluid ''plumes'' in association with faulting are present within the Sonoma Valley area. A 5.8 km{sup 2} geothermal zone

  5. Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities

    SciTech Connect

    Not Available

    1992-10-01

    This report includes the printouts from the International Geothermal Power Plant Data Base and the Geothermally Active Entity Data Base. Also included are the explanation of the abbreviations used in the power plant data base, maps of geothermal installations by country, and data base questionnaires and mailing lists.

  6. Building geomechanical characteristic model in Ilan geothermal area, NE Taiwan

    NASA Astrophysics Data System (ADS)

    Chiang, Yu-Hsuan; Hung, Jih-Hao

    2015-04-01

    National Energy Program-Phase II (NEPPII) was initiated to understand the geomechanical characteristic in Ilan geothermal area. In this study, we integrate well cores and logs (e.g. Nature Gamma-ray, Normal resistivity, Formation Micro Imager) which were acquired in HongChaiLin (HCL), Duck-Field (DF) and IC21 to determine the depth of fracture zone, in-situ stress state, the depth of basement and lithological characters. In addition, the subsurface in-situ stress state will be helpful to analyze the fault reactivation potential and slip tendency. By retrieved core from HCL well and the results of geophysical logging, indicated that the lithological character is slate (520m ~ 1500m) and the basement depth is around 520m. To get the minimum and maximum horizontal stress, several hydraulic fracturing tests were conducted in the interval of 750~765m on HCL well. The horizontal maximum and minimum stresses including the hydrostatic pressure are calculated as 15.39MPa and 13.57MPa, respectively. The vertical stress is decided by measuring the core density from 738m to 902m depth. The average core density is 2.71 g/cm3, and the vertical stress is 19.95 MPa (at 750m). From DF well, the basement depth is 468.9m. Besides, by analyzing the IC21 well logging data, we know the in-situ orientation of maximum horizontal stress is NE-SW. Using these parameters, the fault reactivation potential and slip tendency can be analyzed with 3DStress, Traptester software and demonstrated on model. On the other hand, we interpreted the horizons and faults from the nine seismic profiles including six N-S profiles, two W-E profiles and one NE-SW profile to construct the 3D subsurface structure model with GOCAD software. The result shows that Zhuosui fault and Kankou Formation are dip to north, but Hanxi fault and Xiaonanao fault are dip to south. In addition, there is a syncline-like structure on Nansuao Formation and the Chingshuihu member of the Lushan Formation. However, there is a conflict

  7. Geothermal materials development: FY 1990 accomplishments and current activities

    SciTech Connect

    Kukacka, L.E.

    1991-01-01

    Advances in the development of hydrothermally stable materials, the commercial availabilities of which are considered essential for the attainment of the Geothermal Division's (GD) Hydrothermal Category Objectives, continue to be made. Fiscal year 1990 R D was focused on reducing well drilling and completion costs, energy conversion costs, and on mitigating corrosion in well casing. Activities on lost circulation control materials, CO{sub 2}-resistant lightweight cements and thermally conductive corrosion and scale-resistant linear systems have reached the final development stages. In addition, field tests to determine the feasibility for the use of polymer cement liners to mitigate HCl-induced corrosion at the Geysers were performed. Technology transfer efforts on high temperature elastomers for use in drilling tools such as drillpipe protectors and rotating head seals were continued under Geothermal Drilling Organization sponsorship. Recent accomplishments and ongoing work on each of these activities are described in the paper. 8 refs.

  8. Geothermal pipeline

    SciTech Connect

    1997-08-01

    The Geothermal Pipeline is a progress and development update from the Geothermal Progress Monitor and includes brief descriptions of various geothermal projects around the world. The following topics are covered: The retirement of Geo-Heat Center Director Paul Lienau, announcement of two upcoming geothermal meetings, and a proposed geothermal power plant project in the Medicine Lake/Glass Mountain area of California. Also included is an article about the Bonneville Power Administration`s settlements with two California companies who had agreed to build geothermal power plants on the federal agency`s behalf, geothermal space heating projects and use of geothermal energy for raising red crayfish in Oregon, and some updates on geothermal projects in Minnesota, Pennsylvania, and China.

  9. Reconnaissance of hydrologic monitoring sites and preliminary monitoring plan for the Vale, Oregon, geothermal area

    USGS Publications Warehouse

    Gannett, Marshall W.; Caldwell, Rodney R.

    1996-01-01

    The Bonneville Power Administration is working with private industry to develop a geothermal demonstration project in the Known Geothermal Resources Area (KGRA) near Vale, Oregon. Hydrologic monitoring in the area is planned in order to evaluate any impacts from the proposed development. The hydrology in and around the Vale KGRA is not well known. Additionally, little is known about the targeted geothermal reservoir and the nature of its connection to the shallow ground-water system. Given this uncertainty, a variety of features were selected to ensure adequate monitoring coverage. Wells and springs in and around the geothermal area were evaluated, and 19 were selected as potential monitoring sites. In selecting wells and springs for monitoring, particular emphasis was placed on those with a known or probable connection with the geothermal system because they would most likely be the first to show any effects from development. The selected features include thermal wells in the hot-spring area near the town of Vale and a hot spring south of the KGRA. Several warm wells (70 to 90 degrees Fahrenheit) near the KGRA were also selected because it is likely that the water produced from these wells includes a component of geothermal water. In order to identify any effects of development, it is necessary to have an understanding of natural and man-caused variations and trends prior to development. A quarterly measurement schedule is proposed to help characterize these variations and trends. It is anticipated that the proposed monitoring plan will be modified as exploration and development proceed and more is learned about the geothermal system.

  10. Plant adaptation to extreme environments: the example of Cistus salviifolius of an active geothermal alteration field.

    PubMed

    Bartoli, Giacomo; Bottega, Stefania; Forino, Laura M C; Ciccarelli, Daniela; Spanò, Carmelina

    2014-02-01

    Cistus salviifolius is able to colonise one of the most extreme active geothermal alteration fields in terms of both soil acidity and hot temperatures. The analyses of morpho-functional and physiological characters, investigated in leaves of plants growing around fumaroles (G leaves) and in leaves developed by the same plants after transfer into growth chamber under controlled conditions (C leaves) evidenced the main adaptive traits developed by this pioneer plant in a stressful environment. These traits involved leaf shape and thickness, mesophyll compactness, stomatal and trichome densities, chloroplast size. Changes of functional and physiological traits concerned dry matter content, peroxide and lipid peroxidation, leaf area, relative water and pigment contents. A higher reducing power and antioxidant enzymatic activity were typical of G leaves. Though the high levels of stress parameters, G leaves showed stress-induced specific morphogenic and physiological responses putatively involved in their surviving in active geothermal habitats.

  11. Geothermal handbook

    USGS Publications Warehouse

    1976-01-01

    The Bureau of Land Management offered over 400,000 hectares (one million acres) for geothermal exploration and development in 1975, and figure is expected to double this year. The Energy Research and Development Administration hopes for 10-15,000 megawatts of geothermal energy by 1985, which would require, leasing over 16.3 million hectares (37 million acres) of land, at least half of which is federal land. Since there is an 8 to 8-1/2 year time laf between initial exploration and full field development, there would have to be a ten-fold increase in the amount of federal land leased within the next three years. Seventy percent of geothermal potential, 22.3 million hectares (55 million acres), is on federal lands in the west. The implication for the Service are enormous and the problems immediate. Geothermal resource are so widespread they are found to some extent in most biomes and ecosystems in the western United States. In most cases exploitation and production of geothermal resources can be made compatible with fish and wildlife management without damage, if probable impacts are clearly understood and provided for before damage has unwittingly been allowed to occur. Planning for site suitability and concern with specific operating techniques are crucial factors. There will be opportunities for enhancement: during exploration and testing many shallow groundwater bodies may be penetrated which might be developed for wildlife use. Construction equipment and materials needed for enhancement projects will be available in areas heretofore considered remote projects will be available in areas heretofore considered remote by land managers. A comprehensive knowledge of geothermal development is necessary to avoid dangers and seize opportunities. This handbook is intended to serve as a working tool in the field. It anticipated where geothermal resource development will occur in the western United States in the near future. A set of environmental assessment procedures are

  12. Microbial life in volcanic/geothermal areas: how soil geochemistry shapes microbial communities

    NASA Astrophysics Data System (ADS)

    Gagliano, Antonina Lisa; D'Alessandro, Walter; Franzetti, Andrea; Parello, Francesco; Tagliavia, Marcello; Quatrini, Paola

    2015-04-01

    Extreme environments, such as volcanic/geothermal areas, are sites of complex interactions between geosphere and biosphere. Although biotic and abiotic components are strictly related, they were separately studied for long time. Nowadays, innovative and interdisciplinary approaches are available to explore microbial life thriving in these environments. Pantelleria island (Italy) hosts a high enthalpy geothermal system characterized by high CH4 and low H2S fluxes. Two selected sites, FAV1 and FAV2, located at Favara Grande, the main exhalative area of the island, show similar physical conditions with a surface temperature close to 60° C and a soil gas composition enriched in CH4, H2 and CO2. FAV1 soil is characterized by harsher conditions (pH 3.4 and 12% of H2O content); conversely, milder conditions were recorded at site FAV2 (pH 5.8 and 4% of H2O content). High methanotrophic activity (59.2 nmol g-1 h-1) and wide diversity of methanotrophic bacteria were preliminary detected at FAV2, while no activity was detected at FAV1(1). Our aim was to investigate how the soil microbial communities of these two close geothermal sites at Pantelleria island respond to different geochemical conditions. Bacterial and Archaeal communities of the sites were investigated by MiSeq Illumina sequencing of hypervariable regions of the 16S rRNA gene. More than 33,000 reads were obtained for Bacteria and Archaea from soil samples of the two sites. At FAV1 99% of the bacterial sequences were assigned to four main phyla (Proteobacteria, Firmicutes, Actinobacteria and Chloroflexi). FAV2 sequences were distributed in the same phyla with the exception of Chloroflexi that was represented below 1%. Results indicate a high abundance of thermo-acidophilic chemolithotrophs in site FAV1 dominated by Acidithiobacillus ferrooxidans (25%), Nitrosococcus halophilus (10%), Alicyclobacillus spp. (7%) and the rare species Ktedonobacter racemifer (11%). The bacterial community at FAV2 soil is dominated by

  13. Western Sicily (Italy), a key area for understanding geothermal system within carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Montanari, D.; Bertini, G.; Botteghi, S.; Catalano, R.; Contino, A.; Doveri, M.; Gennaro, C.; Gianelli, G.; Gola, G.; Manzella, A.; Minissale, A.; Montegrossi, G.; Monteleone, S.; Trumpy, E.

    2012-12-01

    Oil exploration in western Sicily started in the late 1950s when several exploration wells were drilled, and continued with the acquisition of many seismic reflection profiles and the drilling of new wells in the1980s. The geological interpretation of these data mainly provided new insights for the definition of geometric relationships between tectonic units and structural reconstruction at depth. Although it has not produced completely satisfactory results for oil industry, this hydrocarbon exploration provided a great amount of data, resulting very suitable for geothermal resource assessment. From a geothermal point of view western Sicily is, indeed, a very promising area, with the manifestation at surface of several thermal springs, localized areas of high heat flux and thick carbonates units uninterruptedly developing from surface up top great depths. These available data were often collected with the modalities and purposes typical of oil exploration, not always the finest for geothermal exploration as in the case of temperature measurements. The multidisciplinary and integrated review of these data, specifically corrected for geothermal purposes, and the integration with new data acquired in particular key areas such as the Mazara Del Vallo site in the southern part of western Sicily, allowed us to better understand this medium-enthalpy geothermal system, to reconstruct the modalities and peculiarities of fluids circulation, and to evaluate the geothermal potentialities of western Sicily. We suggest that western Sicily can be taken as a reference for the understanding of geothermal systems developed at a regional scale within carbonate rocks. This study was performed within the framework of the VIGOR project (http://www.vigor-geotermia.it).

  14. Geothermal direct-heat utilization assistance. Quarterly project progress report, July 1995--September 1995

    SciTech Connect

    Lienau, P.

    1995-12-01

    The report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the fourth quarter of FY-95. It describes 80 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment and resources. Research activities are summarized on low-temperature resource assessment, geothermal energy cost evaluation and marketing strategy for geothermal district heating. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

  15. Predicting Ground Motion from Induced Earthquakes in Geothermal Areas

    NASA Astrophysics Data System (ADS)

    Douglas, J.; Edwards, B.; Convertito, V.; Sharma, N.; Tramelli, A.; Kraaijpoel, D.; Cabrera, B. M.; Maercklin, N.; Troise, C.

    2013-06-01

    Induced seismicity from anthropogenic sources can be a significant nuisance to a local population and in extreme cases lead to damage to vulnerable structures. One type of induced seismicity of particular recent concern, which, in some cases, can limit development of a potentially important clean energy source, is that associated with geothermal power production. A key requirement for the accurate assessment of seismic hazard (and risk) is a ground-motion prediction equation (GMPE) that predicts the level of earthquake shaking (in terms of, for example, peak ground acceleration) of an earthquake of a certain magnitude at a particular distance. Few such models currently exist in regard to geothermal-related seismicity, and consequently the evaluation of seismic hazard in the vicinity of geothermal power plants is associated with high uncertainty. Various ground-motion datasets of induced and natural seismicity (from Basel, Geysers, Hengill, Roswinkel, Soultz, and Voerendaal) were compiled and processed, and moment magnitudes for all events were recomputed homogeneously. These data are used to show that ground motions from induced and natural earthquakes cannot be statistically distinguished. Empirical GMPEs are derived from these data; and, although they have similar characteristics to recent GMPEs for natural and mining-related seismicity, the standard deviations are higher. To account for epistemic uncertainties, stochastic models subsequently are developed based on a single corner frequency and with parameters constrained by the available data. Predicted ground motions from these models are fitted with functional forms to obtain easy-to-use GMPEs. These are associated with standard deviations derived from the empirical data to characterize aleatory variability. As an example, we demonstrate the potential use of these models using data from Campi Flegrei.

  16. 3D Model of the Tuscarora Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    The Tuscarora geothermal system sits within a ~15 km wide left-step in a major west-dipping range-bounding normal fault system. The step over is defined by the Independence Mountains fault zone and the Bull Runs Mountains fault zone which overlap along strike. Strain is transferred between these major fault segments via and array of northerly striking normal faults with offsets of 10s to 100s of meters and strike lengths of less than 5 km. These faults within the step over are one to two orders of magnitude smaller than the range-bounding fault zones between which they reside. Faults within the broad step define an anticlinal accommodation zone wherein east-dipping faults mainly occupy western half of the accommodation zone and west-dipping faults lie in the eastern half of the accommodation zone. The 3D model of Tuscarora encompasses 70 small-offset normal faults that define the accommodation zone and a portion of the Independence Mountains fault zone, which dips beneath the geothermal field. The geothermal system resides in the axial part of the accommodation, straddling the two fault dip domains. The Tuscarora 3D geologic model consists of 10 stratigraphic units. Unconsolidated Quaternary alluvium has eroded down into bedrock units, the youngest and stratigraphically highest bedrock units are middle Miocene rhyolite and dacite flows regionally correlated with the Jarbidge Rhyolite and modeled with uniform cumulative thickness of ~350 m. Underlying these lava flows are Eocene volcanic rocks of the Big Cottonwood Canyon caldera. These units are modeled as intracaldera deposits, including domes, flows, and thick ash deposits that change in thickness and locally pinch out. The Paleozoic basement of consists metasedimenary and metavolcanic rocks, dominated by argillite, siltstone, limestone, quartzite, and metabasalt of the Schoonover and Snow Canyon Formations. Paleozoic formations are lumped in a single basement unit in the model. Fault blocks in the eastern

  17. Area development plan of the geothermal potential in planning region 8, Roosevelt - Custer area

    SciTech Connect

    Not Available

    1980-07-01

    Geothermal resource data, the Roosevelt-Custer Region development plan, and energy, economic, and institutional considerations are presented. Environmental considerations and water availability are discussed. (MHR)

  18. Geothermal Heat Flux Assessment Using Remote Sensing Land Surface Temperature and Simulated Data. Case Studies at the Kenyan Rift and Yellowstone Geothermal Areas

    NASA Astrophysics Data System (ADS)

    Romaguera, M.; Vaughan, R. G.; Ettema, J.; Izquierdo-Verdiguier, E.; Hecker, C.; van der Meer, F. D.

    2015-12-01

    In this work we propose an innovative approach to assess the geothermal heat flux anomalies in the regions of the Kenyan Rift and the Yellowstone geothermal areas. The method is based on the land surface temperature (LST) differences obtained between remote sensing data and land surface model simulations. The hypothesis is that the model simulations do not account for the subsurface geothermal heat source in the formulation. Remote sensing of surface emitted radiances is able to detect at least the radiative portion of the geothermal signal that is not in the models. Two methods were proposed to assess the geothermal component of LST (LSTgt) based on the aforementioned hypothesis: a physical model and a data mining approach. The LST datasets were taken from the Land Surface Analysis Satellite Application Facilities products over Africa and the Copernicus Programme for North America, at a spatial resolution of 3-5 km. These correspond to Meteosat Second Generation and Geostationary Operational Environmental Satellite system satellites data respectively. The Weather Research and Forecasting model was used to simulate LST based on atmospheric and surface characteristics using the Noah land surface model. The analysis was carried out for a period of two months by using nighttime acquisitions. Higher spatial resolution images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer data were also used on the Kenyan area to produce similar outputs employing existing methods. The comparison of the results from both methods and areas illustrated the potential of the data and methodologies for geothermal applications.

  19. Time-dependent seismic tomography and its application to the Coso geothermal area, 1996-2006

    SciTech Connect

    Julian, Bruce R.; Foulger, Gillian R.; Monastero, Francis C.

    2008-03-31

    Measurements of temporal changes in Earth structure are commonly determined using local-earthquake tomography computer programs that invert multiple seismic-wave arrival time data sets separately and assume that any differences in the structural results arise from real temporal variations. This assumption is dangerous because the results of repeated tomography experiments would differ even if the structure did not change, simply because of variation in the seismic ray distribution caused by the natural variation in earthquake locations. Even if the source locations did not change (if only explosion data were used, for example), derived structures would inevitably differ because of observational errors. A better approach is to invert multiple data sets simultaneously, which makes it possible to determine what changes are truly required by the data. This problem is similar to that of seeking models consistent with initial assumptions, and techniques similar to the “damped least squares” method can solve it. We have developed a computer program, dtomo, that inverts multiple epochs of arrival-time measurements to determine hypocentral parameters and structural changes between epochs. We shall apply this program to data from the seismically active Coso geothermal area, California, in the near future. The permanent network operated there by the US Navy, supplemented by temporary stations, has provided excellent earthquake arrival-time data covering a span of more than a decade. Furthermore, structural change is expected in the area as a result of geothermal exploitation of the resource. We have studied the period 1996 through 2006. Our results to date using the traditional method show, for a 2-km horizontal grid spacing, an irregular strengthening with time of a negative VP/VS anomaly in the upper ~ 2 km of the reservoir. This progressive reduction in VP/VS results predominately from an increase of VS with

  20. Attenuation and source properties at the Coso Geothermal area, California

    USGS Publications Warehouse

    Hough, S.E.; Lees, J.M.; Monastero, F.

    1999-01-01

    We use a multiple-empirical Green's function method to determine source properties of small (M -0.4 to 1.3) earthquakes and P- and S-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method. Stress-drop values of at least 0.5-1 MPa are inferred for all of the events; in many cases, the corner frequency is outside the usable bandwidth, and the stress drop can only be constrained as being higher than 3 MPa. P- and S-wave stress-drop estimates are identical to the resolution limits of the data. These results are indistinguishable from numerous EGF studies of M 2-5 earthquakes, suggesting a similarity in rupture processes that extends to events that are both tiny and induced, providing further support for Byerlee's Law. Whole-path Q estimates for P and S waves are determined using the multiple-empirical Green's function (MEGF) method of Hough (1997), whereby spectra from clusters of colocated events at a given station are inverted for a single attenuation parameter, ??, with source parameters constrained from EGF analysis. The ?? estimates, which we infer to be resolved to within 0.01 sec or better, exhibit almost as much scatter as a function of hypocentral distance as do values from previous single-spectrum studies for which much higher uncertainties in individual ?? estimates are expected. The variability in ?? estimates determined here therefore suggests real lateral variability in Q structure. Although the ray-path coverage is too sparse to yield a complete three-dimensional attenuation tomographic image, we invert the inferred ?? value for three-dimensional structure using a damped least-squares method, and the results do reveal significant lateral variability in Q structure. The inferred attenuation variability corresponds to the heat-flow variations within the geothermal region. A central low

  1. Geothermal Energy.

    ERIC Educational Resources Information Center

    Bufe, Charles Glenn

    1983-01-01

    Major activities, programs, and conferences in geothermal energy during 1982 are highlighted. These include first comprehensive national assessment of U.S. low-temperature geothermal resources (conducted by U.S. Geological Survey and Department of Energy), map production by U.S. Geological Survey, geothermal plant production, and others. (JN)

  2. Time-dependent seismic tomography of the Coso geothermal area, 1996-2004

    SciTech Connect

    Julian, Bruce R.; Foulger, Gillian R.; Richards-Dinger, Keith; Monastero, Francis

    2006-03-31

    Local-earthquake tomographic images were calculated for each of the years 1996 - 2004 using arrival times from the U.S. Navy’s permanent seismometer network at the Coso geothermal area, California. The results show irregular strengthening with time of the wave-speed ratio VP/VS at shallow depths. These changes result predominately from progressive relative increase in VS with respect to VP, and could result from processes associated with geothermal operations such as decrease in fluid pressure and the drying of argillaceous minerals such as illite.

  3. Tectonic and Structural Controls of Geothermal Activity in the Great Basin Region, Western USA

    NASA Astrophysics Data System (ADS)

    Faulds, J. E.; Hinz, N.; Kreemer, C. W.

    2012-12-01

    We are conducting a thorough inventory of structural settings of geothermal systems (>400 total) in the extensional to transtensional Great Basin region of the western USA. Most of the geothermal systems in this region are not related to upper crustal magmatism and thus regional tectonic and local structural controls are the most critical factors controlling the locations of the geothermal activity. A system of NW-striking dextral faults known as the Walker Lane accommodates ~20% of the North American-Pacific plate motion in the western Great Basin and is intimately linked to N- to NNE-striking normal fault systems throughout the region. Overall, geothermal systems are concentrated in areas with the highest strain rates within or proximal to the eastern and western margins of the Great Basin, with the high temperature systems clustering in transtensional areas of highest strain rate in the northwestern Great Basin. Enhanced extension in the northwestern Great Basin probably results from the northwestward termination of the Walker Lane and the concomitant transfer of dextral shear into west-northwest directed extension, thus producing a broad transtensional region. The capacity of geothermal power plants also correlates with strain rates, with the largest (hundreds of megawatts) along the Walker Lane or San Andreas fault system, where strain rates range from 10-100 nanostrain/yr to 1,000 nanostrain/yr, respectively. Lesser systems (tens of megawatts) reside in the Basin and Range (outside the Walker Lane), where local strain rates are typically < 10 nanostrain/yr. Of the 250+ geothermal fields catalogued, step-overs or relay ramps in normal fault zones serve as the most favorable setting, hosting ~32% of the systems. Such areas have multiple, overlapping fault strands, increased fracture density, and thus enhanced permeability. Other common settings include a) intersections between normal faults and strike-slip or oblique-slip faults (27%), where multiple minor

  4. Thermal Modeling of an Area N-W of the Larderello Geothermal Field, Italy.

    NASA Astrophysics Data System (ADS)

    Bellani, S.; Gherardi, F.

    2008-12-01

    A wide area enclosed between the ancient Etruscan town of Volterra and the northern rim of the Larderello high enthalpy geothermal field (Tuscany, Italy) shows thermal features which suggest further investigations aimed at mid-low enthalpy geothermal energy exploitation. Thermal gradients are in the range 75 - 100 C°/km, while surface heat flow spans between 100 - 150 mW/m2. Numerical simulations were performed to predict the spatial distribution of temperature and fluid circulation paths, constrained by field data. Temperature control based on real data is allowed by a few deep exploratory geothermal wells along with several shallower gradient wells, down to a maximum of about 3 km. The model domain extends over an area 20 by 10 km; thickness is 6 km. Local geology is simplified in four different terrains, according to the generalized stratigraphy of the area. Several sets of simulations were carried out running SHEMAT and TOUGH2 numerical codes, considering various boundary conditions, inner geometries and hydraulic permeabilities. The model was realized by means of unsteady forward simulations, under the assumptions of impervious and isothermal top and bottom boundaries, lateral adiabatic faces and variable internal physical properties. The results indicate that the present temperature and pressure distribution of hot fluids with depth in the northern border area of the Larderello field allows to hypothesize a fruitful exploitation of the medium- enthalpy geothermal resources, possibly with low-boiling point fluids binary plants for electricity generation.

  5. The nature of the Ellidaar geothermal area in SW-Iceland

    SciTech Connect

    Tomasson, J. )

    1993-08-01

    The Ellidaar low-temperature system is situated in Quaternary strata in SW-Iceland. It has been utilized for space heating in the city of Reykjavik since 1968. The subsurface rocks may be divided into an upper basalt group, a hyaloclastite group and a lower basalt group. A temperature reversal between 400 and 1,200 m depth with a maximum temperature of 100--110 C is observed inside the production field of the Ellidaar area. This indicates a hot water inflow from the north. Hydrological barriers are believed to separate the Ellidaar area from the Laugarnes geothermal area 2--3 km to the west. The Ellidaar area is situated next to a deep cold water system, associated with the Krysuvik fissure swarm, which interacts with the geothermal system. The cold water penetrates from the surface down to 750--1,000 m depth. It is suggested that a flow of colder water from the fissure swarm to the Ellidaar system mines heat along the way. During production colder water from groundwater systems above and adjacent to the geothermal system replaces the geothermal water produced. This has caused a 7--36 C drop in production temperatures.

  6. Different Behaviour of Heat Flow and Helium Anomalies Through the Geothermal Areas of Central Italy

    NASA Astrophysics Data System (ADS)

    Bellani, S.; Magro, G.

    2005-12-01

    The high enthalpy geothermal areas and more than 30% of the Italian spas are concentrated in central Italy (Tuscany and Latium regions). A wide part of this area is affected by a large heat-flow anomaly, with maxima corresponding to the geothermal fields of Larderello, Mt. Amiata and Latera. Mt.Amiata and Latera are located in areas of quaternary quiescent volcanism, while there are no outcrops of extrusive rocks in the Larderello geothermal field. Surface heat flow in a continental area has an average value of 50-60 mW/m2. The background regional value in these geothermal areas is 120-150 mW/m2, with peaks up to 1000 mW/m2 at Larderello, 600 mW/m2 at Mt. Amiata and 300 mW/m2 at Latera. Anomalous heat flow is very often related to the presence of 3He-enriched fluids. In central Italy the He isotopic ratio (3He/4He expressed as R/Ra), in gases from cold and thermal manifestations and in geothermal wells ranges from 0.2 to 3.2 R/Ra. In particular, Larderello fluids range between 0.5 and 3.2, while the interval for Mt. Amiata and Latera fluids spans from 0.2 to 0.6. The R/Ra and heat flow profiles through central Italy, NW-SE trending, show no straightforward correlation between the two parameters. A phased correlation exists between heat flow and R/Ra relative maxima at Larderello, while they are decoupled at Mt. Amiata and Latera geothermal fields. Different heat and He transport mechanisms through the crust are the most likely explanation: mantle 3He-enriched fluids move upwards mainly via fluid filled conduits, while heat diffuses faster than He throughout the entire bulk rock. At Larderello, the almost constant values of R/Ra in geothermal wells and paleo-fluids (fluid inclusions) indicate that the contribution of hot 3He-enriched fluids must have occurred through deeply rooted faults at least in the last 1 Ma. In the Mt. Amiata area the presence of several spas, marked by low R/Ra ratios down to crustal values, could indicate the addition of radiogenic 4He. Rock

  7. Review of international geothermal activities and assessment of US industry opportunities: Final report

    SciTech Connect

    Not Available

    1987-08-01

    This study was initiated to review and assess international developments in the geothermal energy field and to define business opportunities for the US geothermal industry. The report establishes data bases on the status of worldwide geothermal development and the competitiveness of US industry. Other factors identified include existing legislation, tax incentives, and government institutions or agencies and private sector organizations that promote geothermal exports. Based on the initial search of 177 countries and geographic entities, 71 countries and areas were selected as the most likely targets for the expansion of the geothermal industry internationally. The study then determined to what extent their geothermal resource had been developed, what countries had aided or participated in this development, and what plans existed for future development. Data on the energy, economic, and financial situations were gathered.

  8. Review of international geothermal activities and assessment of US industry opportunities: Summary report

    SciTech Connect

    Not Available

    1987-08-01

    This report summarizes a study initiated to review and assess international developments in the geothermal energy field and to define business opportunities for the US geothermal industry. The report establishes data bases on the status of worldwide geothermal development and the competitiveness of US industry. Other factors identified include existing legislation, tax incentives, and government institutions or agencies and private sector organizations that promote geothermal exports. Based on the initial search of 177 countries and geographic entities, 71 countries and areas were selected as the most likely targets for the expansion of the geothermal industry internationally. The study then determined to what extent their geothermal resource had been developed, what countries had aided or participated in this development, and what plans existed for future development. Data on the energy, economic, and financial situations were gathered.

  9. Review of International Geothermal Activities and Assessment of US Industry Opportunites: Final Report

    SciTech Connect

    1987-08-01

    This report contains detailed summaries, with bibliographies, of past, present, and planned geothermal development in 71 selected countries and areas. The report gives a pretty good description of types of work that had been done in each country by the mid 1980s, but does not tell much about which geothermal-provider country did the work. There are maps for most of the countries. There are numbers for market factors, but not for estimated geothermal potential. The information in this document has been superceded by the country summaries in the World Geothermal Congress Transactions of 1995, 2000, and 2005. This report was prepared by Meridian Corporation, Alexandria, VA. (DJE 2005)

  10. Evaluation of a superheater enhanced geothermal steam power plant in the Geysers area. Final report

    SciTech Connect

    Janes, J.

    1984-06-01

    This study was conducted to determine the attainable generation increase and to evaluate the economic merits of superheating the steam that could be used in future geothermal steam power plants in the Geyser-Calistoga Known Geothermal Resource Area (KGRA). It was determined that using a direct gas-fired superheater offers no economic advantages over the existing geothermal power plants. If the geothermal steam is heated to 900/sup 0/F by using the exhaust energy from a gas turbine of currently available performance, the net reference plant output would increase from 65 MW to 159 MW (net). Such hybrid plants are cost effective under certain conditions identified in this document. The power output from the residual Geyser area steam resource, now equivalent to 1437 MW, would be more than doubled by employing in the future gas turbine enhancement. The fossil fuel consumed in these plants would be used more efficiently than in any other fossil-fueled power plant in California. Due to an increase in evaporative losses in the cooling towers, the viability of the superheating concept is contingent on development of some of the water resources in the Geysers-Calistoga area to provide the necessary makeup water.

  11. Interpretation of Magnetic Anomalies in Salihli (Turkey) Geothermal Area Using 3-D Inversion and Edge Detection Techniques

    NASA Astrophysics Data System (ADS)

    Timur, Emre

    2016-04-01

    There are numerous geophysical methods used to investigate geothermal areas. The major purpose of this magnetic survey is to locate the boudaries of active hydrothermal system in the South of Gediz Graben in Salihli (Manisa/Turkey). The presence of the hydrothermal system had already been inferred from surface evidence of hydrothermal activity and drillings. Firstly, 3-D prismatic models were theoretically investigated and edge detection methods were utilized with an iterative inversion method to define the boundaries and the parameters of the structure. In the first step of the application, it was necessary to convert the total field anomaly into a pseudo-gravity anomaly map. Then the geometric boudaries of the structures were determined by applying a MATLAB based software with 3 different edge detection algorithms. The exact location of the structures were obtained by using these boundary coordinates as initial geometric parameters in the inversion process. In addition to these methods, reduction to pole and horizontal gradient methods were applied to the data to achieve more information about the location and shape of the possible reservoir. As a result, the edge detection methods were found to be successful, both in the field and as theoretical data sets for delineating the boundaries of the possible geothermal reservoir structure. The depth of the geothermal reservoir was determined as 2,4 km from 3-D inversion and 2,1 km from power spectrum methods.

  12. Geothermal Technologies Program: Utah

    SciTech Connect

    Not Available

    2005-06-01

    Geothermal Technologies Program Utah fact sheet describes the geothermal areas and use in Utah, focusing on power generation as well as direct use, including geothermally heated greenhouses, swimming pools, and therapeutic baths.

  13. Constraining chemical geothermometry with reactive transport models: An example study of the Dixie Valley geothermal area

    NASA Astrophysics Data System (ADS)

    Wanner, C.; Peiffer, L.; Spycher, N.; Sonnenthal, E. L.; Iovenitti, J. L.; Kennedy, B. M.

    2012-12-01

    In this study, 1D and 2D reactive transport simulations of the Dixie Valley geothermal area (Nevada, USA) were performed using Toughreact [1] to evaluate the fluid flow pathways and rates of equilibration of hydrothermal fluids. Modeling studies were combined with new multicomponent geothermometry, which is being used to estimate the temperature of geothermal reservoirs based on chemical analysis of geothermal springs. The concept is based on the assumption of chemical equilibrium between the thermal fluid and minerals of the reservoir rock [2]. If re-equilibration occurs between the reservoir at depth and the surface, then the 'deep' chemical signature of the fluid is lost and the obtained reservoir temperature is underestimated. The simulations were run for a vertical cross-section that has been structurally and geologically characterized. Model calibration was performed using available site information such as chemical analysis of geothermal springs, isotherms inferred from geothermal wells and results of a previous flow simulation study [3]. Model runs included the simulation of typical near-surface processes such as dilution, mixing and salt leaching occurring at the Dixie Valley geothermal area. Each reactive transport model produced 'synthetic' waters that were processed using the multicomponent chemical geothermometer code GeoT [4]. This code computes the saturation indices of reservoir minerals as a function of the temperature. Reservoir temperature is inferred when mineral saturation indices all cluster around zero. GeoT results were also compared with classical solute geothermometers (silica, Na-K-(Ca), K-Mg) [5]. Simulation results reveal that a minimum vertical fluid velocity on the order of a meter per day is needed to preserve the geochemical signature of a geothermal reservoir and to predict its temperature. The simulations also show that deep geochemical signatures are well preserved if fracture surfaces are partially coated by secondary minerals

  14. Origin and distribution of thiophenes and furans in gas discharges from active volcanoes and geothermal systems.

    PubMed

    Tassi, Franco; Montegrossi, Giordano; Capecchiacci, Francesco; Vaselli, Orlando

    2010-03-31

    The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C(2)-C(20) species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C(4)H(8)O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection.

  15. Origin and Distribution of Thiophenes and Furans in Gas Discharges from Active Volcanoes and Geothermal Systems

    PubMed Central

    Tassi, Franco; Montegrossi, Giordano; Capecchiacci, Francesco; Vaselli, Orlando

    2010-01-01

    The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C2–C20 species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C4H8O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection. PMID:20480029

  16. Teleseismic evidence for a low-velocity body under the Coso geothermal area

    SciTech Connect

    Reasenberg, P.; Ellisworth, W.; Walter, A.

    1980-05-10

    Teleseismic P wave arrivals were recorded by a dense array of seismograph stations located in the Coso geothermal area, California. The resulting pattern of relative residuals an area showing approximately 0.2-s excess travel time that migrates with changing source azimuth, suggesting that the area is the 'delay shadow' produced by a deep, low-velocity body. Inversion of the relative residual data for three-dimensional velocity structure determines the lateral variations in velocity to a depth of 22.5 km beneath the array. An intense low-velocity body, which concides with the surface expressions of late Pleistocene rhyolitic volcanism, high heat flow, and hydrothermal activity, is resolved between 5- and 20-km depth. It has maximum velocity contrast of over 8% between 10 and 17.5 km. The shallowest part of this body is centered below the region of highest heat flow; at depth it is elongate in approximately the N-S direction. The hypothesis that this low-velocity body is caused by the presence of partial melt in the middle crust is consistent with the local seismic, geologic, and thermal data.

  17. Geothermal tomorrow 2008

    SciTech Connect

    None, None

    2009-01-18

    Contributors from the Geothermal Technologies Program and the geothermal community highlight the current status and activities of the Program and the development of the global resource of geothermal energy.

  18. Effects of potential geothermal development in the Corwin Springs Known Geothermal Resources Area, Montana, on the thermal features of Yellowstone National Park. Water Resources Investigation

    SciTech Connect

    Sorey, M.L.

    1991-01-01

    A two-year study by the U.S. Geological Survey, in collaboration with the National Park Service, Argonne National Laboratory, and Los Alamos National Laboratory was initiated in 1988 to determine the effects of potential geothermal development in the Corwin Springs Known Geothermal Resources Area (KGRA), Montana, on the thermal features of Yellowstone National Park. The study addressed three principal issues: (1) the sources of thermal water in the hot springs at Mammoth, La Duke, and Bear Creek; (2) the degree of subsurface connection between these areas; and (3) the effects of geothermal development in the Corwin Springs KGRA on the Park's thermal features. The authors investigations included, but were not limited to, geologic mapping, electrical geophysical surveys, chemical sampling and analyses of waters and rocks, determinations of the rates of discharge of various thermal springs, and hydrologic tracer tests.

  19. Airborne Geophysical Surveys Illuminate the Geologic and Hydrothermal Framework of the Pilgrim Springs Geothermal Area, Alaska

    NASA Astrophysics Data System (ADS)

    McPhee, D. K.; Glen, J. M.; Bedrosian, P. A.

    2012-12-01

    An airborne magnetic and frequency-domain electromagnetic (EM) survey of the Pilgrim Springs geothermal area, located on the Seward Peninsula in west-central Alaska, delineates key structures controlling hydrothermal fluid flow. Hot springs, nearby thawed regions, and high lake temperatures are indicative of high heat flow in the region that is thought to be related to recent volcanism. By providing a region-wide geologic and geophysical framework, this work will provide informed decisions regarding drill-site planning and further our understanding of geothermal systems in active extensional basins. Helicopter magnetic and EM data were acquired using a Fugro RESOLVE system equipped with a high sensitivity cesium magnetometer and a multi-coil, multi-frequency EM system sensitive to the frequency range of 400-140,000 Hz. The survey was flown ~40 m above ground along flight lines spaced 0.2-0.4 km apart. Various derivative and filtering methods, including maximum horizontal gradient of the pseudogravity transformation of the magnetic data, are used to locate faults, contacts, and structural domains. A dominant northwest trending anomaly pattern characterizes the northeastern portion of the survey area between Pilgrim Springs and Hen and Chickens Mountain and may reflect basement structures. The area south of the springs, however, is dominantly characterized by east-west trending, range-front-parallel anomalies likely caused by late Cenozoic structures associated with the north-south extension that formed the basin. Regionally, the springs are characterized by a magnetic high punctuated by several east-west trending magnetic lows, the most prominent occurring directly over the springs. The lows may result from demagnetization of magnetic material along range-front parallel features that dissect the basin. We inverted in-phase and quadrature EM data along each profile using the laterally-constrained inversion of Auken et al. (2005). Data were inverted for 20-layer

  20. Geothermal direct-heat utilization assistance: Quarterly project progress report, January--March 1995

    SciTech Connect

    1995-05-01

    The report summarizes geothermal activities of the Geo-Heat Center at Oregon Institute of Technology for the second quarter of FY-95. It describes 92 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, resources and equipment. Research activities are summarized on geothermal energy cost evaluation, low temperature resource assessment and ground-source heat pump case studies and utility programs. Outreach activities include the publication of a geothermal direct heat Bulletin, dissemination of information, geothermal library, and progress monitor reports on geothermal resources and utilization.

  1. The importance of methanotrophic activity in geothermal soils of Pantelleria island (Italy)

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Walter; Gagliano, Antonina Lisa; Quatrini, Paola; Parello, Francesco

    2013-04-01

    Methane is a major contributor to the greenhouse effect, its atmospheric concentration being more than doubled since the XIX century. Every year 22 Tg of methane are released to the atmosphere from several natural and anthropogenic sources. Natural sources include geothermal/volcanic areas but the estimation of the total methane emission from these areas is currently not well defined since the balance between emission through degassing and microbial oxidation within the soils is not well known. Microbial oxidation in soils contributes globally for about 3-9% to the removal of methane from the atmosphere and recent studies evidenced methanotrophic activity also in soils of volcanic/geothermal areas despite their harsh environmental conditions (high temperatures, low pH and high concentrations of H2S and NH3). Methanotrophs are a diverse group of bacteria that are able to metabolize methane as their only source of carbon and energy and are found within the Alpha and Gamma classes of Proteobacteria and within the phylum Verrucomicrobia. Our purpose was to study the interaction between methanotrophic communities and the methane emitted from the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission has been previously estimated in about 2.5 t/a. Laboratory incubation experiments with soil samples from Favara Grande showed methane consumption values of up to 9500 ng g-1 dry soil per hour while soils collected outside the geothermal area consume less than 6 ng g-1 h-1. The maximum consumption was measured in the shallowest part of the soil profile (1-3 cm) and high values (>100 ng g-1 h-1) were maintained up to a depht of 15 cm. Furthermore, the highest consumption was measured at 37°C, and a still recognizable consumption (>20 ng g-1 h-1) at 80°C, with positive correlation with the methane concentration in the incubation atmosphere. These results can be considered a clear evidence of the presence of methanotrophs that

  2. Hot dry rock geothermal potential of Roosevelt Hot Springs area: review of data and recommendations

    SciTech Connect

    East, J.

    1981-05-01

    The Roosevelt Hot Springs area in west-central Utah possesses several features indicating potential for hot dry rock (HDR) geothermal development. The area is characterized by extensional tectonics and a high regional heat flow of greater than 105 mW/m/sup 2/. The presence of silicic volcanic rocks as young as 0.5 to 0.8 Myr and totaling 14 km/sup 3/ in volume indicates underlying magma reservoirs may be the heat source for the thermal anomaly. Several hot dry wells have been drilled on the periphery of the geothermal field. Information obtained on three of these deep wells shows that they have thermal gradients of 55 to 60/sup 0/C/km and bottom in impermeable Tertiary granitic and Precambrian gneissic units. The Tertiary granite is the preferred HDR reservoir rock because Precambrian gneissic rocks possess a well-developed banded foliation, making fracture control over the reservoir more difficult. Based on a fairly conservative estimate of 160 km/sup 2/ for the thermal anomaly present at Roosevelt Hot Springs, the area designated favorable for HDR geothermal exploration may be on the order of seven times or more than the hydrogeothermal area currently under development.

  3. A novel heat flux study of a geothermally active lake - Lake Rotomahana, New Zealand

    NASA Astrophysics Data System (ADS)

    Tivey, Maurice A.; de Ronde, Cornel E. J.; Tontini, Fabio Caratori; Walker, Sharon L.; Fornari, Daniel J.

    2016-03-01

    A new technique for measuring conductive heat flux in a lake was adapted from the marine environment to allow for multiple measurements to be made in areas where bottom sediment cover is sparse, or even absent. This thermal blanket technique, pioneered in the deep ocean for use in volcanic mid-ocean rift environments, was recently used in the geothermally active Lake Rotomahana, New Zealand. Heat flow from the lake floor propagates into the 0.5 m diameter blanket and establishes a thermal gradient across the known blanket thickness and thereby provides an estimate of the conductive heat flux of the underlying terrain. This approach allows conductive heat flux to be measured over a spatially dense set of stations in a relatively short period of time. We used 10 blankets and deployed them for 1 day each to complete 110 stations over an 11-day program in the 6 × 3 km lake. Results show that Lake Rotomahana has a total conductive heat flux of about 47 MW averaging 6 W/m2 over the geothermally active lake. The western half of the lake has two main areas of high heat flux; 1) a high heat flux area averaging 21.3 W/m2 along the western shoreline, which is likely the location of the pre-existing geothermal system that fed the famous Pink Terraces, mostly destroyed during the 1886 eruption 2) a region southwest of Patiti Island with a heat flux averaging 13.1 W/m2 that appears to be related to the explosive rift that formed the lake in the 1886 Tarawera eruption. A small rise in bottom water temperature over the survey period of 0.01 °C/day suggests the total thermal output of the lake is ~ 112-132 MW and when compared to the conductive heat output suggests that 18-42% of the total thermal energy is by conductive heat transfer.

  4. Impact of Subglacial Geothermal Activity on Meltwater Quality in the JÖKULSÁ Á SÓLHEIMASANDI System, Southern Iceland

    NASA Astrophysics Data System (ADS)

    Lawler, D. M.; Björnsson, H.; Dolan, M.

    1996-04-01

    The influence of subglacial geothermal activity on the hydrochemistry of the Jökulsá á Sólheimasandi glacial meltwater river, south Iceland, is discussed. A radio echosounding and Global Positioning System survey of south-west Myrdalsjökull, the parent ice-cap of the valley glacier Sólheimajökull, establishes the geometry and position of a subglacial caldera. A cauldron in the ice-cap surface at the basin head is also defined, signifying one location of geothermally driven ablation processes. Background H2S concentrations for the Jökulsá meltwaters in summer 1989 show that leakage of geothermal fluids into the glacial drainage network takes place throughout the melt season. Chemical geothermometry (Na+/K+ ratio) applied to the bulk meltwaters tentatively suggests that the subglacial geothermal area is a high-temperature field with a reservoir temperature of 289-304°C. A major event of enhanced geothermal fluid injection was also detected. Against a background of an apparently warming geothermal reservoir, the event began on Julian day 205 (24 July) with a burst of subglacial seismic activity. Meltwater hydrochemical perturbations followed on day 209 and peaked on day 213, finally leading to a sudden and significant increase in flow on day 214. The hydrochemical excursions were characterized by strong peaks in meltwater H2S, SO2-4 and total carbonate concentrations, transient decreases in pH, small increases in Ca2+ and Mg2+ and sustained increases in electrical conductivity. The event may relate to temporary invigoration of the subglacial convective hydrothermal circulation, seismic disturbance of patterns of groundwater flow and geothermal fluid recruitment to the subglacial drainage network, or a cyclic sweeping out of the geothermal zone by the annual wave of descending groundwater. Time lags between seismic events and meltwater electrical conductivity responses suggest mean and maximum intraglacial throughflow velocities of 0.032-0.132 m s-1

  5. Temperature Effects on Biomass and Regeneration of Vegetation in a Geothermal Area

    PubMed Central

    Nishar, Abdul; Bader, Martin K.-F.; O’Gorman, Eoin J.; Deng, Jieyu; Breen, Barbara; Leuzinger, Sebastian

    2017-01-01

    Understanding the effects of increasing temperature is central in explaining the effects of climate change on vegetation. Here, we investigate how warming affects vegetation regeneration and root biomass and if there is an interactive effect of warming with other environmental variables. We also examine if geothermal warming effects on vegetation regeneration and root biomass can be used in climate change experiments. Monitoring plots were arranged in a grid across the study area to cover a range of soil temperatures. The plots were cleared of vegetation and root-free ingrowth cores were installed to assess above and below-ground regeneration rates. Temperature sensors were buried in the plots for continued soil temperature monitoring. Soil moisture, pH, and soil chemistry of the plots were also recorded. Data were analyzed using least absolute shrinkage and selection operator and linear regression to identify the environmental variable with the greatest influence on vegetation regeneration and root biomass. There was lower root biomass and slower vegetation regeneration in high temperature plots. Soil temperature was positively correlated with soil moisture and negatively correlated with soil pH. Iron and sulfate were present in the soil in the highest quantities compared to other measured soil chemicals and had a strong positive relationship with soil temperature. Our findings suggest that soil temperature had a major impact on root biomass and vegetation regeneration. In geothermal fields, vegetation establishment and growth can be restricted by low soil moisture, low soil pH, and an imbalance in soil chemistry. The correlation between soil moisture, pH, chemistry, and plant regeneration was chiefly driven by soil temperature. Soil temperature was negatively correlated to the distance from the geothermal features. Apart from characterizing plant regeneration on geothermal soils, this study further demonstrates a novel approach to global warming experiments

  6. Temperature Effects on Biomass and Regeneration of Vegetation in a Geothermal Area.

    PubMed

    Nishar, Abdul; Bader, Martin K-F; O'Gorman, Eoin J; Deng, Jieyu; Breen, Barbara; Leuzinger, Sebastian

    2017-01-01

    Understanding the effects of increasing temperature is central in explaining the effects of climate change on vegetation. Here, we investigate how warming affects vegetation regeneration and root biomass and if there is an interactive effect of warming with other environmental variables. We also examine if geothermal warming effects on vegetation regeneration and root biomass can be used in climate change experiments. Monitoring plots were arranged in a grid across the study area to cover a range of soil temperatures. The plots were cleared of vegetation and root-free ingrowth cores were installed to assess above and below-ground regeneration rates. Temperature sensors were buried in the plots for continued soil temperature monitoring. Soil moisture, pH, and soil chemistry of the plots were also recorded. Data were analyzed using least absolute shrinkage and selection operator and linear regression to identify the environmental variable with the greatest influence on vegetation regeneration and root biomass. There was lower root biomass and slower vegetation regeneration in high temperature plots. Soil temperature was positively correlated with soil moisture and negatively correlated with soil pH. Iron and sulfate were present in the soil in the highest quantities compared to other measured soil chemicals and had a strong positive relationship with soil temperature. Our findings suggest that soil temperature had a major impact on root biomass and vegetation regeneration. In geothermal fields, vegetation establishment and growth can be restricted by low soil moisture, low soil pH, and an imbalance in soil chemistry. The correlation between soil moisture, pH, chemistry, and plant regeneration was chiefly driven by soil temperature. Soil temperature was negatively correlated to the distance from the geothermal features. Apart from characterizing plant regeneration on geothermal soils, this study further demonstrates a novel approach to global warming experiments

  7. Photogeologic and thermal infrared reconnaissance surveys of the Los Negritos-Ixtlan de los Hervores geothermal area, Michoacan, Mexico

    USGS Publications Warehouse

    Gomez, Valle R.; Friedman, J.D.; Gawarecki, S.J.; Banwell, C.J.

    1970-01-01

    New techniques, involving interpretation of panchromatic, ektachrome and ektachrome infrared aerographic photogaphs and thermographic infrared imagery recording emission from the earth's surface in middle and far infrared wavelengths (3-5??m and 8-14??m), are being introduced in geothermal investigations in Mexico to identify outstanding structural and geologic features in a rapid and economical manner. The object of this work is to evaluate the new airborne infrared techniques and equipment as a complement to the data obtained from panchromatic aerial photography. This project is part of the Mexican remote sensing program of natural resources carried out under the auspices of the Comision Nacional del Espacio Exterior and in which the Research Institute (Instituto de Investigaciones de la Industria Electrica) is actively participating. The present study was made cooperatively with the U.S. National Aeronautics and Space Administration and the U.S. Geological Survey. The Los Negritos-Ixtlan de los Hervores geothermal fields are located east of Lake Chapala at the intersection of the Sierra Madre occidental and the west-central segment of the neovolcanic axis of Mexico. The two principal zones of hydrothermal activity occur in a tectonic trench filled with lake sediments of the Quaternary intercalated with Quaternary and Holocene volcanic rocks and characterized by an intricate system of block-fault tectonics, part of the Chapala-Acambay tectonic system, along which there has been volcanic activity in modern time. Surface manifestations of geothermal activity consist of relatively high heat flow and hot springs, small geysers and small steam vents aligned along an E-W axis at Ixtlan, possibly at the intersection of major fault trends and mud volcanoes and hot pools aligned NE-SW at Los Negritos. More than 20 exit points of thermal waters are shown on infrared imagery to be aligned along an extension of the Ixtlan fault between Ixtlan and El Salitre. A narrow zone of

  8. Hydrogeochemistry of geothermal waters in the Magumsan and Bugok area, southern part of Korea

    NASA Astrophysics Data System (ADS)

    Park, S.; Yun, S.; So, C.; Chae, G.; Koh, Y.

    2001-12-01

    Hydrogeochemical and environmental isotopic studies of geothermal waters in the Bugok and Magumsan area were conducted to understand the subsurface evolution of geothermal system in South Korea. Hydrochemically, the Bugok thermal waters (BTW; outflowing temperature = 45.8-78.0 degree in centigrade) belong to the Na-SO4 type, whereas the Magumsan thermal waters (MTW; 27.5-54.8 degree in centigrade) represent the Na-Cl type. Peripheral groundwaters (17.2-22.4 degree in centigrade) in both areas belong to the Ca-HCO3 type. Both BTW and MTW show a good correlation between TDS and SiO2 content. The thermodynamic calculation using SOLVEQ indicates that all the BTW and MTW are saturated or supersaturated with respect to albite, quartz, calcite, kaolinite, anorthite, muscovite and paragonite, and are undersaturated with respect to gypsum, anhydrite and chalcedony. A good correlation among in-situ temperature, oxygen (and hydrogen) isotope values, and tritium content is observed for BTW and MTW. The high chlorine concentration of MTW reflects the substantial mixing of paleoseawater in the geothermal system, as also suggested by Na, Br, SO4, and Cl concentrations. We propose a hydrogeochemical model for MTW, which includes the paleoseawater mixing and addition of sedimentary SO4 by water-rock interaction during the descent of meteoric recharged water and the calcite dissolution and successive CO2 degassing during the ascent of heated waters. In the case of BTW, we propose an alternative model which includes complex processes such as the recharge of meteoric waters at higher elevation, the prolonged water-rock interaction including the dissolution of sedimentary (evaporitic?) sulfates, the reduction of sulfate to form H2S, the CO2 degassing and associated calcite precipitation, and the re-oxidation of H2S to SO4. We consider that the geothermal system responsible for both MTW and BTW are located nearer to a deep heat source, compared to the other geothermal systems found in

  9. The Geysers-Clear Lake area, California: thermal waters, mineralization, volcanism, and geothermal potential

    USGS Publications Warehouse

    Donnelly-Nolan, J. M.; Burns, M.G.; Goff, F.E.; Peters, E.K.; Thompson, J.M.

    1993-01-01

    Manifestations of a major thermal anomaly in the Geysers-Clear Lake area of northern California include the late Pliocene to Holocene Clear Lake Volcanics, The Geysers geothermal field, abundant thermal springs, and epithermal mercury and gold mineralization. The epithermal mineralization and thermal springs typically occur along high-angle faults within the broad San Andreas transform fault system that forms the western boundary of the North American plate in this area. The young volcanic rocks overlie Mesozoic marine rocks of the Great Valley sequence which have been thrust above the coeval Franciscan Complex and penecontemporaneously dropped back down along low-angle detachment faults. Geothermal power production has peaked at The Geysers and pressure declines indicate significant depletion of the fluid resource. It is proposed that recently discovered, isotopically shifted steam in the northwest Geysers area indicates the presence not of deep connate water but rather of boiled-down, boron-rich Franciscan evolved meteoric water. This water is likely to be present in limited quantities and will not provide a significant hot water resource for geothermal power production at The Geysers field or from the main Clear Lake volcanic field. -from Authors

  10. Geology and geochemistry of the Geyser Bight Geothermal Area, Umnak Island, Aleutian Islands, Alaska

    SciTech Connect

    Nye, C.J. . Geophysical Inst. Alaska Dept. of Natural Resources, Fairbanks, AK . Div. of Geological and Geophysical Surveys); Motyka, R.J. . Div. of Geological and Geophysical Surveys); Turner, D.L. . Geophysical Inst.); Liss, S.A. (Alaska Dept. of Natural Resources, Fairba

    1990-10-01

    The Geyser Bight geothermal area is located on Umnak Island in the central Aleutian Islands. It contains one of the hottest and most extensive areas of thermal springs and fumaroles in Alaska, and is only documented site in Alaska with geysers. The zone of hot springs and fumaroles lies at the head of Geyser Creek, 5 km up a broad, flat, alluvial valley from Geyser Bight. At present central Umnak is remote and undeveloped. This report describes results of a combined program of geologic mapping, K-Ar dating, detailed description of hot springs, petrology and geochemistry of volcanic and plutonic rock units, and chemistry of geothermal fluids. Our mapping documents the presence of plutonic rock much closer to the area of hotsprings and fumaroles than previously known, thus increasing the probability that plutonic rock may host the geothermal system. K-Ar dating of 23 samples provides a time framework for the eruptive history of volcanic rocks as well as a plutonic cooling age.

  11. South Dakota Geothermal Commercialization Project. Final report, July 1979-October 1985

    SciTech Connect

    Wegman, S.

    1985-01-01

    This report describes the activities of the South Dakota Energy Office in providing technical assistance, planning, and commercialization projects for geothermal energy. Projects included geothermal prospect identification, area development plans, and active demonstration/commercialization projects. (ACR)

  12. Raft River Geothermal Area Data Models - Conceptual, Logical and Fact Models

    DOE Data Explorer

    Cuyler, David

    2012-07-19

    Conceptual and Logical Data Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses at Raft River a. Logical Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses, David Cuyler 2010 b. Fact Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses, David Cuyler 2010 Derived from Tables, Figures and other Content in Reports from the Raft River Geothermal Project: "Technical Report on the Raft River Geothermal Resource, Cassia County, Idaho," GeothermEx, Inc., August 2002. "Results from the Short-Term Well Testing Program at the Raft River Geothermal Field, Cassia County, Idaho," GeothermEx, Inc., October 2004.

  13. Contribution of Persistent Scatterer Interferometry (PSI) to map surface displacement in the Travale - Radicondoli Geothermal area (Tuscany, Italy)

    NASA Astrophysics Data System (ADS)

    Botteghi, S.; Del Ventisette, C.; Montanari, D.; Manzella, A.; Moretti, S.

    2012-12-01

    Synthetic Aperture Radar Interferometry (InSAR) has been successfully used to map the deformation of the earth surface. Multi-interferogram techniques, known as Persistent Scatterer Interferometry (PSInSAR), are a powerful tools to monitoring surface deformation connected with seismic and volcanic activity, landslides, and subsidence due to fluid extraction. The availability of many data acquired by space agencies, as well as European Space Agency (ESA), and the high spatial resolution of PSI methodology, allow to reconstruct the temporal evolution of the ground surface deformations, measuring relative displacements of individual points (Permanent Scatterers, or PS) and estimating the velocity of deformation recorded in the period covered by satellites acquisitions. The possibility to detect the continuous ground surface displacement can provide an important information about reservoir behavior during production, helping to improve the development of a geothermal field (e.g. Hole et al. 2007; JVGR). The present study aims to test PSInSAR techniques over Travale-Radicondoli area, in order to assess the surface deformation connected with the exploitation of this geothermal field. The Travale-Radicondoli area is located about 15 km E-SE of the well-known Larderello-geothermal filed - southwestern Tuscany, Italy-, extending at the south-western margin of the Anqua-Radicondoli Basin. In this area two different reservoir have been identified: a shallow steam dominated reservoir, consisting of carbonate and evaporitic units, and a deep superheated steam reservoir, within metamorphic basement units and thermometamorphic rocks. Industrial exploitation of geothermal resources in the Travale-Radicondoli area began in 1950 and concerned only a small zone on the southern margin of the area, known as the "old field", characterized by a water dominated system. Since 1973, an intensive exploitation started in a more productive area located north-east of the "old field", where the

  14. Geothermal assessment of the MX deployment area in Nevada. Final report, April 1, 1981-April 30, 1982

    SciTech Connect

    Trexler, D.T.; Bruce, J.L.; Cates, D.; Dolan, H.H.; Covington, C.H.

    1982-06-01

    A preliminary geothermal resource assessment of the MX deployment area in Nevada focused on Coyote Spring Valley in southeastern Nevada. Initially, an extensive literature search was conducted and a bibliography consisting of 750 entries was compiled covering all aspects of geology pertaining to the study area. A structural study indicates that Coyote Spring Valley lies in a tectonically active area which is favorable for the discovery of geothermal resources. Hot water may be funneled to the near-surface along an extensive fracture and fault system which appears to underlie the valley, according to information gathered during the literature search and aerial photo survey. A total of 101 shallow temperature probes were emplanted in Coyote Spring Valley. Three anomalous temperature points all lying within the same vicinity were identified in the north-central portion of the valley near a fault. A soil-mercury study also identified one zone of anomalous mercury concentrations around the north end of the Arrow Canyon Range. A literature search covering regional fluid geochemistry indicated that the three fluid samples taken from Coyote Spring Valley have a higher concentration of Na + K. During field work, seven fluid samples were collected in Coyote Spring Valley which also appear to be derived from volcanic units due to the presence of Ca-Mg or Na-K carbonate-bicarbonate. A temperature gradient study of six test water wells indicates that only one geothermal well with a temperature of 35.5/sup 0/C (96/sup 0/F) exists in the central portion of the valley at the north end of Arrow Canyon Range near the zone of anomalous soil-mercury points. A cultural assessment of Coyote Spring Valley was performed prior to field work.

  15. Marine and land active-source seismic imaging of mid-Miocene to Holocene-aged faulting near geothermal prospects at Pyramid Lake, Nevada

    SciTech Connect

    Eisses, A.; Kell, A.; Kent, G.; Driscoll, N.; Karlin, R.; Baskin, R.; Louie, J.; Pullammanappallil, S.

    2016-08-01

    Amy Eisses, Annie Kell, Graham Kent, Neal Driscoll, Robert Karlin, Rob Baskin, John Louie, and Satish Pullammanappallil, 2011, Marine and land active-source seismic imaging of mid-Miocene to Holocene-aged faulting near geothermal prospects at Pyramid Lake, Nevada: Geothermal Resources Council Transactions, 35, 7 pp. Preprint at http://crack.seismo.unr.edu/geothermal/Eisses-GRCpaper-sm.pdf The Pyramid Lake fault zone lies within a vitally important area of the northern Walker Lane where not only can transtension can be studied through a complex arrangement of strike-slip and normal faults but also geothermal activity can be examined in the extensional regime for productivity. This study used advanced and economical seismic methods in attempt to develop the Paiute Tribe’s geothermal reservoir and to expand upon the tectonics and earthquake hazard knowledge of the area. 500 line-kilometers of marine CHIRP data were collected on Pyramid Lake combined with 27 kilometers of vibrator seismic on-land data from the northwest side of the basin were collected in 2010 that highlighted two distinct phases of faulting. Preliminary results suggest that the geothermal fluids in the area are controlled by the late Pleistoceneto Holocene-aged faults and not through the mid-Miocene-aged conduits as originally hypothesized.

  16. The hot dry rock geothermal potential of the Susanville (CA) area

    SciTech Connect

    Brown, D.W.

    1996-10-01

    A portion of northeastern California that lies within the Basin and Range Province represents a large, untapped geothermal energy resource in the form of hot, but essential impermeable, rock. If a means of developing sufficient permeability in the deep, granitic basement can be demonstrated, the electric power generation potential would be considerable. The objective of this study is to look at the specific geographical region extending from northeast to southeast of the village of Litchfield to the Nevada border as a target area for the first commercial application of Hot Dry Rock reservoir stimulation techniques. The ultimate goal is to provide background information that could lead to the creation of a commercial-scale, engineered geothermal reservoir in granitic basement rock of low permeability.

  17. Geothermal Target Areas in Colorado as Identified by Remote Sensing Techniques

    DOE Data Explorer

    Hussein, Khalid

    2012-02-01

    Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Publication Date: 2012 Title: Target Areas Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder, Colorado Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: This layer contains the areas identified as targets of potential geothermal activity. The Criteria used to identify the target areas include: hot/warm surface exposures modeled from ASTER/Landsat satellite imagery and geological characteristics, alteration mineral commonly associated with hot springs (clays, Si, and FeOx) modeled from ASTER and Landsat data, Coloradodo Geological Survey (CGS) known thermal hot springs/wells and heat-flow data points, Colorado deep-seated fault zones, weakened basement identified from isostatic gravity data, and Colorado sedimentary and topographic characteristics Spatial Domain: Extent: Top: 4546251.530446 m Left: 151398.567298 m Right: 502919.587395 m Bottom: 4095100.068903 m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System ’1984 (WGS ’1984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

  18. Geology of the platanares geothermal area, Departamento de Copan, Honduras

    USGS Publications Warehouse

    Heiken, G.; Ramos, N.; Duffield, W.; Musgrave, J.; Wohletz, K.; Priest, S.; Aldrich, J.; Flores, W.; Ritchie, A.; Goff, F.; Eppler, D.; Escobar, C.

    1991-01-01

    Platanares is located 16 km west of Santa Rosa de Copan, Honduras, along the Quebrada del Agua Caliente. The thermal manifestations are along faults in tuffs, tuffaceous sedimentary rocks, and lavas of the Padre Miguel Group. These tuffs are silicified near the faults, are fractured, and may provide the fracture permeability necessary for the hydrothermal system. Tuffs are overlain by a wedge of terrace gravels up to 60 m thick. Quaternary conglomerates of the Quebrada del Agua Caliente are cemented by silica sinter. The Platanares area contains numerous faults, all of which appear to be extensional. There are four groups of faults (N80/sup 0/E to N70/sup 0/W, N30/sup 0/ to 60/sup 0/W, N40/sup 0/ to 65/sup 0/E, and N00/sup 0/ to 05/sup 0/W). All hot springs at this site are located along faults that trend mostly northwest and north. Twenty-eight spring groups were described over an area of 0.2 km/sup 2/; half were boiling. Based on surface temperatures and flow rates, between 0.7 and 1.0 MW thermal energy is estimated for the area. The increased temperature of the stream flowing through the thermal area indicates that several megawatts of thermal energy are being added to the stream. We recommend that a dipole-dipole resistivity line be run along the Quebrada del Agua Caliente to identify zones of fracture permeability associated with buried faults and hot water reservoirs within those fault zones. A thermal gradient corehole should be drilled at Platanares to test temperatures, lithologies, and permeability of the hydrothermal system.

  19. Thermal modelling of the SE side of Mt. Amiata geothermal area, Italy

    NASA Astrophysics Data System (ADS)

    Bellani, S.; Borgna, A.; Brogi, A.; Gherardi, F.; Meccheri, M.; Liotta, D.

    2010-12-01

    Mount Amiata, a quiescent quaternary volcano located in Tuscany, central Italy, hosts a high enthalpy water-dominated geothermal field which has been exploited for electricity generation since the 60s’. The current Mt. Amiata power-stations installed capacity is about 88 MWe. A new geological study carried out in the south-eastern side of the Mt. Amiata area made available a wide set of integrated data which allowed the reconstruction of 1:10.000 scale geological sections. Two of the geological sections were chosen to carry out a 2-D thermal modelling using the HYDROTHERM computer code. The model domain extends over an area 10 (length) by 5 (thickness) km in both geological sections. Gridding specifications are based on the merging of downward extrapolation of the detailed surface geological survey, interpreted seismic profiles and data from deep exploratory geothermal wells located in the nearby geothermal field, which allow temperature control down to about 4 km. The geology was divided in up to nine rock units, according to the stratigraphy of the area. The numerical modeling was performed considering various boundary conditions, inner geometries and hydraulic permeabilities. The models were realized by means of unsteady forward simulations, under the assumptions of impervious and isothermal top and bottom boundaries, lateral adiabatic faces and variable internal physical properties. Several sets of simulations were carried out, with different bottom boundary temperatures and different hydraulic permeability and thermal conductivity values for the various layers. The aim was to compare the sensitivity of the numerical results to the variation of selected parameters. The effects on deep water circulation and temperature distribution of the several faults mapped in the area were also thoroughly investigated. The results indicate the present temperature distribution with depth in the SE areas of the Mt. Amiata area to be strongly dependent on the deep reservoir

  20. Geophysical reconnaissance of prospective geothermal areas on the Island of Hawaii using electrical methods

    SciTech Connect

    Kauahikaua, J.; Mattice, M.

    1981-12-01

    Resistivity data from several areas were compiled, analyzed, and interpreted in terms of possible geologic models. On the basis of this analysis alone, two areas have been ruled out for possible geothermal exploitation, two have been interpreted to have a moderate-temperature resource, and two have been interpreted to have a high-temperature resource. The two areas which have been ruled out are the Keaau and South Point areas. The Kawaihae area and the lower northwest rift zone of Hualalai appear to have anomalous resistivity structures which suggest a moderate-temperature resource in each of these areas. Finally, specific areas in the lower southwest and lower east rift zones of Kilaauea have been outlined as locations where high-temperature fluids may exist at depth.

  1. Geophysical reconnaissance of prospective geothermal areas on the island of Hawaii using electrical methods

    SciTech Connect

    Kauahikaua, J.; Mattice, M.

    1981-07-01

    Resistivity data from several areas were compiled, analyzed, and interpreted in terms of possible geologic models. On the basis of this analysis alone, two areas have been ruled out for possible geothermal exploitation, two have been interpreted to have a moderate-temperature resource, and two have been interpreted to have a high-temperature resource. The two areas which have been ruled out are the Keaau and South Point areas. The Kawaihae area and the lower northwest rift zone of Hualalai appear to have anomalous resistivity structures, which suggest a moderate-temperature resource in each of these areas. Finally, specific areas in the lower southwest and lower east rift zones of Kilauea have been outlined as locations where high-temperature fluids may exist at depth.

  2. Source processes of industrially-induced earthquakes at the Geysers geothermal area, California

    USGS Publications Warehouse

    Ross, A.; Foulger, G.R.; Julian, B.R.

    1999-01-01

    Microearthquake activity at The Geysers geothermal area, California, mirrors the steam production rate, suggesting that the earthquakes are industrially induced. A 15-station network of digital, three-component seismic stations was operated for one month in 1991, and 3,900 earthquakes were recorded. Highly-accurate moment tensors were derived for 30 of the best recorded earthquakes by tracing rays through tomographically derived 3-D VP and VP / VS structures, and inverting P-and S-wave polarities and amplitude ratios. The orientations of the P-and T-axes are very scattered, suggesting that there is no strong, systematic deviatoric stress field in the reservoir, which could explain why the earthquakes are not large. Most of the events had significant non-double-couple (non-DC) components in their source mechanisms with volumetric components up to ???30% of the total moment. Explosive and implosive sources were observed in approximately equal numbers, and must be caused by cavity creation (or expansion) and collapse. It is likely that there is a causal relationship between these processes and fluid reinjection and steam withdrawal. Compensated linear vector dipole (CLVD) components were up to 100% of the deviatoric component. Combinations of opening cracks and shear faults cannot explain all the observations, and rapid fluid flow may also be involved. The pattern of non-DC failure at The Geysers contrasts with that of the Hengill-Grensdalur area in Iceland, a largely unexploited water-dominated field in an extensional stress regime. These differences are poorly understood but may be linked to the contrasting regional stress regimes and the industrial exploitation at The Geysers.

  3. Evaluation of Seismicity Using Density Analysis of 2000-2015 Earthquakes in The West Coastal Zone of Anatolia (Turkey) And Its Correlation with Geothermal Areas

    NASA Astrophysics Data System (ADS)

    Bakak, Özde

    2016-10-01

    The purpose of the study is to evaluate the seismic activity using the density analysis methods (point density and Kernel density analysis) for 2000-2015 earthquake catalogue belonging to the study area surrounded by Qanakkale to the north, Fethiye to the south and Denizli (Buharkent) to the east, and also to apply its correlation with geothermal regions. The earthquake data, in total 6.675 earthquakes with M>3 magnitudes were obtained from DDA Catalogue of Prime Ministry Disaster & Emergency Management Authority (AFAD) official website. In this survey, data analysis and maps were prepared using ArcGIS (version_10.1) program. The analysis maps present (1) the intensity clustered earthquakes dominant in Sigacik and Gokova Gulfs, (2) regions which have high seismic risk were determined according to Buffer analysis for 2 km distance, (3) geothermal areas (21.4-153°C) in the west coastal zone of Anatolia were mapped, (4) regions the most affected by seismic activity for the last 15 years were detected from 2015 population data, and as latest (5) Seferihisar, Urla, Gulbahge, Demircili, Bodrum, and Datga provinces are identified as areas having high seismic activity for the last 15 years. Consequently, all analysis results were compared with the geothermal areas, and the review made that earthquake catalogue has not the relationship with hot regions and also these shocks triggered by active faults in this region using ArcGIS program. the author recommends that these regions should be investigated the earthquake sensitivity analysis in the near future.

  4. Modelling geothermal conditions in part of the Szczecin Trough - the Chociwel area

    NASA Astrophysics Data System (ADS)

    Miecznik, Maciej; Sowiżdżał, Anna; Tomaszewska, Barbara; Pająk, Leszek

    2015-09-01

    The Chociwel region is part of the Szczecin Trough and constitutes the northeastern segment of the extended Szczecin-Gorzów Synclinorium. Lower Jurassic reservoirs of high permeability of up to 1145 mD can discharge geothermal waters with a rate exceeding 250 m3/h and temperatures reach over 90°C in the lowermost part of the reservoirs. These conditions provide an opportunity to generate electricity from heat accumulated in geothermal waters using binary ORC (Organic Rankine Cycle) systems. A numerical model of the natural state and exploitation conditions was created for the Chociwel area with the use of TOUGH2 geothermal simulator (i.e., integral finite-difference method). An analysis of geological and hydrogeothermal data indicates that the best conditions are found to the southeast of the town of Chociwel, where the bottom part of the reservoir reaches 3 km below ground. This would require drilling two new wells, namely one production and one injection. Simulated production with a flow rate of 275 m3/h, a temperature of 89°C at the wellhead, 30°C injection temperature and wells being 1.2 km separated from each other leads to a small temperature drop and moderate requirements for pumping power over a 50 years' time span. The ORC binary system can produce at maximum 592.5 kW gross power with the R227ea found as the most suitable working fluid. Geothermal brine leaving the ORC system with a temperature c. 53°C can be used for other purposes, namely mushroom growing, balneology, swimming pools, soil warming, de-icing, fish farming and for heat pumps.

  5. Impacts of geothermal energy developments on hydrological environment in hot spring areas

    NASA Astrophysics Data System (ADS)

    Taniguchi, M.

    2015-12-01

    Water-energy nexus such as geothermal energy developments and its impacts on groundwater, river water, and coastal water is one of the key issues for the sustainable society. This is because the demand of both water and energy resources will be increasing in near future, and the tradeoff between both resources and conflict between stakeholders will be arisen. Geothermal power generation, hot springs heat power generation, and steam power generation, are developing in hot spring areas in Ring of Fire countries including Japan, as renewable and sustainable energy. Impacts of the wasted hot water after using hot springs heat and steam power generation on ecosystem in the rivers have been observed in Beppu, Oita prefecture, Japan. The number of the fish species with wasted hot water in the Hirata river is much less than that without wasted hot water in Hiyakawa river although the dominant species of tilapia was found in the Hirata river with wasted hot water. The water temperature in Hirata rive is increased by wasted hot water by 10 degree C. The impacts of the developments of steam power generations on hot spring water and groundwater in downstream are also evaluated in Beppu. The decreases in temperature and volume of the hot spring water and groundwater after the development are concerning. Stakeholder analysis related to hot spa and power generation business and others in Beppu showed common interests in community development among stakeholders and gaps in prerequisite knowledge and recognition of the geothermal resource in terms of economic/non-economic value and utilization as power generation/hot-spring. We screened stakeholders of four categories (hot spring resorts inhabitants, industries, supporters, environmentalists), and set up three communities consisting of 50 persons of the above categories. One remarkable result regarding the pros and cons of geothermal power in general terms was that the supporter count increased greatly while the neutralities count

  6. Alaska geothermal bibliography

    SciTech Connect

    Liss, S.A.; Motyka, R.J.; Nye, C.J.

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  7. The Hengill geothermal area, Iceland: variation of temperature gradients deduced from the maximum depth of seismogenesis

    USGS Publications Warehouse

    Foulger, G.R.

    1995-01-01

    Given a uniform lithology and strain rate and a full seismic data set, the maximum depth of earthquakes may be viewed to a first order as an isotherm. These conditions are approached at the Hengill geothermal area, S. Iceland, a dominantly basaltic area. The temperature at which seismic failure ceases for the strain rates likely at the Hengill geothermal area is determined by analogy with oceanic crust, and is about 650 ?? 50??C. The topographies of the top and bottom of the seismogenic layer were mapped using 617 earthquakes. The thickness of the seismogenic layer is roughly constant and about 3 km. A shallow, aseismic, low-velocity volume within the spreading plate boundary that crosses the area occurs above the top of the seismogenic layer and is interpreted as an isolated body of partial melt. The base of the seismogenic layer has a maximum depth of about 6.5 km beneath the spreading axis and deepens to about 7 km beneath a transform zone in the south of the area. -from Author

  8. The Geysers-Clear Lake geothermal area, California - an updated geophysical perspective of heat sources

    USGS Publications Warehouse

    Stanley, W.D.; Blakely, R.J.

    1995-01-01

    The Geysers-Clear Lake geothermal area encompasses a large dry-steam production area in The Geysers field and a documented high-temperature, high-pressure, water-dominated system in the area largely south of Clear Lake, which has not been developed. An updated view is presented of the geological/geophysical complexities of the crust in this region in order to address key unanswered questions about the heat source and tectonics. Forward modeling, multidimensional inversions, and ideal body analysis of the gravity data, new electromagnetic sounding models, and arguments made from other geophysical data sets suggest that many of the geophysical anomalies have significant contributions from rock property and physical state variations in the upper 7 km and not from "magma' at greater depths. Regional tectonic and magmatic processes are analyzed to develop an updated scenario for pluton emplacement that differs substantially from earlier interpretations. In addition, a rationale is outlined for future exploration for geothermal resources in The Geysers-Clear Lake area. -from Authors

  9. Depositional setting, structural style, and sandstone distribution in three geopressured geothermal areas, Texas Gulf Coast

    SciTech Connect

    Winker, C.D.; Morton, R.A.; Ewing, T.E.; Garcia, D.D.

    1983-01-01

    Three areas in the Texas Gulf Coastal Plain were studied using electric logs and seismic-reflection data to interpret their depositional and structural history and to compare their potential as geopressured-geothermal reservoirs. The Cuero study area, on the lower Wilcox (upper Paleocene) growth-fault trend, is characterized by closely and evenly spaced, subparallel, down-to-the-basin growth faults, relatively small expansion ratios, and minor block rotation. Distributary-channel sandstones in the geopressured lower Wilcox Group of the South Cook fault block appear to be the best geothermal aquifers in the Cuero area. The Blessing study area, on the lower Frio (Oligocene) growth-fault trend, shows wider and more variable fault spacing and much greater expansion ratios and block rotation, particularly during early Frio time. Thick geopressured sandstone aquifers are laterally more extensive in the Blessing area than in the Cuero area. The Pleasant Bayou study area, like the Blessing area, is on the Frio growth-fault trand, and its early structural development was similar rapid movement of widely spaced faults resulted in large expansion ratios and major block rotation. However, a late-stage pattern of salt uplift and withdrawal complicated the structural style. Thick geopressured lower Frio sandstone aquifers are highly permeable and laterally extensive, as in the Blessing area. In all three areas, geopressured aquifers were created where early, rapid movement along down-to-the-basin growth faults juxtaposed shallow-water sands against older shales, probably deposited in slope environments. Major transgressions followed the deposition of reservoir sands and probably also influenced the hydraulic isolation that allowed the build up of abnormal pressures. 26 refs., 49 figs., 8 tabs.

  10. [Hydrogen and oxygen isotopes of lake water and geothermal spring water in arid area of south Tibet].

    PubMed

    Xiao, Ke; Shen, Li-Cheng; Wang, Peng

    2014-08-01

    The condition of water cycles in Tibet Plateau is a complex process, and the hydrogen and oxygen isotopes contain important information of this process. Based on the analysis of isotopic composition of freshwater lake, saltwater lake and geothermal water in the southern Tibetan Plateau, this study investigated water cycling, composition and variation of hydrogen and oxygen isotopes and the influencing factors in the study area. The study found that the mean values of delta18O and deltaD in Daggyaima lake water (-17.0 per thousand for delta18O and -138. 6 per thousand for deltaD), Langcuo lake water (-6.4 per thousand for delta18O and -87.4 per thousand for deltaD) and Dagejia geothermal water (-19.2 per thousand for delta18 and -158.2 per thousand for deltaD) all showed negative delta18O and deltaD values in Tibetan Plateau by the influence of altitude effects. Lake water and geothermal water were influenced by evaporation effects in inland arid area, and the slope of evaporation line was less than 8. Deuterium excess parameters of lake water and geothermal water were all negative. The temperature of geothermal reservoirs in Dagejia geothermal field was high,and oxygen shift existed in the relationship of hydrogen and oxygen isotopes.

  11. Geothermal Energy.

    ERIC Educational Resources Information Center

    Nemzer, Marilyn; Page, Deborah

    This curriculum unit describes geothermal energy in the context of the world's energy needs. It addresses renewable and nonrenewable energy sources with an in-depth study of geothermal energy--its geology, its history, and its many uses. Included are integrated activities involving science, as well as math, social studies, and language arts.…

  12. Mineral and geothermal resource potential of Wild Cattle Mountain and Heart Lake roadless areas Plumas, Shasta, and Tehama Counties, California

    SciTech Connect

    Muffler, L.J.P.; Clynne, M.A.; Cook, A.L.

    1982-01-01

    The results of geological, geochemical, and geophysical surveys in Wild Cattle Mountain and Heart Lake Roadless Areas indicate no potential for metallic or non-metallic mineral resources in the areas and no potential for coal or petroleum energy resources. However, Wild Cattle Mountain Roadless Area and part of Heart Lake Roadless Area lie in Lassen Known Geothermal Resources Area, and much of the rest of Heart Lake Roadless Area is subject to non-competitive geothermal lease applications. Both areas are adjacent to Lassen Volcanic National Park, which contains extensive areas of fumaroles, hot springs, and hydrothermally altered rock; voluminous silicic volcanism occurred here during late Pleistocene and Holocene time. Geochemical data and geological interpretation indicate that the thermal manifestations in the Park and at Morgan and Growler Hot Springs (immediately west of Wild Cattle Mountain Roadless Area) are part of the same large geothermal system. Consequently, substantial geothermal resources are likely to be discovered in Wild Cattle Mountain Roadless Area and cannot be ruled out for Heart Lake Roadless Area.

  13. Federal Assistance Program Quarterly Project Progress Report. Geothermal Energy Program: Information Dissemination, Public Outreach, and Technical Analysis Activities. Reporting Period: January 1 - March 31, 2001 [Final report

    SciTech Connect

    Lund, John W.

    2002-03-22

    The final report of the accomplishments of the geothermal energy program: information dissemination, public outreach and technical analysis activities by the project team consisting of the Geo-Heat Center, Geothermal Resources Council, Geothermal Education Office, Geothermal Energy Association and the Washington State University Energy Program.

  14. Design of a geothermal monitoring network in a coastal area and the evaluation system

    NASA Astrophysics Data System (ADS)

    Ohan Shim, Byoung; Lee, Chulwoo; Park, Chanhee

    2016-04-01

    In Seockmodo Island (area of 48.2 km2) located at the northwest of South Korea, a renewable energy development project to install photovoltaic 136 kW and geothermal 516.3 kW is initiated. Since the 1990s, more than 20 deep geothermal wells for hot springs, greenhouse and aquaculture have been developed along coastal areas. The outflow water of each site has the pumping capacity between 300 and 4,800 m3/day with the salinity higher than 20,000 mg/l, and the maximum temperature shows 70 ?C. Because of the required additional well drillings, the increased discharge rate can cause serious seawater intrusion into freshwater aquifers, which supply groundwater for drinking and living purposes from 210 wells. In order to manage the situation, advanced management skills are required to maintain the balance between geothermal energy development and water resources protection. We designed real-time monitoring networks with monitoring stations for the sustainable monitoring of the temperature and salinity. Construction of borehole temperature monitoring for deep and shallow aquifer consists with the installation of automated temperature logging system and cellular telemetry for real-time data acquisition. The DTS (distributed temperature sensing) system and fiber optic cables will be installed for the logging system, which has enough temperature resolution and accuracy. The spatial distribution and the monitoring points can be determined by geological and hydrological situations associated with the locations of current use and planned facilities. The evaluation of the temperature and salinity variation will be conducted by the web-based monitoring system. The evaluation system will be helpful to manage the balance between the hot water development and the fresh water resources conservation.

  15. Geothermal direct-heat utilization assistance. Federal Assistance Program, Quarterly project progress report, October--December 1994

    SciTech Connect

    Not Available

    1994-12-31

    The report summarizes activities of the Geo-Heat Center (GHC) at Oregon Institute of Technology for the first quarter of Fiscal Year 1995. It describes contacts with parties during this period related to assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, resources and equipment. Research is also being conducted on geothermal energy cost evaluation, low-temperature geothermal resource assessment, use of silica waste from the Cerro Prieto geothermal field as construction materials and geothermal heat pumps. Outreach activities include the publication of a quarterly Bulletin on direct heat applications and dissemination of information on low-temperature geothermal resources and utilization.

  16. Geotherm: the U.S. geological survey geothermal information system

    USGS Publications Warehouse

    Bliss, J.D.; Rapport, A.

    1983-01-01

    GEOTHERM is a comprehensive system of public databases and software used to store, locate, and evaluate information on the geology, geochemistry, and hydrology of geothermal systems. Three main databases address the general characteristics of geothermal wells and fields, and the chemical properties of geothermal fluids; the last database is currently the most active. System tasks are divided into four areas: (1) data acquisition and entry, involving data entry via word processors and magnetic tape; (2) quality assurance, including the criteria and standards handbook and front-end data-screening programs; (3) operation, involving database backups and information extraction; and (4) user assistance, preparation of such items as application programs, and a quarterly newsletter. The principal task of GEOTHERM is to provide information and research support for the conduct of national geothermal-resource assessments. The principal users of GEOTHERM are those involved with the Geothermal Research Program of the U.S. Geological Survey. Information in the system is available to the public on request. ?? 1983.

  17. Geotherm: the U.S. geological survey geothermal information system

    NASA Astrophysics Data System (ADS)

    Bliss, J. D.; Rapport, A.

    GEOTHERM is a comprehensive system of public databases and software used to store, locate, and evaluate information on the geology, geochemistry, and hydrology of geothermal systems. Three main databases address the general characteristics of geothermal wells and fields, and the chemical properties of geothermal fluids; the last database is currently the most active. System tasks are divided into four areas: (1) data acquisition and entry, involving data entry via word processors and magnetic tape; (2) quality assurance, including the criteria and standards handbook and front-end data-screening programs; (3) operation, involving database backups and information extraction; and (4) user assistance, preparation of such items as application programs, and a quarterly newsletter. The principal task of GEOTHERM is to provide information and research support for the conduct of national geothermal-resource assessments. The principal users of GEOTHERM are those involved with the Geothermal Research Program of the U.S. Geological Survey. Information in the system is available to the public on request.

  18. Geothermal direct-heat utilization assistance. Quarterly report, October--December 1996

    SciTech Connect

    1996-12-31

    This report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-97. It describes 174 contracts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics and resources. Research activities are summarized on greenhouse peaking. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

  19. Sensitivity of predicted scaling and permeability in Enhanced Geothermal Systems to Thermodynamic Data and Activity Models

    NASA Astrophysics Data System (ADS)

    Hingerl, Ferdinand F.; Wagner, Thomas; Kulik, Dmitrii A.; Kosakowski, Georg; Driesner, Thomas; Thomsen, Kaj

    2010-05-01

    A consortium of research groups from ETH Zurich, EPF Lausanne, the Paul Scherrer Institut and the University of Bonn collaborates in a comprehensive program of basic research on key aspects of the Enhanced Geothermal Systems (EGSs). As part of this GEOTHERM project (www.geotherm.ethz.ch), we concentrate on the fundamental investigation of thermodynamic models suitable for describing fluid-rock interactions at geothermal conditions. Predictions of the fluid-rock interaction in EGS still face several major challenges. Slight variations in the input thermodynamic and kinetic parameters may result in significant differences in the predicted mineral solubilities and stable assemblage. Realistic modeling of mineral precipitation in turn has implications onto our understanding of the permeability evolution of the geothermal reservoir, as well as the scaling in technical installations. In order to reasonably model an EGS, thermodynamic databases and activity models must be tailored to geothermal conditions. We therefore implemented in GEMS code the Pitzer formalism, which is the standard model used for computing thermodynamic excess properties of brines at elevated temperatures and pressures. This model, however, depends on a vast amount of interaction parameters, which are to a substantial extend unknown. Furthermore, a high order polynomial temperature interpolation makes extrapolation unreliable if not impossible. As an alternative we additionally implemented the EUNIQUAC activity model. EUNIQUAC requires fewer empirical fit parameters (only binary interaction parameters needed) and uses simpler and more stable temperature and pressure extrapolations. This results in an increase in computation speed, which is of crucial importance when performing coupled long term simulations of geothermal reservoirs. To achieve better performance under geothermal conditions, we are currently partly reformulating EUNIQUAC and refitting the existing parameter set. First results of the

  20. Geothermal Geodatabase for Rico Hot Springs Area and Lemon Hot Springs, Dolores and San Miguel Counties, Colorado

    DOE Data Explorer

    Zehner, Richard

    2012-11-01

    Geothermal Geodatabase for Rico Hot Springs Area and Lemon Hot Springs, Dolores and San Miguel Counties, Colorado By Richard “Rick” Zehner Geothermal Development Associates Reno Nevada USA For Flint Geothermal LLC, Denver Colorado Part of DOE Grant EE0002828 2013 This is an ESRI geodatabase version 10, together with an ESRI MXD file version 10.2 Data is in UTM Zone 13 NAD27 projection North boundary: approximately 4,215,000 South boundary: approximately 4,160,000 West boundary: approximately 216,000 East boundary: approximately 245,000 This geodatabase was built to cover several geothermal targets developed by Flint Geothermal in 2012 during a search for high-temperature systems that could be exploited for electric power development. Several of the thermal springs have geochemistry and geothermometry values indicative of high-temperature systems. In addition, the explorationists discovered a very young Climax-style molybdenum porphyry system northeast of Rico, and drilling intersected thermal waters at depth. The datasets in the geodatabase are a mixture of public domain data as well as data collected by Flint Geothermal, now being made public. It is assumed that the user has internet access, for the mxd file accesses ESRI’s GIS servers. Datasets include: 1. Structural data collected by Flint Geothermal 2. Point information 3. Mines and prospects from the USGS MRDS dataset 4. Results of reconnaissance shallow (2 meter) temperature surveys 5. Air photo lineaments 6. Areas covered by travertine 7. Groundwater geochemistry 8. Land ownership in the Rico area 9. Georeferenced geologic map of the Rico Quadrangle, by Pratt et al. 10. Various 1:24,000 scale topographic maps

  1. Calc-silicate mineralization in active geothermal systems

    SciTech Connect

    Bird, D.K.; Schiffman, P.; Elders, W.A.; Williams, A.E.; McDowell, S.D.

    1983-01-01

    The detailed study of calc-silicate mineral zones and coexisting phase relations in the Cerro Prieto geothermal system were used as examples for thermodynamic evaluation of phase relations among minerals of variable composition and to calculate the chemical characteristics of hydrothermal solutions compatible with the observed calc-silicate assemblages. In general there is a close correlation between calculated and observed fluid compositions. Calculated fugacities of O{sub 2} at about 320{degrees}C in the Cerro Prieto geothermal system are about five orders of magnitude less than that at the nearby Salton Sea geothermal system. This observation is consistent with the occurrence of Fe{sup 3+} rich epidotes in the latter system and the presence of prehnite at Cerro Prieto.

  2. The geothermal area of El Pilar-Casanay, State of Sucre, Venezuela: Geochemical exploration and model

    SciTech Connect

    D'Amore, F.; Gianelli, G.; Corazza, E. . Istituto Internazionale Ricerche Geotermiche)

    1994-06-01

    A geochemical survey was carried out in the El Pilar-Casanay area, State of Sucre, Venezuela, in order to ascertain its geothermoelectric potential. The area is characterized by many natural manifestations with temperatures in the range 80--100 C. The area investigated seems capable of producing high-enthalpy geothermal fluids; a deep reservoir is inferred, composed of a medium salinity (< 5,000 ppm) and neutral brine, with computed temperatures between 250 and 300 C, and with a high CO[sub 2] partial pressure. Second shallower reservoir is assumed to exist, with a temperature of the order of 200--220 C. The deep reservoir is shown to be liquid-dominated, while water and steam occupy the shallow one. The piezometric level (elevation 150 m) regulates the areal distribution of water springs and fumaroles. A partial self-sealing (mineral alteration) along outflows allows accumulation of hot fluids, while recharge is from local meteoric water.

  3. Relationship of geological and geothermal field properties: Midcontinent area, USA, an example

    USGS Publications Warehouse

    Forster, A.; Merriam, D.F.; Brower, J.C.

    1993-01-01

    negative or slightly positive. These results are clearly shown by the cluster analysis and the principal components. Considering a close relationship between temperature and thermal conductivity of the sediments as observed for most of the Midcontinent area and relatively homogeneous heat-flow density conditions for the study area these results support the following assumptions: (1) undifferentiated geothermal gradients, computed from temperatures of different depth intervals and differing sediment properties, cannot contribute to an improved understanding of the temperature structure and its controls within the sedimentary cover, and (2) the quantitative approach of revealing such relations needs refined datasets of temperature information valid for the different depth levels or stratigraphic units. ?? 1993 International Association for Mathematical Geology.

  4. Hydrothermal models of the Perth metropolitan area, Western Australia: implications for geothermal energy

    NASA Astrophysics Data System (ADS)

    Schilling, Oliver; Sheldon, Heather A.; Reid, Lynn B.; Corbel, Soazig

    2013-05-01

    Hydrothermal simulations are used to provide insight into the subsurface thermal regime of the Perth metropolitan area (PMA) in Western Australia. High average permeabilities and estimated fluid flow rates in shallow aquifers of the PMA suggest that advection and convection may occur in these aquifers. These processes are simulated, using a new geological model of the PMA to constrain the geometry of aquifers, aquitards and faults. The results show that advection has a strong influence on subsurface temperature, especially in the north of the PMA, where aquifer recharge creates an area of anomalously low temperature. Convection may be important, depending on the permeability of the Yarragadee Aquifer. If convection occurs, it creates thermal highs and lows with a spacing of approximately 5 km. Some of these thermal anomalies migrate over geological time due to coupling between advection and convection, but they are stationary on human timescales. Fault permeability influences the pattern of convection. Advection and convection cause variations in the geothermal gradient which cannot be predicted by conductive models; therefore, these processes should be considered in any model that is used for assessment of geothermal resources in the PMA.

  5. Geologic framework and hot dry rock geothermal potential of the Castle Dome area, Yuma County, Arizona

    SciTech Connect

    Gutmann, J.T.

    1981-02-01

    The Castle Dome Mountains and surrounding ranges constitute a voluminous pile of silicic volcanic rocks within the Basin and Range province of southwestern Arizona. Previously reported as Cretaceous and Quaternary in age, these volcanics all are of late Oligocene to early Miocene age as indicated by five new K-Ar dates. Reconnaissance field studies indicate that the volcanic section locally has undergone large rotations that contrast with the usual structural style of the Basin and Range and resemble the thin-skinned rotational tectonics documented for earlier, mid-Tertiary extensional deformation in ranges to the north and northeast. Significant geothermal potential of the Castle Dome area is suggested by a shallow depth to the Curie isotherm and by the apparent presence of a good electrical conductor at anomalously shallow depth in the crust. Warm wells exist in the area and Shearer (1979) reported a geothermal gradient of about 70/sup 0/C/km in a dry well near the center of the gravity low. Radiogenic heat production in the silicic batholith inferred above constitutes a reasonable candidate for a shallow regional heat source.

  6. Imperial County geothermal development. Quarterly report, April 1, 1980-June 30, 1981

    SciTech Connect

    Not Available

    1981-01-01

    Three areas are reported: Geothermal Administration, Geothermal Planning; and other Geothermal Activities. Geothermal Administration addresses the status of the Imperial Valley Environmental Project (IVEP) transfer, update of the Geothermal Resource Center, and findings of Geothermal field inspections. Field inspections will cover the four new wells drilled by Magma at the Salton Sea in preparation for 28 MW power plant, the progress at Sperry at East Mesa, and the two on-line power plants in East Mesa and North Brawley. Evaluation of cooperative efforts will cover the Geothermal Subsidence Detection Network Resurvey, Master EIR for the Salton Sea and the Annual Imperial County Geothermal meeting. The status of Geothermal development throughout the County will cover existing proposed facilities. The summary of the Geothermal meeting (Appendix A) will also provide the status of several projects. Geothermal Planning addresses the EIR Notice of Exemption from CEQA, progress on the Master EIR for the Salton Sea, and the EIR for Phillips Petroleum for 6 exploratory wells in the Truckhaven area. Other Geothermal Activity addresses the Department of Energy Region IX meeting hosted by Imperial County, the Annual Imperial County Geothermal meeting, Class II-1 geothermal hazardous waste disposal siting study, and Imperial County Geothermal Direct Heat Study.

  7. Reservoir depletion at The Geysers geothermal area, California, shown by four-dimensional seismic tomography

    USGS Publications Warehouse

    Gunasekera, R.C.; Foulger, G.R.; Julian, B.R.

    2003-01-01

    Intensive geothermal exploitation at The Geysers geothermal area, California, induces myriads of small-magnitude earthquakes that are monitored by a dense, permanent, local seismometer network. Using this network, tomographic inversions were performed for the three-dimensional Vp and Vp/Vs structure of the reservoir for April 1991, February 1993, December 1994, October 1996, and August 1998. The extensive low-Vp/Vs anomaly that occupies the reservoir grew in strength from a maximum of 9% to a maximum of 13.4% during the 7-year study period. This is attributed to depletion of pore liquid water in the reservoir and replacement with steam. This decreases Vp by increasing compressibility, and increases Vs because of reduction in pore pressure and the drying of argillaceous minerals, e.g., illite, which increase the shear modulus. These effects serendipitously combine to lower Vp/Vs, resulting in a strong overall effect that provides a convenient tool for monitoring reservoir depletion. Variations in the Vp and Vs fields indicate that water depletion is the dominant process in the central part of the exploited reservoir, and pressure reduction and mineral drying in the northwest and southeast parts of the reservoir. The rate at which the Vp/Vs anomaly grew in strength in the period 1991-1998 suggests most of the original anomaly was caused by exploitation. Continuous monitoring of Vp, Vs, and Vp/Vs is an effective geothermal reservoir depletion monitoring tool and can potentially provide information about depletion in parts of the reservoir that have not been drilled.

  8. Seasonal and geothermal production variations in concentrations of He and CO2 in soil gases, Roosevelt Hot Springs Known Geothermal Resource Area, Utah, U.S.A.

    USGS Publications Warehouse

    Hinkle, M.E.

    1991-01-01

    To increase understanding of natural variations in soil gas concentrations, CO2, He, O2 and N2 were measured in soil gases collected regularly for several months from four sites at the Roosevelt Hot Springs Known Geothermal Resource Area, Utah. Soil temperature, air temperature, per cent relative humidity, barometric pressure and amounts of rain and snowfall were also monitored to determine the effect of meteorological parameters on concentrations of the measured gases. Considerable seasonal variation existed in concentrations of CO2 and He. The parameters that most affected the soil-gas concentrations were soil and air temperatures. Moisture from rain and snow probably affected the soil-gas concentrations also. However, annual variations in meteorological parameters did not appear to affect measurements of anomalous concentrations in samples collected within a time period of a few days. Production from some of the geothermal wells probably affected the soil-gas concentrations. ?? 1990.

  9. Heating the New Mexico Tech Campus with geothermal energy. Final report, July 1, 1978-October 31, 1979

    SciTech Connect

    LeFebre, V.; Miller, A.

    1980-01-01

    An area between the base of Socorro Peak and the New Mexico Tech Campus (located in central New Mexico) has been proposed as a site for geothermal exploratory drilling. The existing site environment is summarized, a program for site monitoring is proposed, impacts of geothermal production and reinjection are listed, and problems associated with geothermal development are examined. The most critical environmental impact is the increased seismic activity that may be associated with geothermal fluid migration resulting from geothermal production and reinjection.

  10. An Alternative Approach to Estimating the Geothermal Potential of an Area: Applications to the Northeast and Elsewhere

    NASA Astrophysics Data System (ADS)

    Rhodes, J. M.; Koteas, C.; Mabee, S. B.

    2011-12-01

    Conventionally, heat flow data is the prime parameter for estimating the potential of Enhanced Geothermal Systems (EGS). From this, together with knowledge, or assumptions, regarding the stratigraphy, heat production and thermal conductivity, it is possible to calculate temperature - depth profiles and assess the geothermal potential of an area. According to conventional wisdom, Massachusetts (and most of the northeastern U.S. and eastern Canada) has little or no geothermal resources. This is based on the low values of very sparse heat flow measurements from mainly shallow wells. There may, however, be local pockets with geothermal potential missed by the regional heat flow coverage. For example, granite bodies constitute about 30% of the bedrock of Massachusetts and are abundant throughout New England. We suspect that some granites may provide potential local geothermal resources, especially when covered by thick sediments. This is because granites and meta-granites typically contain more of the heat-producing elements K, U, Th than other crustal rocks. We have therefore adopted an alternative approach for estimating the geothermal potential of an area. We are systematically sampling these granite bodies and measuring the concentrations of their heat-producing elements and their density, in order to determine their heat production. Not all granites are created equal and some are potentially hotter than others. Then, with measurements of thermal conductivity and knowledge, or assumptions, about stratigraphy and heat flow from the lower crust and mantle, we can estimate temperature-depth profiles and the geothermal potential of the area. A useful outcome of this approach is an estimate of heat flow, which could serve as a test of the method if appropriate targets are discovered. To date, we estimate that the temperatures of most granites at depths between 4 and 6 km range from 70 to 110 degrees C (see Koteas et al., this session). These are possible low

  11. An evaluation of the geothermal potential of the Tecuamburro Volcano area of Guatemala

    SciTech Connect

    Heiken, G.; Duffield, W.

    1990-09-01

    Radiometric ages indicate that the Tecuamburro Volcano and three adjacent lava domes grew during the last 38,300 years, and that a 360-m-wide phreatic crater, Laguna Ixpaco, was formed near the base of these domes about 2900 years ago. Laguna Ixpaco is located within the Chupadero crater, from which pyroxene pumice deposits were erupted 38,300 years ago. Thus, the likelihood is great for a partly molten or solid-but-still-hot near-surface intrusion beneath the area. Fumaroles and hot springs issue locally from the Tecuamburro volcanic complex and near Laguna Ixpaco. Analyses of gas and fluid samples from these and other nearby thermal manifestations yield chemical-geothermometer temperatures of about 150{degree} to 300{degree}C, with the highest temperatures at Ixpaco. The existence of a commercial-grade geothermal reservoir beneath the Ixpaco area seems likely. 84 refs., 70 figs., 12 tabs.

  12. Chemical analyses of ground water related to geothermal investigations in the Teton River area, eastern Idaho

    USGS Publications Warehouse

    Crosthwaite, E.G.

    1979-01-01

    Water samples from 31 wells and springs in eastern Idaho and western Wyoming were collected to help evaluate the potential geothermal resources in the Teton River area. Water analyses included anions and cations, oxygen-18, deuterium, and several minor elements. Actual temperature of the thermal waters ranged from 23 to 49C. Estimated aquifer temperatures, as derived from geochemical thermometers, ranged from 45 to 145C based on sodium-potassium-calcium ratios. Using the cation thermometer, two analyses indicated aquifer temperatures lower than actual measured temperatures. Using a mixing model method, estimated temperatures ranged from 205 to 320C, the higher being of questionable value. The different methods used showed little correlation. Based on isotope data, the warm waters may be of local meteoric origin and not heated enough to react significantly with aquifer rocks; or, they originated as precipitation at high altitude and great distance from the area. (Woodard-USGS)

  13. Flora of the Mayacmas Mountains. [Listing of 679 species in the Geysers Geothermal Resource area

    SciTech Connect

    Neilson, J.A.

    1981-09-01

    This flora describes the plants that occur within the Mayacmas Mountain Range of northern California. It is the result of ten years of environmental assessment by the author in the Geysers Geothermal Resource area, located in the center of the Mayacmas Range. The flora includes notes on plant communities and ecology of the area, as well as habitat and collection data for most of the 679 species covered. Altogether 74 families, 299 genera and 679 species are included in the flora. The work is divided into eight subdivisions: trees; shrubs; ferns and fern allies; aquatic plants; tules, sedges, and rushes; lilies and related plants; dicot herbs; and grasses. Within each subdivision, family, genera and species are listed alphabetically. Keys are provided at the beginning of each subdivision. A unique combination of physical, environmental and geologic factors have resulted in a rich and diverse flora in the Mayacmas. Maps have been provided indicating known locations for species of rare or limited occurrence.

  14. Geothermal Field Development in the European Community Objectives, Achievements and Problem Areas

    SciTech Connect

    Ungemach, Pierre

    1983-12-15

    Achievements and problem areas are reviewed with respect to various engineering implications of geothermal field development in the European Community (EC). Current and furture development goals address three resource settings. (a) low enthalpy sources (30-150{degrees}C), an outlook common to all Member states as a result of hot water aquifers flowing in large sedimentary units with normal heat flow, widespread thoughout the EC; (b) high enthalpy sources (<150{degrees}C) in areas of high heat flow which, as a consequence of the geodynamics of the Eurasian plate, are limited to Central and South-West Italy and to Eastern Greece; (c) hot dry rocks (HDR), whose potential for Europe, and also the difficulties in implementing the heat mining concept, are enormous. A large scale experiment conducted at medium depth in Cornwall (UK) proves encouraging though. It has provided the right sort of scientific inputs to the understanding of the mechanics of anisotropic brittle basement rocks.

  15. Industrially induced changes in Earth structure at the geysers geothermal area, California

    USGS Publications Warehouse

    Foulger, G.R.; Grant, C.C.; Ross, A.; Julian, B.R.

    1997-01-01

    Industrial exploitation is causing clearly-measurable changes in Earth structure at The Geysers geothermal area, California. Production at The Geysers peaked in the late 1980s at ???3.5 ?? 103 kg s-1 of steam and 1800 MW of electricity. It subsequently decreased by about 10% per year [Barker et al., 1992] because of declining reservoir pressure. The steam reservoir coincides with a strong negative anomaly (???0.16, ???9%) in the compressional-to-shear seismic wave speed ratio vP/vS, consistent with the expected effects of low-pressure vapor-phase pore fluid [Julian et al., 1996]. Between 1991 and 1994 this anomaly increased in amplitude by up to about 0.07 (???4%). This is consistent with the expected effects of continued pressure reduction and conversion of pore water to steam as a result of exploitation. These unique results show that vP/vS tomography can easily detect saturation changes caused by exploitation of reservoirs, and is a potentially valuable technique for monitoring environmental change. They also provide geophysical observational evidence that geothermal energy is not a renewable energy source.

  16. Three-dimensional Q -1 model of the Coso Hot Springs Known Geothermal Resource Area

    NASA Astrophysics Data System (ADS)

    Young, Chi-Yuh; Ward, Ronald W.

    1980-05-01

    Observations of teleseismic P waves above geothermal systems exhibit travel time delays and anomalously high seismic attenuation, which is extremely useful in estimating the thermal regime and the potential of the system. A regional telemetered network of sixteen stations was operated by the U.S. Geological Survey in the Coso Hot Springs Known Geothermal Resources Area (KGRA) for such studies from September 1975 to October 1976. Subsequently, they deployed a portable Centipede array of 26 three-component stations near the center of the anomaly. The seismograms of 44 events recorded by the telemetered array and nine events by the Centipede array were analyzed using the reduced spectral ratio technique to determine the differential attenuation factor δt* for the events recorded with the highest signal-to-noise ratio. The δt* variation observed across the Coso Hot Springs KGRA were small (<0.2 s). A three-dimensional generalized linear inversion of the δt* observations was performed using a three-layer model. A shallow zone of high attenuation exists within the upper 5 km in a region bounded by Coso Hot Springs, Devils Kitchen, and Sugarloaf Mountain probably corresponding to a shallow vapor liquid mixture or `lossy' near surface lithology. No zones of significantly high attenuation occur between 5- and 12- km depth. Between the depth of 12-20 km a thick zone of high attenuation (Q <50) exists, offset toward the east from the surface anomaly.

  17. Seismic Activity at tres Virgenes Volcanic and Geothermal Field

    NASA Astrophysics Data System (ADS)

    Antayhua, Y. T.; Lermo, J.; Quintanar, L.; Campos-Enriquez, J. O.

    2013-05-01

    The volcanic and geothermal field Tres Virgenes is in the NE portion of Baja California Sur State, Mexico, between -112°20'and -112°40' longitudes, and 27°25' to 27°36' latitudes. Since 2003 Power Federal Commission and the Engineering Institute of the National Autonomous University of Mexico (UNAM) initiated a seismic monitoring program. The seismograph network installed inside and around the geothermal field consisted, at the beginning, of Kinemetrics K2 accelerometers; since 2009 the network is composed by Guralp CMG-6TD broadband seismometers. The seismic data used in this study covered the period from September 2003 - November 2011. We relocated 118 earthquakes with epicenter in the zone of study recorded in most of the seismic stations. The events analysed have shallow depths (≤10 km), coda Magnitude Mc≤2.4, with epicentral and hypocentral location errors <2 km. These events concentrated mainly below Tres Virgenes volcanoes, and the geothermal explotation zone where there is a system NW-SE, N-S and W-E of extensional faults. Also we obtained focal mechanisms for 38 events using the Focmec, Hash, and FPFIT methods. The results show normal mechanisms which correlate with La Virgen, El Azufre, El Cimarron and Bonfil fault systems, whereas inverse and strike-slip solutions correlate with Las Viboras fault. Additionally, the Qc value was obtained for 118 events. This value was calculated using the Single Back Scattering model, taking the coda-waves train with window lengths of 5 sec. Seismograms were filtered at 4 frequency bands centered at 2, 4, 8 and 16 Hz respectively. The estimates of Qc vary from 62 at 2 Hz, up to 220 at 16 Hz. The frequency-Qc relationship obtained is Qc=40±2f(0.62±0.02), representing the average attenuation characteristics of seismic waves at Tres Virgenes volcanic and geothermal field. This value correlated with those observed at other geothermal and volcanic fields.

  18. Low Temperature Geothermal Resource Evaluation of the Moses Lake-Ritzville-Connell Area, Washington

    SciTech Connect

    Widness, Scott

    1983-11-01

    The study area is located in portions of Adams, Grant, Lincoln, and Franklin counties of eastern Washington. The area is representative of a complex stratigraphic and geohydrologic system within the basalt flows of the Columbia River Basalt Group. The regional piezometric surface and stratigraphic units dip towards the southwest. Fluid temperature data were collected by three different agencies. The Geological Engineering Section (WSU) at Washington State University, runs a continuous fluid temperature (FT) log as part of a complete suite of geophysical logs. The US Geological Survey (USGS) runs a continuous fluid FT log in conjunction with caliper and natural-gamma logs. Southern Methodist University (SMU) and the Washington State Department of Natural Resources, Division of Geology and Earth Resources (DNR), have cooperated in gathering FT data. The DNR-SMU data were collected by taking temperature measurements at 5 m intervals. Bottom-hole temperatures (BHT) and bottom-hole depths (BHD) of selected wells in the study area are given in table 2. Some of the BHT data in table 2 may vary from those previously reported by WSU. These discrepancies are the result of changes in the calibration method of the FT tool. A technique developed by Giggane (1982) was used to determine the geothermal gradients within the area. A least squares linear regression analysis of the relationship between the BHT and BHD was used to determine the geothermal gradient of a given well data group (WDG). Well data groups were selected on the premises of geographic proximity, position within the regional groundwater flow system, land slope azimuth, and land slope dip. Some data points have been excluded from the linear regression analysis on the basis of factors such as duplicate logging of the same hole, down-hole flow, holes not logged to total depth, and questionable FT tool responses.

  19. The nature of magmatism at Palinpinon geothermal field, Negros Island, Philippines: implications for geothermal activity and regional tectonics

    NASA Astrophysics Data System (ADS)

    Rae, Andrew J.; Cooke, David R.; Phillips, David; Zaide-Delfin, Maribel

    2004-01-01

    The Palinpinon geothermal field, Negros Island, Philippines is a high-temperature, liquid-dominated geothermal system in an active island-arc volcanic setting. This paper presents a regional context for the Palinpinon geology, discusses the petrogenetic evolution of magmatism in the district and assesses the genetic relationships between intrusion and geothermal circulation. The oldest rock formation, the Lower Puhagan Volcanic Formation (Middle Miocene), is part of a volcanic sequence that is traceable throughout the Visayas region and is related to subduction of the Sulu Sea oceanic basin in a southeasterly direction beneath the Sulu arc. Late Miocene to Early Pliocene times mark a period of regional subsidence and marine sedimentation. A thick sequence of calcareous sediments (Okoy Formation) was deposited during this period. Magmatism in Early Pliocene to Recent times coincided with commencement of subduction at the Negros-Sulu Arc. This produced basaltic andesites and andesites belonging to the Southern Negros and Cuernos Volcanic Formations. During this time the Puhagan dikes and the Nasuji Pluton intruded Middle Miocene, Late Miocene and Early-Late Pliocene formations. Based on radiogenic ( 40Ar/ 39Ar) dating of hornblende, the Puhagan dikes are 4.1-4.2 Ma and the Nasuji Pluton 0.3-0.7 Ma. This age difference confirms these intrusions are not genetically related. The Early Pliocene age of the Puhagan dikes also confirms they are not the heat source for the current geothermal system and that a much younger intrusion is situated beyond drill depths. Igneous rock formations in southern Negros are the products of regional island-arc magmatism with medium K, calc-alkaline, basaltic to dacitic compositions. Their adakitic affinity implies that the melting of subducted oceanic basalt has influenced magmatism in this region. Considering the regional tectonic history the most likely scenarios for the generation of slab melts are: (1) during the Middle Miocene, by the

  20. Geothermal mineralized scales in the pipe system of the geothermal Piancastagnaio power plant (Mt. Amiata geothermal area): a key to understand the stibnite, cinnabarite and gold mineralization of Tuscany (central Italy)

    NASA Astrophysics Data System (ADS)

    Morteani, Giulio; Ruggieri, Giovanni; Möller, Peter; Preinfalk, Christine

    2011-02-01

    The CO2-rich geothermal fluids produced in the Piancastagnaio geothermal field (Mt. Amiata geothermal area, Southern Tuscany, Italy) show temperatures up to 360°C and pressures of about 200 bar at depths of around 3,500 m (Giolito, Ph.D. thesis, Università degli Studi di Firenze, Italy, pp 1-147, 2005). CaCO3- and/or SiO2-dominated scales are deposited in the pipes leading to the pressure and atmospheric separators of the geothermal wells. High content of metastibnite and/or stibnite in both calcite and silica scales and Sb contents of up to 50 mg/L in the fluids indicate their mineralising potential. The red or black colours of the scales depend on the predominance of red metastibnite or black stibnite, respectively. In our condensation experiments, as well as during deposition of the scales, metastibnite is the first Sb2S3 mineral to form. In a second stage, metastibnite is transformed to stibnite. During depressurization the Hg content of geothermal fluids partitions preferentially into the gas phase, whereas Sb and As remain in the liquid phase. This separation explains the often observed areal separation of Hg and Sb mineralization. The multistage deposition of Sb in the mining district of Tuscany is due to a periodic restoration of the permeability of the ore-bearing faults by microseismic events and subsequent host rock brecciation. The still ongoing microseismic events are induced by the accumulation of high-pressure CO2-rich fluids along faults followed by mechanical failure of the faults.

  1. Non-double-couple earthquake mechanisms at the Geysers geothermal area, California

    USGS Publications Warehouse

    Ross, A.; Foulger, G.R.; Julian, B.R.

    1996-01-01

    Inverting P- and S-wave polarities and P:SH amplitude ratios using linear programming methods suggests that about 20% of earthquakes at The Geysers geothermal area have significantly non-double-couple focal mechanisms, with explosive volumetric components as large as 33% of the seismic moment. This conclusion contrasts with those of earlier studies, which interpreted data in terms of double couples. The non-double-couple mechanisms are consistent with combined shear and tensile faulting, possibly caused by industrial water injection. Implosive mechanisms, which might be expected because of rapid steam withdrawal, have not been found. Significant compensated-linear-vector-dipole (CLVD) components in some mechanisms may indicate rapid fluid flow accompanying crack opening. Copyright 1996 by the American Geophysical Union.

  2. Active Management of Integrated Geothermal-CO2 Storage Reservoirs in Sedimentary Formations

    DOE Data Explorer

    Buscheck, Thomas A.

    2012-01-01

    Active Management of Integrated Geothermal–CO2 Storage Reservoirs in Sedimentary Formations: An Approach to Improve Energy Recovery and Mitigate Risk: FY1 Final Report The purpose of phase 1 is to determine the feasibility of integrating geologic CO2 storage (GCS) with geothermal energy production. Phase 1 includes reservoir analyses to determine injector/producer well schemes that balance the generation of economically useful flow rates at the producers with the need to manage reservoir overpressure to reduce the risks associated with overpressure, such as induced seismicity and CO2 leakage to overlying aquifers. Based on a range of well schemes, techno-economic analyses of the levelized cost of electricity (LCOE) are conducted to determine the economic benefits of integrating GCS with geothermal energy production. In addition to considering CO2 injection, reservoir analyses are conducted for nitrogen (N2) injection to investigate the potential benefits of incorporating N2 injection with integrated geothermal-GCS, as well as the use of N2 injection as a potential pressure-support and working-fluid option. Phase 1 includes preliminary environmental risk assessments of integrated geothermal-GCS, with the focus on managing reservoir overpressure. Phase 1 also includes an economic survey of pipeline costs, which will be applied in Phase 2 to the analysis of CO2 conveyance costs for techno-economics analyses of integrated geothermal-GCS reservoir sites. Phase 1 also includes a geospatial GIS survey of potential integrated geothermal-GCS reservoir sites, which will be used in Phase 2 to conduct sweet-spot analyses that determine where promising geothermal resources are co-located in sedimentary settings conducive to safe CO2 storage, as well as being in adequate proximity to large stationary CO2 sources.

  3. Subsurface geology and geopressured/geothermal resource evaluation of the Lirette-Chauvin-Lake Boudreaux area, Terrebonne Parish, Louisiana

    SciTech Connect

    Lyons, W.S.

    1982-12-01

    The geology of a 125 square mile area located about 85 miles southeast of Baton Rouge and about 12 miles southeast of Houma, Louisiana, has been studied to evaluate its potential for geopressured/geothermal energy resources. Structure, stratigraphy, and sedimentation were studied in conjunction with pressure and temperature distributions over a broad area to locate and identify reservoirs that may be prospective. Recommendations concerning future site specific studies within the current area are proposed based on these findings.

  4. Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey, PSInSAR and Kinematic Structural Analysis

    SciTech Connect

    Teplow, William J.; Warren, Ian

    2015-08-12

    The DOE cost-share program applied innovative and cutting edge seismic surveying and processing, permanent scatter interferometry-synthetic aperture radar (PSInSAR) and structural kinematics to the exploration problem of locating and mapping largeaperture fractures (LAFs) for the purpose of targeting geothermal production wells. The San Emidio geothermal resource area, which is under lease to USG, contains production wells that have encountered and currently produce from LAFs in the southern half of the resource area (Figure 2). The USG lease block, incorporating the northern extension of the San Emidio geothermal resource, extends 3 miles north of the operating wellfield. The northern lease block was known to contain shallow thermal waters but was previously unexplored by deep drilling. Results of the Phase 1 exploration program are described in detail in the Phase 1 Final Report (Teplow et al., 2011). The DOE cost shared program was completed as planned on September 30, 2014. This report summarizes results from all of Phase 1 and 2 activities.

  5. Chronology of late Pleistocene and Holocene volcanics, Long Valley and Mono Basin geothermal areas, eastern California

    USGS Publications Warehouse

    Wood, S.H.

    1983-01-01

    mono magma chamber suggests that rhyolite magma may have been emplaced in the shallow crust as recently as 32,000 to 40,000 yrs ago. Calculations by Lachenbruch et al. (1976, Jour. Geophys. Research, v. 81, p. 769-784) that a thermal disturbance at this age would have propagated upward by solid conduction only 4 km and offer an explanation for the lack of a heat-flow anomaly and surface indications of hydrothermal activity over the Mono magma chamber and its associated ring-fracture system. This report also contains new information on the age and chemistry of volcanics on the Mono Lake island, the Inyo domes, and tephras within the Long Valley Caldera. A newly discovered rhyolite tuff ring of late Quaternary age in the Toowa volcanic field of the southern Sierra Nevada is briefly described for it represents a new area that should be examined for potential as a geothermal area.

  6. Geothermal direct-heat utilization assistance. Quarterly project progress report, July 1996--September 1996. Federal Assistance Program

    SciTech Connect

    Lienau, P.

    1996-11-01

    This report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the fourth quarter of FY-96. It describes 152 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics and resources. Research activities are summarized on greenhouse peaking. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

  7. Interpretation of a dipole-dipole electrical resistivity survey, Colado geothermal area, Pershing County, Nevada

    SciTech Connect

    Mackelprang, C.E.

    1980-09-01

    An electrical resistivity survey in the Colado geothermal area, Pershing County, Nevada has defined areas of low resistivity on each of five lines surveyed. Some of these areas appear to be fault controlled. Thermal fluids encountered in several drill holes support the assumption that the hot fluids may be associated with areas of low resistivity. The evidence of faulting as interpreted from modeling of the observed resistivity data is therefore particularly significant since these structures may be the conduits for the thermal fluids. Sub-allurial fault zones are interpreted to occur between stations 0 to 5 NW on Line D and on Line A between stations 4 NW and 4 SE. Fault zones are also interpreted on Line C near stations 1 NW, 1 SE, and 3 SE, and on Line E between stations 2 to 4 NW and near 1 SE. No faulting is evident under the alluvial cover on the southwest end of Line B. A deep conductive zone is noted within the mountain range on two resistivity lines. There is no definite indication that thermal fluids are associated with this resistivity feature.

  8. Low-temperature geothermal potential of the Ojo Caliente warm springs area, northern New Mexico

    SciTech Connect

    Vuataz, F.D.; Stix, J.; Goff, F.; Pearson, C.F.

    1984-05-01

    A detailed geochemical investigation of 17 waters (thermal and cold, mineralized and dilute) was performed in the Ojo Caliente-La Madera area. Two types of thermomineral waters have separate and distinctive geologic, geochemical, and geothermal characteristics. The water from Ojo Caliente Resort emerges with temperatures less than or equal to 54/sup 0/C from a Precambrian metarhyolite. Its chemistry, typically Na-HCO/sub 3/, has a total mineralization of 3600 mg/l. Isotopic studies have shown that the thermal water emerges from the springs and a hot well without significant mixing with the cold shallow aquifer of the valley alluvium. However, the cold aquifer adjacent to the resort does contain varying amounts of thermal water that originates from the warm spring system. Geothermometry calculations indicate that the thermal water may be as hot as 85/sup 0/C at depth before its ascent toward surface. Thermodynamic computations on the reaction states of numerous mineral phases suggest that the thermal water will not cause major scaling problems if the hot water is utilized for direct-use geothermal applications. By means of a network of very shallow holes, temperature and electrical conductivity anomalies have been found elsewhere in the valley around Ojo Caliente, and resistivity soundings have confirmed the presence of a plume of thermal water entering the shallow aquifer. The group of lukewarm springs around La Madera, with temperatures less than or equal to 29/sup 0/C, chemical type of NaCaMg-HCO/sub 3/Cl and with a total mineralization less than or equal to 1500 mg/l behaves as a different system without any apparent relation to the Ojo Caliente system. Its temperature at depth is not believed to exceed 35 to 40/sup 0/C.

  9. Geothermic activity and seismotectonics in the altitude of the Tibetan plateau

    NASA Astrophysics Data System (ADS)

    Xu, Jiren; Zhao, Zhixin

    2009-12-01

    In the present analysis on the relationships among the depth of lithosphere brittle fracture, seismotectonics and geothermal anomalous active in Tibetan plateau were investigated using the seismic dada from ISC and Chinese seismic net and geothermal data. The results suggest that the region of anomalously geothermal activity almost coincides with that of the normal faulting type earthquake. The geothermal anomaly activity region coincides spatially with that of the events deeper than 60 km as well as. The normal faulting earthquakes may be mainly tectonic activity regimes until 110 km deep in the thermal anomaly region. The strike directions of events are likely the N-S direction, coinciding with the strike of the thermal anomaly active belts. The earthquakes align along the normal faults and faulted-depression zone with the N-S direction. The thermal anomaly activity also distributes along the faulted-depression zone. Many events deeper than 60 km exist in the anomalously geothermal activity region in the plateau. Events extend to bottom of the lithosphere of 110 km from the surface, like columnar seismic crowd. The lithosphere extends along the E-W direction due to the E-W extensional stress in the central and southern Tibetan plateau, altitude of the plateau. The tensional stress in the E-W results in the lithosphere fractures and the normal faults striking N-S direction, grabens and faulted-depression zones. Thermal material from the asthenosphere wells upward to the surface along deep seismic fractures and faults through the thick crust. The anomalously thermal activities are attributable to the upwelling thermal material from the mantle in the altitude of Tibetan plateau.

  10. Volcano-tectonic structures, gravity and helium in geothermal areas of Tuscany and Latium (Vulsini volcanic district), Italy

    USGS Publications Warehouse

    Di, Filippo M.; Lombardi, S.; Nappi, G.; Reimer, G.M.; Renzulli, A.; Toro, B.

    1999-01-01

    Since the early 1980s, geological and structural mapping, gravity, and helium soil-gas studies have been performed in the eastern sector of the Vulsini Volcanic District (Roman Magmatic Province) in an attempt to locate potential geothermal reservoirs. This area is characterised by an anomalous geothermal gradient of > 100??C/km, and by widespread hydrothermal mineralization, thermal springs, high gas fluxes, and fossil and current travertine deposits. The results of these surveys indicate the existence of a number of fault systems, with N-S and E-W structures that appear to be superimposed on older NW-SE and NE-SW features. Comparison of the results of the various studies also reveals differences in permeability and potential reservoir structures at depth.Since the early 1980s, geological and structural mapping, gravity, and helium soil-gas studies have been performed in the eastern sector of the Vulsini Volcanic District (Roman Magmatic Province) in an attempt to locate potential geothermal reservoirs. This area is characterised by an anomalous geothermal gradient of > 100??C/km, and by widespread hydrothermal mineralization, thermal springs, high gas fluxes, and fossil and current travertine deposits. The results of these surveys indicate the existence of a number of fault systems, with N-S and E-W structures that appear to be superimposed on older NW-SE and NE-SW features. Comparison of the results of the various studies also reveals differences in permeability and potential reservoir structures at depth.

  11. Incidence of cancer among residents of high temperature geothermal areas in Iceland: a census based study 1981 to 2010

    PubMed Central

    2012-01-01

    Background Residents of geothermal areas are exposed to geothermal emissions and water containing hydrogen sulphide and radon. We aim to study the association of the residence in high temperature geothermal area with the risk of cancer. Methods This is an observational cohort study where the population of a high-temperature geothermal area (35,707 person years) was compared with the population of a cold, non-geothermal area (571,509 person years). The cohort originates from the 1981 National Census. The follow up from 1981 to 2010 was based on record linkage by personal identifier with nation-wide death and cancer registries. Through the registries it was possible to ascertain emigration and vital status and to identify the cancer cases, 95% of which had histological verification. The hazard ratio (HR) and 95% confidence intervals (CI) were estimated in Cox-model, adjusted for age, gender, education and housing. Results Adjusted HR in the high-temperature geothermal area for all cancers was 1.22 (95% CI 1.05 to 1.42) as compared with the cold area. The HR for pancreatic cancer was 2.85 (95% CI 1.39 to 5.86), breast cancer 1.59 (95% CI 1.10 to 2.31), lymphoid and hematopoietic cancer 1.64 (95% CI 1.00 to 2.66), and non-Hodgkins lymphoma 3.25 (95% CI 1.73 to 6.07). The HR for basal cell carcinoma of the skin was 1.61 (95% CI 1.10 to 2.35). The HRs were increased for cancers of the nasal cavities, larynx, lung, prostate, thyroid gland and for soft tissue sarcoma; however the 95% CIs included unity. Conclusions More precise information on chemical and physical exposures are needed to draw firm conclusions from the findings. The significant excess risk of breast cancer, and basal cell carcinoma of the skin, and the suggested excess risk of other radiation-sensitive cancers, calls for measurement of the content of the gas emissions and the hot water, which have been of concern in previous studies in volcanic areas. There are indications of an exposure

  12. Geothermal resources of Utah, 1980

    SciTech Connect

    Not Available

    1980-01-01

    This map shows heat flow, Known Geothermal Resources Areas, thermal springs and wells, and areas of low-temperature geothermal waters. Also shown are Indian reservations, military reservation, national or state forests, and parks, wildlife refuges, wilderness areas, etc. (MHR)

  13. Geothermal exploration in Indonesia

    SciTech Connect

    Radja, V.T.

    1984-03-01

    Indonesia is blessed with geothermal resources. This fortunate aspect is directly related to the fact that the archipelago is an island arc created by a subduction zone. Evidence of geothermal activity is common throughout the Islands. Among the islands' many active volcanos are numerous geothermal phenomena. Almost half of the volcanic centers in Indonesia (88 out of 177 centers) contain fumarole and sulfatare features. A brief history of the exploration for geothermal energy in Indonesia is presented.

  14. Engineered Geothermal System Demonstration Project

    SciTech Connect

    Petty, Susan

    2014-06-19

    In June 2009, AltaRock Energy began field work on a project supported by the U.S. Department of Energy entitled “Use of Multiple Stimulations to Improve Economics of Engineered Geothermal Systems in Shallow High Temperature Intrusives.” The goal of the project was to develop an Engineered Geothermal System (EGS) in the portion of The Geysers geothermal field operated by the Northern California Power Agency (NCPA). The project encountered several problems while deepening Well E-7 which culminated in the suspension of field activities in September 2009. Some of the problems encountered are particular to The Geysers area, while others might be encountered in any geothermal field, and they might be avoided in future operations.

  15. Geothermal energy: a brief assessment

    SciTech Connect

    Lunis, B.C.; Blackett, R.; Foley, D.

    1982-07-01

    This document includes discussions about geothermal energy, its applications, and how it is found and developed. It identifies known geothermal resources located in Western's power marketing area, and covers the use of geothermal energy for both electric power generation and direct applications. Economic, institutional, environmental, and other factors are discussed, and the benefits of the geothermal energy resource are described.

  16. Geophysical studies of the Crump Geyser known geothermal resource area, Oregon, in 1975

    USGS Publications Warehouse

    Plouff, Donald

    2006-01-01

    The U.S. Geological Survey (USGS) conducted geophysical studies in support of the resource appraisal of the Crump Geyser Known Geothermal Resource Area (KGRA). This area was designated as a KGRA by the USGS, and this designation became effective on December 24, 1970. The land classification standards for a KGRA were established by the Geothermal Steam Act of 1970 (Public Law 91-581). Federal lands so classified required competitive leasing for the development of geothermal resources. The author presented an administrative report of USGS geophysical studies entitled 'Geophysical background of the Crump Geyser area, Oregon, KGRA' to a USGS resource committee on June 17, 1975. This report, which essentially was a description of geophysical data and a preliminary interpretation without discussion of resource appraisal, is in Appendix 1. Reduction of sheets or plates in the original administrative report to page-size figures, which are listed and appended to the back of the text in Appendix 1, did not seem to significantly degrade legibility. Bold print in the text indicates where minor changes were made. A colored page-size index and tectonic map, which also show regional geology not shown in figure 2, was substituted for original figure 1. Detailed descriptions for the geologic units referenced in the text and shown on figures 1 and 2 were separately defined by Walker and Repenning (1965) and presumably were discussed in other reports to the committee. Heavy dashed lines on figures 1 and 2 indicate the approximate KGRA boundary. One of the principal results of the geophysical studies was to obtain a gravity map (Appendix 1, fig. 10; Plouff, and Conradi, 1975, pl. 9), which reflects the fault-bounded steepness of the west edge of sediments and locates the maximum thickness of valley sediments at about 10 kilometers south of Crump Geyser. Based on the indicated regional-gravity profile and density-contrast assumptions for the two-dimensional profile, the maximum

  17. Drone with thermal infrared camera provides high resolution georeferenced imagery of the Waikite geothermal area, New Zealand

    NASA Astrophysics Data System (ADS)

    Harvey, M. C.; Rowland, J. V.; Luketina, K. M.

    2016-10-01

    Drones are now routinely used for collecting aerial imagery and creating digital elevation models (DEM). Lightweight thermal sensors provide another payload option for generation of very high-resolution aerial thermal orthophotos. This technology allows for the rapid and safe survey of thermal areas, often present in inaccessible or dangerous terrain. Here we present a 2.2 km2 georeferenced, temperature-calibrated thermal orthophoto of the Waikite geothermal area, New Zealand. The image represents a mosaic of nearly 6000 thermal images captured by drone over a period of about 2 weeks. This is thought by the authors to be the first such image published of a significant geothermal area produced by a drone equipped with a thermal camera. Temperature calibration of the image allowed calculation of heat loss (43 ± 12 MW) from thermal lakes and streams in the survey area (loss from evaporation, conduction and radiation). An RGB (visible spectrum) orthomosaic photo and digital elevation model was also produced for this area, with ground resolution and horizontal position error comparable to commercially produced LiDAR and aerial imagery obtained from crewed aircraft. Our results show that thermal imagery collected by drones has the potential to become a key tool in geothermal science, including geological, geochemical and geophysical surveys, environmental baseline and monitoring studies, geotechnical studies and civil works.

  18. Geothermal exploration assessment and interpretation, Upper Klamah Lake Area, Klamath Basin, Oregon

    SciTech Connect

    Stark, M.; Goldstein, N.E.; Wollenberg, H.A.

    1980-09-01

    Data from public and private sources on the Klamath Basin geothermal resource are reviewed, synthesized, and reinterpreted. In this, the second and final phase of the work, geological, remote sensing, geochemical, temperature gradient, gravity, aeromagnetic, and electrical resistivity data sets are examined. These data were derived from surveys concentrated on the east and west shores of Upper Klamath Lake. The geological, remote sensing, and potential field data suggest a few northeast-trending discontinuities, which cross the regional north-westerly strike. The near-surface distribution of warm water appears to be related to the intersections of these lineaments and northwest-trending faults. The groundwater geochemical data are reviewed and the various reservoir temperature estimates compared. Particular attention is given to specific electrical conductivities of waters as an interpretational aid to the subsurface resistivity results. A clear trend emerges in the Klamath Falls/Olene Gap area; hotter waters are associated with higher specific conductivities. In the Nuss Lake/Stukel Mountain area the opposite trend prevails, although the relationship is somewhat equivocal.

  19. Slip and Dilation Tendency Analysis of the San Emidio Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes

  20. Slip and Dilation Tendency Anlysis of McGinness Hills Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Slip and Dilation Tendency in focus areas Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998

  1. Geothermal energy in Nevada

    SciTech Connect

    Not Available

    1980-01-01

    The nature of goethermal resources in Nevada and resource applications are discussed. The social and economic advantages of utilizing geothermal energy are outlined. Federal and State programs established to foster the development of geothermal energy are discussed. The names, addresses, and phone numbers of various organizations actively involved in research, regulation, and the development of geothermal energy are included. (MHR)

  2. Geothermal direct-heat utilization assistance. Quarterly project progress report, January--March 1996

    SciTech Connect

    1996-05-01

    This report summarizes geothermal technical assistance, R&D, and technology transfer activities of the Geo-Heat Center. It describes 95 contacts with parties during this period related to technical assistance with goethermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics, and resources. Research activities are summarized on geothermal district heating system cost evaluation and silica waste utilization project. Outreach activities include publication of a geothermal direct use Bulletin, dissemination of information, goethermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

  3. Spatial Characteristics of Geothermal Spring Temperatures and Discharge Rates in the Tatun Volcanic Area, Taiwan

    NASA Astrophysics Data System (ADS)

    Jang, C. S.; Liu, C. W.

    2014-12-01

    The Tatun volcanic area is the only potential volcanic geothermal region in the Taiwan island, and abundant in hot spring resources owing to stream water mixing with fumarolic gases. According to the Meinzer's classification, spring temperatures and discharge rates are the most important properties for characterizing spring classifications. This study attempted to spatially characterize spring temperatures and discharge rates in the Tatun volcanic area, Taiwanusing indicator kriging (IK). First, data on spring temperatures and discharge rates, which were collected from surveyed data of the Taipei City Government, were divided into high, moderate and low categories according to spring classification criteria, and the various categories were regarded as estimation thresholds. Then, IK was adopted to model occurrence probabilities of specified temperatures and discharge rates in springs, and to determine their classifications based on estimated probabilities. Finally, nine combinations were obtained from the classifications of temperatures and discharge rates in springs. Moreover, the combinations and features of spring water were spatially quantified according to seven sub-zones of spring utilization. A suitable and sustainable development strategy of the spring area was proposed in each sub-zone based on probability-based combinations and features of spring water.The research results reveal that the probability-based classifications using IK provide an excellent insight in exploring the uncertainty of spatial features in springs, and can provide Taiwanese government administrators with detailed information on sustainable spring utilization and conservation in the overexploited spring tourism areas. The sub-zones BT (Beitou), RXY (Rd. Xingyi), ZSL (Zhongshanlou) and LSK (Lengshuikeng) with high or moderate discharge rates are suitable to supply spring water for tourism hotels.Local natural hot springs should be planned in the sub-zones DBT (Dingbeitou), ZSL, XYK

  4. Water-quality investigation near the Chico and Hunters geothermal lease-application areas, Park and Sweet Grass Counties, Montana

    USGS Publications Warehouse

    Leonard, Robert B.; Shields, Ronald R.; Midtlyng, Norman A.

    1978-01-01

    Water quality in and adjacent to geothermal lease-application areas in Montana near Chico and Hunters Hot Springs was investigated during two surveys in October 1976 and April 1977. The data were needed to evaluate the effects of proposed geothermal exploration and development on the Yellowstone River and its tributaries. Water from the two hot springs, the Yellowstone River, and its tributaries that drain the proposed lease areas are generally suitable for drinking, except for excessive concentrations of fluoride and hydrogen sulfide in waters from Hunters Hot Springs. The water from Chico Hot Springs is suitable for irrigation, but the water from Hunters Hot Springs presents a very high sodium and medium salinity hazard and is generally unsatisfactory for irrigation. The effect of the thermal waters on streamflow and chemical discharge of the Yellowstone River during the surveys was negligible. (Woodard-USGS)

  5. Slip and Dilation Tendency Analysis of the Salt Wells Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes

  6. The geothermal potential of the Campania volcanic district and new heat exchanger technologies for exploitation of highly urbanised areas.

    NASA Astrophysics Data System (ADS)

    Carlino, S.; Somma, R.; Troiano, A.; Di Giuseppe, M. G.; Troise, C.; De Natale, G.

    2012-04-01

    The geothermal research in Campania region (Italy), started since the 1930, and continued until the '80 by the SAFEN, ENEL and AGIP companies. Such exploration activity highlighted that most of the volcanic districts of the Campania Region have a very high geothermal gradient and heat flow. In particular, inside the Campi Flegrei caldera and at Ischia island the geothermal gradient measured inside the deep wells reaches temperatures above 100° C between few tens and few hundreds of metres of depth, while the heat flow varies between 120-160 mWm-2 at Agnano and Mofete (Campi Flegrei main drill sites) to more than 500 mWm-2 at Ischia island (south-western sector). A general review of the available literature data (temperature at depth, stratigraphic sections, logs etc.) of the deep wells (down to 3 km b.s.l.) allowed us to quantify the geothermal potential (thermal and electric) of such district. The geothermal potential is about 6 GWy for the Campi Flegrei (Mofete and S. Vito sectors) and 11 GWy for the Ischia island (south-western sector) showing a geothermal reservoir with water and vapour dominant respectively. This results in strong potential interest for economic exploitation of the geothermal resource, both in the range of low-medium enthalpy at few hundreds of meters depth and of high enthalpy at depths of 1-2 km. In this study we try to model the effectiveness of new technologies of boreholes heat exchangers, which would allow to avoid fluid withdrawal, then strongly decreasing the environmental impact. The proposed technology consists of a double-pipe placed in a borehole heat exchange that can work coupled with an ORC. The two pipes, one inside the other, are located in the well in order to transfer the thermal energy to the working fluid during the descent in the external pipe and then go back through the internal pipe properly isolated. We propose a complete design of the borehole heat exchangers. The design activity is performed on a theoretical basis

  7. Geothermal investigation in Idaho. Part 14. Geochemical and isotopic investigations of thermal water occurrences of the Boise Front Area, Ada County, Idaho

    SciTech Connect

    Mayo, A.L.; Muller, A.B.; Mitchell, J.C.

    1984-12-01

    A limited chemical and isotopic investigation was undertaken and geological, geophysical, and hydrological data in the literature were reviewed to evaluate the geothermal potential of the Boise area. 68 refs., 12 figs., 4 tabs. (ACR)

  8. Basic data from five core holes in the Raft River geothermal area, Cassia County, Idaho

    USGS Publications Warehouse

    Crosthwaite, E. G.

    1976-01-01

    meters) were completed in the area (Crosthwaite, 1974), and the Aerojet Nuclear Company, under the auspices of the U.S. Energy Research and Development Administration, was planning some deep drilling 4,000 to 6,000 feet (1,200 to 1,800 meters) (fig. 1). The purpose of the core drilling was to provide information to test geophysical interpretations of the subsurface structure and lithology and to provide hydrologic and geologic data on the shallow part of the geothermal system. Samples of the core were made available to several divisions and branches of the Geological Survey and to people and agencies outside the Survey. This report presents the basic data from the core holes that had been collected to September 1, 1975, and includes lithologic and geophysical well logs, chemical analyses of water (table 1), and laboratory analyses of cores (table 2) that were completed as of the above date. The data were collected by the Idaho District office, Hydrologic Laboratory, Borehole Geophysics Research Project, and Drilling, Sampling, and Testing Section, all of the Water Resources Division, and the Branch of Central Environmental Geology of the Geologic Divison.

  9. Resource investigation of low- and moderate-temperature geothermal areas in Paso Robles, California

    SciTech Connect

    Campion, L.F.; Chapman, R.H.; Chase, G.W.; Youngs, L.G.

    1983-01-01

    Ninety-eight geothermal wells and springs were identified and plotted, and a geologic map and cross sections were compiled. Detailed geophysical, geochemical, and geological surveys were conducted. The geological and geophysical work delineated the basement highs and trough-like depressions that can exercise control on the occurrence of the thermal waters. The Rinconada fault was also evident. Cross sections drawn from oil well logs show the sediments conforming against these basement highs and filling the depressions. It is along the locations where the sediments meet the basement highs that three natural warm springs in the area occur. Deep circulation of meteoric waters along faults seems to be a reasonable source for the warm water. The Santa Margarita, Pancho Rico, and Paso Robles Formations would be the first permeable zones that abut the faults through which water would enter. Temperatures and interpretation of well logs indicate the warmest aquifer at the base of the Paso Robles Formation. Warm water may be entering higher up in the section, but mixing with water from cooler zones seems to be evident. Geothermometry indicates reservoir temperatures could be as high as 91/sup 0/C (196/sup 0/F).

  10. Geothermal monitor report

    NASA Astrophysics Data System (ADS)

    1982-06-01

    Geothermal Progress Monitor Report No. 6 presents a state-by-state summary of the status of geothermal leasing, exploration, and development in major physiographic regions where geothermal resource potential has been identified. Recent state-specific activities are reported at the end of each state status report, while recent activities of a more general nature are summarized briefly in Part 2 of the report. A list of recent publications of potential interest to the geothermal community and a directory of contributors to the geothermal progress monitoring system are also included.

  11. Reno Industrial Park geothermal district heating system

    SciTech Connect

    Lienau, P.J.

    1997-04-01

    Ten miles south of Reno, on U.S. 395 near the junction of the road to historic Virginia City, is Steamboat Hot Springs, a popular stop for travelers since the mid-1800s. Legend has it that Mark Twain named the geothermal area because it looked and sounded like a chugging Mississippi River paddle-wheeler. It is said when he first saw the steam rising from the ground he exclaimed, {open_quotes}Behold! A Steamboat in the desert.{close_quotes} Over the years, the area has been used for its relaxing and curative qualities by Indians, settlers, and geothermal experts. Since the mid-1980s five geothermal power plants have been built at Steamboat Springs and in December 1996 it was announced that the proposed largest geothermal district heating system in the U.S. would supply an industrial park in the area. The active geothermal area is located within the north-south trending graben like trough between the Carson and Virginia Ranges at the southern end of Truckee Meadows. Hot springs and other geothermal features occur over an area of about one square mile. The mid-basin location is controlled by faulting more or less parallel to the major mountain-front faults. It is believed that the heat source for the system is a cooling magmatic body at depth. The Steamboat geothermal area consists of a deep, high-temperature (215{degrees}C to 240{degrees} C) geothermal system, a shallower, moderate-temperature (160{degrees}C to 18{degrees} C) system, and a number of shallow low-temperature (30{degrees}C to 80{degrees}C) subsystems. The higher temperature systems are used for electric-power generation. It is proposed that the exit fluids from the electric power plants be used for the geothermal district heating system.

  12. Induced Microseismic Activity in non Pressure Stimulated Geothermal System - an Example From Southern Germany

    NASA Astrophysics Data System (ADS)

    Wassermann, J. M.; Megies, T.

    2011-12-01

    In order to be efficient in selling heat and electric power, the most favorable locations for deep geothermal power plants are in close proximity to urbanized areas. This advantage bears the inherent danger of induced earthquakes especially during the stimulation and production phase of enhanced geothermal systems, which at least are partially felt in the near surroundings. Felt earthquakes, however, severely reduce the level of acceptance of residents close to the plant. The Bavarian Molasse basin is characterized by its highly permeable, deep groundwater bearing limestone layers. This high permeability permits the abdication of pressure stimulation of the geothermal reservoir and makes the close proximity to the densely populated area around Munich possible. In addition to this favorable production conditions, the Bavarian Molasse Basin is being considered as generally aseismic. In contrast to this obvious advantages five Ml > 2.0 events south of Munich which were felt by local residents attracted public attention. These events were located in the vicinity of a geothermal plant that took up production about half a year earlier. In the last two years a temporary network was set up that recorded more than 80 events with magnitudes mainly ranging from Ml -0.5 to 1.5. Events below magnitude 1.5 could not be detected and located prior to the production stage of the geothermal plant in the main network of the local earthquake service Erdbebendienst Bayern. Still, the exact mechanism leading to the seismicity remains unknown. Most likely the orientation of pre-existing faults, which are pierced by the open-hole part of wells with respect to present stress field and the volume of re-injected cold water play a key role in understanding the mechanisms leading to the observed seismicity. Within the framework of a project financed by the German federal ministry of Environment, further field experiments are conducted to address these open questions and test some working

  13. Resource investigation of low- and moderate-temperature geothermal areas in San Bernardino, California. Part of the third year report, 1980-81, of the US Department of Energy-California State-Coupled Program for Reservoir Assessment and Confirmation

    SciTech Connect

    Youngs, L.G.; Bezore, S.P.; Chapman, R.H.; Chase, G.W.

    1981-08-01

    Ninety-seven geothermal wells and springs were identified and plotted on a compiled geologic map of the 40-square-mile study area. These wells and springs were concentrated in three distinguishable resource areas: Arrowhead Hot Springs; South San Bernardino; and Harlem Hot Springs - in each of which detailed geophysical, geochemical, and geological surveys were conducted. The Arrowhead Hot Springs geothermal area lies just north of the City of San Bernardino in the San Bernardino Mountains astride a shear zone (offshoot of the San Andreas fault) in pre-Cambrian gneiss and schist. The Harlem Hot Springs geothermal area, on the east side of the City, and the south San Bernardino geothermal area, on the south side, have geothermal reservoirs in Quaternary alluvial material which overlies a moderately deep sedimentary basin bound on the southwest by the San Jacinto fault (a ground water barrier). Geothermometry calculations suggest that the Arrowhead Hot Springs geothermal area, with a maximum reservoir temperature of 142/sup 0/C, may have the highest maximum reservoir temperature of the three geothermal areas. The maximum temperature recorded by CDMG in the south San Bernardino geothermal area was 56/sup 0/C from an artesian well, while the maximum temperature recorded in the Harlem Hot Springs geothermal area was 49.5/sup 0/C at 174 meters (570 feet) in an abandoned water well. The geophysical and geological surveys delineated fault traces in association with all three of the designated geothermal areas.

  14. Explosively activated egress area

    NASA Technical Reports Server (NTRS)

    Bement, L. J.; Bailey, J. W. (Inventor)

    1983-01-01

    A lightweight, add on structure which employs linear shaped pyrotechnic charges to smoothly cut an airframe along an egress area periphery is provided. It compromises reaction surfaces attached to the exterior surface of the airframe's skin and is designed to restrict the skin deflection. That portion of the airframe within the egress area periphery is jettisoned. Retention surfaces and sealing walls are attached to the interior surface of the airframe's skin and are designed to shield the interior of the aircraft during detonation of the pyrotechnic charges.

  15. Absence of remote earthquake triggering within the Coso and Salton Sea geothermal production fields

    NASA Astrophysics Data System (ADS)

    Zhang, Qiong; Lin, Guoqing; Zhan, Zhongwen; Chen, Xiaowei; Qin, Yan; Wdowinski, Shimon

    2017-01-01

    Geothermal areas are long recognized to be susceptible to remote earthquake triggering, probably due to the high seismicity rates and presence of geothermal fluids. However, anthropogenic injection and extraction activity may alter the stress state and fluid flow within the geothermal fields. Here we examine the remote triggering phenomena in the Coso geothermal field and its surrounding areas to assess possible anthropogenic effects. We find that triggered earthquakes are absent within the geothermal field but occur in the surrounding areas. Similar observation is also found in the Salton Sea geothermal field. We hypothesize that continuous geothermal operation has eliminated any significant differential pore pressure between fractures inside the geothermal field through flushing geothermal precipitations and sediments out of clogged fractures. To test this hypothesis, we analyze the pore-pressure-driven earthquake swarms, and they are found to occur outside or on the periphery of the geothermal production field. Therefore, our results suggest that the geothermal operation has changed the subsurface fracture network, and differential pore pressure is the primary controlling factor of remote triggering in geothermal fields.

  16. Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)

    NASA Astrophysics Data System (ADS)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-10-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a-1 (t a-1). Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values of up to 59.2 nmol g-1 soil d.w. h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile, the maximum methane consumption was measured in the top-soil layer, and values greater than 6.23 nmol g-1 h-1 were still detected up to a depth of 13 cm. The highest consumption rate was measured at 37 °C, but a still detectable consumption at 80 °C (> 1.25 nmol g-1 h-1) was recorded. The soil total DNA extracted from the three samples was probed by Polymerase Chain Reaction (PCR) using standard proteobacterial primers and newly designed verrucomicrobial primers, targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected at sites FAV2 and FAV3, but not at FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site (FAV2) pointed to a high diversity of gammaproteobacterial methanotrophs, distantly related to Methylocaldum-Metylococcus genera, and the presence of the newly discovered acido-thermophilic Verrucomicrobia methanotrophs. Alphaproteobacteria of the genus Methylocystis were isolated from enrichment cultures under a methane

  17. Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy)

    NASA Astrophysics Data System (ADS)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-04-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission was previously estimated in about 2.5 t a-1. Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values up to 950 ng g-1 dry soil h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile and the maximum methane consumption was measured in the top-soil layer but values > 100 ng g-1 h-1 were maintained up to a depth of 15 cm. The highest consumption rate was measured at 37 °C, but a still recognizable consumption at 80 °C (> 20 ng g-1 h-1) was recorded. In order to estimate the bacterial diversity, total soil DNA was extracted from Favara Grande and analysed using a Temporal Temperature Gradient gel Electrophoresis (TTGE) analysis of the amplified bacterial 16S rRNA gene. The three soil samples were probed by PCR using standard proteobacterial primers and newly designed verrucomicrobial primers targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected in sites FAV2 and FAV3, but not in FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site FAV2 pointed out a high diversity of gammaproteobacterial methanotrophs distantly related to Methylococcus/Methylothermus genera and the presence of the newly discovered acido-thermophilic methanotrophs

  18. Subsurface geology and potential for geopressured-geothermal energy in the Turtle Bayou field-Kent Bayou field area, Terrebonne Parish, Louisiana

    SciTech Connect

    Moore, D.R.

    1982-09-01

    A 216 square mile area approximately 65 miles southwest of New Orleans, Louisiana, has been geologically evaluated to determine its potential for geopressured-geothermal energy production. The structural and stratigraphic analyses were made with emphasis upon the Early and Middle Miocene age sediments which lie close to and within the geopressured section. Three geopressured sands, the Robulus (43) sand, Cibicides opima sand, and Cristellaria (I) sand, are evaluated for their potential of producing geothermal energy. Two of these sands, the Robulus (43) sand and the Cibicides opima sand, meet several of the United States Department of Energy's suggested minimum requirements for a prospective geopressured-geothermal energy reservoir.

  19. Structural investigations of Great Basin geothermal fields: Applications and implications

    SciTech Connect

    Faulds, James E; Hinz, Nicholas H.; Coolbaugh, Mark F

    2010-11-01

    Because fractures and faults are commonly the primary pathway for deeply circulating hydrothermal fluids, structural studies are critical to assessing geothermal systems and selecting drilling targets for geothermal wells. Important tools for structural analysis include detailed geologic mapping, kinematic analysis of faults, and estimations of stress orientations. Structural assessments are especially useful for evaluating geothermal fields in the Great Basin of the western USA, where regional extension and transtension combine with high heat flow to generate abundant geothermal activity in regions having little recent volcanic activity. The northwestern Great Basin is one of the most geothermally active areas in the USA. The prolific geothermal activity is probably due to enhanced dilation on N- to NNE-striking normal faults induced by a transfer of NW-directed dextral shear from the Walker Lane to NW-directed extension. Analysis of several geothermal fields suggests that most systems occupy discrete steps in normal fault zones or lie in belts of intersecting, overlapping, and/or terminating faults. Most fields are associated with steeply dipping faults and, in many cases, with Quaternary faults. The structural settings favoring geothermal activity are characterized by subvertical conduits of highly fractured rock along fault zones oriented approximately perpendicular to the WNW-trending least principal stress. Features indicative of these settings that may be helpful in guiding exploration for geothermal resources include major steps in normal faults, interbasinal highs, groups of relatively low discontinuous ridges, and lateral jogs or terminations of mountain ranges.

  20. Hydrothermal mineralogy and fluid inclusions chemistry to understand the roots of active geothermal systems

    NASA Astrophysics Data System (ADS)

    Chambefort, I. S.; Dilles, J. H.; Heinrich, C.

    2013-12-01

    An integrated study to link magmatic textures, magmatic mineral compositions, hydrothermal alteration zoning, hydrothermal mineral chemistry, and fluid inclusion compositions has been undertaken to link an intrusive complex and its degassing alteration halo with their surface equivalent in an active geothermal system. Ngatamariki geothermal system, New Zealand, presents a unique feature in the Taupo Volcanic Zone (TVZ). Drilling intercepted an intrusive complex with a high temperature alteration halo similarly to what is observed in magmatic-derived ore deposits. Thus it presents the perfect opportunity to study the magmatic-hydrothermal transition of the TVZ by characterizing the nature of the deep magmatic fluids link to the heat source of the world known geothermal fields. The record of magmatic-hydrothermal fluid-rock interactions preserved at Ngatamariki may be analogous of processes presently occurring at depth beneath TVZ geothermal systems. The intrusive complex consists of over 5 km3 of tonalite, diorite, basalt and aplitic dykes. Evidence of undercooling subsolidus magmatic textures such as myrmekite and skeletal overgrowth are commonly observed and often linked to volatile loss. The fluids released during the crystallization of the intrusive complex are interpreted to be at the origin of the surrounding high temperature alteration halo. Advanced argillic to potassic alteration and high temperature acidic assemblage is associated with high-temperature quartz veining at depth and vuggy silica at the paleo-surface. Major element compositions of the white micas associated with the high temperature halo show a transition from, muscovite to phengite, muscovitic illite away from the intrusion, with a transition to pyrophyllite and/ or topaz, and andalusite characteristic of more acidic conditions. Abundant high-density (up to 59 wt% NaCl eq and homogenization temperatures of 550 degree Celsius and above) coexist with low-density vapor fluid inclusions. This

  1. Life cycle of a geyser discharge apron: Evidence from Waikite Geyser, Whakarewarewa geothermal area, North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Jones, Brian; Renaut, Robin W.; Owen, R. Bernhart

    2011-05-01

    Waikite, a geyser located in the Whakarewarewa geothermal area on the North Island, New Zealand, has a history of eruptive-dormancy cycles that have been attributed to natural and anthropogenic causes. The last cycle involved an active period from ~ 1932 to 1968/69 that was followed by a period of dormancy that continues today. Such cycles are important because they control the temporal development of the discharge apron. When the geyser is active, growth of the discharge apron is dictated by the precipitation of opal-A, which is controlled by factors such as discharge patterns, water chemistry, pH, temperature, rate of cooling, and the resident microbiota. With dormancy, conditions change radically because water no longer flows down the discharge apron. Instead, the discharge apron lapses into a phase of degradation that, on Waikite, is evident from (1) deflation of the apron surface, (2) blocks splaying off the apron margins along margin-parallel fractures, (3) tension fractures, (4) saucer-shaped collapse zones, (5) increasingly unstable surfaces resulting from subsurface opal-A dissolution, (6) fractures, from which steam and other gases emanate, and (7) incursion of native vegetation around the edge of the apron and on the distal parts of the discharge apron. When the geyser becomes active again, silica precipitation will resume and the discharge apron will once again accrete vertically and expand laterally. Analysis of the Waikite system shows that successions that develop on geyser discharge aprons are formed of unconformity-bounded packages of sinter that reflect the eruptive-dormancy history of the parent geyser.

  2. Neural network modeling and prediction of resistivity structures using VES Schlumberger data over a geothermal area

    NASA Astrophysics Data System (ADS)

    Singh, Upendra K.; Tiwari, R. K.; Singh, S. B.

    2013-03-01

    This paper presents the effects of several parameters on the artificial neural networks (ANN) inversion of vertical electrical sounding (VES) data. Sensitivity of ANN parameters was examined on the performance of adaptive backpropagation (ABP) and Levenberg-Marquardt algorithms (LMA) to test the robustness to noisy synthetic as well as field geophysical data and resolving capability of these methods for predicting the subsurface resistivity layers. We trained, tested and validated ANN using the synthetic VES data as input to the networks and layer parameters of the models as network output. ANN learning parameters are varied and corresponding observations are recorded. The sensitivity analysis of synthetic data and real model demonstrate that ANN algorithms applied in VES data inversion should be considered well not only in terms of accuracy but also in terms of high computational efforts. Also the analysis suggests that ANN model with its various controlling parameters are largely data dependent and hence no unique architecture can be designed for VES data analysis. ANN based methods are also applied to the actual VES field data obtained from the tectonically vital geothermal areas of Jammu and Kashmir, India. Analysis suggests that both the ABP and LMA are suitable methods for 1-D VES modeling. But the LMA method provides greater degree of robustness than the ABP in case of 2-D VES modeling. Comparison of the inversion results with known lithology correlates well and also reveals the additional significant feature of reconsolidated breccia of about 7.0 m thickness beneath the overburden in some cases like at sounding point RDC-5. We may therefore conclude that ANN based methods are significantly faster and efficient for detection of complex layered resistivity structures with a relatively greater degree of precision and resolution.

  3. Area- and site-specific geothermal leasing/permitting profiles; updated geothermal leasing/permitting performance assessment

    SciTech Connect

    Beeland, G.V.; Schumann, E.; Wieland, M.

    1982-02-01

    Sufficient discussion of the elements of the leasing and permitting programs is included to place the information developed in proper context. A table and process flow diagram developed previously which outline the steps in the non-competitive leasing process, is reprinted. Computer printout profiles are presented on 195 identifiable areas in the following states: Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. Sufficient information on the boundaries of these areas is contained in the report to permit identification of their general location on any map of the appropriate state which shows township and range locations.

  4. Microbial Diversity of Acidic Hot Spring (Kawah Hujan B) in Geothermal Field of Kamojang Area, West Java-Indonesia

    PubMed Central

    Aditiawati, Pingkan; Yohandini, Heni; Madayanti, Fida; Akhmaloka

    2009-01-01

    Microbial communities in an acidic hot spring, namely Kawah Hujan B, at Kamojang geothermal field, West Java-Indonesia was examined using culture dependent and culture independent strategies. Chemical analysis of the hot spring water showed a characteristic of acidic-sulfate geothermal activity that contained high sulfate concentrations and low pH values (pH 1.8 to 1.9). Microbial community present in the spring was characterized by 16S rRNA gene combined with denaturing gradient gel electrophoresis (DGGE) analysis. The majority of the sequences recovered from culture-independent method were closely related to Crenarchaeota and Proteobacteria phyla. However, detail comparison among the member of Crenarchaeota showing some sequences variation compared to that the published data especially on the hypervariable and variable regions. In addition, the sequences did not belong to certain genus. Meanwhile, the 16S Rdna sequences from culture-dependent samples revealed mostly close to Firmicute and gamma Proteobacteria. PMID:19440252

  5. Water information bulletin No. 30, part 13: geothermal investigations in Idaho. Preliminary geologic reconnaissance of the geothermal occurrences of the Wood River Drainage Area

    SciTech Connect

    Anderson, J.E.; Bideganeta, K.; Mitchell, J.C.

    1985-04-01

    Pre-tertiary sediments of the Milligen and Wood River Formations consisting primarily of argillite, quartzite, shale and dolomite are, for the most part, exposed throughout the area and are cut locally by outliers of the Idaho Batholith. At some locations, Tertiary-age Challis Volcanics overlay these formations. Structurally the area is complex with major folding and faulting visible in many exposures. Many of the stream drainages appear to be fault controlled. Hydrologic studies indicate hot spring occurrences are related to major structural trends, as rock permeabilities are generally low. Geochemical studies using stable isotopes of hydrogen and oxygen indicate the thermal water in the Wood River region to be depleted by about 10 0/00 in D and by 1 to 2 0/00 in /sup 18/0 relative to cold water. This suggests the water could be meteoric water that fell during the late Pleistocene. The geological data, as well as the chemical data, indicate the geothermal waters are heated at depth, and subsequently migrate along permeable structural zones. In almost all cases the chemical data suggest slightly different thermal histories and recharge areas for the water issuing from the hot springs. Sustained use of the thermal water at any of the identified springs is probably limited to flow rates approximating the existing spring discharge. 28 refs., 16 figs., 3 tabs.

  6. The circular vertical sounding method applied to the exploration of the Dhamar-Rada'a (Y. A. R. ) geothermal area

    SciTech Connect

    Stangalino, G.F.; Aumento, F.; Magri, A.; Noaman, T.

    1982-10-01

    The authors illustrate the use of a new geophysical prospecting method in the detailed investigations of a geothermal field. The method, called ''Circular Vertical Soundings'' (C.V.S.) is useful in determining the predominant orientation of deep fracturing of rocks and of their schistosity. In geothermal studies it is particularly useful to know the direction or directions of the predominant basement fracture systems since these could be the conduits responsible for the flow of hot fluids. The method is based on the Quadripole Schlumberger Technique, and in practice one carries out 4 to 6 vertical electrical soundings (V.E.S.) with the same centre but different azimuth (say every 30-45/sup 0/), thereby permitting one to measure the relationship between apparent resistivity and azimuth; results are plotted on polar diagrams. The validity of the method is demonstrated through its application to the Dhamar-Rada'a (Y.A.R.) geothermal area, where four C.V.S. were carried out together with 83 conventional V.E.S.

  7. Cordon Caulle: an active volcanic-geothermal extensional system of Southern Andes of Chile

    NASA Astrophysics Data System (ADS)

    Sepulveda, F.

    2013-05-01

    Cordon Caulle (CC; 40.5° S) is an active volcanic-geothermal system of the Southern Volcanic Zone (SVZ; 37°-44°S). Morphologically, the CC system is a 6 km x 13 km volcanic plateau bordered by NW-trending structures, limited by Puyehue Volcano to the SE and by Caldera Nevada Caldera to the NW. While the SVZ is dominantly basaltic, CC is unique in that it has produced a wide compositional spectrum from basalt to rhyolite. The most recent volcanic activity of Puyehue-CC (last 70 ky) is dominantly silicic, including two historic fissure eruptions (1921-1922; 1960) and a recent central eruption from Puyehue Volcano (2011). Abnormally silicic volcanism was formerly attributed to a localized compression and long-term magma residence and differentiation, resulting from the NW orientation of underlying CC structures with respect to a NE-oriented σ1 (linked to regional strike-slip stress state). However, later studies, including examination of morpho-tectonic features; detailed structural analysis of the 1960 eruption (triggered by Mw 9.5 1960 Chilean Earthquake); InSAR deformation and gravity surveys, point to both historic and long-term extension at CC with σhmax oriented NNW to NW. The pre-2011 (i.e. Puyehue Volcano eruption) geothermal features of CC included boiling hot springs and geysers (Caldera Nevada) and fumaroles (CC and Puyehue Volcano). Both water and gas chemistry surveys were undertaken to assess the source fluid composition and equilibrium temperature. The combination of water and gas geothermometers led to a conceptual model of a stratified geothermal reservoir, with shallow, low-chloride, steam-heated aquifers equilibrated at temperatures between 150°-180°C, overlying a deeper, possibly dominated reservoir with temperatures in excess of 280°C. Gas chemistry also produced the highest He ratios of the SVZ, in agreement with a relatively pure, undiluted magmatic signature and heat source fueling the geothermal system. Other indicators such as N2/Ar

  8. Geothermal energy abstract sets. Special report No. 14

    SciTech Connect

    Stone, C.

    1985-01-01

    This bibliography contains annotated citations in the following areas: (1) case histories; (2) drilling; (3) reservoir engineering; (4) injection; (5) geothermal well logging; (6) environmental considerations in geothermal development; (7) geothermal well production; (8) geothermal materials; (9) electric power production; (10) direct utilization of geothermal energy; (11) economics of geothermal energy; and (12) legal, regulatory and institutional aspects. (ACR)

  9. Active Management of Integrated Geothermal-CO2 Storage Reservoirs in Sedimentary Formations: Data used in Geosphere Journal Article

    SciTech Connect

    Thomas A. Buscheck

    2015-06-01

    This data submission is for Phase 2 of Active Management of Integrated Geothermal-CO2 Storage Reservoirs in Sedimentary Formations, which focuses on multi-fluid (CO2 and brine) geothermal energy production and diurnal bulk energy storage in geologic settings that are suitable for geologic CO2 storage. This data submission includes all data used in the Geosphere Journal article by Buscheck et al (2016). All assumptions are discussed in that article.

  10. Final report. Geothermal Energy Program: Information dissemination, public outreach, and technical analysis activities. April 1, 1999 to December 31, 2001. USDOE Grant No. DE-FG01-99-EE35098

    SciTech Connect

    Lund, John W.

    2002-03-22

    This is the final report of the accomplishments of the geothermal energy program: information dissemination, public outreach, and technical analysis activities by the project team consisting of the Geo-Heat Center, Geothermal Resources Council, Geothermal Education Office, Geothermal Energy Association, and the Washington State University Energy Program.

  11. Geological and geothermal 3D modelling of the Vienna Basin, Austria - pilot area of the project TRANSENERGY

    NASA Astrophysics Data System (ADS)

    Hoyer, S.; Bottig, M.; Zekiri, F.; Fuchsluger, M.; Götzl, G.; Schubert, G.; Brüstle, A.

    2012-04-01

    In general, sedimentary basins show high potential for the use of geothermal energy. Since the Vienna Basin is a densely populated area, (approximately 1.7 million people in the city of Vienna plus surroundings) geothermal power and heat could play a significant role in the future. The Vienna basin is a relatively cold system where the 100 °C isotherm is to be found at a minimum of about 2500 meters. This fact, meaning the need of deep thus expensive wells, adding the problem of space for drillings and geothermal power plants are challenging subjects in terms of exploitation. The aim of the present work is to model the thermal regime of the Vienna basin and take a closer look on two exploitation scenarios in different hydrological systems (parts of the Bajuvaric and Juvavic nappes in the basement and the horizon of Aderklaa conglomerates in the Neogene sediments). In the first phase, a geological 3D model was created using published data (surface geology, interpreted cross sections from drilling and seismic data) as well as markers from selected wells (data derived from OMV). The geometrical model was built in GoCADTM, where in a first step surfaces were created, displaced along major faults and further exported for the following numerical simulations. In total, 14 Surfaces were created, seven Neogene layers and seven structuring the basement. The thermal modelling is realized using the finite-element software COMSOL Multiphysics© and FEFLOW. Major surfaces were imported into COMSOL as geometry objects, which is not practicable for very complex, fine structures. To represent smaller units inside the subdomains, the associated material parameters had to be imported as functions of the three space coordinates. To gain initial values for the exploitation scenario modelling a steady-state solution has to be achieved. For the lower model boundary, a Neumann boundary condition was set using a newly derived heat flow density map (project TRANSENERGY, Geological Survey

  12. Geology and geothermal resources of the Santiam Pass area of the Oregon Cascade Range, Deschutes, Jefferson and Linn Counties, Oregon

    SciTech Connect

    Hill, B.E.

    1992-10-01

    This open-file report presents the results of the Santiam Pass drilling program. The first phase of this program was to compile all available geological, geophysical and geothermal data for the Santiam Pass area and select a drill site on the basis of these data (see Priest and others, 1987a), A summary of the drilling operations and costs associated with the project are presented in chapter 1 by Hill and Benoit. An Overview of the geology of the Santiam Pass area is presented by Hill and Priest in chapter 2. Geologic mapping and isotopic age determinations in the Santiam Pass-Mount Jefferson area completed since 1987 are summarized in chapter 2. One of the more important conclusions reached in chapter 2 is that a minimum of 2 km vertical displacement has occurred in the High Cascade graben in the Santiam Pass area. The petrology of the Santiam Pass drill core is presented by Hill in chapter 3. Most of the major volcanic units in the core have been analyzed for major, minor, and trace element abundances and have been studied petrographically. Three K-Ar ages are interpreted in conjunction with the magnetostratigraphy of the core to show that the oldest rocks in the core are approximately 1.8 Ma. Geothermal and geophysical data collected from the Santiam Pass well are presented by Blackwell in chapter 4. The Santiam Pass well failed to penetrate beneath the zone of lateral groundwater flow associated with highly permeable Quaternary volcanic rocks. Calculated geothermal gradients range from about 50[degree]C/km at depth 700-900 m, to roughly 110[degree]C/km from 900 m to the bottom of the well at 929 m. Heat-flow values for the bottom part of the hole bracket the regional average for the High Cascades. Blackwell concludes that heat flow along the High Cascades axis is equal to or higher than along the western edge of the High Cascades.

  13. Enhanced Geothermal Systems in Urban Areas - Lessons Learned from the 2006 Basel ML3.4 Earthquake

    NASA Astrophysics Data System (ADS)

    Kraft, T.; Mai, P. M.; Wiemer, S.; Deichmann, N.; Ripperger, J.; Kästli, P.; Bachmann, C. E.; Fäh, D.; Woessner, J.; Giardini, D.

    2009-12-01

    We report on a recent deep-heat mining experiment carried out in 2006/2007 in the city of Basel (Switzerland). This pilot project was designed to produce renewable geothermal energy using the Enhanced Geothermal System (EGS) methodology. For developing the geothermal reservoir, a deep borehole was brought down to 5 km depth. Then, in December 2006, the deep-heat-mining project entered the first critical phase when the water injections started for generating micro-fracturing of the rock. These fractures increase the permeability of the host rock, needed for efficient heat exchange between the rock and the cold water; however, these fracture are also source of micro-seismicity - small earthquakes that are continuously recorded and monitored by dedicated local seismic networks. In this stimulation phase, the seismic activity increased rapidly above the usual background seismicity, and culminated in a widely felt ML 3.4 earthquake, which caused some damage in the city of Basel. Due to the higher-than-expected seismic activity, and the reaction of the population, the media, and the politicians, the experiment was stalled only 6 days after the stimulations began. Although the injected water was allowed to escape immediately after the mainshock and pressure at the wellhead dropped rapidly, the seismic activity declined only slowly, with three ML > 3 events occurring one to two months later. Although the EGS technology has been applied and studied at various sites since the 1970s, the physical processes and parameters that control injection-induced seismicity - in terms of earthquake rate, size distribution and maximum magnitude - are still poorly understood. Consequently, the seismic hazard and risk associated with the creation and operation of EGS are difficult to estimate. The very well monitored Basel seismic sequence provides an excellent opportunity to advance the understanding of the physics of EGS. The Swiss Seismological Service (SED) is investigating the Basel

  14. Changes in physical-thermal properties of soil related to very shallow geothermal systems in urban areas

    NASA Astrophysics Data System (ADS)

    Di Sipio, Eloisa; Psyk, Mario; Popp, Thomas; Bertermann, David

    2016-04-01

    In the near future the population living in urban areas is expected to increase. This worldwide trend will lead to a high concentrations of infrastructures in confined areas, whose impact on land use and shallow subsurface must be well evaluated. Since shallow geothermal energy resource is becoming increasingly important as renewable energy resource, due to its huge potential in providing thermal energy for residential and tertiary buildings and in contributing to reduce greenhouse gas emission, the number of installed geothermal systems is expected to continue to rise in the near future. However, a leading question concerns the short and long-term effect of an intensive thermal use of the shallow subsurface for heat generation, cooling and thermal energy storage. From an environmental and technical point of view, changes on ground temperatures can influence the physical-thermal properties of soil and groundwater as well as their chemical and biological features. In this study the preliminary results of ITER Project are presented. This project, funded by European Union, focuses on improving heat transfer efficiency of very shallow geothermal systems, as horizontal collector systems or special forms (i.e. helix system), interesting the first 2 m of depth from ground level. Given the heterogeneity of sedimentary deposits in alluvial plain and the uncertainties related to the estimation of thermal parameters for unconsolidated material affected by thermal use, physical-thermal parameters (i.e. moisture content, bulk density, thermal conductivity...) where determined in laboratory for sand, clay and loamy sand samples. In addition, preliminary results from a field test site located within an urban area will be also shown. The main aim is to improve our knowledge of heat transfer process in the soil body in order (i) to create a reference database to compare subsequently the impact of temperature variations on the same properties and (ii) to provide reliable data for

  15. Slip and Dilation Tendency Anlysis of Neal Hot Springs Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Slip and Dilation Tendency in focus areas Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998

  16. Crustal deformation due to fluid extraction and re-injection in the Hengill geothermal area in Southwest Iceland

    NASA Astrophysics Data System (ADS)

    Juncu, D.; Arnadottir, T.; Budzińska, K.; Hooper, A. J.

    2014-12-01

    Several geothermal energy production fields are currently harnessed in Iceland. One of these is located at the Hengill triple junction, where the oblique plate motion along the Reykjanes peninsula is partitioned between the E-W oriented transform along the South Iceland Seismic Zone (SISZ) and spreading across the Western Volcanic Zone in SW Iceland. The Hengill volcano has high temperature geothermal areas utilized by the Hellisheiði and Nesjavellir power plants. The region around the power plants is subject to motion and deformation of the Earth's surface due to several processes. These include the motion of the Earth's crust due to plate spreading, co- and post seismic deformation due to earthquakes in the South Iceland Seismic Zone and deformation due to water and steam extraction and wastewater re-injection near geothermal power plants. We measure surface displacement using both GPS and InSAR data. The former are obtained from four continuous and more than 15 campaign GPS stations, with time-series starting after two M6 earthquakes on 29 May 2008 in Ölfus - the western most part of the SISZ. The InSAR data consist of 10 images taken on track 41 of the TerraSar-X mission, starting October 2009. We can see a clear subsidence signal in the proximity of the power plants with a maximum of ~18 mm/yr in Line-of-Sight direction (LOS) at Hellisheiði. The subsidence is elongated in NNE-SSW direction and possibly related to the orientation of the Hengill fissure swarm. In addition to subsidence, we observe an uplift signal of ca. 10 mm/yr in LOS west of the Hellisheiði site, potentially due to wastewater re-injection in the area. The area of maximum uplift is located close to the epicenters of two M4 earthquakes that occurred in October 2011. Since the signal around the power plants is the most prominent, we start our investigation with trying to find an appropriate model for deformation due to fluid extraction and re-injection with the aim of simulating the data. By

  17. On the magma chamber characteristics as inferred from surface geology and geochemistry: examples from Mexican geothermal areas

    NASA Astrophysics Data System (ADS)

    Verma, Surendra P.

    1985-12-01

    A procedure is described which enables us to obtain estimates of some physical and chemical characteristics of sub-surface magma chambers. This is applied to three geothermal areas of the Mexican Volcanic Belt (MVB) in central Mexico. The approximate volumes estimated for the underlying chemically and thermally zoned magma chambers are: 1500 km 3 for Los Humeros, 600 km 3 for La Primavera, and 400 km 3 for Los Azufres. These estimates will have to be modified as more geological-geochemical data become available.

  18. Earthquake Swarm Activity Beneath the Tokaanu-Waihi Geothermal System, Lake Taupo, New Zealand

    SciTech Connect

    Hochstein, M.P.; Sherburn, S.; Tikku, J.

    1995-01-01

    The hypocenters of 4 earthquake swarms (total of 54 events), recorded with a local network between 1986 April and 1987 January, occur within upper crustal rocks of the deeper Tokaanu-Waihi geothermal reservoir; all the events had a magnitude M{sub L} {le} 3.2. Most foci are aligned along two NW-trending basement fault structures along which young rhyodacitic extrusions can be found. The swarm activity has been interpreted in terms of injections into basement fractures of magma from deeper chambers (dyke injection swarm activity).

  19. Geothermal Energy.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    An introduction to geothermal energy is provided in this discussion of: (1) how a geothermal reservoir works; (2) how to find geothermal energy; (3) where it is located; (4) electric power generation using geothermal energy; (5) use of geothermal energy as a direct source of heat; (6) geopressured reservoirs; (7) environmental effects; (8)…

  20. Geothermal activity and energy of the Yakedake volcano, Gifu-Nagano, Japan

    SciTech Connect

    Iriyama, Jun

    1996-12-31

    The temperature of the most active solfatara in the summit crater of the Yakedake volcano (altitude 2,455 m Gifu-Nagano, Japan) was 92.2 and 129.4{degrees}C in September 1995 and in October 1994, respectively. The temperature of solfatara in the northern summit dome at an altitude of 2,240 to 2,270 m ranged from 68.2 to 92.5{degrees}C in September 1995. The water sample from a crater pond, Shoga-ike, located on the summit, showed a pH and electrical conductivity of 4.38 and 42.2 {mu}S/cm in October 1991, 4.35 and 42.4 {mu}S/cm in September 1992, 4.11 and 76.6 {mu}S/cm in October 1994, and 4.30 and 45.1 {mu}S/cm in September 1995, respectively. In 1960, the water sample from the same pond showed the pH and electrical conductivity of 3.7 and 80.8 {mu}S/cm, respectively. Although the values of pH and electrical conductivity in 1994 approached to the values at the volcano`s pre-eruption in 1960, the eruption in the summit dome did not occur in 1995. However, a large steam explosion occurred in the Nakanoyu area of the southeastern Mountainside of the volcano. The geothermal energy within the summit dome at an altitude of 2,050 to 2,455 m of the Yakedake volcano is calculated, using new data, to be about 4.8 x 10{sup 17} J, which represents a thermal power output of 5.1 x 10{sup 2} MW{sub th} averaged over 30 yrs.

  1. Evaluation of low-temperature geothermal potential in Utah and Goshen Valleys and adjacent areas, Utah. Part II. Water temperature and chemistry

    SciTech Connect

    Klauk, R.H.; Davis, D.A.

    1984-12-01

    Geothermal reconnaissance techniques have identified five areas in Utah County warranting further investigation for low-temperature geothermal resources. One area in northern Utah Valley is along Utah Lake fault zone and includes Saratoga Hot Springs. Water temperatures within this area range from 21 to 43/sup 0/C. Common ion analyses as well as B and Li concentrations indicate waters sampled in this area are anomalous when compared to other samples from the same aquifer. Two other areas in southern Utah Valley also coincide with the Utah Lake fault zone. Common ion analyses, trace element concentrations, and C1/HCO/sub 3/ ratios distinguish these areas from all other waters in this valley. Temperatures within these southern areas range from 21 to 32/sup 0/C. All three thermal areas are possibly the result of deep circulation of meteoric water being warmed and subsequently migrating upward within the Utah Lake fault zone. The Castilla Hot Springs area has been expanded by this study to include a spring located 3 mi further up Spanish Fork Canyon near the Thistle earthflow. A temperature of 50/sup 0/C was recorded for this spring and chemistry is similar to Castilla. In Goshen Valley, the fifth geothermal area identified, measured temperatures range from 20 to 27/sup 0/C for some wells and springs. Chemical analyses, however, do not discern the location of low-temperature geothermal reservoirs. 18 refs., 7 figs., 5 tabs.

  2. Evaluation of noise associated with geothermal-development activities. Final report, July 31, 1979-April 30, 1982

    SciTech Connect

    Long, M.; Stern, R.

    1982-01-01

    This report was prepared for the purpose of ascertaining the current state of noise generation, suppression, and mitigation techniques associated with geothermal development. A description of the geothermal drilling process is included as well as an overview of geothermal development activities in the United States. Noise sources at the well site, along geothermal pipelines, and at the power plants are considered. All data presented are measured values by workers in the field and by Marshall Long/Acoustics. One particular well site was monitored for a period of 55 continuous days, and includes all sources of noise from the time that the drilling rig was brought in until the time that it was moved off site. A complete log of events associated with the drilling process is correlated with the noise measurements including production testing of the completed well. Data are also presented which compare measured values of geothermal noise with federal, state, county, and local standards. A section on control of geothermal noise is also given. Volume I of this document presents summary information.

  3. Geochemistry of thermal fluids in NW Honduras: New perspectives for exploitation of geothermal areas in the southern Sula graben

    NASA Astrophysics Data System (ADS)

    Capaccioni, Bruno; Franco, Tassi; Alberto, Renzulli; Orlando, Vaselli; Marco, Menichetti; Salvatore, Inguaggiato

    2014-06-01

    The results of a geochemical survey on thermal waters and, for the first time for this site, gas discharges in five geothermal sites (Azacualpa "La Cueva", Río Ulua, Río Gualcarque, El Olivar and Laguna de Agua Caliente) in NW Honduras are here presented and discussed. El Olivar and Laguna de Agua Caliente, in the southern part of the Sula graben are very close to a Quaternary basaltic field, whereas Azacualpa "La Cueva", Río Ulua and Río Gualcarque, located to the southwest of the Yojoa Lake, direcly emerge from the Cretaceous limestone deposits. The measured temperatures range between 37.5 and 104.8 °C. "Mature", alkaline, Na-SO4 thermal waters discharge from Azacualpa "La Cueva", while those from El Olivar and Laguna de Agua Caliente are "immature" and show a Na-HCO3 composition. Chemical equilibria of waters and gases from the Azacualpa "La Cueva" thermal springs indicate temperatures ranging from 150 to 200 °C. Conversely, gas discharges from El Olivar and Laguna de Agua Caliente have attained a partial chemical equilibrium in the liquid phase at slightly higher temperatures (200-250 °C), although gas-gas faster reactions involving CO seem to be adjusted in an isothermally separated vapor phase. Unlike Azacualpa, SiO2 geothermometer at El Olivar and Laguna de Agua Caliente indicates equilibrium temperatures for the liquid phase much lower than those calculated for the gas phase (≤ 120 °C). We conclude that thermal waters from the Azacualpa area likely represent the direct emergence of a water dominated reservoir having temperatures ≤ 150-200 °C. By contrast, at El Olivar and Laguna de Agua Caliente hot springs are supplied by a boiling shallow aquifer fed by a vapor phase rising from a steam-dominated zone. The above geochemical model is consistent with a geothermal reservoir hosted within the Cretaceous carbonate sequences of the Yojoa Group in the whole investigated sites. The reservoir extensively crops out in the Azacualpa area whereas the

  4. Assessment of Ecological and Seismological Situations In The Geothermal Area of Tbilisi By Hydrodynamic Monitoring

    NASA Astrophysics Data System (ADS)

    Chelidze, T.; Buntebarth, G.; Melikadze, G.; Kumsiashvili, G.; Bendukidze, G.

    The paper is devoted to the investigation of the hydrodynamic regime of deep aquifers of the Tbilisi hydrothermal area, in order to delineate the spatial distribution of ther- mal water basins and to understand recorded anomalies quantitatively. Thermal min- eral waters or "sulphur springs" of Tbilisi have been of particular importance for its population during the 1,5 thousand years history of Tbilisi. Water of these springs is hot (40-50 C) and somewhat sulphurous: contain sulphuretted hydrogen and it is used for therapeutic and recreation purposes. The water resort is based on them. Hot natural springs are connected to the exposed sediments of middle Eocene in the river Mtkvari gorge. The water-bearing complex of volcanic type of middle Eocene is abundant at the Tbilisi thermal fields. Through drilling in the North - West part of the city (Lisi dis- trict), several boreholes were opened, where the sulphurous thermal water of 60-70 oC has been encountered. This water is used for room heating. Drilling will be continued for providing the city with hot water. It is planned to warm 30-40 % of the whole Tbil- isi using the geothermal water circulation system. From west to east, these deposits are buried under younger rocks. 20-30 km far from the deposit, oil has been found in an anticline structure. Intensive exploitation of this oil deposit caused the perturbation of the hydraulic regime with consequences in its central part where the thermal springs partly faded out in the eighties. Until present, the hydrodynamical interdependence be- tween these 3 districts has been studied by various authors, but its true character is still unclear. The spatial extent of the thermal waters has also to be investigated. Without detailed research, the sustainable and ecologically correct use of the thermal reservoir is impossible. In the period from July 1999 to July 2001 the monitoring network of water level in boreholes (WLB) and microtemperatures was operating on three wells

  5. Development of Genetic Occurrence Models for Geothermal Prospecting

    NASA Astrophysics Data System (ADS)

    Walker, J. D.; Sabin, A.; Unruh, J.; Monastero, F. C.; Combs, J.

    2007-12-01

    Exploration for utility-grade geothermal resources has mostly relied on identifying obvious surface manifestations of possible geothermal activity, e.g., locating and working near steaming ground or hot springs. This approach has lead to the development of over 130 resources worldwide, but geothermal exploration done in this manner is akin to locating hydrocarbon plays by searching for oil seeps. Confining exploration to areas with such features will clearly not discover a blind resource, that is, one that does not have surface expression. Blind resources, however, constitute the vast majority of hydrocarbon plays; this may be the case for geothermal resources as well. We propose a geothermal exploration strategy for finding blind systems that is based on an understanding of the geologic processes that transfer heat from the mantle to the upper crust and foster the conditions for hydrothermal circulation or enhanced geothermal exploration. The strategy employs a genetically based screening protocol to assess potential geothermal sites. The approach starts at the plate boundary scale and progressively focuses in on the scale of a producing electrical-grade field. Any active margin or hot spot is a potential location for geothermal resources. Although Quaternary igneous activity provides a clear indication of active advection of hot material into the upper crust, it is not sufficient to guarantee a potential utility-grade resource. Active faulting and/or evidence of high strain rates appear to be the critical features associated with areas of utility-grade geothermal potential. This is because deformation on its own can advect sufficient heat into the upper crust to create conditions favorable for geothermal exploitation. In addition, active deformation is required to demonstrate that open pathways for circulation of geothermal fluids are present and/or can be maintained. The last step in the screening protocol is to identify any evidence of geothermal activity

  6. Geothermal Exploration Case Studies on OpenEI (Presentation)

    SciTech Connect

    Young, K.; Bennett, M.; Atkins, D.

    2014-03-01

    The U.S. Geological Survey (USGS) resource assessment (Williams et al., 2008) outlined a mean 30 GWe of undiscovered hydrothermal resource in the western United States. One goal of the U.S. Department of Energy's (DOE) Geothermal Technology Office (GTO) is to accelerate the development of this undiscovered resource. DOE has focused efforts on helping industry identify hidden geothermal resources to increase geothermal capacity in the near term. Increased exploration activity will produce more prospects, more discoveries, and more readily developable resources. Detailed exploration case studies akin to those found in oil and gas (e.g. Beaumont and Foster, 1990-1992) will give developers central location for information gives models for identifying new geothermal areas, and guide efficient exploration and development of these areas. To support this effort, the National Renewable Energy Laboratory (NREL) has been working with GTO to develop a template for geothermal case studies on the Geothermal Gateway on OpenEI. In 2012, the template was developed and tested with two case studies: Raft River Geothermal Area (http://en.openei.org/wiki/Raft_River_Geothermal_Area) and Coso Geothermal Area (http://en.openei.org/wiki/Coso_Geothermal_Area). In 2013, ten additional case studies were completed, and Semantic MediaWiki features were developed to allow for more data and the direct citations of these data. These case studies are now in the process of external peer review. In 2014, NREL is working with universities and industry partners to populate additional case studies on OpenEI. The goal is to provide a large enough data set to start conducting analyses of exploration programs to identify correlations between successful exploration plans for areas with similar geologic occurrence models.

  7. Geothermal energy: 1992 program overview

    SciTech Connect

    Not Available

    1993-04-01

    Geothermal energy is described in general terms with drawings illustrating the technology. A map of known and potential geothermal resources in the US is included. The 1992 program activities are described briefly. (MHR)

  8. Leasing of federal geothermal resources

    NASA Technical Reports Server (NTRS)

    Stone, R. T.

    1974-01-01

    Pursuant to the Geothermal Steam Act of 1970 and the regulations published on December 21, 1973, the first Federal geothermal competitive lease sale was held on January 22, 1974, by the Department of the Interior, offering 33 tracts totalling over 50,000 acres in three Known Geothermal Resource Areas in California. On January 1, 1974, Federal lands outside Known Geothermal Resource Areas were opened to noncompetitive lease applications, of which, 3,763 had been received by June 1, 1974. During fiscal year 1974, a total of 22 competitive leases had been issued in California and Oregon. The principal components in the Department involved in the leasing program are the Geological Survey and the Bureau of Land Management. The former has jurisdiction over drilling and production operations and other activities in the immediate area of operations. The latter receives applications and issues leases and is responsible for managing leased lands under its jurisdiction outside the area of operations. The interrelationships of the above agencies and the procedures in the leasing program are discussed.

  9. Quantifying the undiscovered geothermal resources of the United States

    USGS Publications Warehouse

    Williams, Colin F.; Reed, Marshall J.; DeAngelo, Jacob; Galanis, S. Peter

    2009-01-01

    National Park, are unique in North America and highly unlikely to have counterparts with equivalent characteristics among the systems comprising the undiscovered resources. (2) Historical geothermal exploration has been limited in both the effectiveness of techniques employed and spatial coverage, since most exploration has targeted areas associated with surface thermal manifestations in the most easily accessible lands. (3) As noted by other investigators, in general, the hottest and largest geothermal systems are those with heat sources arising from recent magmatic activity. Consequently, a larger fraction of the undiscovered resource is associated with those areas favorable to the formation of this type of geothermal system, including some relatively remote areas, such as the Aleutian volcanic arc in Alaska.

  10. Diversity and abundance of the arsenite oxidase gene aioA in geothermal areas of Tengchong, Yunnan, China.

    PubMed

    Jiang, Zhou; Li, Ping; Jiang, Dawei; Wu, Geng; Dong, Hailiang; Wang, Yanhong; Li, Bing; Wang, Yanxin; Guo, Qinghai

    2014-01-01

    A total of 12 samples were collected from the Tengchong geothermal areas of Yunnan, China, with the goal to assess the arsenite (AsIII) oxidation potential of the extant microbial communities as inferred by the abundance and diversity of the AsIII oxidase large subunit gene aioA relative to geochemical context. Arsenic concentrations were higher (on average 251.68 μg/L) in neutral or alkaline springs than in acidic springs (on average 30.88 μg/L). aioA abundance ranged from 1.63 × 10(1) to 7.08 × 10(3) per ng of DNA and positively correlated with sulfide and the ratios of arsenate (AsV):total dissolved arsenic (AsTot). Based on qPCR estimates of bacterial and archaeal 16S rRNA gene abundance, aioA-harboring organisms comprised as much as ~15% of the total community. Phylogenetically, the major aioA sequences (270 total) in the acidic hot springs (pH 3.3-4.4) were affiliated with Aquificales and Rhizobiales, while those in neutral or alkaline springs (pH 6.6-9.1) were inferred to be primarily bacteria related to Thermales and Burkholderiales. Interestingly, aioA abundance at one site greatly exceeded bacterial 16S rRNA gene abundance, suggesting these aioA genes were archaeal even though phylogenetically these aioA sequences were most similar to the Aquificales. In summary, this study described novel aioA sequences in geothermal features geographically far removed from those in the heavily studied Yellowstone geothermal complex.

  11. State-coupled low-temperature geothermal-resource-assessment program, Fiscal Year 1980. Final technical report

    SciTech Connect

    Icerman, L.; Starkey, A.; Trentman, N.

    1981-08-01

    Magnetic, gravity, seismic-refraction, and seismic-reflection profiles across the Las Alturas Geothermal Anomaly, New Mexico, are presented. Studies in the Socorro area include the following: seismic measurements of the tertiary fill in the Rio Grande Depression west of Socorro, geothermal data availability for computer simulation in the Socorro Peak KGRA, and ground water circulation in the Socorro Geothermal Area. Regional geothermal exploration in the Truth or Consequences Area includes: geological mapping of the Mud Springs Mountains, hydrogeology of the thermal aquifer, and electrical-resistivity investigation of the geothermal potential. Other studies included are: geothermal exploration with electrical methods near Vado, Chamberino, and Mesquite; a heat-flow study of Dona Ana County; preliminary heat-flow assessment of Southeast Luna County; active fault analysis and radiometric dating of young basalts in southern New Mexico; and evaluation of the geothermal potential of the San Juan Basin in northwestern New Mexico.

  12. Evaluation of geothermal energy in Arizona. Quarterly topical progress report, April 1, 1981-June 30, 1981

    SciTech Connect

    White, D.H.

    1981-01-01

    Activities included the identification and delineation of geothermal prospects, the comparison of conventional energy use patterns with geothermal sources, the preparation of area development plans and the compilation of detailed economic and energy data for each area. Current emphasis is on commercialization. (MHR)

  13. Imperial County geothermal development semi-annual report, October 1, 1980-March 31, 1981

    SciTech Connect

    Not Available

    1981-01-01

    The current geothermal progress in Imperial County is reported. Three areas are reported: Geothermal Administration, Geothermal Planning, and other Geothermal Activities. Geothermal Administration addresses the status of the Imperial Valley Environmental Project (IVEP) transfer, update of the Geothermal Resource Center, and findings of Geothermal field inspections. In addition, the cooperative efforts between industry and the County; Master EIR for the Salton Sea KGRA and the resurveying of the subsidence detection network are covered. Geothermal Planning addresses a Board of Supervisor action on the Union Oil Geothermal Production Permit for 16 wells in the Salton Sea KGRA and a permit for Southern California Edison 10 megawatts power plant in the Salton Sea KGRA. Planning Commission action covers: Amendment of Magma Power's 49 megawatts Geothermal Production Permit to 28 megawatt power plant and relocation of the plant and wells within the Salton Sea KGRA; Exploration permit to Occidental Geothermal for four exploratory wells in East Brawley; Geothermal Production Permit to Southern California Edison to operate a 10 megawatt power plant in the Salton Sea KGRA; and Geothermal production permit to Union Oil for 16 production-injection wells in the Salton Sea KGRA. Lastly, EIR exemptions to CEQA were granted to Chevron for 70 shallow temperature observation holes and Union for fifteen. Other Geothermal Activity addresses the County Direct Heat Development study; the solicitation for district heating and cooling proposals; the new Geothermal Class II-1 disposal site; the DOE Region IX meeting in Tucson; and USGA designating a new KGRA, the East Brawley KGRA, the Westmorland KGRA, and revising the southern border of the Salton Sea KGRA.

  14. Environmental analysis of geopressured-geothermal prospect areas, De Witt and Colorado counties, Texas. Final report, March 1 - August 31, 1979

    SciTech Connect

    Gustavson, T.C.; Reeder, F.S.; Badger, E.A.

    1980-02-01

    Information collected and analyzed for a preliminary environmental analysis of geopressured geothermal prospect areas in Colorado and DeWitt Counties, Texas is presented. Specific environmental concerns for each geopressured geothermal prospect area are identified and discussed. Approximately 218 km/sup 2/(85 mi/sup 2/) were studied in the vicinity of each prospect area to: (1) conduct an environmental analysis to identify more and less suited areas for geopressured test wells; and (2) provide an environmental data base for future development of geopressured geothermal energy resources. A series of maps and tables are included to illustrate environmental characteristics including: geology, water resources, soils, current land use, vegetation, wildlife, and meteorological characteristics, and additional relevant information on cultural resources, power- and pipelines, and regulatory agencies. A series of transparent overlays at the scale of the original mapping has also been produced for the purposes of identifying and ranking areas of potential conflict between geopressured geothermal development and environmental characteristics. The methodology for ranking suitability of areas within the two prospect areas is discussed in the appendix. (MHR)

  15. 3D Model of the McGinness Hills Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    The McGinness Hills geothermal system lies in a ~8.5 km wide, north-northeast trending accommodation zone defined by east-dipping normal faults bounding the Toiyabe Range to the west and west-dipping normal faults bounding the Simpson Park Mountains to the east. Within this broad accommodation zone lies a fault step-over defined by north-northeast striking, west-dipping normal faults which step to the left at roughly the latitude of the McGinness Hills geothermal system. The McGinness Hills 3D model consists of 9 geologic units and 41 faults. The basal geologic units are metasediments of the Ordovician Valmy and Vininni Formations (undifferentiated in the model) which are intruded by Jurassic granitic rocks. Unconformably overlying is a ~100s m-thick section of Tertiary andesitic lava flows and four Oligocene-to-Miocene ash-flow tuffs: The Rattlesnake Canyon Tuff, tuff of Sutcliffe, the Cambell Creek Tuff and the Nine Hill tuff. Overlying are sequences of pre-to-syn-extensional Quaternary alluvium and post-extensional Quaternary alluvium. 10-15º eastward dip of the Tertiary stratigraphy is controlled by the predominant west-dipping fault set. Geothermal production comes from two west dipping normal faults in the northern limb of the step over. Injection is into west dipping faults in the southern limb of the step over. Production and injection sites are in hydrologic communication, but at a deep level, as the northwest striking fault that links the southern and northern limbs of the step-over has no permeability.

  16. Seismic properties of fluid bearing formations in magmatic geothermal systems: can we directly detect geothermal activity with seismic methods?

    NASA Astrophysics Data System (ADS)

    Grab, Melchior; Scott, Samuel; Quintal, Beatriz; Caspari, Eva; Maurer, Hansruedi; Greenhalgh, Stewart

    2016-04-01

    Seismic methods are amongst the most common techniques to explore the earth's subsurface. Seismic properties such as velocities, impedance contrasts and attenuation enable the characterization of the rocks in a geothermal system. The most important goal of geothermal exploration, however, is to describe the enthalpy state of the pore fluids, which act as the main transport medium for the geothermal heat, and to detect permeable structures such as fracture networks, which control the movement of these pore fluids in the subsurface. Since the quantities measured with seismic methods are only indirectly related with the fluid state and the rock permeability, the interpretation of seismic datasets is difficult and usually delivers ambiguous results. To help overcome this problem, we use a numerical modeling tool that quantifies the seismic properties of fractured rock formations that are typically found in magmatic geothermal systems. We incorporate the physics of the pore fluids, ranging from the liquid to the boiling and ultimately vapor state. Furthermore, we consider the hydromechanics of permeable structures at different scales from small cooling joints to large caldera faults as are known to be present in volcanic systems. Our modeling techniques simulate oscillatory compressibility and shear tests and yield the P- and S-wave velocities and attenuation factors of fluid saturated fractured rock volumes. To apply this modeling technique to realistic scenarios, numerous input parameters need to be indentified. The properties of the rock matrix and individual fractures were derived from extensive literature research including a large number of laboratory-based studies. The geometries of fracture networks were provided by structural geologists from their published studies of outcrops. Finally, the physical properties of the pore fluid, ranging from those at ambient pressures and temperatures up to the supercritical conditions, were taken from the fluid physics

  17. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    SciTech Connect

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

    1982-06-01

    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  18. Geologic Map and Cross Sections of the McGinness Hills Geothermal Area - GIS Data

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    Geologic map data in shapefile format that includes faults, unit contacts, unit polygons, attitudes of strata and faults, and surficial geothermal features. 5 cross‐sections in Adobe Illustrator format. Comprehensive catalogue of drill‐hole data in spreadsheet, shapefile, and Geosoft database formats. Includes XYZ locations of well heads, year drilled, type of well, operator, total depths, well path data (deviations), lithology logs, and temperature data. 3D model constructed with EarthVision using geologic map data, cross‐sections, drill‐hole data, and geophysics.

  19. Modelling of Subglacial Volcanic and Geothermal Activity, during the 2014-15 Bárdarbunga-Holuhraun Eruption and Caldera Collapse

    NASA Astrophysics Data System (ADS)

    Reynolds, H. I.; Gudmundsson, M. T.; Hognadottir, T.

    2015-12-01

    Seismic unrest was observed within the subglacial caldera of Bárdarbunga on 16 August 2014, followed by seismicity tracing the path of a lateral dyke extending underneath the Vatnajökull glacier out to 45 km to the north east of the volcano. A short subaerial fissure eruption occurred at the site of the Holuhraun lavas, just north of the glacier edge on 29 August, before recommencing in earnest on 31 August with a large effusive eruption and accompanying slow caldera collapse, which lasted for approximately 6 months. The glacier surface around Bárdarbunga was monitored using aerial altimeter profiling. Several shallow depressions, known as ice cauldrons, formed around the caldera rim and on Dyngjujökull glacier above the dyke propagation path. The cauldrons range in volume from approximately 0.0003 km3 to 0.02 km3. Two types of melting were observed: high initial heat flux over a period of days which gradually disappears; and slower but more sustained melting rates. We present time series data of the development and evolution of these cauldrons, with estimates of the heat flux magnitudes involved.The nature of the heat source required to generate these cauldrons is not obvious. Two scenarios are explored: 1) small subglacial eruptions; or 2) increased geothermal activity induced by the dyke intrusion. We investigate these scenarios using numerical modelling, considering the surface heat flux produced, and timescales and spatial extent of associated surface anomalies. It is found that a magmatic intrusion into rocks where the groundwater is near the boiling point curve can cause rapid increase in geothermal activity, but even a shallow intrusion into a cold groundwater reservoir will have a muted thermal response. Thus, our results indicate that minor subglacial eruptions are the most plausible explanation for the observed rapid melting far from known geothermal areas. These results have implications for the interpretation of thermal signals observed at ice

  20. Tiber delta CO2-CH4 degassing: A possible hybrid, tectonically active Sediment-Hosted Geothermal System near Rome

    NASA Astrophysics Data System (ADS)

    Ciotoli, G.; Etiope, G.; Marra, F.; Florindo, F.; Giraudi, C.; Ruggiero, L.

    2016-01-01

    Fiumicino town in the Tiber River delta, near Rome International Airport (Italy), is historically affected by large amounts of carbon dioxide (CO2) in the ground and gas eruptions triggered by shallow drilling. While it is known that CO2 originates from carbonate thermometamorphism and/or mantle degassing, the origin of methane (CH4) associated with CO2 is uncertain and the outgassing spatial distribution is unknown. Combining isotope gas geochemistry, soil gas, and structural-stratigraphic analyses, we provide evidence for a hybrid fluid source system, classifiable as Sediment-Hosted Geothermal System (SHGS), where biotic CH4 from sedimentary rocks is carried by deep geothermic CO2 through active segments of a half-graben. Molecular and isotopic composition of CH4 and concentration of heavier alkanes (ethane and propane), obtained from gas vents and soil gas throughout the delta area, reveal that thermogenic CH4 (up to 3.7 vol% in soil gas; δ13CCH4: -37 to -40‰ VPDB-Vienna Peedee Belemnite, and δ2HCH4: -162 to -203‰ VSMOW - Vienna Standard Mean Ocean Water in gas vents) prevails over possible microbial and abiotic components. The hydrocarbons likely result from known Meso-Cenozoic petroleum systems of the Latium Tyrrhenian coast. Overmaturation of source rocks or molecular fractionation induced by gas migration are likely responsible for increased C1/C2+ ratios. CO2 and CH4 soil gas anomalies are scattered along NW-SE and W-E alignments, which, based on borehole, geomorphologic, and structural-stratigraphic analyses, coincide with active faults of a half-graben that seems to have controlled the recent evolution of the Tiber delta. This SHGS can be a source of considerable greenhouse gas emissions to the atmosphere and hazards for humans and buildings.

  1. Geothermal direct-heat utilization assistance. Quarterly project progress report, July--September 1997

    SciTech Connect

    1997-10-01

    This report summarizes geothermal technical assistance, R and D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the fourth quarter of FY-97 (July--September 1997). It describes 213 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include requests for general information including maps, geothermal heat pumps, resource and well data, space heating and cooling, greenhouses, acquaculture, equipment, district heating, resorts and spas, and industrial applications. Research activities include the completion of a Comprehensive Greenhouse Developer Package. Work accomplished on the revision of the Geothermal Direct Use Engineering and Design Guidebook are discussed. Outreach activities include the publication of the Quarterly Bulletin (Vol. 18, No. 3), dissemination of information mainly through mailings of publications, geothermal library acquisition and use, participation in workshops, short courses, and technical meetings by the staff, and progress monitor reports on geothermal activities.

  2. Three-dimensional Q/sup -1/ model of the Coso Hot Springs known geothermal resource area

    SciTech Connect

    Young, C.; Ward, R.W.

    1980-05-10

    Observations of teleseismic P waves above geothermal systems exhibit travel time delays and anomalously high seismic attenuation, which is extremely useful in estimating the thermal regime and the potential of the system. A regional telemetered network of sixteen stations was operated by the U.S. Geological Survey in the Coso Hot Springs Known Geothermal Resources Area (KGRA) for such studies from September 1975 to October 1976. Subsequently, they deployed a portable Centipede array of 26 three-component stations near the center of anomaly. The seismograms of 44 events recorded by the telemetered array and nine events by the Centipede array were analyzed using the reduced spectral ratio technique to determine the differential attenuation factordeltat* for the events recorded with the highest signal-to-noise ratio. The deltat* variation observed across the Coso Hot Springs KGRA were small (<0.2 s). A three-dimensional generalized linear inversion of the deltat* observations was performed using a three-layer model. A shallow zone of high attenuation exists within the upper 5 km in a region bounded by Coso Hot Springs, Devils Kitchen, and Sugarloaf Mountain probably corresponding to a shallow vapor liquid mixture or 'lossy' near surface lithology. No zones of significantly high attenuation occur between 5- and 12-km depth. Between the depth of 12--20 km a thick zone of high attenuation (Q<50) exists, offset toward the east from the surface anomaly.

  3. Geothermal direct-heat utilization assistance: Federal assistance program. Quarterly project progress report, October--December 1995

    SciTech Connect

    1996-02-01

    The report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-96. It describes 90 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment and resources. Research activities are summarized on low-temperature resource assessment, geothermal district heating system cost evaluation and silica waste utilization project. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, development of a webpage, and progress monitor reports on geothermal resources and utilization.

  4. Geothermal development attitudes surveyed

    SciTech Connect

    Not Available

    1986-01-01

    The State of Hawaii has conducted several surveys on public opinion towards the development of geothermal energy. The latest poll was designed to: measure public opinion in the County of Hawaii relevant to geothermal development for electrical power supplied to Island of Hawaii residents only; measure public opinion in the County of Hawaii relevant to geothermal development of electricity to be exported for use on Oahu; and identify barriers to, and opportunities for energy conservation programs, including geothermal development. In general, the residents of the County of Hawaii favor some form of geothermal development. Issues on geothermal development of concern to the public were similar to those mentioned in the 1982 study. Basically, the issues amount to a trade-off between the economic advantages and the environmental problems of geothermal development. The strong points in favor of development include a perceived need for more energy, a strong preference for alternate energy forms over petroleum, perceived benefits for the local economy and the employment rates, and the possibility that development may reduce or contain utility bills. On the other hand, it appears that geothermal development will cause health problems for those who live near the wells, be hazardous to flora and fauna in the Puna area, and create noise and odor above tolerable levels. These are oversimplified statements of the reasons behind both support and opposition for geothermal development.

  5. Landscape linkages between geothermal activity and solute composition and ecological response in surface waters draining the Atlantic slope of Costa Rica

    USGS Publications Warehouse

    Pringle, Catherine M.; Rowe, Gary L.; Triska, Frank J.; Fernandez, Jose F.; West, John

    1993-01-01

    Surface waters draining three different volcanoes in Costa Rica, ranging from dormant to moderately active to explosive, have a wide range of solute compositions that partly reflects the contribution of different types of solute-rich, geothermal waters. Three major physical transport vectors affect flows of geothermally derived solutes: thermally driven convection of volcanic gases and geothermal fluids; lateral and gravity-driven downward transport of geothermal fluids; and wind dispersion of ash, gases, and acid rain. Specific vector combinations interact to determine landscape patterns in solute chemistry and biota: indicator taxa of algae and bacteria reflect factors such as high temperature, wind-driven or hydrologically transported acidity, high concentrations of various solutes, and chemical precipitation reactions. Many streams receiving geothermally derived solutes have high levels of soluble reactive phosphorus (SRP) (up to 400 µg liter−1), a nutrient that is typically not measured in geochemical studies of geothermal waters. Regional differences in levels of SRP and other solutes among volcanoes were typically not significant due to high local variation in solute levels among geothermally modified streams and between geothermally modified and unmodified streams on each volcano. Geothermal activity along the volcanic spine of Costa Rica provides a natural source of phosphorus, silica, and other solutes and plays an important role in determining emergent landscape patterns in the solute chemistry of surface waters and aquatic biota.

  6. Analysis of potential geothermal resources and their use: Lebanon Springs area, New York

    SciTech Connect

    Not Available

    1981-04-01

    The feasibility of using thermal waters at Lebanon Springs or elsewhere in the Capital District of New York as an energy source was studied. To evaluate the area, geologic mapping of the Lebanon Springs, New York, to Williamstown, Massachusetts, area was conducted, and efforts made to locate additional thermal waters besides those already known. In addition to mapping, thermal gradients where measured in twenty-five abandoned water wells, and the silica contents and water temperatures of seventy-eight active domestic water wells were determined. Based on the results of that work, Lebanon Springs appears to be the first choice for a demonstration project, but further exploration may confirm that other areas with good potential exist. A preliminary economic analysis of possible uses in the Town of Lebanon Springs was made, and it was determined that a system combining groundwater heat pumps and a microhydroelectric plant could be applied to heating the town hall, town garage, and high school with significant savings.

  7. Geothermal Fields on the Volcanic Axis of Mexico

    SciTech Connect

    Mercado, S.; Gonzalez, A.

    1980-12-16

    At present in Mexico, geothermal energy is receiving a great impulse due to the excellent results obtained in the Cerro Prieto geothermal field, in which a geothermoelectric plant is operated. This plant has four units of 37.5 MW each, with a total capacity of 150 MW, and under program 470 MW more by 1984. The Government Institution, Comisi6n Federal de Electricidad, is in charge of the exploration and exploitation of geothermal fields as well as construction and operation of power plants in Mexico. By this time CFE has an extensive program of exploration in the central part of Mexico, in the Eje Neovolcdnico. In this area, several fields with hydrothermal alteration are under exploration, like the Michoac6n geothermal area, where Los Azufres geothermal field is being developed. Seventeen wells have been drilled and twelve of them presented excellent results, including two dry steam wells. In other areas, such as Arar6, Cuitzeo, San Agustln del Maiz,Ixtldn de Los Hervores and Los Negritos, geological, geophysical and geochemical explorations have been accomplished, including shallow well drilling with good results. Another main geothermal area is in the State of Jalisco with an extension of 5,000 m2, where La Primavera geothermal field shows a lot of volcanic domes and has an intensive hydrothermal activity. Deep wells have been drilled, one of them with a bottom temperature of 29OOC. Other fields in this area, like San Narcos, Hervores de La Vega, La Soledad, Villa Corona, etc., have a good geothermal potential. A new geothermal area has been explored recently in the eastern part of the country named Los Humeros, Puebla. In this area studies are being made and there are plans for well drilling exploration by the beginning of 1981. Like this one, there are many other areas in the country in which 300 hydrothermal alteration zones are been classified and 100 of them are considered economically exploitable.

  8. Geothermal direct-heat utilization assistance. Quarterly project progress report, July 1994--September 1994

    SciTech Connect

    Not Available

    1994-10-01

    This paper is a third quarter 1994 report of activities of the Geo-Heat Center of Oregon Institute of Technology. It describes contacts with parties during this period related to assistance with geothermal direct heat applications. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, resources, and equipment. Research is also being conducted on failures of vertical lineshaft turbines in geothermal wells.

  9. Geothermal energy program overview

    NASA Astrophysics Data System (ADS)

    1991-12-01

    The mission of the Geothermal Energy Program is to develop the science and technology necessary for tapping our nation's tremendous heat energy sources contained within the Earth. Geothermal energy is a domestic energy source that can produce clean, reliable, cost-effective heat and electricity for our nation's energy needs. Geothermal energy - the heat of the Earth - is one of our nation's most abundant energy resources. In fact, geothermal energy represents nearly 40 percent of the total U.S. energy resource base and already provides an important contribution to our nation's energy needs. Geothermal energy systems can provide clean, reliable, cost-effective energy for our nation's industries, businesses, and homes in the form of heat and electricity. The U.S. Department of Energy's (DOE) Geothermal Energy Program sponsors research aimed at developing the science and technology necessary for utilizing this resource more fully. Geothermal energy originates from the Earth's interior. The hottest fluids and rocks at accessible depths are associated with recent volcanic activity in the western states. In some places, heat comes to the surface as natural hot water or steam, which have been used since prehistoric times for cooking and bathing. Today, wells convey the heat from deep in the Earth to electric generators, factories, farms, and homes. The competitiveness of power generation with lower quality hydrothermal fluids, geopressured brines, hot dry rock, and magma (the four types of geothermal energy), still depends on the technical advancements sought by DOE's Geothermal Energy Program.

  10. Geothermal direct-heat utilization assistance. Quarterly report, January - March 1997

    SciTech Connect

    Lienau, P.

    1997-04-01

    This report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the second quarter of FY-97. It describes 176 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics and resources. Research activities are summarized on well pumping in commercial groundwater heat pump systems. A memorandum of understanding between the GHC and EIA is described. Work accomplishments on the Guidebook are discussed. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

  11. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    NASA Astrophysics Data System (ADS)

    Eisses, A.; Kell, A. M.; Kent, G.; Driscoll, N. W.; Karlin, R. E.; Baskin, R. L.; Louie, J. N.; Smith, K. D.; Pullammanappallil, S.

    2011-12-01

    Preliminary slip rates measured across the East Pyramid Lake fault, or the Lake Range fault, help provide new estimates of extension across the Pyramid Lake basin. Multiple stratigraphic horizons spanning 48 ka were tracked throughout the lake, with layer offsets measured across all significant faults in the basin. A chronstratigraphic framework acquired from four sediment cores allows slip rates of the Lake Range and other faults to be calculated accurately. This region of the northern Walker Lake, strategically placed between the right-lateral strike-slip faults of Honey and Eagle Lakes to the north, and the normal fault bounded basins to the southwest (e.g., Tahoe, Carson), is critical in understanding the underlying structural complexity that is not only necessary for geothermal exploration, but also earthquake hazard assessment due to the proximity of the Reno-Sparks metropolitan area. In addition, our seismic CHIRP imaging with submeter resolution allows the construction of the first fault map of Pyramid Lake. The Lake Range fault can be obviously traced west of Anahoe Island extending north along the east end of the lake in numerous CHIRP lines. Initial drafts of the fault map reveal active transtension through a series of numerous, small, northwest striking, oblique-slip faults in the north end of the lake. A previously field mapped northwest striking fault near Sutcliff can be extended into the west end of Pyramid Lake. This fault map, along with the calculated slip rate of the Lake Range, and potentially multiple other faults, gives a clearer picture into understanding the geothermal potential, tectonic regime and earthquake hazards in the Pyramid Lake basin and the northern Walker Lane. These new results have also been merged with seismicity maps, along with focal mechanisms for the larger events to begin to extend our fault map in depth.

  12. Low- to moderate-temperature geothermal resource assessment for Nevada: area specific studies, Pumpernickel Valley, Carlin and Moana. Final report June 1, 1981-July 31, 1982

    SciTech Connect

    Trexler, D.T.; Flynn, T.; Koenig, B.A.; Bell, E.J.; Ghusn, G. Jr.

    1982-01-01

    Geological, geophysical and geochemical surveys were used in conjunction with temperature gradient hole drilling to assess the geothermal resources in Pumpernickel Valley and Carlin, Nevada. This program is based on a statewide assessment of geothermal resources that was completed in 1979. The exploration techniques are based on previous federally-funded assessment programs that were completed in six other areas in Nevada and include: literature search and compilation of existing data, geologic reconnaissance, chemical sampling of thermal and non-thermal fluids, interpretation of satellite imagery, interpretation of low-sun angle aerial photographs, two-meter depth temperature probe survey, gravity survey, seismic survey, soil-mercury survey, and temperature gradient drilling.

  13. Marine and land active-source seismic imaging of mid-Miocene to Holocene-aged faulting near geothermal prospects at Pyramid Lake, Nevada

    SciTech Connect

    Eisses, A.; Kell, A.; Kent, G.; Driscoll, N.; Karlin, R.; Baskin, R.; Louie, J.; Pullammanappallil, S.

    2016-08-01

    Amy Eisses, Annie Kell, Graham Kent, Neal Driscoll, Robert Karlin, Rob Baskin, John Louie, and Satish Pullammanappallil, 2011, Marine and land active-source seismic imaging of mid-Miocene to Holocene-aged faulting near geothermal prospects at Pyramid Lake, Nevada: presented at Geothermal Resources Council Annual Meeting, San Diego, Oct. 23-26.

  14. Rare earth elements geochemistry in springs from Taftan geothermal area SE Iran

    NASA Astrophysics Data System (ADS)

    Shakeri, Ata; Ghoreyshinia, Sayedkazem; Mehrabi, Behzad; Delavari, Morteza

    2015-10-01

    Concentrations of rare earth elements (REEs) were determined in springs and andesitic-dacitic rocks of Taftan geothermal field. Hydrochemical results of major ions indicate that thermal springs are Na-SO4-Cl and Ca-SO4-Cl types. Concentrations of REEs are in ranges of 10- 4 to 1.2 and 49 to ~ 62 times of chondrite for springwater and rock samples, respectively. The thermal (STS and TTS) and the cold (APS) springs with low pH values exhibit a very high REE contents (0.64 to 3.15 mg/l). Saturation index indicates that Fe and Al phases can control dissolved REE concentration in FTS and PF cold springs. The speciation of REE complexes indicates dominant presence of LnSO4+ and free ion in the Taftan thermal springs. In APS cold spring with pH ~ 4, fluoride complexes are dominate over the free ion and sulfate species, while in PF and FTS cold springs with pH 6.4 and 7, respectively, carbonate complexes (LnCO3+) are predominant species. Chondrite-normalized pattern for the low-pH waters show very distinctive gull-wing patterns, characteristic feature of acid-sulfate geothermal systems, and are similar to those of the host rocks. Chemical characteristics of rare earth elements in spring and volcanic rock samples indicate that REEs are originated from the andesitic-dacitic host rocks. Whole-rock-normalized REE patterns and petrographic evidences show that rare earth elements leached mainly from marginal alteration of minerals and matrix decomposition in volcanic rocks. In chondrite-normalized REE patterns, significant negative Eu anomaly in the cold springs compare to the thermal and acidic springs indicates that alteration of plagioclase is more intense in the later, corresponding to increasing in temperature and acidic state of reactant water.

  15. Interactive Maps from the Great Basin Center for Geothermal Energy

    DOE Data Explorer

    The Great Basin Center for Geothermal Energy, part of the University of Nevada, Reno, conducts research towards the establishment of geothermal energy as an economically viable energy source within the Great Basin. The Center specializes in collecting and synthesizing geologic, geochemical, geodetic, geophysical, and tectonic data, and using Geographic Information System (GIS) technology to view and analyze this data and to produce favorability maps of geothermal potential. The interactive maps are built with layers of spatial data that are also available as direct file downloads (see DDE00299). The maps allow analysis of these many layers, with various data sets turned on or off, for determining potential areas that would be favorable for geothermal drilling or other activity. They provide information on current exploration projects and leases, Bureau of Land Management land status, and map presentation of each type of scientific spatial data: geothermal, geophysical, geologic, geodetic, groundwater, and geochemical.

  16. Relative Contributions of Geothermal Pumping and Long-Term Earthquake Rate to Seismicity at California Geothermal Fields

    NASA Astrophysics Data System (ADS)

    Weiser, D. A.; Jackson, D. D.

    2015-12-01

    In a tectonically active area, a definitive discrimination between geothermally-induced and tectonic earthquakes is difficult to achieve. We focus our study on California's 11 major geothermal fields: Amedee, Brawley, Casa Diablo, Coso, East Mesa, The Geysers, Heber, Litchfield, Salton Sea, Susanville, and Wendel. The Geysers geothermal field is the world's largest geothermal energy producer. California's Department of Oil Gas and Geothermal Resources provides field-wide monthly injection and production volumes for each of these sites, which allows us to study the relationship between geothermal pumping activities and seismicity. Since many of the geothermal fields began injecting and producing before nearby seismic stations were installed, we use smoothed seismicity since 1932 from the ANSS catalog as a proxy for tectonic earthquake rate. We examine both geothermal pumping and long-term earthquake rate as factors that may control earthquake rate. Rather than focusing only on the largest earthquake, which is essentially a random occurrence in time, we examine how M≥4 earthquake rate density (probability per unit area, time, and magnitude) varies for each field. We estimate relative contributions to the observed earthquake rate of M≥4 from both a long-term earthquake rate (Kagan and Jackson, 2010) and pumping activity. For each geothermal field, respective earthquake catalogs (NCEDC and SCSN) are complete above at least M3 during the test period (which we tailor to each site). We test the hypothesis that the observed earthquake rate at a geothermal site during the test period is a linear combination of the long-term seismicity and pumping rates. We use a grid search to determine the confidence interval of the weighting parameters.

  17. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    SciTech Connect

    Eisses, A.; Kell, A.; Kent, G.; Driscoll, N.; Karlin, R.; Baskin, R.; Louie, J.; Pullammanappallil, S.

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  18. Geothermal reservoirs in hydrothermal convection systems

    SciTech Connect

    Sorey, M.L.

    1982-01-01

    Geothermal reservoirs commonly exist in hydrothermal convection systems involving fluid circulation downward in areas of recharge and upwards in areas of discharge. Because such reservoirs are not isolated from their surroundings, the nature of thermal and hydrologic connections with the rest of the system may have significant effects on the natural state of the reservoir and on its response to development. Conditions observed at numerous developed and undeveloped geothermal fields are discussed with respect to a basic model of the discharge portion of an active hydrothermal convection system. Effects of reservoir development on surficial discharge of thermal fluid are also delineated.

  19. Imperial County geothermal development. Quarterly report, April 1-June 30, 1982

    SciTech Connect

    Not Available

    1982-06-30

    The activities of the Geothermal Office during the quarter are discussed, including: important geothermal events, geothermal waste disposal, a grant award by the California Energy Commission, the geothermal development meeting, and the current status of geothermal development in Imperial County. Activities of the Geothermal Planner are addressed, including permits, processing of EIR's, and other planning activities. Progress on the direct heat study is reported.

  20. Geothermal Monitoring in Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Heasler, H. P.; Jaworowski, C.; Susong, D. D.; Lowenstern, J. B.

    2007-12-01

    When the first exploring parties surveyed the Yellowstone region in the late 19th Century, it was the geologic wonders - geysers, hot springs, mudpots, fumaroles - that captured their imaginations. Because of these treasures, the U.S. Congress set aside and dedicated this land of "natural curiosities" as the world's first "public pleasuring ground". Protection of Yellowstone's unique geothermal features is a key mission of Yellowstone National Park as mandated by U. S. Congressional law. In response to that mandate, the Yellowstone National Park Geology Program developed a peer-reviewed, Geothermal Monitoring Plan in 2003. With partial Congressional funding of the Plan in 2005, implementation of a scientific monitoring effort began. Yellowstone's scientific geothermal monitoring effort includes the acquisition of time-temperature data using electronic data loggers, basic water quality data, chloride flux data, estimates of radiative heat flux using airborne, thermal infrared imagery, geothermal gas monitoring, and the monitoring of groundwater wells. Time- temperature data are acquired for geysers, hot springs, steam vents, wells, rivers, and the ground. Uses of the time-temperature data include public safety, calibrating airborne thermal infrared-imagery, monitoring selected thermal features for potential hydrothermal explosions, and determining the spatial and temporal changes in thermal areas. Since 2003, upgrades of Yellowstone's stream gaging network have improved the spatial and temporal precision of the chloride flux, water quality, and groundwater components of the Geothermal Monitoring Plan. All of these methods serve both for geothermal monitoring and volcano monitoring as part of the Yellowstone Volcano Observatory. A major component of the Geothermal Monitoring Plan is remote sensing of the Yellowstone volcano and its active hydrothermal areas at various scales. The National Center for Landscape Fire Analysis at the University of Montana and the USDA

  1. Fluid inclusion from drill hole DW-5, Hohi geothermal area, Japan: Evidence of boiling and procedure for estimating CO2 content

    USGS Publications Warehouse

    Sasada, M.; Roedder, E.; Belkin, H.E.

    1986-01-01

    Fluid inclusion studies have been used to derive a model for fluid evolution in the Hohi geothermal area, Japan. Six types of fluid inclusions are found in quartz obtained from the drill core of DW-5 hole. They are: (I) primary liquid-rich with evidence of boiling; (II) primary liquid-rich without evidence of boiling; (III) primary vapor-rich (assumed to have been formed by boiling); (IV) secondary liquid-rich with evidence of boiling; (V) secondary liquid-rich without evidence of boiling; (VI) secondary vapor-rich (assumed to have been formed by boiling). Homogenization temperatures (Th) range between 196 and 347??C and the final melting point of ice (Tm) between -0.2 and -4.3??C. The CO2 content was estimated semiquantitatively to be between 0 and 0.39 wt. % based on the bubble behavior on crushing. NaCl equivalent solid solute salinity of fluid inclusions was determined as being between 0 and 6.8 wt. % after minor correction for CO2 content. Fluid inclusions in quartz provide a record of geothermal activity of early boiling and later cooling. The CO2 contents and homogenization temperatures of fluid inclusions with evidence of boiling generally increase with depth; these changes, and NaCl equivalent solid solute salinity of the fluid can be explained by an adiabatic boiling model for a CO2-bearing low-salinity fluid. Some high-salinity inclusions without CO2 are presumed to have formed by a local boiling process due to a temperature increase or a pressure decrease. The liquid-rich primary and secondary inclusions without evidence of boiling formed during the cooling process. The salinity and CO2 content of these inclusions are lower than those in the boiling fluid at the early stage, probably as a result of admixture with groundwater. ?? 1986.

  2. Geothermal development. Semi-annual report, October 1, 1980-March 31, 1981

    SciTech Connect

    Not Available

    1981-03-31

    Three areas are reported: geothermal administration, geothermal planning, and other geothermal activities. Administration covers the status of the Imperial Valley Environmental Project transfer, update of the Geothermal Resource Center, and findings of the geothermal field inspections. Planning addresses Board of Supervisor actions, Planning Commission actions, notice of exemptions, and the master Environmental Impact Report for Salton Sea. The other activity includes the County Direct Heat Development study; the solicitation for district heating and cooling proposals; the new Geothermal Class II-1 disposal site; the DOE Region IX meeting in Tucson; and USGA designating a new KGRA, the East Brawley KGRA, the Westmoreland KGRA, and revising the southern border of the Salton Sea KGRA. (MHR)

  3. Preliminary assessment of the geologic setting, hydrology, and geochemistry of the Hueco Tanks geothermal area, Texas and New Mexico. Geological Circular 81-1

    SciTech Connect

    Henry, C.D.; Gluck, J.K.

    1981-01-01

    The Hueco Tanks geothermal area contains five known but now inactive hot wells (50/sup 0/ to 71/sup 0/C). The area trends north-south along the east side of Tularosa-Hueco Bolson astride the Texas-New Mexico border approximately 40 km northeast of El Paso. Because of its proximity to El Paso, geothermal water in the Hueco Tanks area could be a significant resource. Hueco Bolson is an asymmetric graben. Greatest displacement along boundary faults is on the west side adjacent to the Franklin Mountains. Faults, probably with less displacement, also form an irregular boundary on the east side of the bolson. Several probable faults may allow the rise of thermal waters from depth. Ground water in the central part of Hueco Bolson flows southward to the Rio Grande. However, four of the five hot wells occur in a ground-water trough along the eastern margin of the bolson. The trough may be bounded by one of the postulated faults serving as a barrier to ground-water flow. Data on permeability of potential reservoir rocks, including basin fill and fractured bedrock, suggest that they may be sufficiently permeable for development of geothermal water. The concentration of dissolved solids in the geothermal waters varies from 1100 to at least 12,500 mg/L, but most waters show high concentrations. They are Na-Cl-(SO/sub 4/) waters similar in composition to nonthermal waters in basin fill. The composition probably results from contact with evaporite deposits either in basin fill or in Paleozoic bedrock. Shallow reservoirs reach maximum temperatures of about 80/sup 0/ to 110/sup 0/C. Available data are too limited to evaluate adequately the resource potential of geothermal water in the Hueco Tanks area.

  4. Seismic monitoring of EGS tests at the Coso Geothermal area, California, using accurate MEQ locations and full moment tensors

    SciTech Connect

    Foulger, Gillian R.; Julian, Bruce R.; Monastero, Francis C.

    2008-03-31

    In this study, we studied high-resolution relative locations and full moment tensors of microearthquakes (MEQs) occurring before, during and following Enhanced Geothermal Systems (EGS) experiments in two wells at the Coso geothermal area, California. The objective was to map new fractures, determine the mode and sense of failure, and characterize the stress cycle associated with injection. New software developed for this work combines waveform cross-correlation measurement of arrival times with relative relocation methods, and assesses confidence regions for moment tensors derived using linear-programming methods. For moment tensor determination we also developed a convenient Graphical User Interface (GUI), to streamline the work. We used data from the U.S. Navy’s permanent network of three-component digital borehole seismometers and from 14 portable three-component digital instruments. The latter supplemented the permanent network during injection experiments in well 34A-9 in 2004 and well 34-9RD2 in 2005. In the experiment in well 34A-9, the co-injection earthquakes were more numerous, smaller, more explosive and had more horizontal motion, compared with the pre-injection earthquakes. In the experiment in well 34-9RD2 the relocated hypocenters reveal a well-defined planar structure, 700 m long and 600 m high in the depth range 0.8 to 1.4 km below sea level, striking N 20° E and dipping at 75° to the WNW. The moment tensors show that it corresponds to a mode I (opening) crack. Finally, for both wells, the perturbed stress state near the bottom of the well persisted for at least two months following the injection.

  5. Geothermal resources in the Banbury Hot Springs area, Twin Falls County, Idaho

    USGS Publications Warehouse

    Lewis, R.E.; Young, H.W.

    1980-01-01

    Thermal water (30.0 to 72.0 degrees Celsius) is produced from 26 wells and 2 springs in the vicinity of Banbury Hot Springs near Buhl, Idaho. Thermal water is used for space heating of private residences, catfish and tropical fish production, greenhouse operation, swimming pools, and therapeutic baths. In 1979, 10 ,300 acre-feet of thermal water was utilized; heat discharged convectively from the geothermal system was about 1.09 x 10 to the 7th power calories per second. Decline in artesian head and discharge apparent in recorder charts from two wells may represent seasonal fluctuations or may reflect aquifer response to development of the resource. Thermal waters sampled are sodium bicarbonate in character and slightly alkaline. Mixing of a hot (72 degrees Celsius) water with local, cooler ground water can be shown from various relations between stable isotopes, chloride, and enthalpy. On the basis of concentration of trituim , age of the waters sampled is at least 100 years an perhaps more than 1,000 years. One water (33 degress Celsius) may be as young as 29 years. On the basis of silica, sodium-potassium-calcium, and sulfate-water geothermometers, best estimate of the maximum reservoir temperature for the thermal waters is between about 70 and 100 degrees Celsius. (USGS)

  6. Geothermal resources in the Banbury Hot Springs area, Twin Falls County, Idaho

    USGS Publications Warehouse

    Lewis, R.E.; Young, Harold William

    1982-01-01

    Thermal water 30.0 degrees to 72.0 degrees Celsius is produced from 26 wells and 2 springs in the vicinity of Banbury Hot Springs near Buhl, Idaho. Thermal water is used for residence heating, catfish and tropical fish production, greenhouse operation, swimming pools, and therapeutic baths. In 1979, 10,300 acre-feet of thermal water was utilized; heat discharged convectively from the geothermal system was about 1.1 x 107 calories per second. Decline in artesian head and discharge apparent in recorder charts from two wells may represent seasonal fluctuations or may reflect reservoir response to development of the resource. The thermal waters sampled are sodium carbonate or bicarbonate in character and slightly alkaline. Mixing of hot (72 degrees Celsius) water with local cooler ground water can be shown from various relations among stable isotopes, chloride, and enthalpy. On the basis of concentration of tritium, the age of most of the water sampled is at least 100 years and perhaps more than 1,000 years. Some water (33 degrees Celsius) may be as young as 29 years. On the basis of silica, sodium-potassium-calcium, and sulfate-water geothermometers, the best estimate of the maximum reservoir temperature for the thermal water is between 70 degrees and 100 degrees Celsius.

  7. Interpretation of time-domain electromagnetic soundings in the East Rift geothermal area of Kilauea Volcano, Hawaii

    SciTech Connect

    Kauahikaua, J.

    1981-01-01

    A controlled-source time-domain electromagnetic (TDEM) sounding survey was completed on the lower portion of the East Rift of Kilauea Volcano, Hawaii (locally known as the Puna area) during the summer of 1974 as part of the geophysical task of the Hawaii Geothermal Project. Interpretations as obtained by a layered-earth TDEM inversion computer program are presented. Interpretations in terms of layered half-space models can be used to localize low-resistivity zones vertically as well as horizontally. The results show that much of the area is underlain by an anomalously conductive zone at depths of 250 to 1300 below sea level. Twenty-four TDEM soundings were attempted in the area using four different grounded wire current sources and a 42-conductor, horizontal loop sensor. The TDEM sounding data were in the form of voltages (proportional to the time derivative of the induced magnetic field) measured at discrete times after a break in the source current. Seventeen of the soundings are interpreted here.

  8. Geothermal energy survey and technology

    NASA Astrophysics Data System (ADS)

    This is an FY-1990 Annual Report on 'geothermal energy survey and technology' by New Energy and Industrial Technology Development Organization (NEDO). First, concerning geothermal resources exploration project in which surveys have been executed throughout Japan since 1980, outlines of surveys in 1990 and objectives for FY-1992 are summarized. As for surveys for promoting development of geothermal energy, surveys in 8 areas conducted for three years from 1988 to 1990 as well as future plans are also described. Then, the verification investigation for geothermal survey technologies, which has been executed since 1980 for the purpose of establishing geothermal survey technologies to promote the development of geothermal resources in Japan, is introduced with outlines of surveys in 1990 and objectives for FY-1992. Furthermore, development conditions of power generation technologies utilizing geothermal energy such as binary-cycle power generation and hot dry rock power generation are described.

  9. Environmental assessment for a geothermal direct utilization project in Reno, Nevada

    SciTech Connect

    Perino, J.V.; McCloskey, M.H.; Wolterink, T.J.; Wallace, R.C.; Baker, D.W.; Harper, D.L.; Anderson, D.T.; Siteman, J.V.; Sherrill, K.T.

    1980-08-20

    The proposed action involves the development of geothermal wells to provide hot water and heat for five users in Reno, Nevada. Data from nearby wells indicate the sufficient hot water is available from the Moana Known Geothermal Resource Area for this action. Construction activities have been planned to minimize or eliminate problems with noise, runoff, and disturbance of biota as well as other potential environmental effects. Disposal of the geothermal fluids via surface water or injection will be determined based on water quality of the geothermal fluids and geologic effects of injection. The affected environment is described by this document and needed mitigation procedures discussed.

  10. Geothermal progress monitor. Progress report No. 3, March-April 1980

    SciTech Connect

    Not Available

    1980-01-01

    Progress is reviewed in the following areas: electric uses; direct heat uses; drilling activities; exploration; leases; outreach and technical assistance; feasibility studies and application demonstrations; geothermal loan guarantee program; general activities; R and D activities; legal, institutional, and regulatory activities; environmental activities; and state, local, and private sector activities. Also included are a list of reports and publications and a directory of individuals in the geothermal community. (MHR)

  11. Geophysical survey, Paso Robles Geothermal area, California: Part of the Resource Assessment of Low- and Moderate-Temperature Geothermal Resource Areas in California; Part of the Second year Report, 1979-80 of the US Department of Energy-California State-Coupled Program for Reservoir Assessment and Confirmation

    SciTech Connect

    Chapman, Rodger H.; Chase, Gordon W.; Youngs, Les G.

    1980-11-10

    This report presents the details of new geophysical work for the Paso Robles geothermal area, California performed under terms of the second year contract, 1979-80 between the US Department of Energy (DOE) and the California Division of Mines and Geology (CDMG). The report contains two sections. The first section is to provide background for the reader and consists of a reprint from CDMG's first year report (1979-80) to DOE. It describes only the Paso Robles studies performed by CDMG in its first year effort. The second section provides new information developed by CDMG in its 1979-80 studies concerning the geophysical survey of the Paso Robles geothermal area. Included in the first section is some general background information concerning the geology and geothermal occurrences in the Southern Coast Ranges, as well as the more detailed information dealing with the Paso Robles area proper. The second section is concerned only with discussion and interpretation of results for two geophysical methods that have so far been used by CDMG in the area: the ground magnetic and gravity surveys. The CDMG studies of the Paso Robles area are not yet complete and additional studies using newly acquired resistivity equipment are planned for the near future, as are more complete surveys of existing wells and new studies of the geothermal aquifers present in the area. A final report to DOE on the Paso Robles area is planned following completion of those studies.

  12. Play-fairway analysis for geothermal exploration: Examples from the Great Basin, western USA

    SciTech Connect

    Siler, Drew L; Faulds, James E

    2013-10-27

    Elevated permeability within fault systems provides pathways for circulation of geothermal fluids. Future geothermal development depends on precise and accurate location of such fluid flow pathways in order to both accurately assess geothermal resource potential and increase drilling success rates. The collocation of geologic characteristics that promote permeability in a given geothermal system define the geothermal ‘fairway’, the location(s) where upflow zones are probable and where exploration efforts including drilling should be focused. We define the geothermal fairway as the collocation of 1) fault zones that are ideally oriented for slip or dilation under ambient stress conditions, 2) areas with a high spatial density of fault intersections, and 3) lithologies capable of supporting dense interconnected fracture networks. Areas in which these characteristics are concomitant with both elevated temperature and fluids are probable upflow zones where economic-scale, sustainable temperatures and flow rates are most likely to occur. Employing a variety of surface and subsurface data sets, we test this ‘play-fairway’ exploration methodology on two Great Basin geothermal systems, the actively producing Brady’s geothermal system and a ‘greenfield’ geothermal prospect at Astor Pass, NV. These analyses, based on 3D structural and stratigraphic framework models, reveal subsurface characteristics about each system, well beyond the scope of standard exploration methods. At Brady’s, the geothermal fairways we define correlate well with successful production wells and pinpoint several drilling targets for maintaining or expanding production in the field. In addition, hot-dry wells within the Brady’s geothermal field lie outside our defined geothermal fairways. At Astor Pass, our play-fairway analysis provides for a data-based conceptual model of fluid flow within the geothermal system and indicates several targets for exploration drilling.

  13. Geothermal Energy.

    ERIC Educational Resources Information Center

    Reed, Marshall J.

    1979-01-01

    During 1978, exploration for geothermal energy continued at the same moderately low level of the past few years in most countries. The U.S. is the only country where the development of geothermal energy depends on private industry. (BB)

  14. Geothermal Energy

    SciTech Connect

    Steele, B.C.; Harman, G.; Pitsenbarger, J.

    1996-02-01

    Geothermal Energy Technology (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production.

  15. The Geothermal Potential, Current and Opportunity in Taiwan

    NASA Astrophysics Data System (ADS)

    Song, Sheng-Rong

    2016-04-01

    Located in the west Pacific Rim of Fire, Taiwan possesses rich geothermal resources due to volcanic activities and rapid uplifting of plate collision. Based on available data prior to 1980, Taiwan may have about 1 GWe of potential shallow geothermal energy, which is less than 3% of the national gross power generation. A 3-Mw pilot power plant, therefore, was constructed in 1981 and terminated in 1993 in the Chingshui geothermal field of Ilan, northeastern Taiwan. Recently, one of the National Science & Technology Program (NSTP) projects has been conducting research and reevaluating the island-wide deep geothermal energy. Four hot potential sites have been recognized. They are: (1) Tatun Volcano Group of northern Taiwan; (2) I-Lan Plain of NE Taiwan; (3) Lu-Shan area of Central Taiwan; and (4) Hua-Tung area of eastern Taiwan. We found that the geothermal resource in Taiwan may be as high as 160 GWe, with 33.6 GWe of exploitable geothermal energy. There are no any commercial geothermal power plants until now in Taiwan, although the potential is great. However, geothermal energy has been listed as one of major tasks of National Energy Program, Phase II (NEP-II) in Taiwan. We will conduct more detailed geothermal energy surveys on some proposed hot sites and to construct an EGS pilot geothermal plant with 1 MWe capability in a few years. Currently, there are three nuclear power plants, named No. 1, 2 & 3, in operations, which produce 16.5% gross generation of electricity and one (No. 4) is under construction, but is stopped and sealed now in Taiwan. Furthermore, the life-span of 40-year operation for those three power plants will be close-at hand and retire in 2018-2019, 2021-2023 and 2024-2025, respectively. Therefore, to find alternative energy sources, especially on the clean, renewable and sustainable ones for generating electricity are emergent and important for Taiwan's government in next few years. Among various energy sources, geothermal energy can be as base

  16. Evaluation of geothermal energy in Arizona. Quarterly progress report, July 1-September 30, 1981

    SciTech Connect

    White, D.H.; Goldstone, L.A.

    1981-01-01

    Progress is reported on the following: legislative and institutional program, cities program, geothermal applications utilization technology, integrated alcohol/feedlot/geothermal operation, geothermal energy in the mining industry, geothermal space heating and cooling, identification of a suitable industry for a remote geothermal site, irrigation pumping, coal-fired/geothermal-assisted power plants, area development plans, and outreach. (MHR)

  17. Geothermal systems

    NASA Technical Reports Server (NTRS)

    Mohl, C.

    1978-01-01

    Several tasks of JPL related to geothermal energy are discussed. The major task is the procurement and test and evaluation of a helical screw drive (wellhead unit). A general review of geothermal energy systems is given. The presentation focuses attention on geothermal reservoirs in California, with graphs and charts to support the discussion. Included are discussions on cost analysis, systems maintenance, and a comparison of geothermal and conventional heating and cooling systems.

  18. Three-Dimensional Geothermal Fairway Mapping: Examples From the Western Great Basin, USA

    SciTech Connect

    Siler, Drew L.; Faulds, James E.

    2013-09-29

    Elevated permeability along fault systems provides pathways for circulation of geothermal fluids. Accurate location of such fluid flow pathways in the subsurface is crucial to future geothermal development in order to both accurately assess resource potential and mitigate drilling costs by increasing drilling success rates. Employing a variety of surface and subsurface data sets, we present detailed 3D geologic analyses of two Great Basin geothermal systems, the actively producing Brady’s geothermal system and a ‘greenfield’ geothermal prospect at Astor Pass, Nevada. 3D modeling provides the framework for quantitative structural analyses. We combine 3D slip and dilation tendency analysis along fault zones and calculations of fault intersection density in the two geothermal systems with the locations of lithologies capable of supporting dense, interconnected fracture networks. The collocation of these permeability promoting characteristics with elevated heat represent geothermal ‘fairways’, areas with ideal conditions for geothermal fluid flow. Location of geothermal fairways at high resolution in 3D space can help to mitigate the costs of geothermal exploration by providing discrete drilling targets and data-based evaluations of reservoir potential.

  19. Idaho Geothermal Commercialization Program. Idaho geothermal handbook

    SciTech Connect

    Hammer, G.D.; Esposito, L.; Montgomery, M.

    1980-03-01

    The following topics are covered: geothermal resources in Idaho, market assessment, community needs assessment, geothermal leasing procedures for private lands, Idaho state geothermal leasing procedures - state lands, federal geothermal leasing procedures - federal lands, environmental and regulatory processes, local government regulations, geothermal exploration, geothermal drilling, government funding, private funding, state and federal government assistance programs, and geothermal legislation. (MHR)

  20. Geothermal Gases--Community Experiences, Perceptions, and Exposures in Northern California.

    PubMed

    Chiu, Cindy H; Lozier, Matthew J; Bayleyegn, Tesfaye; Tait, Karen; Barreau, Tracy; Copan, Lori; Roisman, Rachel; Jackson, Rebecca; Smorodinsky, Svetlana; Kreutzer, Richard A; Yip, Fuyuen; Wolkin, Amy

    2015-12-01

    Lake County, California, is in a high geothermal-activity area. Over the past 30 years, the city of Clearlake has reported health effects and building evacuations related to geothermal venting. Previous investigations in Clearlake revealed hydrogen sulfide at levels known to cause health effects and methane at levels that can cause explosion risks. The authors conducted an investigation in multiple cities and towns in Lake County to understand better the risk of geothermal venting to the community. They conducted household surveys and outdoor air sampling of hydrogen sulfide and methane and found community members were aware of geothermal venting and some expressed concerns. The authors did not, however, find hydrogen sulfide above the California Environmental Protection Agency air quality standard of 30 parts per billion over one hour or methane above explosive thresholds. The authors recommend improving risk communication, continuing to monitor geothermal gas effects on the community, and using community reports and complaints to monitor and document geothermal venting incidents.

  1. Oxygen and hydrogen isotopes in deep thermal waters from the South Meager Creek geothermal area, British Columbia, Canada

    SciTech Connect

    Ghomshei, M.M. ); Clark, I.D. )

    1993-04-01

    Deuterium and oxygen-18 ([sup 18]O) have been measured in deep thermal, shallow thermal and non-thermal water samples collected at various times between 1982 and 1989 from the Meager Creek area, with the aim of assessing the origin of the thermal waters. The isotopic composition of the reservoir waters ([delta][sup 18]O = [minus]13[per thousand] and [delta]D= [minus]114.8[per thousand]) was calculated from data on post-flash deep thermal waters, using a two-stage steam loss model. The reservoir composition shows an oxygen shift of 2.4[per thousand] relative to the local meteoric water line. The composition of the recharge, obtained by removing the oxygen shift, is isotopically heavier than the average local meteoric waters, suggesting that the recharge may be from an area to the west of Mt Meager where isotopically heavier ground-waters are likely to be found. The small [delta][sup 18]O shift of the deep high-temperature waters is indicative of dominance of fracture-related permeability in the reservoir. Analyses of the chemistry and the temperature of the waters from hot springs and shallow thermal wells suggests that these waters have evolved from the deep geothermal waters through dilution by meteoric waters and about 40C adiabatic cooling (steam loss).

  2. Targeting geothermal exploration sites in the Mount St. Helens area using soil mercury surveys

    SciTech Connect

    Holmes, J.; Waugh, K.

    1983-11-01

    The background mercury level was determined for the areas studied, providing preliminary information for future work. Identification of areas which might merit more intensive sampling was also accomplished. The clusters of samples with high Hg concentrations in both areas may indicate high heat flow and should be investigated further. Problems involving the use of this method in the Cascades were also identified. Both areas north and south of the mountain had approximately the same standard deviation (expressed as a percentage of the mean), even though the sampling horizons seemed much more consistent and less disturbed in the Marble Mountain area than in the Green River Soda Springs area. This may indicate that for these areas, secondary controls are more important, or that Hg anomalies are much smaller than indicated in studies of other areas.

  3. 2008 Geothermal Technologies Market Report

    SciTech Connect

    Cross, J.; Freeman, J.

    2009-07-01

    This report describes market-wide trends for the geothermal industry throughout 2008 and the beginning of 2009. It begins with an overview of the U.S. DOE's Geothermal Technology Program's (GTP's) involvement with the geothermal industry and recent investment trends for electric generation technologies. The report next describes the current state of geothermal power generation and activity within the United States, costs associated with development, financing trends, an analysis of the levelized cost of energy (LCOE), and a look at the current policy environment. The report also highlights trends regarding direct use of geothermal energy, including geothermal heat pumps (GHPs). The final sections of the report focus on international perspectives, employment and economic benefits from geothermal energy development, and potential incentives in pending national legislation.

  4. Gas Geochemistry of Volcanic and Geothermal Areas in the Kenya Rift: Implications for the Role of Fluids in Continental Rifting

    NASA Astrophysics Data System (ADS)

    Lee, H.; Fischer, T. P.; Ranka, L. S.; Onguso, B.; Kanda, I.; Opiyo-Akech, N.; Sharp, Z. D.; Hilton, D. R.; Kattenhorn, S. A.; Muirhead, J.

    2013-12-01

    The East African Rift (EAR) is an active continental rift and ideal to investigate the processes of rift initiation and the breaking apart of continental lithosphere. Mantle and crust-derived fluids may play a pivotal role in both magmatism and faulting in the EAR. For instance, large quantities of mantle-derived volatiles are emitted at Oldoinyo Lengai volcano [1, 2]. Throughout the EAR, CO2-dominated volatile fluxes are prevalent [3, 4] and often associated with faults (i.e. Rungwe area, Tanzania, [5, 6]). The purpose of this study is to examine the relationship between volcanism, faulting and the volatile compositions, focusing on the central and southern Kenyan and northern Tanzanian section of the EAR. We report our analysis results for samples obtained during a 2013 field season in Kenya. Gases were sampled at fumaroles and geothermal plants in caldera volcanoes (T=83.1-120.2°C) and springs (T=40-79.6°C and pH 8.5-10) located near volcanoes, intra-rift faults, and a transverse fault (the Kordjya fault, a key fluid source in the Magadi rift) by 4N-NaOH solution-filled and empty Giggenbach bottles. Headspace gases were analyzed by a Gas Chromatograph and a Quadrupole Mass Spectrometer at the University of New Mexico. Both N2/Ar and N2/He ratios of all gases (35.38-205.31 and 142.92-564,272, respectively) range between air saturated water (ASW, 40 and ≥150,000) and MORB (100-200 and 40-50). In addition, an N2-Ar-He ternary diagram supports that the gases are produced by two component (mantle and air) mixing. Gases in the empty bottles from volcanoes and springs have N2 (90.88-895.99 mmom/mol), CO2 (2.47-681.21 mmom/mol), CH4 (0-214.78 mmom/mol), O2 (4.47-131.12 mmom/mol), H2 (0-35.78 mmom/mol), Ar (0.15-10.65 mmom/mol), He (0-2.21 mmom/mol), and CO (0-0.08 mmom/mol). Although some of the samples show an atmospheric component, CO2 is a major component in most samples, indicating both volcanoes and springs are emitting CO2. Gases from volcanoes are enriched in

  5. Geothermal -- The Energy Under Our Feet: Geothermal Resource Estimates for the United States

    SciTech Connect

    Green, B. D.; Nix, R. G.

    2006-11-01

    On May 16, 2006, the National Renewable Energy Laboratory (NREL) in Golden, Colorado hosted a geothermal resources workshop with experts from the geothermal community. The purpose of the workshop was to re-examine domestic geothermal resource estimates. The participating experts were organized into five working groups based on their primary area of expertise in the following types of geothermal resource or application: (1) Hydrothermal, (2) Deep Geothermal Systems, (3) Direct Use, (4) Geothermal Heat Pumps (GHPs), and (5) Co-Produced and Geopressured. The workshop found that the domestic geothermal resource is very large, with significant benefits.

  6. Geothermal Energy: Evaluation of a Resource

    ERIC Educational Resources Information Center

    Bockemuehl, H. W.

    1976-01-01

    This article suggests the use of geothermal energy for producing electricity, using as an example the development at Wairakei, New Zealand. Other geothermal areas are identified, and economic and environmental co sts of additional development are explored. (Author/AV)

  7. Ethanol and hydrogen production by two thermophilic, anaerobic bacteria isolated from Icelandic geothermal areas.

    PubMed

    Koskinen, Perttu E P; Beck, Steinar R; Orlygsson, Jóhann; Puhakka, Jaakko A

    2008-11-01

    Microbial fermentations are potential producers of sustainable energy carriers. In this study, ethanol and hydrogen production was studied by two thermophilic bacteria (strain AK15 and AK17) isolated from geothermal springs in Iceland. Strain AK15 was affiliated with Clostridium uzonii (98.8%), while AK17 was affiliated with Thermoanaerobacterium aciditolerans (99.2%) based on the 16S rRNA gene sequence analysis. Both strains fermented a wide variety of sugar residues typically found in lignocellulosic materials, and some polysaccharides. In the batch cultivations, strain AK17 produced ethanol from glucose and xylose fermentations of up to 1.6 mol-EtOH/mol-glucose (80% of the theoretical maximum) and 1.1 mol-EtOH/mol-xylose (66%), respectively. The hydrogen yields by AK17 were up to 1.2 mol-H2/ mol-glucose (30% of the theoretical maximum) and 1.0 mol-H2/mol-xylose (30%). The strain AK15 produced hydrogen as the main fermentation product from glucose (up to 1.9 mol-H2/mol-glucose [48%]) and xylose (1.1 mol-H2/mol-xylose [33%]). The strain AK17 tolerated exogenously added ethanol up to 4% (v/v). The ethanol and hydrogen production performance from glucose by a co-culture of the strains AK15 and AK17 was studied in a continuous-flow bioreactor at 60 degrees C. Stable and continuous ethanol and hydrogen co-production was achieved with ethanol yield of 1.35 mol-EtOH/mol-glucose, and with the hydrogen production rate of 6.1 mmol/h/L (H2 yield of 0.80 mol-H2/mol-glucose). PCR-DGGE analysis revealed that the AK17 became the dominant bacterium in the bioreactor. In conclusion, strain AK17 is a promising strain for the co-production of ethanol and hydrogen with a wide substrate utilization spectrum, relatively high ethanol tolerance, and ethanol yields among the highest reported for thermoanaerobes.

  8. Fluid inclusions and preliminary studies of hydrothermal alteration in core hole PLTG-1, Platanares geothermal area, Honduras

    USGS Publications Warehouse

    Bargar, K.E.

    1991-01-01

    The Platanares geothermal area in western Honduras consists of more than 100 hot springs that issue from numerous hot-spring groups along the banks or within the streambed of the Quebrada de Agua Caliente (brook of hot water). Evaluation of this geothermal area included drilling a 650-m deep PLTG-1 drill hole which penetrated a surface mantling of stream terrace deposits, about 550 m of Tertiary andesitic lava flows, and Cretaceous to lower Tertiary sedimentary rocks in the lower 90 m of the drill core. Fractures and cavities in the drill core are partly to completely filled by hydrothermal minerals that include quartz, kaolinite, mixed-layer illite-smectite, barite, fluorite, chlorite, calcite, laumontite, biotite, hematite, marcasite, pyrite, arsenopyrite, stibnite, and sphalerite; the most common open-space fillings are calcite and quartz. Biotite from 138.9-m depth, dated at 37.41 Ma by replicate 40Ar/39 Ar analyses using a continuous laser system, is the earliest hydrothermal mineral deposited in the PLTG-1 drill core. This mid-Tertiary age indicates that at least some of the hydrothermal alteration encountered in the PLTG-1 drill core occured in the distant past and is unrelated to the present geothermal system. Furthermore, homogenization temperatures (Th) and melting-point temperatures (Tm) for fluid inclusions in two of the later-formed hydrothermal minerals, calcite and barite, suggest that the temperatures and concentration of dissolved solids of the fluids present at the time these fluid inclusions formed were very different from the present temperatures and fluid chemistry measured in the drill hole. Liquid-rich secondary fluid inclusions in barite and caicite from drill hole PLTG-1 have Th values that range from about 20??C less than the present measured temperature curve at 590.1-m depth to as much as 90??C higher than the temperature curve at 46.75-m depth. Many of the barite Th measurements (ranging between 114?? and 265??C) plot above the

  9. Study of the Crossborder Geothermal Field in the Sarandoporos- Konitsa Area With Integrated Geophysical and Geochemical Methods.

    NASA Astrophysics Data System (ADS)

    Tsokas, G.; Balliu, E.; Reci, H.

    2005-05-01

    The studied area lies north of the city of Konitsa in Greece and includes the Albanian village of Koukes. Specifically, it lies between the geographic latitude (ö) 40ï 02' up to 40ï 07' and in geographic longitude (ë) 20ï 37' up to 20ï 45'. The geothermic field in Sarandaporos -Konitsa lies in the cross-border area between Albania and Greece. The field has several surface manifestations and extended geological investigations, including tectonic geochemical and geomorfological studies have been carried out. This work presents the conduct and interpretation of vertical electrical soundings (V.E.S.) in both sides of the borders. It is aiming to study the structure down to the depth of 1000m, in a relative large area, where information about the deep structure would have an enormous cost if acquired by a network of boreholes. Thermal springs known in the Greek part of the region are the thermal springs of Kavassila - Piksaria where the water temperature reaches up to 31o C. In the Albanian side the existence of hot springs (Koukes) is also well known, where the water supply is provided by the hot springs situated in the Skordili bridge. Two main geoelectrical formations revealed which coincide with the flysch and the limestone basement. The area appears faulted in the NW-SE and NE-SW directions and a few concealed graben and horst structures exist. Low resistivity values were observed above basement uplifts and major faults. These values were attributed to hot fluid circulation.

  10. Geothermal Energy Retrofit

    SciTech Connect

    Bachman, Gary

    2015-07-28

    The Cleary University Geothermal Energy Retrofit project involved: 1. A thermal conductivity test; 2. Assessment of alternative horizontal and vertical ground heat exchanger options; 3. System design; 4. Asphalt was stripped from adjacent parking areas and a vertical geothermal ground heat exchanger system installed; 5. the ground heat exchanger was connected to building; 6. a system including 18 heat pumps, control systems, a manifold and pumps, piping for fluid transfer and ductwork for conditioned air were installed throughout the building.

  11. Reconstructing the geological and structural history of an active geothermal field: A case study from New Zealand

    NASA Astrophysics Data System (ADS)

    Milicich, S. D.; Wilson, C. J. N.; Bignall, G.; Pezaro, B.; Bardsley, C.

    2013-07-01

    The utilisation of geothermal systems benefits from an understanding of the host-rock geology, locations and controls of permeability pathways, and the nature and timing of magmatic sources providing thermal energy. Kawerau Geothermal Field in the central Taupo Volcanic Zone (TVZ) of New Zealand is currently developed for electricity generation and direct uses of high-temperature steam to ~ 200 MW electrical output. The Kawerau geothermal system is hosted in a sequence of volcanic lithologies (tuffs, lavas and intrusive bodies) and sediments that overlie faulted Mesozoic metasedimentary (greywacke) basement. Identification of lithologies in the volcanic/sedimentary sequence is challenging due to the levels of hydrothermal alteration and lithological similarities. A combination of detailed petrological investigations, consideration of the emplacement processes and greater certainty of crystallisation or eruption ages through U-Pb age determinations on zircons is used to reconstruct the depositional and faulting evolution of the rocks hosting the currently active hydrothermal system. The oldest event inferred is faulting of the greywacke along northwest-southeast orientated, dominantly strike-slip structures to generate half-grabens that were filled with sediments, incorporating two dated ignimbrites (2.38 ± 0.05 and 2.17 ± 0.05 Ma). A 1.46 ± 0.01 Ma ignimbrite was deposited relatively evenly across the field, implying that any topographic relief was subdued at that time. Subsequent deposition of ignimbrites occurred in episodes around 1.0, 0.55-0.6, and 0.32 Ma, interspersed with thin sedimentary sequences that accumulated at average rates of 0.06 mm yr- 1. Andesite lavas from a buried composite cone occur as a conformable package between units dated at 1.0 and 0.6 Ma. Bodies of coherent rhyolite occur at multiple stratigraphic levels: two magma types with associated tuffs were emplaced as domes and sills at 0.36 ± 0.03 Ma, and a third type at 0.138 ± 0.007 Ma

  12. Geothermal Program Review VII: proceedings. DOE Research and Development for the Geothermal Marketplace

    SciTech Connect

    Not Available

    1989-01-01

    Each year the Geothermal Technology Division of the US Department of Energy conducts an indepth review of its entire geothermal R and D program. The 2--3 day conference serves several purposes: a status report on current R and D activities, an assessment of progress and problems, a review of management issues, and a technology transfer opportunity between DOE and the US geothermal industry. This year's conference, Program Review 7, was held in San Francisco on March 21--23, 1989. As indicated by its title, ''DOE Research and Development for the Geothermal Marketplace'', Program Review 7 emphasized developing technologies, concepts, and innovations having potential for commercial application in the foreseeable future. Program Review 7 was comprised of eight sessions including an opening session and a special presentation on the ''Role of Geothermal Energy in Minimizing Global Environmental Problems.'' The five technical sessions covered GTD-sponsored R and D in the areas of hydrothermal (two sessions), hot dry rock, geopressured, and magma. Presentations were made by the relevant field researchers, and sessions were chaired by the appropriate DOE Operations Office Geothermal Program Manager. The technical papers and commentary of invited speakers contained in these Proceedings have been compiled in the order in which they were presented at Program Review 7.

  13. Volcanology and volcanic activity with a primary focus on potential hazard impacts for the Hawaii geothermal project

    SciTech Connect

    Moore, R.B.; Delaney, P.T.; Kauahikaua, J.P.

    1993-10-01

    This annotated bibliography reviews published references about potential volcanic hazards on the Island of Hawaii that are pertinent to drilling and operating geothermal wells. The first two sections of this annotated bibliography list the most important publications that describe eruptions of Kilauea volcano, with special emphasis on activity in and near the designated geothermal subzones. References about historic eruptions from Mauna Loa`s northeast rift zone, as well as the most recent activity on the southern flank of dormant Mauna Kea, adjacent to the Humu`ula Saddle are described. The last section of this annotated bibliography lists the most important publications that describe and analyze deformations of the surface of Kilauea and Mauna Loa volcanoes.

  14. Active metasomatism in the Cerro Prieto geothermal system, Baja California, Mexico: a telescoped low pressure/temperature metamorphic facies series

    SciTech Connect

    Schiffman, P.; Elders, W.A.; Williams, A.E.; McDowell, S.D.; Bird, D.K.

    1983-01-01

    In the Cerro Prieto geothermal field, carbonate-cemented, quartzofeldspathic sediments of the Colorado River delta are being actively metasomatized into calc-silicate metamorphic rocks by reaction with alkali chloride brines between 200/sup 0/ and 370/sup 0/C, low fluid and lithostatic pressures, and low oxygen fugacities. Petrologic investigations of drill cores and cutting from over 50 wells in this field identified a prograde series of calc-silicate mineral zones which include as index minerals: wairakite, epidote, prehnite, and clinopyroxene. Associated divariant mineral assemblages are indicative of a very low pressure/temperature metamorphic facies series which encompasses the clay-carbonate, zeolite, greenschist, and amphibolite facies. This hydrothermal metamorphic facies series, which is becoming increasingly recognized in other active geothermal systems, is characterized by temperature-telescoped dehydration and decarbonation mineral equilibria. Its equivalent should now be sought in fossil hydrothermal systems.

  15. Deep drilling for geothermal energy in Finland

    NASA Astrophysics Data System (ADS)

    Kukkonen, Ilmo

    2016-04-01

    There is a societal request to find renewable CO2-free energy resources. One of the biggest such resources is provided by geothermal energy. In addition to shallow ground heat already extensively used in Finland, deep geothermal energy provides an alternative so far not exploited. Temperatures are high at depth, but the challenge is, how to mine the heat? In this presentation, the geological and geophysical conditions for deep geothermal energy production in Finland are discussed as well as challenges for drilling and conditions at depth for geothermal energy production. Finland is located on ancient bedrock with much lower temperatures than geologically younger volcanically and tectonically active areas. In order to reach sufficiently high temperatures drilling to depths of several kilometres are needed. Further, mining of the heat with, e.g., the principle of Enhanced Geothermal System (EGS) requires high hydraulic conductivity for efficient circulation of fluid in natural or artificial fractures of the rock. There are many issues that must be solved and/or improved: Drilling technology, the EGS concept, rock stress and hydraulic fracturing, scale formation, induced seismicity and ground movements, possible microbial activity, etc. An industry-funded pilot project currently in progress in southern Finland is shortly introduced.

  16. Development of Active Seismic Vector-Wavefield Imaging Technology for Geothermal Applications

    SciTech Connect

    B. A. Hardage; J. L. Simmons, Jr.; M. DeAngelo

    1999-10-01

    This report describes the development and testing of vector-wavefield seismic sources that can generate shear (S) waves that may be valuable in geothermal exploration and reservoir characterization. Also described is a 3-D seismic data-processing effort to create images of Rye Patch geothermal reservoir from 3-D sign-bit data recorded over the geothermal prospect. Two seismic sources were developed and tested in this study that can be used to illuminate geothermal reservoirs with S-waves. The first was an explosive package that generates a strong, azimuth-oriented, horizontal force vector when deployed in a conventional shot hole. This vector-explosive source has never been available to industry before. The second source was a dipole formed by operating two vertical vibrators in either a force or phase imbalance. Field data are shown that document the strong S-wave modes generated by these sources.

  17. Chemical and light-stable isotope characteristics of waters from the raft river geothermal area and environs, cassia county, idaho; box elder county, Utah

    USGS Publications Warehouse

    Nathenson, M.; Nehring, N.L.; Crosthwaite, E.G.; Harmon, R.S.; Janik, C.; Borthwick, J.

    1982-01-01

    Chemical and light-stable isotope data are presented for water samples from the Raft River geothermal area and environs. On the basis of chemical character, as defined by a trilinear plot of per cent milliequivalents, and light-stable isotope data, the waters in the geothermal area can be divided into waters that have and have not mixed with cold water. The non-mixed waters have essentially a constant value of light-stable isotopes but show a large variation in chloride content. The variation of chloride composition is not the usual pattern for deep geothermal waters, where it is normally assumed that the deep water has a single chloride composition. Different mixed waters also have hot-water sources of varying chloride composition. Plots of chloride values on cross-sections show that water circulation patterns are confused, with non-mixed waters having different chloride concentrations located in close proximity. Three models can explain the characteristics of the deep geothermal water: (1) in addition to near-surface mixing of cold and hot water, there is deep mixing of two hot waters with the same enthalpy and isotopic composition but differing chloride concentrations to produce the range of chloride concentrations found in the deep geothermal water; (2) there is a single deep hot water, and the range of chloride concentrations is produced by the water passing through a zone of highly soluble materials (most likely in the sedimentary section above the basement) in which waters have different residence times or slightly different circulation paths; (3) the varying chloride concentrations in space have been caused by varying chloride concentrations in the deep feed water through time. Some of this older water has not been flushed from the system by the natural discharge. Although one model may seem more plausible than the others, the available data do not rule out any of them. Data for water samples from the Raft River and Jim Sage Mountains show that water from

  18. A controlled source audiomagnetotelluric investigation of the Ennis Hot Springs Geothermal Area, Ennis, Montana: Final report: Part 2

    SciTech Connect

    Emilsson, G.R.

    1988-06-01

    A controlled-source audiomagnetotelluric survey (CSAMT) at the Ennis Hot Springs geothermal area revealed a low resistivity anomaly (3 ohm-m to 10 ohm-m) in the vicinity of the hot springs. The hot springs issue from the base of a gravel terrace on the west side of the Madison Valley. Low apparent resistivities extend to the west under the gravel terrace as well as to the north in an elongated ''plume''. To the southwest the apparent resistivity increases rapidly due to an uplift in the valley basement. One-dimensional inverse modeling in the center of the valley indicates a buried conductive layer probably due to a thick layer of clay-bearing sediments since a nearby test well does not show elevated temperatures. Near the hot springs, one-dimensional inverse modeling did not prove useful, partly because of the two and three-dimensional nature of the structure. Two-dimensional forward modeling near the hot springs provides a more quantitative delineation of the low resistivity zone and of the faulted basement uplifts to the west and south. Details of the structure beneath the conductive zone near the hot springs are difficult to resolve and most of the model control in this region is provided by well logs and seismic data. A technique for correcting data collected in the region close to the transmitter where the plane wave assumption is not valid has derived and has been applied to the low frequency data. 29 refs., 35 figs., 1 tab.

  19. Overview of the geothermal field of Slovenia in the area between the Alps, the Dinarides and the Pannonian basin

    NASA Astrophysics Data System (ADS)

    Ravnik, , D.; Rajver, D.; Poljak, M.; Živčić, M.

    1995-11-01

    An updated review of the available geothermal data for Slovenia is presented. In order to evaluate the main tectono-thermal characteristics, an overview of three most relevant geophysical parameters, namely heat flow density, the distribution of shallow seismicity, and the depth of the Mohorovičić boundary, over a much larger, so-called Circum-Adriatic region, extending from the Tyrrhenian Sea to the Pannonian basin, is first given. The pattern and values of these parameters in the Adriatic Sea and just outside this area differ significantly from those of the outlying environment, and thus correspond roughly to the area known as the Adriatic microplate. Slovenia is situated at the northern rim of this geophysically diversified region. In the western part of the country, where the Dinarides and Southern Alps are situated, a good correlation has been found between the deeply lying Mohorovičić discontinuity, the low heat flow density, low temperatures at depth and a large negative Bouguer anomaly, whereas in the eastern part of Slovenia (the Pannonian basin) the rising mantle-crust boundary is associated with the high heat flow density, high temperatures at depth and a positive Bouguer anomaly. At the transition zone between the Southern Alps and the Dinarides, along the area of changing crustal thickness, a shallow seismicity belt is indicated. The only DSS profile in Slovenia, crossing the country in a SW-NE direction from Pula (Croatia) to Maribor, reflects the tectonic relations and seismicity between the Dinarides and the Pannonian basin.

  20. The impact of temperature on microbial diversity and AOA activity in the Tengchong Geothermal Field, China

    PubMed Central

    Li, Haizhou; Yang, Qunhui; Li, Jian; Gao, Hang; Li, Ping; Zhou, Huaiyang

    2015-01-01

    Using a culture-independent method that combines CARD-FISH, qPCR and 16S rDNA, we investigated the abundance, community structure and diversity of microbes along a steep thermal gradient (50–90 °C) in the Tengchong Geothermal Field. We found that Bacteria and Archaea abundance changed markedly with temperature changes and that the number of cells was lowest at high temperatures (90.8 °C). Under low-temperature conditions (52.3–74.6 °C), the microbial communities were dominated by Bacteria, which accounted for 60–80% of the total number of cells. At 74.6 °C, Archaea were dominant, and at 90.8 °C, they accounted for more than 90% of the total number of cells. Additionally, the microbial communities at high temperatures (74.6–90.8 °C) were substantially simpler than those at the low-temperature sites. Only a few genera (e.g., bacterial Caldisericum, Thermotoga and Thermoanaerobacter, archaeal Vulcanisaeta and Hyperthermus) often dominated in high-temperature environments. Additionally, a positive correlation between Ammonia-Oxidizing Archaea (AOA) activity and temperature was detected. AOA activity increased from 17 to 52 pmol of NO2− per cell d−1 with a temperature change from 50 to 70 °C. PMID:26608685

  1. The impact of temperature on microbial diversity and AOA activity in the Tengchong Geothermal Field, China.

    PubMed

    Li, Haizhou; Yang, Qunhui; Li, Jian; Gao, Hang; Li, Ping; Zhou, Huaiyang

    2015-11-26

    Using a culture-independent method that combines CARD-FISH, qPCR and 16S rDNA, we investigated the abundance, community structure and diversity of microbes along a steep thermal gradient (50-90 °C) in the Tengchong Geothermal Field. We found that Bacteria and Archaea abundance changed markedly with temperature changes and that the number of cells was lowest at high temperatures (90.8 °C). Under low-temperature conditions (52.3-74.6 °C), the microbial communities were dominated by Bacteria, which accounted for 60-80% of the total number of cells. At 74.6 °C, Archaea were dominant, and at 90.8 °C, they accounted for more than 90% of the total number of cells. Additionally, the microbial communities at high temperatures (74.6-90.8 °C) were substantially simpler than those at the low-temperature sites. Only a few genera (e.g., bacterial Caldisericum, Thermotoga and Thermoanaerobacter, archaeal Vulcanisaeta and Hyperthermus) often dominated in high-temperature environments. Additionally, a positive correlation between Ammonia-Oxidizing Archaea (AOA) activity and temperature was detected. AOA activity increased from 17 to 52 pmol of NO2(-) per cell d(-1) with a temperature change from 50 to 70 °C.

  2. Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data

    SciTech Connect

    SGP-TR-150-16

    1995-01-26

    Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems is of a vital importance to plan geothermal production and injection drilling, since an active fault zone often acts as a fracture-extensive low-velocity wave guide to seismic waves. We have located an active fault zone in the Coso geothermal field, California, by identifying and analyzing a fault-zone trapped Rayleigh-type guided wave from microearthquake data. The wavelet transform is employed to characterize guided-wave's velocity-frequency dispersion, and numerical methods are used to simulate the guided-wave propagation. The modeling calculation suggests that the fault zone is {approx} 200m wide, and has a P wave velocity of 4.80 km/s and a S wave velocity of 3.00 km/s, which is sandwiched between two half spaces with relatively higher velocities (P wave velocity 5.60 km/s, and S wave velocity 3.20 km/s). zones having vertical or nearly vertical dipping fault planes.

  3. Activity remotely triggered in volcanic and geothermal centers in California and Washington by the 3 November 2002 Mw=7.9 Alaska earthquake

    NASA Astrophysics Data System (ADS)

    Hill, D. P.; Prejean, S.; Oppenheimer, D.; Pitt, A. M.; S. D. Malone; Richards-Dinger, K.

    2002-12-01

    The M=7.9 Alaska earthquake of 3 November 2002 was followed by bursts of remotely triggered earthquakes at several volcanic and geothermal areas across the western United States at epicentral distances of 2,500 to 3,660 km. Husen et al. (this session) describe the triggered response for Yellowstone caldera, Wyoming. Here we highlight the triggered response for the Geysers geothermal field in northern California, Mammoth Mountain and Long Valley caldera in eastern California, the Coso geothermal field in southeastern California, and Mount Rainier in central Washington. The onset of triggered seismicity at each of these areas began 15 to 17 minutes after the Alaska earthquake during the S-wave coda and the early phases of the Love and Raleigh waves with periods of 5 to 40 seconds and dynamic strains of a few microstrain. In each case, the seismicity was characterized by spasmodic bursts of small (M<2 ), brittle-failure earthquakes. The activity persisted for just a few minutes at Mount Rainier and Mammoth Mountain and roughly 30 minutes at the Geysers and Coso geothermal fields. Many of the triggered earthquakes at all three sites were too small for reliable locations (magnitudes M<1), although their small S-P times indicate hypocentral locations within a few km of the nearest seismic station. Borehole dilatometers in vicinity of Mammoth Mountain recorded strain offsets on the order of 0.1 microstrain coincident in time with the triggered seismicity (Johnston et al. this session), and water level in the 3-km-deep LVEW well in the center of Long Valley caldera dropped by ~13 cm during passage of the seismic wave train from the Alaska earthquake followed by a gradual recovery. The Geysers, Coso, and Mount Rainier have no continuous, high-resolution strain instrumentation. A larger earthquake swarm that began 23.5 hours later (21:38 UT on the 4th) in the south moat of Long Valley caldera and included nine M>2 and one M=3.0 earthquake may represent a delayed response to

  4. Assessment of Geothermal Resource Potential at a High-Priority Area on the Utah Testing and Training Range–South (UTTR–S)

    SciTech Connect

    Richard P. Smith, PhD., PG; Robert P. Breckenridge, PhD.; Thomas R. Wood, PhD.

    2012-04-01

    Field investigations conducted during 2011 support and expand the conclusion of the original Preliminary Report that discovery of a viable geothermal system is possible in the northwestern part of the Utah Testing and Training Range-South (UTTR-S), referred to henceforth as Focus Area 1. The investigations defined the southward extent of the Wendover graben into and near Focus Area 1, enhanced the understanding of subsurface conditions, and focused further geothermal exploration efforts towards the northwestern-most part of Focus Area 1. Specifically, the detailed gravity survey shows that the Wendover graben, first defined by Cook et al. (1964) for areas north of Interstate Highway 80, extends and deepens southwest-ward to the northwest corner of Focus Area 1. At its deepest point, the intersection with a northwest-trending graben there is favorable for enhanced permeability associated with intersecting faults. Processing and modeling of the gravity data collected during 2011 provide a good understanding of graben depth and distribution of faults bounding the graben and has focused the interest area of the study. Down-hole logging of temperatures in wells made available near the Intrepid, Inc., evaporation ponds, just north of Focus Area 1, provide a good understanding of the variability of thermal gradients in that area and corroborate the more extensive temperature data reported by Turk (1973) for the depth range of 300-500 m. Moderate temperature gradients in the northern part of the Intrepid area increase to much higher gradients and bottom-hole temperatures southeastward, towards graben-bounding faults, suggesting upwelling geothermal waters along those faults. Water sampling, analysis, and temperature measurements of Blue Lakes and Mosquito Willey's springs, on the western boundary of Focus Area 1, also show elevated temperatures along the graben-bounding fault system. In addition, water chemistry suggests origin of those waters in limestone rocks beneath

  5. Colorado geothermal commercialization program: community development of geothermal energy in Pagosa Springs, Colorado

    SciTech Connect

    Coe, B.A.

    1980-01-01

    A district heating system for the Pagosa Springs central business district is in the planning stage. A detailed analysis of the project is presented. It comprises area and site specific studies and describes in detail the recent, current, anticipated, and postulated geothermal development activities. (MHR)

  6. Pumpernickel Valley Geothermal Project Thermal Gradient Wells

    SciTech Connect

    Z. Adam Szybinski

    2006-01-01

    The Pumpernickel Valley geothermal project area is located near the eastern edge of the Sonoma Range and is positioned within the structurally complex Winnemucca fold and thrust belt of north-central Nevada. A series of approximately north-northeast-striking faults related to the Basin and Range tectonics are superimposed on the earlier structures within the project area, and are responsible for the final overall geometry and distribution of the pre-existing structural features on the property. Two of these faults, the Pumpernickel Valley fault and Edna Mountain fault, are range-bounding and display numerous characteristics typical of strike-slip fault systems. These characteristics, when combined with geophysical data from Shore (2005), indicate the presence of a pull-apart basin, formed within the releasing bend of the Pumpernickel Valley – Edna Mountain fault system. A substantial body of evidence exists, in the form of available geothermal, geological and geophysical information, to suggest that the property and the pull-apart basin host a structurally controlled, extensive geothermal field. The most evident manifestations of the geothermal activity in the valley are two areas with hot springs, seepages, and wet ground/vegetation anomalies near the Pumpernickel Valley fault, which indicate that the fault focuses the fluid up-flow. There has not been any geothermal production from the Pumpernickel Valley area, but it was the focus of a limited exploration effort by Magma Power Company. In 1974, the company drilled one exploration/temperature gradient borehole east of the Pumpernickel Valley fault and recorded a thermal gradient of 160oC/km. The 1982 temperature data from five unrelated mineral exploration holes to the north of the Magma well indicated geothermal gradients in a range from 66 to 249oC/km for wells west of the fault, and ~283oC/km in a well next to the fault. In 2005, Nevada Geothermal Power Company drilled four geothermal gradient wells, PVTG-1

  7. Geophysical investigations of the Baltazor Hot Springs known geothermal resource area and the Painted Hills thermal area, Humboldt County, Nevada

    SciTech Connect

    Edquist, R.K.

    1981-02-01

    Geophysical investigations of the Baltazor Hot Springs KGRA and the Painted Hills thermal area, Humboldt Co., Nevada are described. The study includes a gravity survey of 284 stations covering 750 sq km, numerical modeling and interpretation of five detailed gravity profiles, numerical modeling and inerpretation of 21.8 line-km of dipole-dipole electrical resistivity data along four profiles, and a qualitative inerpretation of 38 line-km of self-potential data along eight profiles. The primary purpose of the investigation is to try to determine the nature of the geologic controls of the thermal anomalies at the two areas.

  8. Active Management of Integrated Geothermal-CO2 Storage Reservoirs in Sedimentary Formations

    DOE Data Explorer

    Buscheck, Thomas A.

    2000-01-01

    Active Management of Integrated Geothermal–CO2 Storage Reservoirs in Sedimentary Formations: An Approach to Improve Energy Recovery and Mitigate Risk: FY1 Final Report The purpose of phase 1 is to determine the feasibility of integrating geologic CO2 storage (GCS) with geothermal energy production. Phase 1 includes reservoir analyses to determine injector/producer well schemes that balance the generation of economically useful flow rates at the producers with the need to manage reservoir overpressure to reduce the risks associated with overpressure, such as induced seismicity and CO2 leakage to overlying aquifers. This submittal contains input and output files of the reservoir model analyses. A reservoir-model "index-html" file was sent in a previous submittal to organize the reservoir-model input and output files according to sections of the FY1 Final Report to which they pertain. The recipient should save the file: Reservoir-models-inputs-outputs-index.html in the same directory that the files: Section2.1.*.tar.gz files are saved in.

  9. Active Management of Integrated Geothermal-CO2 Storage Reservoirs in Sedimentary Formations

    DOE Data Explorer

    Buscheck, Thomas A.

    2012-01-01

    Active Management of Integrated Geothermal–CO2 Storage Reservoirs in Sedimentary Formations: An Approach to Improve Energy Recovery and Mitigate Risk : FY1 Final Report The purpose of phase 1 is to determine the feasibility of integrating geologic CO2 storage (GCS) with geothermal energy production. Phase 1 includes reservoir analyses to determine injector/producer well schemes that balance the generation of economically useful flow rates at the producers with the need to manage reservoir overpressure to reduce the risks associated with overpressure, such as induced seismicity and CO2 leakage to overlying aquifers. This submittal contains input and output files of the reservoir model analyses. A reservoir-model "index-html" file was sent in a previous submittal to organize the reservoir-model input and output files according to sections of the FY1 Final Report to which they pertain. The recipient should save the file: Reservoir-models-inputs-outputs-index.html in the same directory that the files: Section2.1.*.tar.gz files are saved in.

  10. Report on Hawaii geothermal power plant project

    SciTech Connect

    Not Available

    1983-06-01

    The Hawaii Geothermal Generator Project is the first power plant in the State of Hawaii to be powered by geothermal energy. This plant, which is located in the Puna District on the Island of Hawaii, produces three (3) megawatts of electricity utilizing the steam phase from the geothermal well. This project represents the climax of the geophysical research efforts going on for two decades in the Hawaiian Islands which resulted in the discovery of a significant reservoir of geothermal energy which could be put to practical use. In 1978 the Department of Energy, in conjunction with the State of Hawaii, entered into negotiations to design and build a power plant. The purpose and objective of this plant was to demonstrate the feasibility of constructing and operating a geothermal power plant located in a remote volcanically active area. A contract was signed in mid 1978 between the Research Corporation of the University of Hawaii (RCUH) and the Department of Energy (DOE). To date, the DOE has provided 8.3 million dollars with the State of Hawaii and others contributing 2.1 million dollars. The cost of the project exceeded its original estimates by approximately 25%. These increases in cost were principally contributed to the higher cost for construction than was originally estimated. Second, the cost of procuring the various pieces of equipment exceed their estimates by 10 to 20 percent, and third, the engineering dollar per man hour rose 20 to 25 percent.

  11. Geothermal direct-heat utilization assistance. Quarterly project progress report, October--December 1997

    SciTech Connect

    1997-01-01

    This report summarizes geothermal technical assistance, R and D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-98 (October--December 1997). It describes 216 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include requests for general information including maps and material for high school debates, and material on geothermal heat pumps, resource and well data, space heating and cooling, greenhouses, aquaculture, equipment, district heating, resorts and spas, industrial applications, electric power and snow melting. Research activities include work on model construction specifications of lineshaft submersible pumps and plate heat exchangers, a comprehensive aquaculture developer package and revisions to the Geothermal Direct Use Engineering and Design Guidebook. Outreach activities include the publication of the Quarterly Bulletin (Vol. 18, No. 4) which was devoted entirely to geothermal activities in South Dakota, dissemination of information mainly through mailings of publications, tours of local geothermal uses, geothermal library acquisition and use, participation in workshops, short courses and technical meetings by the staff, and progress monitor reports on geothermal activities.

  12. Modern geothermal power: GeoPP with geothermal steam turbines

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.

    2017-03-01

    The first part of the review presents information on the scale and specific features of geothermal energy development in various countries. The classification of geothermal power plant (GeoPP) process flow diagrams by a phase state of the primary heat source (a geothermal fluid), thermodynamic cycle, and applicable turbines is proposed. Features of geothermal plants using methods of flashing and steam separation in the process loop and a flowsheet and thermodynamic process of a geothermal fluid heat-to-power conversion in a GeoPP of the most widespread type using a double-flash separation are considered. It is shown that, for combined cycle power units, the specific power-to-consumption geothermal fluid ratio is 20-25% higher than that for traditional single-loop GeoPP. Information about basic chemical components and their concentration range for geothermal fluids of various formations around the world is presented. Three historic stages of improving geothermal energy technologies are determined, such as development of high-temperature geothermal resources (dry, superheated steam) and application of a two-phase wet-steam geothermal fluid in GeoPP power units with one or two expansion pressures and development of binary cycle GeoPPs. A current trend of more active use of binary power plants in GeoPP technological processes is noted. Design features of GeoPP's steam turbines and steam separating devices, determined by the use of low-potential geothermal saturated steam as a working medium, which is characterized by corrosion aggressiveness and a tendency to form deposits, are considered. Most promising Russian geothermal energy projects are determined. A list of today's most advanced geothermal turbine performance technologies is presented. By an example of a 25 MW steam turbine design, made by JSC Kaluga Turbine Works, advantages of the internal moisture separation with a special turbine-separator stage are shown.

  13. Exploring for hydrocarbons in geothermally and hydrothermally complex areas -- a southern Nevada example

    SciTech Connect

    Harris, A.G.; Repetski, J.E.; Grow, J.A.

    1995-06-01

    Time-based isograd maps using conodont color alteration indices (CAI) have been compiled and interpreted for a large area in southern Nevada that includes Yucca Mountain, the Nevada Test Site, and the Nellis Air Force Bombing and Gunnery Range. These maps were produced to evaluate the controversy about possible important mineral and (or) energy resources near Yucca Mountain, the potential burial site for high-level nuclear waste. The hydrocarbon potential of the Yucca Mountain area has been likened to that of the Railroad and Pine Valley areas, 200 km to the northeast where 35 million barrels of oil have been produced from Paleozoic and lower Tertiary strata. In 1991, two companies with no previous drilling experience in Nevada drilled three oil exploration wells within 20 km of Yucca Mountain and within or close to the Timber Mountain caldera system. No shows of oil or gas were found in these wells. The deepest well was drilled to 5,000 feet and penetrated 2,200 feet of upper Tertiary valley-fill deposits and volcanic rocks overlying an overturned sequence of Upper Cambrian and Lower Ordovician rocks having conodonts with CAI values of 5. Our new conodont sampling, however, has targeted some thermally favorable areas for hydrocarbons east of Yucca mountain, but their maturation history suggests that the potential for oil is substantially lower than in the Railroad and Pine Valley areas. Cambrian through Triassic rocks in the vicinity of Yucca Mountain have experienced temperatures too high for oil to be preserved, except for a narrow zone (20 x 100 km) northeast of Yucca Mountain, where Mississippian through Triassic rocks are just within the upper limit of the oil generating window. Most of this zone, however, lies on Federal lands that are, for now, inaccessible for a variety of security and environmental reasons.

  14. Thermal and tectonic history in the steamboat hills geothermal field: Determination of the age of active hydrothermal activity by application of AFTA{sup {trademark}} (apatite fission track analysis)

    SciTech Connect

    Duddy, I.R.; Green, P.F.; Kamp, P.C. van de

    1995-12-31

    This study, in the Steamboat Hills area of the Carson segment of the northern Walker Lane Belt, was initiated to provide a regional thermal history framework and to investigate the age of the active local hydrothermal system. Seven outcrop samples, representing ?Cretaceous granodiorite and ?Triassic Peavine sequence metamorphosed volcanic flow and volcaniclastic rocks plus six samples of Peavine rocks in vertical sequence from an 0.8 km deep geothermal corehole have been analyzed using AFTA (apatite fission track analysis) and zircon fission track analysis.

  15. Geothermal Energy Development annual report 1979

    SciTech Connect

    Not Available

    1980-08-01

    This report is an exerpt from Earth Sciences Division Annual Report 1979 (LBL-10686). Progress in thirty-four research projects is reported including the following area: geothermal exploration technology, geothermal energy conversion technology, reservoir engineering, and geothermal environmental research. Separate entries were prepared for each project. (MHR)

  16. Depositional setting, structural style, and sandstone distribution in three geopressured geothermal areas, Texas Gulf Coast

    SciTech Connect

    Winker, C.D.; Morton, R.A.; Ewing, T.E.; Garcia, D.D.

    1981-10-01

    Three areas in the Texas Gulf Coast region with different depositional settings, structural styles, and sandstone distribution were studied with well log and seismic data to evaluate some of the controls on subsurface conditions in geopressured aquifers. Structural and stratigraphic interpretations were made primarily on the basis of well log correlations. Seismic data confirm the log interpretations but also are useful in structure mapping at depths below well control.

  17. Philippine geothermal resources: General geological setting and development

    SciTech Connect

    Datuin, R.T.; Troncales, A.C.

    1986-01-01

    The Phillippine Archipelago has a composite geologic structure arising from the multi-stage development of volcanic-tectonic events evidenced by volcanism and seismic activity occurring along the active blocks of the major structural lines which traverse most of the major islands of the Phillipines. The widespread volcanic activity located along the active tectonic block has generated regions of high heat flow, where a vast number of potential rich geothermal resources could be exploited as an alternative source of energy. As part of a systematic geothermal development program launched by the Philippine government after the successful pilot study at the Tiwi geothermal field in 1967 by the Commission on Volcanology (now called the Philippine Institute of Volcanology-PIV), the Philippines developed four geothermal fields in the period 1972-84. These four areas, Tiwi in Albay, Mak-Ban in Laguna, Tongonan in Leyte, and Palinpinon in Southern Negros, have already contributed 891 MW installed capacity to the total electrical power supply of the country, which is mainly dependent on oil resources. The Philippines envisaged that, with its accelerated geothermal energy programme, it would be able to achieve its target of reducing the country's dependence on imported fossil fuel by about 20% within the next decade through the utilization of its vast geothermal energy resources.

  18. Geothermal-resource assessment of the Steamboat-Routt Hot Springs area, Colorado. Resources Series 22

    SciTech Connect

    Pearl, R.H.; Zacharakis, T.G.; Ringrose, C.D.

    1983-01-01

    An assessment of the Steamboat Springs region in northwest Colorado was initiated and carried out in 1980 and 1981. The goal of this program was to delineate the geological features controlling the occurrence of the thermal waters (temperatures in excess of 68/sup 0/F (20/sup 0/C)) in this area at Steamboat Springs and 8 miles (12.8 km) north at Routt Hot Springs. Thermal waters from Heart Spring, the only developed thermal water source in the study area, are used in the municipal swimming pool in Steamboat Springs. The assessment program was a fully integrated program consisting of: dipole-dipole, Audio-magnetotelluric, telluric, self potential and gravity geophysical surveys, soil mercury and soil helium geochemical surveys; shallow temperature measurements; and prepartion of geological maps. The investigation showed that all the thermal springs appear to be fault controlled. Based on the chemical composition of the thermal waters it appears that Heart Spring in Steamboat Springs is hydrologically related to the Routt Hot Springs. This relationship was further confirmed when it was reported that thermal waters were encountered during the construction of the new high school in Strawberry Park on the north side of Steamboat Springs. In addition, residents stated that Strawberry Park appears to be warmer than the surrounding country side. Geological mapping has determined that a major fault extends from the Routt Hot Springs area into Strawberry Park.

  19. Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica)

    NASA Astrophysics Data System (ADS)

    Goyanes, G.; Vieira, G.; Caselli, A.; Cardoso, M.; Marmy, A.; Santos, F.; Bernardo, I.; Hauck, C.

    2014-11-01

    This study aims at understanding the spatial distribution and characteristics of the frozen and unfrozen terrain in an alluvial fan on Deception Island, which is an active strato-volcano located in the Bransfield Strait (South Shetland Islands) with recent eruptions in 1967, 1969 and 1970. The alluvial fan is dominated by debris-flow, run-off and rock fall processes and permafrost occurs in several parts in the vicinity of anomalous geothermal heat flux. The aim is to assess the ways volcanic activity controls permafrost development and associated geomorphic dynamics using shallow subsurface, surface and air temperature measurements as well as thaw depth and electrical resistivity tomography (ERT) surveys. Results show a temperature increase with depth in the lower part of the fan reaching 13 °C at 0.80 m depth, without the presence of permafrost. The shallow borehole located at this site showed a stable thermal stratification all year-round, with only the upper 0.20 m reacting to meteorological forcing. In the upper part of the alluvial fan and debris cones, c. 100 m from the coast, frozen ground is present at c. 0.70 m depth. There, the shallow borehole shows a good coupling with air temperatures and the thermal regime favours the presence of permafrost. ERT shows the lowest resistivity values in the lower part of the alluvial fan and a highly resistivity zone in the upper sector of the fan and in the debris cones. These large variations in resistivity mark the presence of a saline water wedge from the sea into the fan, reaching frozen ground conditions about 100 m inland. It can be shown that the volcano-hydrothermal activity only inhibits frost development very locally, with frozen ground conditions occurring about 100 m away.

  20. Rapid heat-flowing surveying of geothermal areas, utilizing individual snowfalls as calorimeters

    USGS Publications Warehouse

    White, Donald E.

    1969-01-01

    Local differences in rate of heat transfer in vapor and by conduction through the ground in hot spring areas are difficult and time-consuming to measure quantitatively. Individual heavy snowfalls provide a rapid low-cost means of measuring total heat flow from such ground. After a favorable snowfall (heavy, brief duration, little wind, air temperature near 0°C), contacts between snow-covered and snow-free ground are mapped on a suitable base. Each mapped contact, as time elapses after a specific snowfall, is a heat-flow contour representing a decreasing rate of flow. Calibration of each mapped contact or snow line is made possible by the fact that snow remains on insulated surfaces (such as the boardwalks of Yellowstone's thermal areas) long after it has melted on adjacent warm ground. Heat-flow contours mapped to date range from 450 to 5500 μcal/cm2 sec, or 300 to 3700 times the world average of conductive heat flow. The very high rates of heat flow (2000 to > 10,000 μcal/cm2 sec) are probably too high, and the lower heat flows determinable by the method (2 sec) may be too low. Values indicated by the method are, however, probably within a factor of 2 of the total conductive and convective heat flow. Thermal anomalies from infrared imagery are similar in shape to heat-flow contours of a test area near Old Faithful geyser. Snowfall calorimetry provides a rapid means for evaluating the imagery and computer-derived products of the infrared data in terms of heat flow.

  1. Empirical equation estimates geothermal gradients

    SciTech Connect

    Kutasov, I.M. )

    1995-01-02

    An empirical equation can estimate geothermal (natural) temperature profiles in new exploration areas. These gradients are useful for cement slurry and mud design and for improving electrical and temperature log interpretation. Downhole circulating temperature logs and surface outlet temperatures are used for predicting the geothermal gradients.

  2. Transport of tracers and pollutants from the Geysers Geothermal Resource Area

    SciTech Connect

    Orgill, M.M.; Lee, R.N.; Schreck, R.I.

    1983-08-01

    An initial analysis of both surface and aerial SF/sub 6/ tracer data from the Geysers illustrates the importance that terrain, vertical wind shear, time-varying winds and stability have on the downwind distribution of cooling tower effluents during the daytime. Atmospheric stability and near surface winds above 3 m/s results in fumigation and surface impaction of a portion of cooling tower plumes on downwind surfaces and terrain. Vertical wind shear and possible gravity waves in upper-levels (approx. 1800 to 2000 m m.s.l), in addition, to terrain influences assist in distributing plumes horizontally and in the vertical at relative short (approx. 10 to 20 km) distances from the source. Small quantities of gaseous sulfur, primarily H/sub 2/S, are transported up to 20 km or more from the Geysers area. A variety of trace materials such as sulfate, copper, zinc, arsenic, bromine, lead, antimony, selenium and barium appear to be enriched over background levels and transported downwind from the Geysers Area at times.

  3. Microbial Community Structure and Arsenic Biogeochemistry in an Acid Vapor-Formed Spring in Tengchong Geothermal Area, China

    PubMed Central

    Jiang, Zhou; Li, Ping; Jiang, Dawei; Dai, Xinyue; Zhang, Rui; Wang, Yanhong; Wang, Yanxin

    2016-01-01

    Arsenic biogeochemistry has been studied extensively in acid sulfate-chloride hot springs, but not in acid sulfate hot springs with low chloride. In this study, Zhenzhuquan in Tengchong geothermal area, a representative acid sulfate hot spring with low chloride, was chosen to study arsenic geochemistry and microbial community structure using Illumina MiSeq sequencing. Over 0.3 million 16S rRNA sequence reads were obtained from 6-paired parallel water and sediment samples along its outflow channel. Arsenic oxidation occurred in the Zhenxhuquan pool, with distinctly high ratios of arsenate to total dissolved arsenic (0.73–0.86). Coupled with iron and sulfur oxidation along the outflow channel, arsenic accumulated in downstream sediments with concentrations up to 16.44 g/kg and appeared to significantly constrain their microbial community diversity. These oxidations might be correlated with the appearance of some putative functional microbial populations, such as Aquificae and Pseudomonas (arsenic oxidation), Sulfolobus (sulfur and iron oxidation), Metallosphaera and Acidicaldus (iron oxidation). Temperature, total organic carbon and dissolved oxygen significantly shaped the microbial community structure of upstream and downstream samples. In the upstream outflow channel region, most microbial populations were microaerophilic/anaerobic thermophiles and hyperthermophiles, such as Sulfolobus, Nocardia, Fervidicoccus, Delftia, and Ralstonia. In the downstream region, aerobic heterotrophic mesophiles and thermophiles were identified, including Ktedonobacteria, Acidicaldus, Chthonomonas and Sphingobacteria. A total of 72.41–95.91% unassigned-genus sequences were derived from the downstream high arsenic sediments 16S rRNA clone libraries. This study could enable us to achieve an integrated understanding on arsenic biogeochemistry in acid hot springs. PMID:26761709

  4. Microbial Community Structure and Arsenic Biogeochemistry in an Acid Vapor-Formed Spring in Tengchong Geothermal Area, China.

    PubMed

    Jiang, Zhou; Li, Ping; Jiang, Dawei; Dai, Xinyue; Zhang, Rui; Wang, Yanhong; Wang, Yanxin

    2016-01-01

    Arsenic biogeochemistry has been studied extensively in acid sulfate-chloride hot springs, but not in acid sulfate hot springs with low chloride. In this study, Zhenzhuquan in Tengchong geothermal area, a representative acid sulfate hot spring with low chloride, was chosen to study arsenic geochemistry and microbial community structure using Illumina MiSeq sequencing. Over 0.3 million 16S rRNA sequence reads were obtained from 6-paired parallel water and sediment samples along its outflow channel. Arsenic oxidation occurred in the Zhenxhuquan pool, with distinctly high ratios of arsenate to total dissolved arsenic (0.73-0.86). Coupled with iron and sulfur oxidation along the outflow channel, arsenic accumulated in downstream sediments with concentrations up to 16.44 g/kg and appeared to significantly constrain their microbial community diversity. These oxidations might be correlated with the appearance of some putative functional microbial populations, such as Aquificae and Pseudomonas (arsenic oxidation), Sulfolobus (sulfur and iron oxidation), Metallosphaera and Acidicaldus (iron oxidation). Temperature, total organic carbon and dissolved oxygen significantly shaped the microbial community structure of upstream and downstream samples. In the upstream outflow channel region, most microbial populations were microaerophilic/anaerobic thermophiles and hyperthermophiles, such as Sulfolobus, Nocardia, Fervidicoccus, Delftia, and Ralstonia. In the downstream region, aerobic heterotrophic mesophiles and thermophiles were identified, including Ktedonobacteria, Acidicaldus, Chthonomonas and Sphingobacteria. A total of 72.41-95.91% unassigned-genus sequences were derived from the downstream high arsenic sediments 16S rRNA clone libraries. This study could enable us to achieve an integrated understanding on arsenic biogeochemistry in acid hot springs.

  5. 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.

    USGS Publications Warehouse

    Olmsted, F.H.; Ingebritsen, S.E.

    1986-01-01

    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. ?? 1986.

  6. Comparison of Selective Culturing and Biochemical Techniques for Measuring Biological Activity in Geothermal Process Fluids

    SciTech Connect

    Pryfogle, Peter Albert

    2000-09-01

    For the past three years, scientists at the Idaho National Engineering and Environmental Laboratory have been conducting studies aimed at determining the presence and influence of bacteria found in geothermal plant cooling water systems. In particular, the efforts have been directed at understanding the conditions that lead to the growth and accumulation of biomass within these systems, reducing the operational and thermal efficiency. Initially, the methods selected were based upon the current practices used by the industry and included the collection of water quality parameters, the measurement of soluble carbon, and the use of selective medial for the determination of the number density of various types of organisms. This data has been collected on a seasonal basis at six different facilities located at the Geysers’ in Northern California. While this data is valuable in establishing biological growth trends in the facilities and providing an initial determination of upset or off-normal conditions, more detailed information about the biological activity is needed to determine what is triggering or sustaining the growth in these facilities in order to develop improved monitoring and treatment techniques. In recent years, new biochemical approaches, based upon the analyses of phospholipid fatty acids and DNA recovered from environmental samples, have been developed and commercialized. These techniques, in addition to allowing the determination of the quantity of biomass, also provide information on the community composition and the nutritional status of the organisms. During the past year, samples collected from the condenser effluents of four of the plants from The Geysers’ were analyzed using these methods and compared with the results obtained from selective culturing techniques. The purpose of this effort was to evaluate the cost-benefit of implementing these techniques for tracking microbial activity in the plant study, in place of the selective culturing

  7. Natural radioactivity in geothermal waters, Alhambra Hot Springs and nearby areas, Jefferson County, Montana

    USGS Publications Warehouse

    Leonard, Robert B.; Janzer, Victor J.

    1978-01-01

    Radioactive hot springs issue from a fault zone in crystalline rock of the Boulder batholith at Alhambra, Jefferson County, in southwestern Montana. The discharge contains high concentrations of radon, and the gross alpha activity and the concentration of adium-226 exceed maximum levels recommended by the Environmental Protection Agency for drinking water. Part of the discharge is diverted for space heating, bathing, and domestic use. The radioactive thermal waters at measured temperatures of about 60°C are of the sodium bicarbonate type and saturated with respect to calcium carbonate. Radium-226 in the rock and on fractured surfaces or coprecipitated with calcium carbonate probably is the principal source of radon that is dissolved in the thermal water and discharged with other gases from some wells and springs. Local surface water and shallow ground water are of the calcium bicarbonate type and exhibit low background activity. The temperature, percent sodium, and radioactivity of mixed waters adjacent to the fault zone increase with depth. Samples from most of the major hot springs in southwestern Montana have been analyzed for gross alpha and beta activity. The high level of radioactivity at Alhambra appears to be related to leaching of radioactive material from siliceous veins by ascending thermal waters and is not a normal characteristic of hot springs issuing from fractured crystalline rock in Montana.

  8. Non-shear focal mechanisms of earthquakes at The Geysers, California and Hengill, Iceland, geothermal areas

    USGS Publications Warehouse

    Julian, B.R.; Miller, A.D.; Foulger, G.R.; ,

    1993-01-01

    Several thousand earthquakes were recorded in each area. We report an initial investigation of the focal mechanisms based on P-wave polarities. Distortion by complicated three-dimensional crustal structure was minimized using tomographically derived three-dimensional crustal models. Events with explosive and implosive source mechanisms, suggesting cavity opening and collapse, have been tentatively identified at The Geysers. The new data show that some of these events do not fit the model of tensile cracking accompanied by isotropic pore pressure decreases that was suggested in earlier studies, but that they may instead involve combination of explosive and shear processes. However, the confirmation of earthquakes dominated by explosive components supports the model that the event are caused by crack opening induced by thermal contraction of the heat source.

  9. Comparison of the microbial communities of hot springs waters and the microbial biofilms in the acidic geothermal area of Copahue (Neuquén, Argentina).

    PubMed

    Urbieta, María Sofía; González-Toril, Elena; Bazán, Ángeles Aguilera; Giaveno, María Alejandra; Donati, Edgardo

    2015-03-01

    Copahue is a natural geothermal field (Neuquén province, Argentina) dominated by the Copahue volcano. As a consequence of the sustained volcanic activity, Copahue presents many acidic pools, hot springs and solfataras with different temperature and pH conditions that influence their microbial diversity. The occurrence of microbial biofilms was observed on the surrounding rocks and the borders of the ponds, where water movements and thermal activity are less intense. Microbial biofilms are particular ecological niches within geothermal environments; they present different geochemical conditions from that found in the water of the ponds and hot springs which is reflected in different microbial community structure. The aim of this study is to compare microbial community diversity in the water of ponds and hot springs and in microbial biofilms in the Copahue geothermal field, with particular emphasis on Cyanobacteria and other photosynthetic species that have not been detected before in Copahue. In this study, we report the presence of Cyanobacteria, Chloroflexi and chloroplasts of eukaryotes in the microbial biofilms not detected in the water of the ponds. On the other hand, acidophilic bacteria, the predominant species in the water of moderate temperature ponds, are almost absent in the microbial biofilms in spite of having in some cases similar temperature conditions. Species affiliated with Sulfolobales in the Archaea domain are the predominant microorganism in high temperature ponds and were also detected in the microbial biofilms.

  10. Feasibility of Geothermal Energy Extraction from Non-Activated Petroleum Wells in Arun Field

    NASA Astrophysics Data System (ADS)

    Syarifudin, M.; Octavius, F.; Maurice, K.

    2016-09-01

    The big obstacle to develop geothermal is frequently came from the economical viewpoint which mostly contributed by the drilling cost. However, it potentially be tackled by converting the existing decommissioned petroleum well to be converted for geothermal purposes. In Arun Field, Aceh, there are 188 wells and 62% of them are inactive (2013). The major obstacle is that the outlet water temperature from this conversion setup will not as high as the temperature that come out from the conventional geothermal well, since it will only range from 60 to 180oC depending on several key parameters such as the values of ground temperature, geothermal gradient in current location, the flow inside of the tubes, and type of the tubes (the effect from these parameters are studied). It will just be considered as low to medium temperature, according to geothermal well classification. Several adjustments has to be made such as putting out pipes inside the well that have been used to lift the oil/gas and replacing them with a curly long coil tubing which act as a heat exchanger. It will convert the cold water from the surface to be indirectly heated by the hot rock at the bottom of the well in a closed loop system. In order to make power production, the binary cycle system is used so that the low to medium temperature fluid is able to generate electricity. Based on this study, producing geothermal energy for direct use and electricity generation in Arun Field is technically possible. In this study case, we conclude that 2900 kW of electricity could be generated. While for-direct utility, a lot of local industries in Northern Sumatera could get the benefits from this innovation.

  11. Preliminary assessment of the geothermal potential of Rosario de la Frontera area (Salta, NW Argentina): Insight from hydro-geological, hydro-geochemical and structural investigations

    NASA Astrophysics Data System (ADS)

    Invernizzi, C.; Pierantoni, P. P.; Chiodi, A.; Maffucci, R.; Corrado, S.; Baez, W.; Tassi, F.; Giordano, G.; Viramonte, J.

    2014-10-01

    This work is part of a project aimed to the development and application of hydrogeological, hydrogeochemical and geological methodologies for the study of the geothermal system of Rosario de La Frontera (NW Argentina). The surface thermal manifestations of this area, whose temperatures range from 22.6 to 92.6 °C, are mainly located in the northern sector of Sierra de la Candelaria anticline. This regional structure crops out between the provinces of Salta and Tucuman (NW Argentina), at the foothills of the central Andean retro-wedge. The present investigation focuses on hydrogeological and structural data, and isotopic compositions (18O, D and 3H) of thermal springs. Preliminary results allowed to define: i) the meteoric origin of spring water and their long (more than 50 years) residence time at depth, ii) a positive water balance, ranging between 2 and 4 millions of m3/yr, and iii) a conservative geothermal reservoir volume of about 39 km3, iv) a geothermal potential with Er = 5.6*1018 J and Ef = 0.8*1018 J.

  12. Ambient Seismic Noise Tomography of a Deep Geothermal Area in the Upper Rhine Graben from the EstOF Dense Regional Array

    NASA Astrophysics Data System (ADS)

    Vergne, J.; LE Chenadec, A.; Lehujeur, M.; Schmittbuhl, J.

    2015-12-01

    Passive imaging from ambient noise correlation has proven to be a robust tool to probe the internal structure of the Earth. Assessing the potential of this technique for the exploration of deep geothermal reservoirs was the main motivation of the EstOF project. In September 2014, we deployed a regular grid of 288 Zland nodes over a 30km wide disc (1.5km inter-node spacing) in the Outre-Forêt region (Bas-Rhin, France) encompassing the geothermal sites of Soultz-sous-Forêts and Rittershoffen. The correlation of one month of ambient noise data provides thousands of usable correlations in the 0.2-5Hz frequency range. We clearly observe body waves as well as the fundamental and first harmonic modes of the Rayleigh wave. The latter phases have been used to retrieve group and phase velocity maps using the Eikonal tomography thanks to the high density of the array. Depth inversion of these maps for various frequencies allows us to construct a 3D model of shear wave velocities of the region down to 5km depth. This model, having a lateral resolution of about 2km, appears to be in good agreement with our geological knowledge of the region. This case study validates the use of ambient noise recorded by spatially dense arrays at regional scale as a cheap and robust technique for the exploration of geothermal areas.

  13. Shallow hydrothermal regime of the East Brawley and Glamis known geothermal resource areas, Salton Trough, California

    SciTech Connect

    Mase, C.W.; Sass, J.H.; Brook, C.A.; Munroe, R.J.

    1981-01-01

    Thermal gradients and thermal conductivities were obtained in real time using an in situ heat-flow technique in 15 shallow (90 to 150 m) wells drilled between Brawley and Glamis in the Imperial Valley, Southern California. The in situ measurements were supplemented by follow-up conventional temperature logs in seven of the wells and by laboratory measurements of thermal conductivity on drill cuttings. The deltaic sedimentary material comprising the upper approx. 100 m of the Salton Trough generally is poorly sorted and high in quartz resulting in quite high thermal conductivities (averaging 2.0 Wm/sup -1/ K/sup -1/ as opposed to 1.2 to 1.7 for typical alluvium). A broad heat-flow anomaly with maximum of about 200 mWm/sup -2/ (approx. 5 HFU) is centered between Glamis and East Brawley and is superimposed on a regional heat-flow high in excess of 100 mWm/sup -2/ (> 2.5 HFU). The heat-flow high corresponds with a gravity maximum and partially with a minimum in electrical resistivity, suggesting the presence of a hydrothermal system at depth in this area.

  14. Imperial County geothermal development annual meeting: summary

    SciTech Connect

    Not Available

    1983-01-01

    All phases of current geothermal development in Imperial County are discussed and future plans for development are reviewed. Topics covered include: Heber status update, Heber binary project, direct geothermal use for high-fructose corn sweetener production, update on county planning activities, Brawley and Salton Sea facility status, status of Imperial County projects, status of South Brawley Prospect 1983, Niland geothermal energy program, recent and pending changes in federal procedures/organizations, plant indicators of geothermal fluid on East Mesa, state lands activities in Imperial County, environmental interests in Imperial County, offshore exploration, strategic metals in geothermal fluids rebuilding of East Mesa Power Plant, direct use geothermal potential for Calipatria industrial Park, the Audubon Society case, status report of the Cerro Prieto geothermal field, East Brawley Prospect, and precision gravity survey at Heber and Cerro Prieto geothermal fields. (MHR)

  15. The Philippines geothermal success story

    NASA Astrophysics Data System (ADS)

    Birsic, R. J.

    1980-09-01

    Geothermal electrical plants currently in operation in the Philippines are presented. Following a brief review of the geographical and energy situation of the nation, attention is given to the first 55,000-kW unit of the Tiwi Geothermal Electric Plant, which commenced operation in January 1979, the portable 3,000-kE Leyte Geothermal Pilot Plant, which commenced operation in July, 1977 as the first geothermal power plant in the country, the Makiling-Banahaw (Mak-Ban) Geothermal Power Plant, the first 55,000-kW unit of which began operation in May, 1979 and the second 55,000-kW unit of the Tiwi plant, which came into service in June, 1979, thus making the Philippines the fourth largest producer of geothermal electricity in the world. Factors favoring the use of geothermal plants in developing nations are pointed out, including low capital costs, no foreign exchange costs for fuel, small units, and little environmental impact, and the start-up of two more plants, the second 55,000-kW unit at Mak-Ban in September 1979 and the third Tiwi unit in January 1980, are noted. It is predicted that in 1981, when the Philippines is expected to become the largest user of geothermal energy from hot-water fields, it will have a total capacity of 552 MW from the Mak-Ban, Tiwi and Leyte sites. Further areas with geothermal potential are also pointed out.

  16. Geothermal Energy

    SciTech Connect

    Steele, B.C.; Pichiarella, L.S.; Kane, L.S.; Henline, D.M.

    1995-01-01

    Geothermal Energy (GET) announces on a bimonthly basis the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past two months.

  17. New geochemical investigations in Platanares and Azacualpa geothermal sites (Honduras)

    NASA Astrophysics Data System (ADS)

    Barberi, Franco; Carapezza, Maria Luisa; Cioni, Roberto; Lelli, Matteo; Menichini, Matia; Ranaldi, Massimo; Ricci, Tullio; Tarchini, Luca

    2013-05-01

    Platanares and Azacualpa geothermal sites of Honduras are located in an inner part of the Caribbean Plate far from the active volcanic front of Central America. Here geology indicates that there are not the conditions for the occurrence of shallow magmatic heat sources for high-enthalpy geothermal resources. Geothermal perspectives are related to the possibility of a deep circulation of meteoric water along faults and the storage of the heated fluid in fractured permeable reservoirs. Geochemical geothermometers indicate a temperature for the deeper part of the geothermal reservoir close to 200 °C for Platanares and of 150-170 °C for Azacualpa. Calcite scaling, with subordinate silica deposition has to be expected in both sites. CO2 soil flux investigations have been carried out in both areas and reveal the presence of positive anomalies likely corresponding to the presence at depth of fractured degassing geothermal reservoirs. Compared with the geothermal areas of Central Italy whose reservoirs are hosted in carbonate rocks, e.g. Latera (Chiodini et al., 2007), the CO2 soil flux measured in Honduras is significantly lower (mean of 17 g/m2day at Platanares and of 163 g/m2day at Azacualpa) probably because of the dominant silicate nature of the deep reservoirs.

  18. Geology and geothermal resources of the Santiam Pass area of the Oregon Cascade Range, Deschutes, Jefferson and Linn Counties, Oregon. Final report

    SciTech Connect

    Hill, B.E.

    1992-10-01

    This open-file report presents the results of the Santiam Pass drilling program. The first phase of this program was to compile all available geological, geophysical and geothermal data for the Santiam Pass area and select a drill site on the basis of these data (see Priest and others, 1987a), A summary of the drilling operations and costs associated with the project are presented in chapter 1 by Hill and Benoit. An Overview of the geology of the Santiam Pass area is presented by Hill and Priest in chapter 2. Geologic mapping and isotopic age determinations in the Santiam Pass-Mount Jefferson area completed since 1987 are summarized in chapter 2. One of the more important conclusions reached in chapter 2 is that a minimum of 2 km vertical displacement has occurred in the High Cascade graben in the Santiam Pass area. The petrology of the Santiam Pass drill core is presented by Hill in chapter 3. Most of the major volcanic units in the core have been analyzed for major, minor, and trace element abundances and have been studied petrographically. Three K-Ar ages are interpreted in conjunction with the magnetostratigraphy of the core to show that the oldest rocks in the core are approximately 1.8 Ma. Geothermal and geophysical data collected from the Santiam Pass well are presented by Blackwell in chapter 4. The Santiam Pass well failed to penetrate beneath the zone of lateral groundwater flow associated with highly permeable Quaternary volcanic rocks. Calculated geothermal gradients range from about 50{degree}C/km at depth 700-900 m, to roughly 110{degree}C/km from 900 m to the bottom of the well at 929 m. Heat-flow values for the bottom part of the hole bracket the regional average for the High Cascades. Blackwell concludes that heat flow along the High Cascades axis is equal to or higher than along the western edge of the High Cascades.

  19. Geothermal progress monitor. Progress report No. 7

    SciTech Connect

    Not Available

    1983-04-01

    A state-by-state review of major geothermal-development activities during 1982 is presented. It also inlcudes a summary of recent drilling and exploration efforts and the results of the 1982 leasing program. Two complementary sections feature an update of geothermal direct-use applications and a site-by-site summary of US geothermal electric-power development.

  20. Investigation of the geothermal potential of the UK. A preliminary assessment. Final report

    SciTech Connect

    Not Available

    1982-01-01

    Geologically, Britain is an extremely stable area without active volcanism. In this situation the development of geothermal resources depends upon the occurrence of permeable rocks in deep sedimentary basins or the successful development of the hot dry rock concept. The average geothermal gradient is about 25C/km, but two belts of above average heat flow extend across northern and south-western England. In these areas the gradient can be 30C/km or more. The principal aquifers occur in the Mesozoic and the greatest geothermal potential is in sandstones of the Permo-Triassic where their occurrence at depth coincides with the high heat flow belts.

  1. Geothermal development plan: northern Arizona

    SciTech Connect

    White, D.H.; Goldstone, L.A.

    1981-01-01

    Much of the northern counties (Apache, Coconino, Gila, Mohave, Navajo and Yavapai) is located in the Colorado Plateau province, a region of low geothermal potential. Two areas that do show some potential are the Flagstaff - San Francisco Peaks area and the Springerville area. Flagstaff is rapidly becoming the manufacturing center of Arizona and will have many opportunities to use geothermal energy to satisfy part of its increasing need for energy. Using a computer simulation model, projections of geothermal energy on line as a function of time are made for both private and city-owned utility development of a resource.

  2. Development of concepts for the management of shallow geothermal resources in urban areas - Experience gained from the Basel and Zaragoza case studies

    NASA Astrophysics Data System (ADS)

    García-Gil, Alejandro; Epting, Jannis; Mueller, Matthias H.; Huggenberger, Peter; Vázquez-Suñé, Enric

    2015-04-01

    In urban areas the shallow subsurface often is used as a heat resource (shallow geothermal energy), i.e. for the installation and operation of a broad variety of geothermal systems. Increasingly, groundwater is used as a low-cost heat sink, e.g. for building acclimatization. Together with other shallow geothermal exploitation systems significantly increased groundwater temperatures have been observed in many urban areas (urban heat island effect). The experience obtained from two selected case study cities in Basel (CH) and Zaragoza (ES) has allowed developing concepts and methods for the management of thermal resources in urban areas. Both case study cities already have a comprehensive monitoring network operating (hydraulics and temperature) as well as calibrated high-resolution numerical groundwater flow and heat-transport models. The existing datasets and models have allowed to compile and compare the different hydraulic and thermal boundary conditions for both groundwater bodies, including: (1) River boundaries (River Rhine and Ebro), (2) Regional hydraulic and thermal settings, (3) Interaction with the atmosphere under consideration of urbanization and (4) Anthropogenic quantitative and thermal groundwater use. The potential natural states of the considered groundwater bodies also have been investigated for different urban settings and varying processes concerning groundwater flow and thermal regimes. Moreover, concepts for the management of thermal resources in urban areas and the transferability of the applied methods to other urban areas are discussed. The methods used provide an appropriate selection of parameters (spatiotemporal resolution) that have to be measured for representative interpretations of groundwater flow and thermal regimes of specific groundwater bodies. From the experience acquired from the case studies it is shown that understanding the variable influences of the specific geological and hydrogeological as well as hydraulic and thermal

  3. Middlesex Community College Geothermal Project

    SciTech Connect

    Klein, Jessie; Spaziani, Gina

    2013-03-29

    The purpose of the project was to install a geothermal system in the trustees house on the Bedford campus of Middlesex Community College. In partnership with the environmental science faculty, learning activities for environmental science courses were developed to explain geothermal energy and more specifically the newly installed system to Middlesex students. A real-time monitoring system highlights the energy use and generation.

  4. Geothermal development plan: Yuma County

    SciTech Connect

    White, D.H.; Goldstone, L.A.

    1982-08-01

    The Yuma County Area Development Plan evaluated the county-wide market potential for utilizing geothermal energy. The study identified four potential geothermal resource areas with temperatures less than 90/sup 0/C (194/sup 0/F), and in addition, two areas are inferred to contain geothermal resources with intermediate (90/sup 0/C to 150/sup 0/C, 194/sup 0/F to 300/sup 0/F) temperature potential. The resource areas are isolated, although one resource area is located near Yuma, Arizona. One resource site is inferred to contain a hot dry rock resource. Anticipated population growth in the county is expected to be 2 percent per year over the next 40 years. The primary employment sector is agriculture, though some light industry is located in the county. Water supplies are found to be adequate to support future growth without advese affect on agriculture. Six firms were found in Yuma County which may be able to utilize geothermal energy for process heat needs. In addition, several agricultural processors were found, concentrated in citrus processing and livestock raising. Geothermal energy utilization projections suggest that by the year 2000, geothermal energy may economically provide the energy equivalent of 53,000 barrels of oil per year to the industrial sector if developed privately. Geothermal utilization projections increase to 132,000 barrels of oil per year by 2000 if a municipal utility developed the resource.

  5. Evaluation of geothermal energy in Arizona. Quarterly topical progress report, July 1-September 30, 1981

    SciTech Connect

    White, D.H.

    1981-01-01

    Progress is reported on the following: the legislative and institutional program, cities program, outreach, the integrated alcohol/feedlot/geothermal operation, geothermal energy in the mining industry, geothermal space heating and cooling, identification of a suitable industry for a remote geothermal site, irrigation pumping, coal-fired/geothermal-assisted power plants, and area development plans. (MHR)

  6. Federal Geothermal Research Program Update - Fiscal Year 2001

    SciTech Connect

    Laney, P.T.

    2002-08-31

    This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 2001. The information contained in this Research Update illustrates how the mission and goals of the Office of Geothermal Technologies are reflected in each R&D activity. The Geothermal Program, from its guiding principles to the most detailed research activities, is focused on expanding the use of geothermal energy.

  7. Geothermal hydrogen sulfide removal

    SciTech Connect

    Urban, P.

    1981-04-01

    UOP Sulfox technology successfully removed 500 ppM hydrogen sulfide from simulated mixed phase geothermal waters. The Sulfox process involves air oxidation of hydrogen sulfide using a fixed catalyst bed. The catalyst activity remained stable throughout the life of the program. The product stream composition was selected by controlling pH; low pH favored elemental sulfur, while high pH favored water soluble sulfate and thiosulfate. Operation with liquid water present assured full catalytic activity. Dissolved salts reduced catalyst activity somewhat. Application of Sulfox technology to geothermal waters resulted in a straightforward process. There were no requirements for auxiliary processes such as a chemical plant. Application of the process to various types of geothermal waters is discussed and plans for a field test pilot plant and a schedule for commercialization are outlined.

  8. Goechemical and Hydrogeochemical Properties of Cappadocia Geothermal Province

    NASA Astrophysics Data System (ADS)

    Furkan Sener, Mehmet; Sener, Mehmet; Uysal, Tonguc

    2016-04-01

    In order to determine the geothermal resource potential of Niǧde, Nevşehir and Aksaray provinces in Central Anatolian Volcanic Province (CAVP), geothermal fluids, surface water, and alteration rock samples from the Cappadocia volcanic zone in Turkey were investigated for their geochemical and stable isotopic characteristics in light of published geological and tectonic studies. Accordingly, the Cappadocia Geothermal Province (CGP) has two different geothermal systems located along tectonic zones including five active and two potential geothermal fields, which are located between Tuzgölü Fault Zone and Keçiboyduran-Melendiz Fault and north of Keçiboyduran-Melendiz Fault. Based on water chemistry and isotope compositions, samples from the first area are characterized by Ca-Mg-HCO3 ve Ca-HCO3 type mineral poor waters and Ca-Na-SO4 and Ca-Mg-SO4 type for the cold waters and the hot waters, respectively, whereas hot waters from the second area are Na-Cl-HCO3 and Ca-Na-HCO3 type mineral poor waters. According to δ18O and δ2H isotope studies, the geothermal waters are fed from meteoric waters. Results of silica geothermometer indicate that the reservoir temperature of Dertalan, Melendiz Mount, Keçiboyduran Mount, Hasan Mount (Keçikalesi), Ziga, Acıgöl, and Derinkuyu geothermal waters are 150-173 oC, 88-117 oC, 91-120 oC, 94-122 oC, 131-156 oC, 157-179 oC; 152-174 oC and 102-130 oC, respectively. The REE composition of geothermal fluids, surface water, and mineral precipitates indicate that temperature has a strong effect on REE fractionation of the sampled fluids. Eu- and Ce- anomalies (Eu/Eu*, Ce/Ce*) are visible in several samples, which are related to the inheritance from the host reservoir rocks and redox-controlled fractionation of these elements during water-rock interactions. REE and Yttrium geochemistry results of altered rock samples and water samples, which were taken from same locations exhibited quite similar features in each system. Hence, it was

  9. Geothermal progress monitor report No. 6

    SciTech Connect

    Not Available

    1982-06-01

    Geothermal Progress Monitor Report No. 6 presents a state-by-state summary of the status of geothermal leasing, exploration, and development in major physiographic regions where geothermal resource potential has been identified. Recent state-specific activities are reported at the end of each state status report, while recent activities of a more general nature are summarized briefly in Part II of the report. A list of recent publications of potential interest to the geothermal community and a directory of contributors to the geothermal progress monitoring system are also included.

  10. The role of active and ancient geothermal systems in evolution of Grant Canyon oil field, Railroad Valley, Nye County, Nevada

    SciTech Connect

    Hulen, J.B. ); Bereskin, S.R. ); Bortz, L.C.

    1991-06-01

    Since discovery in 1983, the Grant Canyon field has been among the most prolific oil producers (on a per-well basis) in the US. Production through June 1990 was 12,935,630 bbl of oil, principally from two wells which in tandem have consistently yielded more than 6,000 bbl of oil per day. The field is hosted by highly porous Devonian dolomite breccia loosely cemented with hydrothermal quartz. Results of fluid-inclusion and petrographic research in progress at Grant Canyon suggest that paleogeothermal and perhaps currently circulating geothermal systems may have played a major role in oil-reservoir evolution. For example, as previously reported, the breccia-cementing quartz hosts primary aqueous, aqueous/oil, and oil fluid inclusions which were trapped at about 120C (average homogenization temperature) and document initial oil migration and entrapment as droplets or globules dispersed in dilute (< 2.2 wt.% equivalent NaCl) aqueous solutions. Additional evidence of geothermal connection is that the horst-block trap at Grant Canyon is top and side sealed by valley-fill clastic and volcanic rocks which are locally hydrothermally altered and calcite flooded. These secondary seals are enhanced by disseminated, solid asphaltic residues locally accounting for 23% (volume) of the rock. Current reservoir temperatures at Grant Canyon (120C) and the adjacent Bacon Flat field (171C) attest to vigorous contemporary geothermal activity. Based on results of the authors' Grant Canyon work to date, they suggest that active and paleohydrothermal systems could be viable petroleum exploration targets in otherwise favorable terrain elsewhere in the Basin and Range.

  11. National Geothermal Data System

    NASA Astrophysics Data System (ADS)

    Anderson, A. F.; Cuyler, D.; Snyder, W. S.; Allison, M. L.; Blackwell, D. D.; Williams, C. F.

    2011-12-01

    The goal of the U.S. Department of Energy's National Geothermal Data System is to design, build, implement, deploy and populate a national, sustainable, distributed, interoperable network of data and service (application) providers. These providers will develop, collect, serve, and maintain geothermal-relevant data that operates as an integral component of NGDS. As a result the geothermal industry, the public, and policy makers will have access to consistent and reliable data, which in turn, reduces the amount of staff time devoted to finding, retrieving, integrating, and verifying information. With easier access to information, the high cost and risk of geothermal power projects (especially exploration drilling) is reduced. Five separate NGDS projects provide the data support, acquisition, and access to cyber infrastructure necessary to reduce cost and risk of the nation's geothermal energy strategy and US DOE program goals focused on the production and utilization of geothermal energy. The U.S DOE Office of Energy Efficiency and Renewable Energy Geothermal Technologies Program is developing the knowledge and data foundation necessary for discovery and development of large-scale energy production while the Buildings Technology Program is focused on other practical applications such as direct use and residential/commercial ground source heat pumps. The NGDS provides expanded reference and resource data for research and development activities (a subset of the US DOE goals) and includes data from across all fifty states and the nation's leading academic geothermal centers. Thus, the project incorporates not only high-temperature potential but also moderate and low-temperature locations incorporating US DOE's goal of adding more geothermal electricity to the grid. The program, through its development of data integration cyberinfrastructure, will help lead to innovative exploration technologies through increased data availability on geothermal energy capacity. Finally

  12. Environmental Assessment Lakeview Geothermal Project

    SciTech Connect

    Treis, Tania

    2012-04-30

    The Town of Lakeview is proposing to construct and operate a geothermal direct use district heating system in Lakeview, Oregon. The proposed project would be in Lake County, Oregon, within the Lakeview Known Geothermal Resources Area (KGRA). The proposed project includes the following elements: Drilling, testing, and completion of a new production well and geothermal water injection well; construction and operation of a geothermal production fluid pipeline from the well pad to various Town buildings (i.e., local schools, hospital, and Lake County Industrial Park) and back to a geothermal water injection well. This EA describes the proposed project, the alternatives considered, and presents the environmental analysis pursuant to the National Environmental Policy Act. The project would not result in adverse effects to the environment with the implementation of environmental protection measures.

  13. Geothermal industry assessment

    SciTech Connect

    Not Available

    1980-07-01

    An assessment of the geothermal industry is presented, focusing on industry structure, corporate activities and strategies, and detailed analysis of the technological, economic, financial, and institutional issues important to government policy formulation. The study is based principally on confidential interviews with executives of 75 companies active in the field. (MHR)

  14. Geothermal Program Review IV: proceedings

    SciTech Connect

    Not Available

    1985-01-01

    The research and development program of DOE's Geothermal Technology Division is reviewed in separate presentations according to program area. Separate abstracts have been prepared for the individual papers. (ACR)

  15. Enhanced geothermal systems

    SciTech Connect

    McLarty, L.; Grabowski, P.

    1998-07-01

    A vast amount of geothermal energy is stored in the upper portion of the earth's crust; this energy is accessible with current drilling technology. The US Geological Survey has estimated that in the US, the heat energy stored in the upper 10 kilometers of the earth's crust is over 33 {times} 10{sup 24} Joules. Only a small fraction of this energy could conceivably be extracted. However, just one tenth of one percent of this energy is sufficient to provide the US with all its current level of non-transportation energy needs for over 500 years. Current technology is being used widely to extract geothermal energy in areas where subterranean water contacted hot rock formations, became heated, and was trapped by an impermeable layer in the earth's crust, forming a geothermal hydrothermal reservoir. The water serves as a medium to transport the heat to the surface through a conventional well similar to an oil well. Unfortunately, hydrothermal reservoirs are not widespread and represent only a minuscule portion of the geothermal energy that is accessible with current technology. Scientists and engineers in the US, Europe, Japan, and Australia, are developing systems that extract heat from the earth where there is insufficient permeability or water in the rock formation to transport the heat to the surface. Such systems are referred to as Enhanced Geothermal Systems.

  16. Utilization of geothermal energy in the production of fuel grade ethanol in the San Luis Valley, Colorado

    SciTech Connect

    Hewlett, E.M.; Erickson, M.V.; Walter, K.M.

    1981-10-01

    The San Luis Valley, a high alpine valley in south-central Colorado, is an area of known geothermal activity. The valley is a sparsely populated agricultural area whose principal crops are potatoes, beer barley, and wheat. In the surrounding mountains there are several lumber operations. This combination of a geothermal heat source and a biomass feedstock source makes the valley a candidate area for the production of fermentation ethanol. Therefore, a study was initiated to investigate the engineering, environmental, institutional and economic feasibility of utilizing geothermal energy for the commercial production of 76 to 189 million liters (20 to 50 million gallons) of fuel grade ethanol in the San Luis Valley.

  17. Combining Satellite and Ground-Based Radar Interferometry Data to Measure Surface Deformation Associated with EGS Pumping Activities at Newberry Crater, OR Geothermal Site

    NASA Astrophysics Data System (ADS)

    Vincent, P.; Cladouhos, T. T.; Schultz, A.; Rose, K.; Urquhart, S.

    2013-12-01

    TerraSAR-X (TSX) satellite data are combined with data collected using a ground-based real aperture radar interferometer (GAMMA Remote Sensing AG Portable Radar Interferometer-2, GPRI2) to remotely image surface deformation arising from enhanced geothermal system (EGS) pumping activity at the geothermal site located off the western flank of Newberry Crater, OR. Due to the heavily forested area impeding the utility of interferometric measurements at X-band (TSX) and Ku-band (GPRI2) wavelengths, 100 aluminum radar corner reflectors (CRs) were fabricated and installed in pairs approximately 5-8 meters above the ground in 50 large trees for optimal visibility and wind stability. One CR in each pair was aimed up at the ascending orbit track look direction for TSX, and the other was simultaneously aimed at the descending orbit track look direction for TSX and to Paulina Peak 6 km to the southwest for line-of-sight to the GPRI2 antenna position. The combination of 11-day repeat orbit acquisitions from a near vertical look direction from TSX with on-demand (up to daily) acquisitions from a near horizontal look direction from the GPRI2 instrument allows for full 3D displacement vector determination for each target imaged. Standard and point-target processing techniques are used to maximize the utility of the data collected and the transient nature of the pumping activities and resulting surface deformation signals demand this high level of spatial-temporal sampling. Preliminary data quality and deformation signal results will be presented and put in context with well-log data such as pressure, volume and flow rate, as well as data from microseismic array, MT, and gravity surveys.

  18. Geothermal direct-heat utilization assistance. Federal Assistance Program quarterly project progress report, April 1--June 30, 1998

    SciTech Connect

    1998-07-01

    This report summarizes geothermal technical assistance, R and D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the third quarter of FY98 (April--June, 1998). It describes 231 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with included requests for general information including material for high school and university students, and material on geothermal heat pumps, resource and well data, spacing heating and cooling, greenhouses, aquaculture, equipment, district heating, resorts and spas, industrial applications, snow melting and electric power. Research activities include work on model construction specifications for line shaft submersible pumps and plate heat exchangers, and a comprehensive aquaculture developers package. A brochure on Geothermal Energy in Klamath County was developed for state and local tourism use. Outreach activities include the publication of the Quarterly Bulletin (Vol. 19, No. 2) with articles on research at the Geo-Heat Center, sustainability of geothermal resources, injection well drilling in Boise, ID and a greenhouse project in the Azores. Other outreach activities include dissemination of information mainly through mailings of publications, tours of local geothermal uses, geothermal library acquisitions and use, participation in workshops, short courses and technical meetings by the staff, and progress monitor reports on geothermal activities.

  19. Geothermal development plan: Pima County

    NASA Astrophysics Data System (ADS)

    White, D. H.; Goldstone, L. A.

    1982-08-01

    The Pima County Area Development evaluated the county-wide market potential for utilizing geothermal energy. Four potential geothermal resource areas with temperatures less than 1000 C (2120 F) were identified. In addition, one area is identified as having a temperature of 1470 F (2970 F). Geothermal resources are found to occur in Tecson where average population growth rates of two to three percent per year are expected over the next 40 years. Rapid growth in the manufacturing sector and the existence of major copper mines provide opportunities for the direct utilization of geothermal energy. However, available water supplies are identified as a major constraing to projected growth. A regional energy analysis, future predictions for energy consumption, and energy prices are given. Potential geothermal users in Pima County are identified and projections of maximum economic geothermal utilization are given. One hundred fifteen firms in 32 industrial classes have some potential for geothermal use are identified. In addition, 26 agribusiness firms were found in the county.

  20. Geothermal resources of California sedimentary basins

    USGS Publications Warehouse

    Williams, C.F.; Grubb, F.V.; Galanis, S.P.

    2004-01-01

    The 2004 Department of Energy (DOE) Strategic Plan for geothermal energy calls for expanding the geothermal resource base of the United States to 40,000 MW of electric power generating potential. This will require advances in technologies for exploiting unconventional geothermal resources, including Enhanced Geothermal Systems (EGS) and geopressured geothermal. An investigation of thermal conditions in California sedimentary basins through new temperature and heat flow measurements reveals significant geothermal potential in some areas. In many of the basins, the combined cooling effects of recent tectonic and sedimentary processes result in relatively low (<60 mW/m2) heat flow and geothermal gradients. For example, temperatures in the upper 3 km of San Joaquin, Sacramento and Ventura basins are typically less than 125??C and do not reach 200??c by 5 km. By contrast, in the Cuyama, Santa Maria and western Los Angeles basins, heat flow exceeds 80 mW/m2 and temperatures near or above 200??C occur at 4 to 5 km depth, which represents thermal conditions equivalent to or hotter than those encountered at the Soultz EGS geothermal site in Europe. Although the extractable geothermal energy contained in these basins is not large relative to the major California producing geothermal fields at The Geysers or Salton Sea, the collocation in the Los Angeles basin of a substantial petroleum extraction infrastructure and a major metropolitan area may make it attractive for eventual geothermal development as EGS technology matures.

  1. Technical support for geopressured-geothermal well activities in Louisiana; Final report, 1 January 1992--31 December 1993

    SciTech Connect

    John, C.J.

    1994-01-01

    The US Department of Energy has operated continuous-recording, microearthquake monitoring networks at geopressured-geothermal test well sites since 1980. These microseismic networks were designed to detect microearthquakes indicative of fault activation and/or subsidence that can potentially result from the deep subsurface withdrawal and underground disposal of large volumes of brine during well testing. Seismic networks were established before the beginning of testing to obtain background levels of seismicity. Monitoring continued during testing and for some time after cessation of flow testing to assess any delayed microseismicity caused by the time dependence of stress migration within the earth. No flow testing has been done at the Hulin well since January 1990, and the Pleasant Bayou well has been shut down since September 1992. Microseismic monitoring continued at the Hulin and Pleasant Bayou sites until 31 December 1992, at which time both operations were shut down and field sites dismantled. During 1992, the networks recorded seismic signals from earthquakes, sonic booms, geophysical blasting, thunderstorms, etc. However, as in previous years, no local microseismic activity attributable to geopressured-geothermal well testing was recorded.

  2. Vegetation component of geothermal EIS studies: Introduced plants, ecosystem stability, and geothermal development

    NASA Astrophysics Data System (ADS)

    1994-10-01

    This paper contributes new information about the impacts from introduced plant invasions on the native Hawaiian vegetation as consequences of land disturbance and geothermal development activities. In this regard, most geothermal development is expected to act as another recurring source of physical disturbance which favors the spread and maintenance of introduced organisms throughout the region. Where geothermal exploration and development activities extend beyond existing agricultural and residential development, they will become the initial or sole source of disturbance to the naturalized vegetation of the area. Kilauea has a unique ecosystem adapted to the dynamics of a volcanically active landscape. The characteristics of this ecosystem need to be realized in order to understand the major threats to the ecosystem and to evaluate the effects of and mitigation for geothermal development in Puna. The native Puna vegetation is well adapted to disturbances associated with volcanic eruption, but it is ill-adapted to compete with alien plant species in secondary disturbances produced by human activities. Introduced plant and animal species have become a major threat to the continued presence of the native biota in the Puna region.

  3. Vegetation component of geothermal EIS studies: Introduced plants, ecosystem stability, and geothermal development

    SciTech Connect

    1994-10-01

    This paper contributes new information about the impacts from introduced plant invasions on the native Hawaiian vegetation as consequences of land disturbance and geothermal development activities. In this regard, most geothermal development is expected to act as another recurring source of physical disturbance which favors the spread and maintenance of introduced organisms throughout the region. Where geothermal exploration and development activities extend beyond existing agricultural and residential development, they will become the initial or sole source of disturbance to the naturalized vegetation of the area. Kilauea has a unique ecosystem adapted to the dynamics of a volcanically active landscape. The characteristics of this ecosystem need to be realized in order to understand the major threats to the ecosystem and to evaluate the effects of and mitigation for geothermal development in Puna. The native Puna vegetation is well adapted to disturbances associated with volcanic eruption, but it is ill-adapted to compete with alien plant species in secondary disturbances produced by human activities. Introduced plant and animal species have become a major threat to the continued presence of the native biota in the Puna region of reference.

  4. Geothermal heating

    SciTech Connect

    Aureille, M.

    1982-01-01

    The aim of the study is to demonstrate the viability of geothermal heating projects in energy and economic terms and to provide nomograms from which an initial estimate may be made without having to use data-processing facilities. The effect of flow rate and temperature of the geothermal water on drilling and on the network, and the effect of climate on the type of housing are considered.

  5. Geothermal-resource survey of the Tennessee Valley Region

    SciTech Connect

    Staub, W.P.; Treat, N.L.

    1982-08-01

    An overview appraisal of the geothermal resources in the Tennessee Valley Region revealed geothermal resources of potential usefulness in two of 13 subregions: the New Madrid Seismic Zone and the central segment of the Northern Gulf Coastal Plain. The appraisal was based on geologic features of the region (hot springs, groundwater aquifers, and structure) and temperature data for oil and gas wells and shallow water wells. Site-specific exploration for economic appraisal was not carried out. The geothermal gradient for each of the subregions was established by linear regression of all of the bottom-hole temperature data for the oil and gas wells. A routine statistical procedure identified all unusually warm wells within each subregion, and their locations were plotted. Hot spots in a subregion were identified by localized clustering of such wells in numbers exceeding statistical expectations based on the intensity of drilling activity. Of the two areas most likely for extraction of geothermal energy, the New Madrid Seismic Zone has a high geothermal gradient at shallow depths (less than 500 meters). However, the higher gradient does not continue at greater depth since convective circulation is the probable cause of the higher-than-normal groundwater temperatures. Although a high geothermal gradient does persist at depth in the central segment of the Northern Gulf Coastal Plain, engineering problems are likely to hinder the current economic use of geothermal energy in this subregion. The extraction of geothermal resources in the 11 other subregions is not considered to be feasible at present because (1) the heat source is too deep, or (2) there are no suitable aquifers.

  6. Geothermal areas as analogues to chemical processes in the near-field and altered zone of the potential Yucca Mountain, Nevada repository

    SciTech Connect

    Bruton, C.J.; Glassley, W.E.; Meike, A.

    1995-02-01

    The need to bound system performance of the potential Yucca Mountain repository for thousands of years after emplacement of high-level nuclear waste requires the use of computer codes. The use of such codes to produce reliable bounds over such long time periods must be tested using long-lived natural and historical systems as analogues. The geothermal systems of the Taupo Volcanic Zone (TVZ) in New Zealand were selected as the site most amenable to study. The rocks of the TVZ are silicic volcanics that are similar in composition to Yucca Mountain. The area has been subjected to temperatures of 25 to 300 C which have produced a variety of secondary minerals similar to those anticipated at Yucca Mountain. The availability of rocks, fluids and fabricated materials for sampling is excellent because of widespread exploitation of the systems for geothermal power. Current work has focused on testing the ability of the EQ3/6 code and thermodynamic data base to describe mineral-fluid relations at elevated temperatures. Welfare starting long-term dissolution/corrosion tests of rocks, minerals and manufactured materials in natural thermal features in order to compare laboratory rates with field-derived rates. Available field data on rates of silica precipitation from heated fluids have been analyzed and compared to laboratory rates. New sets of precipitation experiments are being planned. The microbially influenced degradation of concrete in the Broadlands-Ohaaki geothermal field is being characterized. The authors will continue to work on these projects in FY 1996 and expand to include the study of naturally occurring uranium and thorium series radionuclides, as a prelude to studying radionuclide migration in heated silicic volcanic rocks. 32 refs.

  7. 2008 Geothermal Technologies Market Report

    SciTech Connect

    Jonathan Cross

    2009-07-01

    This report describes market-wide trends for the geothermal industry throughout 2008 and the beginning of 2009. It begins with an overview of the GTP’s involvement with the geothermal industry and recent investment trends for electric generation technologies. The report next describes the current state of geothermal power generation and activity within the United States, costs associated with development, financing trends, an analysis of the levelized cost of energy (LCOE), and a look at the current policy environment. The report also highlights trends regarding direct use of geothermal energy, including GHPs.† The final sections of the report focus on international perspectives, employment and economic benefits from geothermal energy development, and potential incentives in pending national legislation.

  8. Exploration and drilling for geothermal heat in the Capital District, New York. Volume 4. Final report

    SciTech Connect

    Not Available

    1983-08-01

    The Capital District area of New York was explored to determine the nature of a hydrothermal geothermal system. The chemistry of subsurface water and gas, the variation in gravity, magnetism, seismicity, and temperature gradients were determined. Water and gas analyses and temperature gradient measurements indicate the existence of a geothermal system located under an area from Ballston Spa, southward to Altamont, and eastward toward Albany. Gravimetric and magnetic surveys provided little useful data but microseismic activity in the Altamont area may be significant. Eight wells about 400 feet deep, one 600 feet and one 2232 feet were drilled and tested for geothermal potential. The highest temperature gradients, most unusual water chemistries, and greatest carbon dioxide exhalations were observed in the vicinity of the Saratoga and McGregor faults between Saratoga Springs and Schenectady, New York, suggesting some fault control over the geothermal system. Depths to the warm fluids within the system range from 500 meters (Ballston Spa) to 2 kilometers (Albany).

  9. Exploration and drilling for geothermal heat in the Capital District, New York. Final report

    SciTech Connect

    Not Available

    1983-08-01

    The Capital District area of New York was explored to determine the nature of a hydrothermal geothermal system. The chemistry of subsurface water and gas, the variation in gravity, magnetism, seismicity, and temperature gradients were determined. Water and gas analyses and temperature gradient measurements indicate the existence of a geothermal system located under an area from Ballston Spa, southward to Altamont, and eastware toward Albany. Gravimetric and magnetic surveys provided little useful data but microseismic activity in the Altamont area may be significant. Eight wells about 400 feet deep, one 600 feet and one 2232 feet were drilled and tested for geothermal potential. The highest temperature gradients, most unusual water chemistries, and greatest carbon dioxide exhalations were observed in the vicinity of the Saratoga and McGregor faults between Saratoga Springs and Schenectady, New York, suggesting some fault control over the geothermal system. Depths to the warm fluids within the system range from 500 meters (Ballston Spa) to 2 kilometers (Albany).

  10. Snohomish County Public Utility District Geothermal Energy Exploration Study Final Technical Report

    SciTech Connect

    Lewis, Adam; Collar, Craig W.

    2012-10-04

    Supported by funds from this award, the District thoroughly explored the feasibility of a hydrothermal geothermal development within its service territory. The District successfully planned and drilled six exploratory geothermal wells and added significantly to the knowledge of the geology of the area. The Straight Creek Fault region, which was the sole location that showed significant potential for hydrothermal development in the District's service territory, was determined not to be feasible for development. The District subsequently expanded its search for geothermal development locations to include all of Washington State. Mount Baker has been identified as the area of the state with the greatest potential for geothermal development. Having gathered additional information about the Mount Baker region with support from this award, the District is actively pursuing exploration and development in the area.

  11. Sperry Low Temperature Geothermal Conversion System, Phase I and Phase II. Volume IV. Field activities. Final report

    SciTech Connect

    Harvey, C.

    1984-01-01

    This volume describes those activities which took place at the Sperry DOE Gravity Head plant site at the East Mesa Geothermal Reservoir near Holtville, California between February 1980, when site preparation was begun, and November 1982, when production well 87-6 was permanently abandoned. Construction activities were terminated in July 1981 following the liner collapse in well 87-6. Large amounts of program time manpower, materials, and funds had been diverted in a nine-month struggle to salvage the production well. Once these efforts proved futile, there was no rationale for continuing with the site work unless and until sufficient funding to duplicate well 87-6 was obtained. Activities reported here include: plant construction and pre-operational calibration and testing, drilling and completion of well 87-6, final repair effort on well 87-6, abandonment of well 87-6, and performance evaluation of well 87.6. (MHR)

  12. Geothermal progress monitor: Report No. 17

    SciTech Connect

    1995-12-01

    DOE is particularly concerned with reducing the costs of geothermal power generation, especially with the abundant moderate to low-temperature resources in the US. This concern is reflected in DOE`s support of a number of energy conversion projects. Projects which focus on the costs and performance of binary cycle technology include a commercial demonstration of supersaturated turbine expansions, which earlier studies have indicated could increase the power produced per pound of fluid. Other binary cycle projects include evaluations of the performance of various working fluid mixtures and the development and testing of advanced heat rejection systems which are desperately needed in water-short geothermal areas. DOE is also investigating the applicability of flash steam technology to low-temperature resources, as an economic alternative to binary cycle systems. A low-cost, low-pressure steam turbine, selected for a grant, will be constructed to utilize fluid discharged from a flash steam plant in Nevada. Another project addresses the efficiency of high-temperature flash plants with a demonstration of the performance of the Biphase turbine which may increase the power output of such installations with no increase in fluid flow. Perhaps the most noteworthy feature of this issue of the GPM, the 17th since its inception in 1980, is the high degree of industry participation in federally-sponsored geothermal research and development. This report describes geothermal development activities.

  13. Hawaii geothermal resource assessment: 1982

    SciTech Connect

    Thomas, D.M.; Cox, M.; Kavahikaua, J.P.; Lienert, B.R.; Mattice, M.

    1982-10-01

    The Geothermal Resource Assessment Program of the Hawaii Institute of Geophysics has conducted a series of geochemical and geophysical surveys throughout the State of Hawaii since February 1978. The results compiled during this study have been used to prepare a map of potential geothermal resource areas throughout the state. Approximately thirteen separate locations on three islands have been studied in detail. Of these, four areas are known to have direct evidence of a geothermal anomaly (Kilauea East Rift Zone, Kilauea Southwest Rift Zone, Kawaihae, and Olowalu-Ukumehame) and three others are strongly suspected of having at least a low-temperature resource (Hualalai west flank, Haleakala Southwest Rift, and Lualualei Valley). In the remainder of the areas surveyed, the data obtained either were contradictory or gave no evidence of a geothermal resource.

  14. Proceedings of a Topical Meeting On Small Scale Geothermal Power Plants and Geothermal Power Plant Projects

    SciTech Connect

    1986-02-12

    These proceedings describe the workshop of the Topical Meeting on Small Scale Geothermal Power Plants and Geothermal Power Plant Projects. The projects covered include binary power plants, rotary separator, screw expander power plants, modular wellhead power plants, inflow turbines, and the EPRI hybrid power system. Active projects versus geothermal power projects were described. In addition, a simple approach to estimating effects of fluid deliverability on geothermal power cost is described starting on page 119. (DJE-2005)

  15. Hydraulic Fracture Stimulation and Acid Treatment of Well Baca 20; Geothermal Reservoir Well Stimulation Program

    SciTech Connect

    1983-07-01

    The U.S. Department of Energy-sponsored Geothermal Reservoir Well Stimulation Program was initiated in February 1979 to pursue industry interest in geothermal well stimulation work and to develop technical expertise in areas directly related to geothermal well stimulation activities. This report provides an overview of the two experiments conducted in the high-temperature reservoir in Baca, New Mexico. The report discusses resource and reservoir properties, and provides a description of the stimulation experiment, a description of the treatment evaluation, and a summary of the experiment costs. (DJE-2005)

  16. World Geothermal Congress WGC-2015

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.

    2016-08-01

    This article discusses materials and results of the World Geothermal Congress that was held in Melbourne (Australia) from April 19 to April 25, 2015. Information on the extent and technological features of utilization of geothermal resources for heat supply and power production, as well as in other economic areas, is given. A stable growth in the capacity and number of geothermal power systems that is determined by ecological cleanliness, economic efficiency, and the highest (among renewable energy sources) indicators of installed capacity utilization is shown. It was noted that combined schemes of geothermal power plants (GPPs), such as turbine units of different type (binary units, units with one or two separation pressures, etc.), have become more frequently used to increase the efficiency of utilization of geothermal heat carrier. Actual data determining room heating systems with the total worldwide capacity of nearly 50000 MW thermal (MWt) as the most currently significant segment of consumption of geothermal waters are given. In addition, geothermal resources are also utilized in soil pumps, balneological and sports basins, greenhouse complexes, and other manufactures. It was noted that geological studies were carried out in more than 40 countries, with the development of methods of simulation of tanks for the existing and new geothermal fields. Trends of development and the role of geothermal power engineering in the energy supply of many countries are shown. It was shown that prospects for the development of geothermal power generation are significantly associated with utilization of low-temperature geothermal sources in binary power generating units, as well as with the increase in installed capacity of operating geothermal power plants (GPPs) without drilling additional wells, i.e., by using waste geothermal heat carrier in binary-cycle or combined-cycle power plants. The article provides data on a pilot binary power unit at Pauzhetka GPP and on a

  17. Geothermal energy program summary

    SciTech Connect

    Not Available

    1990-01-01

    The Geothermal Technology Division (GTD) of the US Department of Energy (DOE) is charged with the lead federal role in the research and development (R D) of technologies that will assist industry in economically exploiting the nation's vast geothermal resources. The GTD R D Program represents a comprehensive, balanced approach to establishing all forms of geothermal energy as significant contributors to the nation's energy supply. It is structured both to maintain momentum in the growth of the existing hydrothermal industry and to develop long-term options offering the greatest promise for practical applications. This volume, Volume 2, contains a detailed compilation of each GTD-funded R D activity performed by national laboratories or under contract to industrial, academic, and nonprofit research institutions.

  18. Geothermal hazards - Mercury emission

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.; Siegel, B. Z.

    1975-01-01

    Enthusiasm for intensified geothermal exploration may induce many participants to overlook a long-term potential toxicity hazard possibly associated with the tapping of magmatic steam. The association of high atmospheric Hg levels with geothermal activity has been established both in Hawaii and Iceland, and it has been shown that mercury can be introduced into the atmosphere from fumaroles, hot springs, and magmatic sources. These arguments, extended to thallium, selenium, and other hazardous elements, underscore the need for environmental monitoring in conjunction with the delivery of magmatic steam to the surface.

  19. Geothermal properties and groundwater flow estimated with a three-dimensional geological model in a late Pleistocene terrace area, central Japan

    NASA Astrophysics Data System (ADS)

    Funabiki, A.; Takemura, T.; Hamamoto, S.; Komatsu, T.

    2012-12-01

    1. Introduction The ground source heat pump (GSHP) is a highly efficient and renewable energy technology for space heating and cooling, with benefits that include energy conservation and reductions in greenhouse gas emissions. One result of the huge Tohoku-oki earthquake and tsunami and the subsequent nuclear disasters is that GSHPs are receiving more attention from the media and they are being introduced by some local governments. Heat generated by underground GSHP installation, however, can pollute the geothermal environment or change groundwater flow patterns . In this study, we estimated possible effects from the use of GSHPs in the Tokyo area with a three-dimensional (3D) geological model. 2. Geological model The Tokyo Metropolitan Area is surrounded by the Late Pleistocene terraces called the Musashino uplands. The terrace surfaces are densely populated residential areas. One of these surfaces, the Shimosueyohi surface, formed along the Tama River during the last deglacial period. The CRE-NUCHS-1 core (Funabiki et al., 2011) was obtained from this surface, and the lithology, heat transfer coefficients, and chemical characteristics of the sediments were analyzed. In this study, we used borehole log data from a 5 km2 area surrounding the CRE-NUCHS-1 core site to create a 3D geological model. In this area, the Pleistocene Kazusa Group is overlain by terrace gravels and a volcanic ash layer called the Kanto Loam. The terrace gravels occur mainly beneath the Kanda, Kitazawa, and Karasuyama rivers , which flow parallel to the Tama River, whereas away from the rivers , the Kanto Loam directly overlies the Kazusa Group sediments. 3. Geothermal disturbance and groundwater flow Using the geological model, we calculated the heat transfer coefficients and groundwater flow velocities in the sediments. Within the thick terrace gravels, which are at relatively shallow depth (8-20 m), heat transfer coefficients were high and groundwater flow was relatively fast. The amount

  20. Using Facilities And Potential Of Geothermal Resources In The Canakkale Province - NW Turkey

    NASA Astrophysics Data System (ADS)

    Deniz, Ozan; Acar Deniz, Zahide

    2016-04-01

    Turkey, due to its geological location, has a rich potential in point of geothermal resources. Çanakkale province is located northwestern (NW) part of Turkey and it has important geothermal fields in terms of geothermal energy potential. Geothermal resources reach to the surface both effects of past volcanic activity and extensions of fault zones associated with complex tectonic systems in the region. The aim of this study is to summarize hydrogeochemical characteristics, using facilities and potential of hot springs and spas located in the Çanakkale province. There are 13 geothermal fields in the region and the surface temperatures of hot springs are ranging between 28 centigrade degree and 175 centigrade degree. Hydrogeochemical compositions of thermal water display variable chemical compositions. Na, Ca, SO4, HCO3 and Cl are the dominant ions in these waters. Thermal waters of Tuzla and Kestanbol geothermal fields which is located the near coastal area can be noted NaCl type. Because these two geothermal waters have high TDS values, scaling problems are seen around the hot springs and pipelines. Geothermal waters in the province are meteoric origin according to oxygen-18, deuterium and tritium isotopes data. Long underground residence times of these waters and its temperatures have caused both more water - rock interaction and low tritium values. Geothermal energy is utilized in many areas in Turkey today. It is generally used for space heating, balneotherapy and electricity generation. Explorations of geothermal resources and investments in geothermal energy sector have risen rapidly in the recent years particularly in western Turkey. High-temperature geothermal fields are generally located in this region related to the Aegean Graben System and the North Anotalian Fault Zone. All geothermal power plants in Turkey are located in this region. Considering the Çanakkale province, most geothermal fields are suitable for multipurpose usage but many of them have

  1. Remote sensing application on geothermal exploration

    NASA Astrophysics Data System (ADS)

    Gaffar, Eddy Z.

    2013-09-01

    Geothermal energy is produced when water coming down from the surface of the earth and met with magma or hot rocks, which the heat comes from the very high levels of magma rises from the earth. This process produced a heated fluid supplied to a power generator system to finally use as energy. Geothermal field usually associated with volcanic area with a component from igneous rocks and a complex geological structures. The fracture and fault structure are important geological structures associated with geothermal. Furthermore, their geothermal manifestations also need to be evaluated associated their geological structures. The appearance of a geothermal surface manifestation is close to the structure of the fracture and the caldera volcanic areas. The relationship between the fault and geothermal manifestations can be seen in the form of a pattern of alignment between the manifestations of geothermal locations with other locations on the fault system. The use of remote sensing using electromagnetic radiation sensors to record images of the Earth's environment that can be interpreted to be a useful information. In this study, remote sensing was applied to determine the geological structure and mapping of the distribution of rocks and alteration rocks. It was found that remote sensing obtained a better localize areas of geothermal prospects, which in turn could cut the chain of geothermal exploration to reduce a cost of geothermal exploration.

  2. Structural controls on a geothermal system in the Tarutung Basin, north central Sumatra

    NASA Astrophysics Data System (ADS)

    Nukman, Mochamad; Moeck, Inga

    2013-09-01

    The Sumatra Fault System provides a unique geologic setting to evaluate the influence of structural controls on geothermal activity. Whereas most of the geothermal systems in Indonesia are controlled by volcanic activity, geothermal systems at the Sumatra Fault System might be controlled by faults and fractures. Exploration strategies for these geothermal systems need to be verified because the typical pattern of heat source and alteration clays are missing so that conventional exploration with magnetotelluric surveys might not provide sufficient data to delineate favorable settings for drilling. We present field geological, structural and geomorphological evidence combined with mapping of geothermal manifestations to allow constraints between fault dynamics and geothermal activity in the Tarutung Basin in north central Sumatra. Our results indicate that the fault pattern in the Tarutung Basin is generated by a compressional stress direction acting at a high angle to the right-lateral Sumatra Fault System. NW-SE striking normal faults possibly related to negative flower structures and NNW-SSE to NNE-SSW oriented dilative Riedel shears are preferential fluid pathways whereas ENE-WSW striking faults act as barriers in this system. The dominant of geothermal manifestations at the eastern part of the basin indicates local extension due to clockwise block rotation in the Sumatra Fault System. Our results support the effort to integrate detailed field geological surveys to refined exploration strategies even in tropical areas where outcrops are limited.

  3. Advanced geothermal technologies

    SciTech Connect

    Whetten, J.T.; Murphy, H.D.; Hanold, R.J.; Myers, C.W.; Dunn, J.C.

    1988-01-01

    Research and development in advanced technologies for geothermal energy production continue to increase the energy production options for the Nation. The high-risk investment over the past few years by the US Department of Energy in geopressured, hot dry rock, and magma energy resources is producing new means to lower production costs and to take advantage of these resources. The Nation has far larger and more regionally extensive geothermal resources than heretofore realized. At the end of a short 30-day closed-loop flow test, the manmade hot dry rock reservoir at Fenton Hill, New Mexico, was producing 10 MW thermal - and still climbing - proving the technical feasibility of this new technology. The scientific feasibility of magma energy extraction has been demonstrated, and new field tests to evaluate this technology are planned. Analysis and field tests confirm the viability of geopressured-geothermal energy and the prospect that many dry-hole or depleted petroleum wells can be turned into producing geopressured-geothermal wells. Technological advances achieved through hot dry rock, magma, geopressured, and other geothermal research are making these resources and conventional hydrothermal resources more competitive. Noteworthy among these technological advances are techniques in computer simulation of geothermal reservoirs, new means for well stimulation, new high-temperature logging tools and packers, new hard-rock penetration techniques, and new methods for mapping fracture flow paths across large underground areas in reservoirs. In addition, many of these same technological advances can be applied by the petroleum industry to help lower production costs in domestic oil and gas fields. 5 refs., 4 figs.

  4. The influence of variability of calculation grids on the results of numerical modeling of geothermal doublets - an example from the Choszczno area, north-western Poland

    NASA Astrophysics Data System (ADS)

    Wachowicz-Pyzik, A.; Sowiżdżał, A.; Pająk, L.

    2016-09-01

    The numerical modeling enables us to reduce the risk related to the selection of best localization of wells. Moreover, at the stage of production, modeling is a suitable tool for optimization of well operational parameters, which guarantees the long life of doublets. The thorough selection of software together with relevant methodology applied to generation of numerical models significantly improve the quality of obtained results. In the following paper, we discuss the impact of density of calculation grid on the results of geothermal doublet simulation with the TOUGH2 code, which applies the finite-difference method. The study area is located between the Szczecin Trough and the Fore-sudetic Monocline, where the Choszczno IG-1 well has been completed. Our research was divided into the two stages. At the first stage, we examined the changes of density of polygon calculation grids used in computations of operational parameters of geothermal doublets. At the second stage, we analyzed the influence of distance between the production and the injection wells on variability in time of operational parameters. The results demonstrated that in both studied cases, the largest differences occurred in pressures measured in production and injection wells whereas the differences in temperatures were less pronounced.

  5. Geothermal Small Business Workbook [Geothermal Outreach and Project Financing

    SciTech Connect

    Elizabeth Battocletti

    2003-05-01

    Small businesses are the cornerstone of the American economy. Over 22 million small businesses account for approximately 99% of employers, employ about half of the private sector workforce, and are responsible for about two-thirds of net new jobs. Many small businesses fared better than the Fortune 500 in 2001. Non-farm proprietors income rose 2.4% in 2001 while corporate profits declined 7.2%. Yet not all is rosy for small businesses, particularly new ones. One-third close within two years of opening. From 1989 to 1992, almost half closed within four years; only 39.5% were still open after six years. Why do some new businesses thrive and some fail? What helps a new business succeed? Industry knowledge, business and financial planning, and good management. Small geothermal businesses are no different. Low- and medium-temperature geothermal resources exist throughout the western United States, the majority not yet tapped. A recent survey of ten western states identified more than 9,000 thermal wells and springs, over 900 low- to moderate-temperature geothermal resource areas, and hundreds of direct-use sites. Many opportunities exist for geothermal entrepreneurs to develop many of these sites into thriving small businesses. The ''Geothermal Small Business Workbook'' (''Workbook'') was written to give geothermal entrepreneurs, small businesses, and developers the tools they need to understand geothermal applications--both direct use and small-scale power generation--and to write a business and financing plan. The Workbook will: Provide background, market, and regulatory data for direct use and small-scale (< 1 megawatt) power generation geothermal projects; Refer you to several sources of useful information including owners of existing geothermal businesses, trade associations, and other organizations; Break down the complicated and sometimes tedious process of writing a business plan into five easy steps; Lead you--the geothermal entrepreneur, small company, or

  6. Geothermal energy

    NASA Astrophysics Data System (ADS)

    Manzella, A.

    2015-08-01

    Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is stored in rocks and in fluids circulating in the underground. Electricity generation usually requires geothermal resources temperatures of over 100°C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology), spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Geothermal technology, which has focused so far on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth's crust.

  7. Geothermal pipeline

    SciTech Connect

    Not Available

    1992-12-01

    A number of new ideas for geothermal power development and use have been proposed or initiated. British engineers have proposed using North Sea oil rigs as geothermal power stations. These stations would use the low temperature heat from the water that now occupies the former oil reservoirs to generate electricity. NASA recently retrofitted its engine test facility to enable it to use warm water from an underground aquifer as source water in a heat pump. A major policy guideline regarding electricity is issued by the California Energy Commission (CEC) every two years. This year, CEC appears to be revising its method for determining the total societal cost of various electricity supply options. The change may impact geothermal energy usage in a positive way. Virtually untapped geothermal resources in Preston, Idaho will be utilized for warm water catfish farming. Stockton State College in New Jersey will be the site of one of the nation's largest geothermal projects when it is completed in 1993. It is designed to satisfy the college's energy requirements at an estimated cost savings of $300,000 per year. Aquaculture projects using thermal springs are under consideration in Utah and Washington State. Utah may be the site of an alligator farm and Washington State is being considered for raising golden tilapia, a food fish.

  8. Federal Geothermal Research Program Update Fiscal Year 1999

    SciTech Connect

    Not Available

    2004-02-01

    The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal and Wind Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The following mission and goal statements guide the overall activities of the Office of Geothermal and Wind Technologies. This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 1999. The information contained in this Research Update illustrates how the mission and goals of the Office of Geothermal and Wind Technologies are reflected in each R&D activity. The Geothermal Program, from its guiding principles to the most detailed research activities, is focused on expanding the use of geothermal energy.

  9. Colorado Geothermal Commercialization Program

    SciTech Connect

    Healy, F.C.

    1980-04-01

    Chaffee County, located in central Colorado, has immense potential for geothermal development. This report has been prepared to assist residents and developers in and outside the area to develop the hydrothermal resources of the county. Data has been collected and interpreted from numerous sources in order to introduce a general description of the area, estimate energy requirements, describe the resources and postulate a development plan. Electric power generation and direct heat application potential for the region are described.

  10. Geologic remote sensing for geothermal exploration: A review

    NASA Astrophysics Data System (ADS)

    van der Meer, Freek; Hecker, Christoph; van Ruitenbeek, Frank; van der Werff, Harald; de Wijkerslooth, Charlotte; Wechsler, Carolina

    2014-12-01

    This paper is a comprehensive review of the potential for remote sensing in exploring for geothermal resources. Temperature gradients in the earth crust are typically 25-30 °C per kilometer depth, however in active volcanic areas situated in subduction or rift zones gradients of up to 150 °C per kilometer depth can be reached. In such volcanic areas, meteoric water in permeable and porous rocks is heated and hot water is trapped to form a geothermal reservoir. At the Earth's surface hot springs and fumaroles are evidence of hot geothermal water. In low enthalpy systems the heat can be used for heating/cooling and drying while in high enthalpy systems energy is generated using hot water or steam. In this paper we review the potential of remote sensing in the exploration for geothermal resources. We embark from the traditional suite of geophysical and geochemical prospecting techniques to arrive at parameters at the Earth surface that can be measured by earth observing satellites. Next, we summarize direct and indirect detection of geothermal potential using alteration mineralogy, temperature anomalies and heat fluxes, geobotanical anomalies and Earth surface deformation. A section of this paper is dedicated to published remote sensing studies illustrating the principles of mapping: surface deformation, gaseous emissions, mineral mapping, heat flux measurements, temperature mapping and geobotany. In a case study from the La Pacana caldera (Chili) geothermal field we illustrate the cross cutting relationships between various surface manifestations of geothermal reservoirs and how remotely sensed indicators can contribute to exploration. We conclude that although remote sensing of geothermal systems has not reached full maturity, there is great potential for integrating these surface measurements in a exploration framework. A number of recommendations for future research result from our analysis of geothermal systems and the present contributions of remote sensing to

  11. Overview of Resources for Geothermal Absorption Cooling for Buildings

    SciTech Connect

    Liu, Xiaobing; Gluesenkamp, Kyle R; Mehdizadeh Momen, Ayyoub

    2015-06-01

    This report summarizes the results of a literature review in three areas: available low-temperature/coproduced geothermal resources in the United States, energy use for space conditioning in commercial buildings, and state of the art of geothermal absorption cooling.

  12. Geothermal progress monitor. Progress report No. 4

    SciTech Connect

    Not Available

    1980-09-01

    The following are included: geothermal power plants proposed and on-line; direct heat applications proposed and operational; trends in drilling activities; exploration; leases; outreach and technical assistance; feasibility studies and application demonstrations; geothermal loan guaranty program; research and development activities; legal, institutional, and regulatory activities; environmental activities; reports and publications; and a directory. (MHR)

  13. Preliminary geothermal investigations at Manley Hot Springs, Alaska

    SciTech Connect

    East, J.

    1982-04-01

    Manley Hot Springs is one of several hot springs which form a belt extending from the Seward Peninsula to east-central Alaska. All of the hot springs are low-temperature, water-dominated geothermal systems, having formed as the result of circulation of meteoric water along deepseated fractures near or within granitic intrusives. Shallow, thermally disturbed ground at Manley Hot Springs constitutes an area of 1.2 km by 0.6 km along the lower slopes of Bean Ridge on the north side of the Tanana Valley. This area includes 32 springs and seeps and one warm (29.1/sup 0/C) well. The hottest springs range in temperature from 61/sup 0/ to 47/sup 0/C and are presently utilized for space heating and irrigation. This study was designed to characterize the geothermal system present at Manley Hot Springs and delineate likely sites for geothermal drilling. Several surveys were conducted over a grid system which included shallow ground temperature, helium soil gas, mercury soil and resistivity surveys. In addition, a reconnaissance ground temperature survey and water chemistry sampling program was undertaken. The preliminary results, including some preliminary water chemistry, show that shallow hydrothermal activity can be delineated by many of the surveys. Three localities are targeted as likely geothermal well sites, and a model is proposed for the geothermal system at Manley Hot Springs.

  14. Geothermal resource assessment in Oklahoma

    SciTech Connect

    Harrison, W.E.; Luza, K.V.; Prater, M.L.; Cheung, P.K.; Ruscetta, C.A.

    1982-07-01

    The procedures and methods used to develop a geothermal gradient map of Oklahoma are discussed. Two areas, Haskell and Pittsburg Counties, in the Arkoma Basin, are discussed in detail. Three sandstone units, the Spiro, Cromwell, and Hartshorne were selected as potential low-temperature geothermal water sources. The average temperature ranged from 103/sup 0/F at Hartshorne to 158/sup 0/F at Cromwell. (MJF)

  15. Sustainability assessment of geothermal exploitation by numerical modelling: the example of high temperature Mofete geothermal field at Campi Flegrei caldera (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Carlino, Stefano; Troiano, Antonio; Giulia Di Giuseppe, Maria; Tramelli, Anna; Troise, Claudia; Somma, Renato; De Natale, Giuseppe

    2015-04-01

    The active volcanic area of Campi Flegrei caldera has been the site of many geothermal investigations, since the early XX century. This caldera is characterised by high heat flow, with maximum value > 150 mWm-2, geothermal gradients larger than 200°Ckm-1 and diffuse magmatic gases discharge at the surface. These features encouraged an extensive campaign for geothermal investigation, started in 1939, with many drillings performed at Campanian volcanoes (Campi Flegrei and Ischia) and later at Vesuvius. Several wells aimed to the exploitation of high enthalpy geothermal energy, were drilled in the Campi Flegrei caldera, down to a maximum depth of ~3 km involving mainly two sites (Mofete and S.Vito geothermal fields) located in western and northern sector of caldera respectively. The most interesting site for geothermal exploitation was the Mofete zone, where a number of 4 productive wells were drilled and tested to produce electrical power. Based on data inferred from the productive tests it was established a potential electrical extractable power from Mofete field of at least 10MWe. More recently an empirical evaluation of the whole geothermal potential of the caldera provides a value of more than 1 GWe. The results of AGIP-ENEL exploration at Campi Flegrei highlighted the feasibility of geothermal exploitation. Here, we show for the first time the results of numerical simulations (TOUGH2 code ®) of fluids extraction and reinjection from the Mofete geothermal field, in order to produce at least 5MWe from zero emission power plant (Organic Rankine Cycle type). The simulation is aimed to understand the perturbation of the geothermal reservoir in terms of temperature, pressure change, and possible related seismicity, after different simulated time of exploitation. The modeling is mainly constrained by the data derived from geothermal exploration and productive tests performed since 1979 by AGIP-ENEL Companies. A general assessment of the maximum potential magnitude

  16. Mapping temperature and radiant geothermal heat flux anomalies in the Yellowstone geothermal system using ASTER thermal infrared data

    USGS Publications Warehouse

    Vaughan, R. Greg; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.; Jaworowski, Cheryl; Heasler, Henry

    2012-01-01

    The purpose of this work was to use satellite-based thermal infrared (TIR) remote sensing data to measure, map, and monitor geothermal activity within the Yellowstone geothermal area to help meet the missions of both the U.S. Geological Survey Yellowstone Volcano Observatory and the Yellowstone National Park Geology Program. Specifically, the goals were to: 1) address the challenges of remotely characterizing the spatially and temporally dynamic thermal features in Yellowstone by using nighttime TIR data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and 2) estimate the temperature, geothermal radiant emittance, and radiant geothermal heat flux (GHF) for Yellowstone’s thermal areas (both Park wide and for individual thermal areas). ASTER TIR data (90-m pixels) acquired at night during January and February, 2010, were used to estimate surface temperature, radiant emittance, and radiant GHF from all of Yellowstone’s thermal features, produce thermal anomaly maps, and update field-based maps of thermal areas. A background subtraction technique was used to isolate the geothermal component of TIR radiance from thermal radiance due to insolation. A lower limit for the Yellowstone’s total radiant GHF was established at ~2.0 GW, which is ~30-45% of the heat flux estimated through geochemical (Cl-flux) methods. Additionally, about 5 km2 was added to the geodatabase of mapped thermal areas. This work provides a framework for future satellite-based thermal monitoring at Yellowstone as well as exploration of other volcanic / geothermal systems on a global scale.

  17. Numerical modelling of crustal deformation due to fluid extraction and re-injection in the Hengill geothermal area in South Iceland

    NASA Astrophysics Data System (ADS)

    Juncu, Daniel; Árnadóttir, Thóra; Ali, Tabrez; Hooper, Andrew

    2015-04-01

    Several high temperature geothermal energy production fields are currently harnessed in Iceland. One of these is located at the Hengill triple junction, where the oblique plate motion along the Reykjanes peninsula is partitioned between the E-W oriented transform along the South Iceland Seismic Zone (SISZ) and spreading across the Western Volcanic Zone in SW Iceland. The Hengill volcano is a high temperature geothermal area that is utilized by the Hellisheiði and Nesjavellir power plants. The regions around the power plants are subject to surface deformation due to several processes. These include the motion of the Earth's crust due to plate spreading, co- and post seismic deformation due to earthquakes in the South Iceland Seismic Zone and deformation due to water and steam extraction and wastewater re-injection near geothermal power plants. We measure surface displacement in the Hengill area using both GPS and InSAR data. The former are obtained from four continuous and more than 15 campaign GPS stations in the area, with time-series starting after two M6 earthquakes on 29 May 2008 in Ölfus - the westernmost part of the SISZ. The InSAR data consist of 10 images taken by the TerraSar-X mission, starting October 2009. The InSAR time-series has a temporal resolution of 1 to 3 images per year, taken at an incidence angle of approximately 30° from the vertical. In the InSAR data we can see a clear subsidence signal in the proximity of the power plants with a maximum of ~24 mm/yr in Line-of-Sight direction (LOS) at Hellisheiði, after correcting for plate motion. The subsidence is elongated in NNE-SSW direction and possibly related to the orientation of the Hengill fissure swarm. In addition to subsidence, we observe an uplift signal of ca. 10 mm/yr in LOS west of the Hellisheiði site, potentially due to wastewater re-injection in the area. The area of maximum uplift is located close to the epicenters of two M4 earthquakes that occurred in October 2011. We run

  18. Sulfur-rich geothermal emissions elevate acid aerosol levels in metropolitan Taipei.

    PubMed

    Lin, Chih-Hung; Mao, I-Fang; Tsai, Pei-Hsien; Chuang, Hsin-Yi; Chen, Yi-Ju; Chen, Mei-Lien

    2010-08-01

    Several studies have demonstrated that millions of people globally are potentially exposed to volcanic gases. Hydrogen sulfide is a typical gas in volcanic and geothermal areas. The gas is toxic at high concentrations that predominantly affects the nervous, cardiovascular, and respiratory systems. The WHO air quality guideline for hydrogen sulfide is 150 microg m(-3) (105 ppb). The northwest part of Taipei is surrounded by sulfur-rich geothermal and hot springs. Active fumaroles and bubbling springs around the geothermal area emit acidic gases. In combination with automobile emissions, the pollution of acid aerosols is characteristic of the metropolis. This study considered sulfur-rich geothermal, suburban and downtown locations of this metropolis to evaluate geothermally emitted acid aerosol and H(2)S pollution. Acid aerosols were collected using a honeycomb denuder filter pack sampling system (HDS), and then analyzed by ion chromatography (IC). Results indicated that long-term geothermal emissions, automobile emissions and photochemical reactions have led to significant variations in air pollution among regions of metropolitan Taipei. The highest H(2)S concentration was 1705 ppb in the geothermal area with low traffic density and the mean concentration was 404.06 ppb, which was higher than WHO guideline and might cause eye irritation. The SO(2) concentrations were relatively low (mean concentration was 3.9 ppb) in this area. It may partially result from the chemical reduction reaction in the geothermal emission, which converted the SO(2) gas into SO(4)(2-) and H(2)S. Consequently, very high sulfate concentrations (mean concentration higher than 25.0 microg m(-3)) were also observed in the area. The geothermal areas also emitted relatively high levels of aerosol acidity, Cl(-), F(-), PO(4)(3-), and N-containing aerosols. As a result, concentrations of HNO(3), NO(2)(-), PO(4)(3-), and SO(4)(2-) in metropolitan Taipei are significantly higher than those in other

  19. Reconnaissance evaluation of Honduran geothermal sites. Una evaluacion por medio de reconocimiento de seis areas geotermicas en Honduras

    SciTech Connect

    Eppler, D.; Fakundiny, R.; Ritchie, A.

    1986-12-01

    Six geothermal spring sites were selected on the basis of preliminary investigations conducted in Honduras over the last decade and were evaluated in terms of their development potential. Of the six, the Platanares and San Ignacio sites have high base temperatures and high surface fluid discharge rates and appear to have the best potential for further development as sources of electrical power. A third site, Azacualpa, has a high enough base temperature and discharge rate to be considered as a back-up, but the logistical problems involved in geophysical surveys make it less attractive than the two primary sites. Of the remaining three sites, Pavana may be a source of direct-use heat for local agricultural processing. Sambo Creek and El Olivar have either severe logistical problems that would impede further investigation and development or base temperatures and flow rates that are too low to warrant detailed investigation at this time.

  20. Plant support capabilities of a geothermal fluid

    SciTech Connect

    Robinson, F.E.; Singh, K.; Berry, W.; Thomas, T.R.

    1980-09-01

    Geothermal fluids and shallow groundwater from Republic Geothermal, Inc. lease area of East Mesa in Imperial County, California were used successfully to irrigate sugar beet, alfalfa, asparagus, date palm, tamarisk, and desert climax vegetation. Chemical characteristics of the two irrigation fluids differed, but total dissolved solids content of the fluids were similar and within the 2000 mg/l range. The geothermal fluid contains elements which could be harmful to irrigated plants or plant consumers.

  1. One-pot synthesis of ternary Ag₂CO₃/Ag/AgCl photocatalyst in natural geothermal water with enhanced photocatalytic activity under visible light irradiation.

    PubMed

    Yao, Xiaxi; Liu, Xiaoheng

    2014-09-15

    Geothermal water is a clean, cheap and renewable resource and it is widely distributed all over the world. In this work, ternary Ag2CO3/Ag/AgCl photocatalyst has been successfully synthesized via a one-pot precipitation method in natural geothermal water at room temperature, wherein the geothermal water serves as the source of chlorine and carbonate. The results suggest that the Ag/AgCl nanoparticles are anchored on the surface of Ag2CO3 and Ag2CO3/Ag/AgCl composite shows strong absorption ability in the visible light region. The evaluation of the photocatalytic activity indicates that the as-synthesized Ag2CO3/Ag/AgCl photocatalyst exhibits higher photocatalytic performance for the degradation of methylene blue (MB) aqueous solution under visible light irradiation than one-component (Ag2CO3), two-component (Ag/AgCl, Ag2CO3/AgCl) and the mechanical mixture of Ag2CO3 and Ag/AgCl. The trapping experiments confirmed that holes (h(+)) and (•)O2(-) were the two main active species in the photocatalytic process. Finally, a possible Z-scheme photocatalytic mechanism of the charge transfer was proposed for the enhanced photocatalytic performance. This work may open up new insights into the application of cheap geothermal water resources in the word and provide new opportunities for facile fabrication of Ag/AgCl-based photocatalysts.

  2. Geothermal power development in Hawaii. Volume 1. Review and analysis

    NASA Astrophysics Data System (ADS)

    1982-06-01

    The history of geothermal exploration in Hawaii is reviewed briefly. The nature and occurrences of geothermal resources are presented island by island. An overview of geothermal markets is presented. Other topics covered are: potential markets of the identified geothermal areas, well drilling technology, hydrothermal fluid transport, overland and submarine electrical transmission, community aspects of geothermal development, legal and policy issues associated with mineral and land ownership, logistics and infrastructure, legislation and permitting, land use controls, Regulation 8, public utilities commission, political climate and environment, state plans, county plans, geothermal development risks, and business planning guidelines.

  3. Geothermal power development in Hawaii. Volume I. Review and analysis

    SciTech Connect

    Not Available

    1982-06-01

    The history of geothermal exploration in Hawaii is reviewed briefly. The nature and occurrences of geothermal resources are presented island by island. An overview of geothermal markets is presented. Other topies covered are: potential markets of the identified geothermal areas, well drilling technology, hydrothermal fluid transport, overland and submarine electrical transmission, community aspects of geothermal development, legal and policy issues associated with mineral and land ownership, logistics and infrastructure, legislation and permitting, land use controls, Regulation 8, Public Utilities Commission, political climate and environment, state plans, county plans, geothermal development risks, and business planning guidelines.

  4. Geothermal Progress Monitor report No. 8. Progress report

    SciTech Connect

    Not Available

    1983-11-01

    Geothermal Progress Monitor (GPM) Report Number 8 presents information concerning ongoing technology transfer activities and the mechanisms used to support these activities within geothermal R and D programs. A state-by-state review of major geothermal development activities for the reporting period 1 February 1983 through 31 July 1983 is provided. Recent drilling and exploration efforts and the current status of geothermal electric power plant development in the United States are summarized.

  5. Permafrost and Periglacial Activity Distribution and Geothermal Anomalies in the Chachani and El Misti Volcanoes (Southern Peru)

    NASA Astrophysics Data System (ADS)

    Palacios, D.; Andrés, N.; Úbeda, J.; Alcalá, J.

    2009-04-01

    /year, records only one cycle/year. At the crater, there are 80 yearly cycles at 30 cm and none at 100 cm. The conclusion from the results obtained from the thermometers leads to the following hypothesis: the permafrost distribution on the mountains surrounding Arequipa city starts at an altitude of 5450 m for climatic reasons, but the area of maximum periglacial activity is located in a belt between the altitudes of 4900 and 5400 m, although always at very limited depths, and is non-existent at more than 80 cm. These climatic values are cancelled out on El Misti by substantial geothermal heat which does not only act at a few localized spots, as has been described for other volcanoes (Palacios et al., 2007): it affects the whole volcano, although naturally to a greater extent at the summit, where the crater is located. Even the air temperature is affected, but it is the ground temperature which is basically and drastically changed, eliminating any possibility of glacial accumulation or permafrost, and reducing the depth of periglacial activity to only the first few centimeters of the ground. This activity is more significant at altitudes much greater than expected from the climatic conditions. References.- Dornbusch, U., 2001. Modern and Last Local Glacial Maximum snowlines in the Central Andes of Peru, Bolivia, and Northern Chile. Quaternary Science Reviews 18, 63-84. Paquereau, P.; Thouret, J-C.; Worner, G.; & Fornari, M., 2006. Neogene and Quaternary ignimbrites in the area of Arequipa, southern Peru: stratigraphical and petrological correlations. J Volc Geotherm Res, 154: 251-275. Palacios, D.; Zamorano, J.J.; & Andrés, N., 2007. Permafrost distribution in tropical stratovolcanoes: Popocatépetl and Iztaccíhuatl volcanoes (Mexico). Geophysical Research Abstracts 9: 05615. Thouret, J-C.; Finizola, A.; Fornary, M.; Suni, J. & Frechen. M., 2001. Geology of El Misti volcano near the city of Arequipa, Peru. Geological Society of America Bulletin, 113(12): 593-610.

  6. Geothermal Prospector: Supporting Geothermal Analysis Through Spatial Data Visualization and Querying Tools

    SciTech Connect

    Getman, Daniel; Anderson, Arlene; Augustine, Chad

    2015-09-02

    Determining opportunities for geothermal energy can involve a significant investment in data collection and analysis. Analysts within a variety of industry and research domains collect and use these data; however, determining the existence and availability of data needed for a specific analysis activity can be challenging and represents one of the initial barriers to geothermal development [2]. This paper describes the motivating factors involved in designing and building the Geothermal Prospector application, how it can be used to reduce risks and costs related to geothermal exploration, and where it fits within the larger collection of tools that is the National Geothermal Data System (NGDS) [5].

  7. Geothermal Energy.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Described are the origin and nature of geothermal energy. Included is the history of its development as an energy source, technological considerations affecting its development as an energy source, its environmental effects, economic considerations, and future prospects of development in this field. Basic system diagrams of the operation of a…

  8. Fiscal 1991 geothermal development promotion energy

    NASA Astrophysics Data System (ADS)

    1993-02-01

    The paper surveys the spouting of geothermal fluids in test boring wells, the well logging, and the status of geothermal fluids, as a part of the geothermal development promotion survey in the Mizuwake-Toge south area. In the spouting test of N3-MW-6 well, the 53rd swabbing led successfully to spouting. The spouting amounted to 3.6 tons/h in steam and geothermal water, but stopped spontaneously in 100 minutes. Results of the logging are hardly different between before and after the spouting indicating a maximum temperature of 200 C, barometric pressure of 75, and water levels of a 250-300m section. The geothermal water is a neutral Cl deep-area type. N2-MW-2 well spouted immediately after the 10th swabbing, indicating steam of 3 tons/h at the stable time, geothermal water of 7.3 tons/h, pH9, Cl of 1500ppm, and the total spouting time of 4029 minutes. The place where the geothermal fluid flows in is 635m deep, and when the well head pressure was 1.7-3.9 barometric pressure, the spouted fluid temperature was 199-198 C. The geothermal water is a Cl-HCO3 type. In both wells geothermal water is ground water originated from meteoric water which reacted with peripheral rocks by volcanic heating and was formed in the deep area.

  9. Geothermal resources of Montana

    SciTech Connect

    Metesh, J.

    1994-06-01

    The Montana Bureau of Mines and Geology has updated its inventory of low and moderate temperature resources for the state and has assisted the Oregon Institute of Technology - GeoHeat Center and the University of Utah Research Institute in prioritizing and collocating important geothermal resource areas. The database compiled for this assessment contains information on location, flow, water chemistry, and estimated reservoir temperatures for 267 geothermal well and springs in Montana. For this assessment, the minimum temperature for low-temperature resource is defined as 10{degree} C above the mean annual air temperature at the surface. The maximum temperature for a moderate-temperature resource is defined as greater than 50{degree} C. Approximately 12% of the wells and springs in the database have temperatures above 50{degree} C, 17% are between 30{degree} and 50{degree} C, 29% are between 20{degree} and 30{degree}C, and 42% are between 10{degree} and 20{degree} C. Low and moderate temperature wells and springs can be found in nearly all areas of Montana, but most are in the western third of the state. Information sources for the current database include the MBMG Ground Water Information Center, the USGS statewide database, the USGS GEOTHERM database, and new information collected as part of this program. Five areas of Montana were identified for consideration in future investigations of geothermal development. The areas identified are those near Bozeman, Ennis, Butte, Boulder, and Camas Prairie. These areas were chosen based on the potential of the resource and its proximity to population centers.

  10. Mushroom growing project at the Los Humeros, Mexico geothermal field

    SciTech Connect

    Rangel, M.E.R.

    1998-12-01

    There are several projects of direct (non-electrical) use of geothermal energy in Mexico. Personnel of the Comision Federal de Electricidad (CFE) have experience in various of these projects, like drying of timber and fruits, space heating, food processing, etc. Taking this in consideration, CFE built the Los Humeros mushroom plant using for heat source the geothermal steam from Well H-1. The main purpose of the project was to take advantage of residual geothermal energy in a food production operation and to develop the appropriate technology. In 1992, existing installations were renovated, preparing appropriate areas for pasteurization, inoculation and production. The mushroom Pleurotus ostreatus var. florida and columbinus was used. A year later, CFE proposed the construction of improved facilities for growing edible mushrooms. New materials and equipment, as well as different operation conditions, were proposed on the basis of the experience gained in the initial project. The construction and renovation activities were completed in 1994.

  11. Geology and slope stability in selected parts of The Geysers geothermal resources area: a guide to geologic features indicative of stable and unstable terrain in areas underlain by Franciscan and related rocks

    SciTech Connect

    Bedrossian, T.L.

    1980-01-01

    The results of a 4-month study of various geologic and topographic features related to the stability of Franciscan terrain in The Geysers GRA are presented. The study consisted of investigations of geologic and topographic features, throughout The Geysers GRA, and geologic mapping at a scale of 1:12,000 of approximately 1500 acres (600 hectares) of landslide terrain within the canyon of Big Sulphur Creek in the vicinity of the Buckeye mine (see plate 1). The area mapped during this study was selected because: (1) it is an area of potential future geothermal development, and (2) it illustrates that large areas mapped as landslides on regional scales (McLaughlin, 1974, 1975b; McNitt, 1968a) may contain zones of varying slope stability and, therefore, should be mapped in more detail prior to development of the land.

  12. Fine-grained clay fraction (,0.2 {mu}m): An interesting tool to approach the present thermal and permeability state in active geothermal systems

    SciTech Connect

    Patrier, P.; Papapanagiotou, P.; Beaufort, D.; Traineau, H.; Bril, H.

    1992-01-01

    We have investigated by X-ray diffraction the very fine grained secondary minerals (< 0.2 {micro}m) developed in geothermal systems, in relation with their present thermal and permeability state. Because the smallest particles are the most reactive part of a rock, they are the youngest mineral phases of the geothermal fields. This study has been performed on two active geothermal fields: Milos field, Greece (130 < T < 320 C) and Chipilapa field, Salvador (90 < T < 215 C). In the Milos field, the mineralogical composition of the < 0.2 {micro}m clay fraction observed in the reservoir strongly differs from the overlying altered metamorphic schists in the presence of abundant quantities of saponite and talc/saponite interstratified minerals at unusually high temperature. These phases are considered to be kinetically control-led ''metastable'' minerals which rapidly evolve towards actinolite and talc for present temperatures higher than 300 C. Their occurrence is a good indicator of discharge in highly permeable zones. In the geothermal field of Chipilapa, the mineralogical composition of the < 0.2 {micro}m clay fractions fairly agrees with the temperatures presently measured in the wells, whereas several discrepancies may be pointed out from the compositions of coarser clay fractions (< 5 {micro}m) which contain minerals inherited from higher temperature stages. Permeable zones may be evidenced from an increase of expandable components in the interstratified minerals and a decrease of the coherent domain of the unexpandable clay particles (chlorite).

  13. Geothermal demonstration: Zunil food dehydration facility

    SciTech Connect

    Maldonado, O. ); Altseimer, J.; Thayer, G.R. ); Cooper, L. ); Caicedo, A. . Inst. Nacional de Electrificacion)

    1991-08-01

    A food dehydration facility was constructed near the town of Zunil, Guatemala, to demonstrate the use of geothermal energy for industrial applications. The facility, with some modifications to the design, was found to work quite satisfactorily. Tests using five different products were completed during the time geothermal energy was used in the plant. During the time the plant was not able to use geothermal energy, a temporary diesel-fueled boiler provided the energy to test dehydration on seven other crops available in this area. The system demonstrates that geothermal heat can be used successfully for dehydrating food products. Many other industrial applications of geothermal energy could be considered for Zunil since a considerable amount of moderate-temperature heat will become available when the planned geothermal electrical facility is constructed there. 6 refs., 15 figs., 7 tabs.

  14. Regional geothermal exploration in north central New Mexico. Final report

    SciTech Connect

    Icerman, L.

    1984-02-01

    A broad-based geothermal resource reconnaissance study covering Bernalillo, Los Alamos, Rio Arriba, San Miguel, Sandoval, Santa Fe, Taos, Torrance, and Valencia counties in north central New Mexico was conducted from June 15, 1981, through September 30, 1983. Specific activities included the compilation of actual temperature, bottom-hole temperature gradient, and geotemperature data; tabulation of water chemistry data; field collection of temperature-depth data from existing wells; and drilling of temperature gradient holes in the Ojo Caliente, San Ysidro, Rio Puerco, and Polvadera areas. The data collected were used to perform: (1) a regional analysis of the geothermal energy potential of north central New Mexico; (2) two site-specific studies of the potential relationship between groundwater constrictions and geothermal resources; (3) an evaluation of the geothermal energy potential at Santa Ana Pueblo; (4) a general analysis of the geothermal energy resources of the Rio Grande Rift, including specific data on the Valles Caldera; and (5) an evaluation of the use of geothermometers on New Mexico groundwaters. Separate abstracts were prepared for individual chapters.

  15. Geothermal-resource survey of the Tennessee Valley Region

    NASA Astrophysics Data System (ADS)

    Staub, W. P.; Treat, N. L.

    1982-08-01

    An overview appraisal of the geothermal resources in the Tennessee Valley Region revealed geothermal resources of potential usefulness in two of 13 subregions: the New Madrid Seismic Zone and the central segment of the Northern Gulf Coastal Plain. The appraisal was based on geologic features of the region (hot springs, groundwater aquifers, and structure) and temperature data for oil and gas wells and shallow water wells. Site specific exploration for economic appraisal was not carried out. The geothermal gradient for each of the subregions was established by linear regression of all of the bottom hole temperature data for the oil and gas wells. A routine statistical procedure identified all unusually warm wells within each subregion, and their locations were plotted. Hot spots in a subregion were identified by localized clustering of such wells in numbers exceeding statistical expectations based on the intensity of drilling activity. Of the two areas most likely for extraction of geothermal energy, the New Madrid Seismic Zone has a high geothermal gradient at shallow depths (less than 500 meters).

  16. Geothermal probabilistic cost study

    NASA Astrophysics Data System (ADS)

    Orren, L. H.; Ziman, G. M.; Jones, S. C.; Lee, T. K.; Noll, R.; Wilde, L.; Sadanand, V.

    1981-08-01

    A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model was used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents was analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance were examined.

  17. Geothermal probabilistic cost study

    NASA Technical Reports Server (NTRS)

    Orren, L. H.; Ziman, G. M.; Jones, S. C.; Lee, T. K.; Noll, R.; Wilde, L.; Sadanand, V.

    1981-01-01

    A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model was used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents was analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance were examined.

  18. A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

    SciTech Connect

    Erdlac, Richard J., Jr.

    2006-10-12

    Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities

  19. Geothermal drilling research in the United States

    SciTech Connect

    Varnado, S.G.; Maish, A.B.

    1980-01-01

    The high cost of drilling and completing geothermal wells is an impediment to the development of this resource. The Department of Energy (DOE), Division of Geothermal Energy (DGE), is conducting an R and D program directed at reducing well costs through improvements in geothermal drilling and completion technology. This program includes R and D activities in high temperature drilling hardware, drilling fluids, lost circulation control methods, completion technology, and advanced drilling systems. An overview of the program is presented.

  20. Advances in geothermal energy use

    SciTech Connect

    Kilkis, I.B.; Eltez, M.

    1996-10-01

    One of the earliest examples of large scale use of the geothermal energy is the district heating system in Boise, Idaho. Established in 1892, this system now serves 266 customers--mostly residential. Today, excluding heat pumps, there are about 300 sites in America where geothermal energy is currently used in various applications; including district heating, absorption cooling and refrigeration, industrial processes, aquaculture, horticulture, and snow melting/freeze protection. Among these, 18 geothermal district heating systems are operating with 677 GBtu (714 TJ) total annual heat output. Geothermal activity was first generated in Italy, in 1904, with a 10 kWe capacity. Now, commercial power plants are in service using vapor-dominated and liquid-dominated plants with a world-wide installed capacity of 6 GWe. This paper looks at a hybrid cycle/integrated district HVAC system.

  1. Geothermal Progress Monitor report No. 5. Progress report, June 1981

    SciTech Connect

    Not Available

    1981-01-01

    Updated information is presented on activities and progress in the areas of electric power plants, direct heat applications, deep well drilling, leasing of federal lands, legislative and regulatory actions, research and development, and others. Special attention is given in this report to 1980 highlights, particularly in the areas of electric and direct heat uses, drilling, and the Federal lands leasing program. This report also includes a summary of the DOE FY 1982 geothermal budget request to Congress.

  2. Analysis of geophysical well logs obtained in the State 2-14 borehole, Salton Sea geothermal area, California

    USGS Publications Warehouse

    Paillet, Frederick L.; Morin, R.H.

    1988-01-01

    A complete suite of conventional geophysical well logs was obtained in the upper part of a 3220-m-deep borehole drilled into geothermally altered alluvial sediments on the southeastern edge of the Salton Sea. Geophysical logs obtained in the State 2-14 borehole indicate that neutron porosity, gamma-gamma, and deep-induction logs provide useful information on lithologic trends with depth. The natural gamma log contains almost continuous, high-frequency fluctuations that obscure lithologic trends and that may be related to recent radioisotope redistribution and departure from radiometric equilibrium. Acoustic transit time logs give unrealistically low in situ compressional velocities ranging from 1.8 to 3.0 km/s, whereas acoustic waveform logs indicate that sediment compressional velocities range from less than 3.0 km/s shallower than 1000 m in depth to almost 5.0 km/s at depths greater than 2000 m. Analyses indicate that most log values lie between two lithologic end points: an electrically conductive claystone with moderate neutron porosity, but no effective porosity, and an electrically nonconductive, fully cemented siltstone that has small but finite porosity. -from Authors

  3. Geothermal progress monitor: Report Number 19

    SciTech Connect

    1997-12-01

    Short articles are presented related to activities in the federal government and the geothermal industry, international developments, state and local government activities, technology development, and technology transfer. Power plant tables and a directory of organizations involved in geothermal resource development are included.

  4. Geothermal program overview: Fiscal years 1993--1994

    SciTech Connect

    1995-11-01

    The DOE Geothermal Energy Program is involved in three main areas of research: finding and tapping the resource; power generation; and direct use of geothermal energy. This publication summarizes research accomplishments for FY 1993 and 1994 for the following: geophysical and geochemical technologies; slimhole drilling for exploration; resource assessment; lost circulation control; rock penetration mechanics; instrumentation; Geothermal Drilling Organization; reservoir analysis; brine injection; hot dry rock; The Geysers; Geothermal Technology Organization; heat cycle research; advanced heat rejection; materials development; and advanced brine chemistry.

  5. Geothermal reservoir engineering research at Stanford University. First annual report, October 1, 1980-September 30, 1981

    SciTech Connect

    Brigham, W.E.; Horne, R.N.; Kruger, P.; Miller, F.G.; Ramey, H.J. Jr.

    1981-09-01

    The work on energy extraction experiments concerns the efficiency with which the in-place heat and fluids can be produced. The work on noncondensable gas reservoir engineering covers both the completed and continuing work in these two interrelated research areas: radon emanation from the rock matrix of geothermal reservoirs, and radon and ammonia variations with time and space over geothermal reservoirs. Cooperative research programs with Italy and Mexico are described. The bench-scale experiments and well test analysis section covers both experimental and theoretical studies. The small core model continues to be used for the study of temperature effects on absolute permeability. The unconsolidated sand study was completed at the beginning of this contract period. The Appendices describe some of the Stanford Geothermal program activities that results in interactions with the geothermal community. These occur in the form of SGP Technical Reports, presentations at technical meetings and publications in the open literature.

  6. Numerical modeling and strontium isotopic signal to assess the arsenic distribution in a low-enthalpy hydrothermal system: the case study of Viterbo geothermal area (Italy)

    NASA Astrophysics Data System (ADS)

    Battistel, M.; Barbieri, M.

    2013-12-01

    Several studies on the groundwater geochemistry of the hydrothermal area west of Viterbo, highlight the presence of arsenic and other trace elements. The groundwater of Viterbo area was used as source of drinking water by about 150,000 local inhabitants, until 2010, when it was prohibited the use by EU due to the high level of arsenic. The hydrogeological setting highlights the presence of a shallow volcanic aquifer (composed by alkaline-potassic volcanics), characterized by fresh waters, limited at its base by the semiconfining marly-calcareous-arenaceous complex and low-permeability clays. To the west of Viterbo, vertical upflows of hot waters (with a temperature between 50 and 64°C), are due to the locally uplifted of evaporitic reservoir, the reduced thickness of the semiconfining layer and the high local geothermal gradient. Current study is focused on news geochemical approaches to defining the conditions which control arsenic mobility in groundwater in the low- enthalpy thermal area of Viterbo, related to the interaction between the volcanic aquifer and the geothermal reservoir. In addition to determinate chemical components and chemical-physical properties (T, pH, electrical conductivity) the study provided the isotopic values of 87Sr/86Sr of Viterbo geothermal area. Geochemical modelling is conducted using Phreeqc. The program monitors the significant species and calculates equilibrium concentrations and the pCO2 at desired temperatures. Investigations were undertaken in the area exhibiting thermal manifestations and in the immediate surroundings. On the basis of major ions and temperature, it is possible to subdivide the waters sampled into three main groups: the thermal waters with a sulphate -alkaline-earth facies, the fresh waters with a biocarbonate-alkaline facies, and a group of mixing waters with a undefined facies. The values of strontium isotopic ratio 87Sr/86Sr marks out the different circuits of groundwater. Values lower than 0.70800 are

  7. Probing a deep geothermal area in the upper rhine graben with ambient seismic noise : some results based on permanent networks and the dense temporary Estof array

    NASA Astrophysics Data System (ADS)

    Lehujeur, Maximilien; Vergne, Jérôme; Le Chenadec, Adrien; Schmittbuhl, Jean

    2016-04-01

    Correlation of ambient seismic noise is an emerging technique that allows to probe the subsoil with no natural or induced seismic sources. The method can be used for passive imaging or for monitoring the temporal evolution of the velocity and the diffracting properties of a medium. Recently, these techniques have been generalized to very dense seismological networks, which emerge as a new tool for the exploration, the characterization and the monitoring of deep geothermal reservoirs at much lower costs than active methods. The EstOf experiment that occured in september 2014 proposes to assess the potential of these techniques. Il consists in a dense network of 288 Zland ® seismological stations deployed every ~1.5km over a 15km radius disc around the two geothermal sites of Rittershoffen and Soultz-sous-forêts (Alsace, France). This temporary network complements several permanent and semi-permanent networks initially dedicated to the monitoring of the induced seismicity. The correlation of one month of ambient seismic noise provides thousands of usable correlation functions in the 0.2-5Hz frequency range. We clearly observe body waves as well as the fundamental mode and first overtone of the Rayleigh wave. The latter phases have been used to build a 3D model of shear wave velocities of the region down to 5km depth. This model, having a lateral resolution of about 2km, appears to be in good agreement with our geological knowledge of the region. Furthermore, the temporal analysis of the noise correlation functions between some permanent stations indicate sudden changes in the diffracting properties of the subsoil, which are probably linked to the stimulation phases of the reservoir conducted at Rittershoffen in 2013. However, interpreting these observations remains difficult. Laboratory experiments could be a useful approach to better understand the link between the changes in the medium parameters and the resulting effects on the noise-correlation functions.

  8. Relation between structure and low-temperature geothermal systems in Fukuoka city, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Saibi, H.; Nishijima, J.; Hirano, T.; Fujimitsu, Y.; Ehara, S.

    2008-08-01

    The Fukuoka area is located in the southwestern part of Japan. The Yokote-Ijiri area, located in the southern part of Fukuoka city, has several low-temperature geothermal systems, including eleven hot springs. From 1996 to 2008, the Fukuoka area was investigated by gravity survey, using Scintrex CG-3 and CG-3M gravimeters, in an attempt to delineate its subsurface structure. The surveys were intended to improve the understanding of the relation between the geothermal systems and the subsurface structure as well as to locate the active faults in the surveyed area, which are responsible for generating large earthquakes. The gravity data were analyzed using integrated gradient interpretation techniques, such as the Horizontal Gradient (HG), Tilt Derivative (TDR), and Euler deconvolution methods. With these techniques, many faults were detected, including the famous Kego fault, which is an active fault in Fukuoka city. A 2-D gravity model was constructed to show the relationship between the faults and the geothermal systems. The results of the present study will hopefully lead to an understanding of the relationships between the interpreted faults and the location of the low-temperature geothermal systems and possibly aid in future geothermal exploration of the area.

  9. The Iceland Deep Drilling Project: (III) Evidence for amphibolite grade contact metamorphism in an active geothermal system

    NASA Astrophysics Data System (ADS)

    Marks, N.; Schiffman, P.; Zierenberg, R. A.; Franzson, H.

    2008-12-01

    One of the scientific goals of the Iceland Deep Drilling Project is to reach the depths of transition from greenschist to amphibolite grade metamorphism in an active geothermal system. The deepest borehole to date in the Reykjanes system is RN-17, which was drilled to a depth of 3082 m. This well had been considered as a candidate for deepening by the IDDP until it collapsed during a flow test in November 2005. Temperatures in the lower portion of the borehole were never recorded due to an obstruction at 2100 m depth, but are estimated to be approximately 340°C. Epidote, albite, and actinolite are ubiquitous within pillow basalt, hyaloclastite, and in veins, implying that greenschist grade conditions have been attained throughout much of the well below approximately 1200 m. Intrusive lithologies constitute approximately 50% of the observed cuttings between 2600 and 2700 m. These intrusive rocks have produced small, but recognizable contact metamorphic effects characterized by granoblastic hornfels consisting of amphibolite grade assemblages of quartz + anorthite + diopside + magnetite + titanite. These have, in turn, been locally cut by actinolite veins, presumably reflective of the present-day, thermal state of the hydrothermal system at these depths. Based on their siliceous bulk composition, we believe the hornfels represent the thermally- recrystallized products of earlier-formed, hydrothermal veins consisting of quartz, epidote, and actinolite. The metamorphic plagioclase is distinctly more anorthitic (An90 to An98) than igneous plagioclase in adjacent mafic intrusives (An33 to An80) and also exhibits consistently lower Mg content and higher iron (up to 2.07 wt.% as Fe2O3). Stoichiometry implies that much of the iron in hydrothermal anorthite is Fe3+, which may imply recrystallization from precursor epidote under relatively oxidizing conditions. Diopside compositions (average Wo0.48En0.27Fs0.25) are consistently less calcic than hydrothermal clinopyroxenes

  10. Federal Geothermal Research Program Update Fiscal Year 2004

    SciTech Connect

    Not Available

    2005-03-01

    The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. The Geothermal Technologies Program (GTP) works in partnership with industry to establish geothermal energy as an economically competitive contributor to the U.S. energy supply. Geothermal energy production, a $1.5 billion a year industry, generates electricity or provides heat for direct use applications. The technologies developed by the Geothermal Technologies Program will provide the Nation with new sources of electricity that are highly reliable and cost competitive and do not add to America's air pollution or the emission of greenhouse gases. Geothermal electricity generation is not subject to fuel price volatility and supply disruptions from changes in global energy markets. Geothermal energy systems use a domestic and renewable source of energy. The Geothermal Technologies Program develops innovative technologies to find, access, and use the Nation's geothermal resources. These efforts include emphasis on Enhanced Geothermal Systems (EGS) with continued R&D on geophysical and geochemical exploration technologies, improved drilling systems, and more efficient heat exchangers and condensers. The Geothermal Technologies Program is balanced between short-term goals of greater interest to industry, and long-term goals of importance to national energy interests. The program's research and development activities are expected to increase the number of new domestic geothermal fields, increase the success rate of geothermal well drilling, and reduce the costs of constructing and operating geothermal power plants. These improvements will increase the quantity of economically viable geothermal resources, leading in turn to an increased number of geothermal power facilities serving more energy demand. These new geothermal projects will take advantage of geothermal resources in locations where development is not currently possible or

  11. Federal Geothermal Research Program Update - Fiscal Year 2004

    SciTech Connect

    Patrick Laney

    2005-03-01

    The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. The Geothermal Technologies Program (GTP) works in partnership with industry to establish geothermal energy as an economically competitive contributor to the U.S. energy supply. Geothermal energy production, a $1.5 billion a year industry, generates electricity or provides heat for direct use applications. The technologies developed by the Geothermal Technologies Program will provide the Nation with new sources of electricity that are highly reliable and cost competitive and do not add to America's air pollution or the emission of greenhouse gases. Geothermal electricity generation is not subject to fuel price volatility and supply disruptions from changes in global energy markets. Geothermal energy systems use a domestic and renewable source of energy. The Geothermal Technologies Program develops innovative technologies to find, access, and use the Nation's geothermal resources. These efforts include emphasis on Enhanced Geothermal Systems (EGS) with continued R&D on geophysical and geochemical exploration technologies, improved drilling systems, and more efficient heat exchangers and condensers. The Geothermal Technologies Program is balanced between short-term goals of greater interest to industry, and long-term goals of importance to national energy interests. The program's research and development activities are expected to increase the number of new domestic geothermal fields, increase the success rate of geothermal well drilling, and reduce the costs of constructing and operating geothermal power plants. These improvements will increase the quantity of economically viable geothermal resources, leading in turn to an increased number of geothermal power facilities serving more energy demand. These new geothermal projects will take advantage of geothermal resources in locations where development is not currently possible or

  12. A Geothermal GIS for Nevada: Defining Regional Controls and Favorable Exploration Terrains for Extensional Geothermal Systems

    USGS Publications Warehouse

    Coolbaugh, M.F.; Taranik, J.V.; Raines, G.L.; Shevenell, L.A.; Sawatzky, D.L.; Bedell, R.; Minor, T.B.

    2002-01-01

    Spatial analysis with a GIS was used to evaluate geothermal systems in Nevada using digital maps of geology, heat flow, young faults, young volcanism, depth to groundwater, groundwater geochemistry, earthquakes, and gravity. High-temperature (>160??C) extensional geothermal systems are preferentially associated with northeast-striking late Pleistocene and younger faults, caused by crustal extension, which in most of Nevada is currently oriented northwesterly (as measured by GPS). The distribution of sparse young (160??C) geothermal systems in Nevada are more likely to occur in areas where the groundwater table is shallow (<30m). Undiscovered geothermal systems may occur where groundwater levels are deeper and hot springs do not issue at the surface. A logistic regression exploration model was developed for geothermal systems, using young faults, young volcanics, positive gravity anomalies, and earthquakes to predict areas where deeper groundwater tables are most likely to conceal geothermal systems.

  13. Geothermal GIS coverage of the Great Basin, USA: Defining regional controls and favorable exploration terrains

    USGS Publications Warehouse

    Coolbaugh, M.F.; Sawatzky, D.L.; Oppliger, G.L.; Minor, T.B.; Raines, G.L.; Shevenell, L.; Blewitt, G.; Louie, J.N.

    2003-01-01

    A geographic information system (GIS) of geothermal resources, built last year for the state of Nevada, is being expanded to cover the Great Basin, USA. Data from that GIS is being made available to industry, other researchers, and the public via a web site at the Great Basin Center for Geothermal Energy, Reno, Nevada. That web site features a search engine, supports ArcExplorer?? for on-line map construction, and provides downloadable data layers in several formats. Though data collection continues, preliminary analysis has begun. Contour maps of geothermal temperatures, constructed using geothermometer temperatures calculated from a Great Basin geochemical database compiled by the Geo-Heat Center, reveal distinctive trends and patterns. As expected, magmatic-type and extensional-type geothermal systems have profoundly different associations, with magmatic-type systems following major tectonic boundaries, and extensional-type systems associating with regionally high heat flow, thin crust, active faulting, and high extensional strain rates. As described by earlier researchers, including Rowen and Wetlaufer (1981) and Koenig and McNitt (1983), high-temperature (> 100??C) geothermal systems appear to follow regional northeast trends, most conspicuously including the Humboldt structural zone in Nevada, the "Black Rock-Alvord Desert" trend in Oregon and Nevada, and the "Newcastle-Roosevelt" trend in Utah and Nevada. Weights-of-evidence analyses confirm a preference of high-temperature geothermal systems for young northeast-trending faults, but the distribution of geothermal systems correlates even better with high rates of crustal extension, as measured from global positioning system (GPS) stations in Nevada. A predictive map of geothermal potential based only on areas of high extensional strain rates and high heat flux does an excellent job of regionally predicting the location of most known geothermal systems in Nevada, and may prove useful in identifying blind

  14. Geothermal regimes of the Clearlake region, northern California

    SciTech Connect

    Amador, M.; Burns, K.L.; Potter, R.M.

    1998-06-01

    The first commercial production of power from geothermal energy, at The Geysers steamfield in northern California in June 1960, was a triumph for the geothermal exploration industry. Before and since, there has been a search for further sources of commercial geothermal power in The Geysers--Clear Lake geothermal area surrounding The Geysers. As with all exploration programs, these were driven by models. The models in this case were of geothermal regimes, that is, the geometric distribution of temperature and permeability at depth, and estimates of the physical conditions in subsurface fluids. Studies in microseismicity and heat flow, did yield geophysical information relevant to active geothermal systems. Studies in stable-element geochemistry found hiatuses or divides at the Stoney Creek Fault and at the Collayomi Fault. In the region between the two faults, early speculation as to the presence of steamfields was disproved from the geochemical data, and the potential existence of hot-water systems was predicted. Studies in isotope geochemistry found the region was characterized by an isotope mixing trend. The combined geochemical data have negative implications for the existence of extensive hydrothermal systems and imply that fluids of deep origin are confined to small, localized systems adjacent to faults that act as conduits. There are also shallow hot-water aquifers. Outside fault-localized systems and hot-water aquifers, the area is an expanse of impermeable rock. The extraction of energy from the impermeable rock will require the development and application of new methods of reservoir creation and heat extraction such as hot dry rock technology.

  15. Amedee geothermal power plant

    SciTech Connect

    Hodgson, S.F.

    1988-12-01

    In September 1988, the power plant began generating electricity in Northern California, near Honey Lake. The plant generates 2 megawatts, net, of electricity in the winter, and from 20 to 30% less in the summer, depending on the temperature. Geothermal fluids from two wells are used to operate the plant, and surface discharge is used to dispose of the spent fluids. This is possible because the geothermal fluids have a very low salinity and a composition the same as area hot spring waters. The binary power plant has a Standard Offer No. 4 contract for 5 megawatts with pacific Gas and Electric Company. Sometime in the near future, they will expand the project to add another 3 megawatts of electrical generation.

  16. Reducing the Geothermal Exploration Risk by Carbon Dioxide Soil Flux Investigations

    NASA Astrophysics Data System (ADS)

    Carapezza, Maria Luisa; Barberi, Franco; Ranaldi, Massimo; Ricci, Tullio; Tarchini, Luca; De Simone, Gabriele; Gattuso, Alessandro; Silvestri, Mario

    2013-04-01

    In the exploration of medium to high enthalpy geothermal resources it happens rather frequently that deep wells find high temperatures but are not productive because they don't cross any permeable fractured reservoir. Because of the high cost of deep drillings, this aspect represents one of the main economic risks of geothermal exploration. A detailed survey of diffuse CO2 soil flux may allow to identify from the surface the permeable portions of a deep-seated actively degassing geothermal reservoir, drastically reducing this risk. In order to test the effectiveness of CO2 soil flux as a geothermal exploration tool we selected two volcanic areas north of Rome, Latera caldera and Marta zone near lake Bolsena, both hosting a geothermal reservoir with T>200 °C and where productive and non-productive wells had been drilled in the past. We proved that in both zones productive wells are located on high CO2 soil flux zones, whereas the not-productive wells are sited on low flux areas. In addition the surveys allowed to identify some as yet unexplored portions of the geothermal reservoirs where future wells should be conveniently located. Use of the same technique in the medium enthalpy geothermal system of Torre Alfina, Central Italy (T=140°C) showed that the presence of a thick impervious rock cover may be very effective in preventing gas leakages from the reservoir to the surface. Promising results have been obtained also by CO2 soil flux surveys in some geothermal areas of Honduras (Platanares, Azacualpa) and Costa Rica (Las Pailas). Obviously, CO2 flux cannot provide any estimate of temperature at depth, which has to be assessed with other geochemical or geophysical exploration techniques.

  17. Navy Geothermal Plan

    DTIC Science & Technology

    1984-12-01

    the geothermal portion of the R&D program are those that require attention because of operational expansion and mission-related problems such as...RESOURCE/ PROBLEM MAJOR CLAIMA.. ’ ASSESSMENT - ACTIVITY, CONSULTED , I"" C NI E U R&D J EGTORD OA RECOMMENDSI I NNO FURTHER CONSIDERATION zz7 MILITARY...disposal problems and environmental concerns. Resource Confirmation The exploration methods discussed under the sections titled "Preliminary Site Survey

  18. Geothermal Systems of the Yellowstone Caldera Field Trip Guide

    SciTech Connect

    Foley, Duncan; Neilson, Dennis L.; Nichols, Clayton R.

    1980-09-08

    Geothermal studies are proceedings on two fronts in the West Yellowstone area. High-temperature resources for the generation of electricity are being sought in the Island Park area, and lower temperatures resources for direct applications, primarily space heating, are being explored for near the town of West Yellowstone. Potential electric geothermal development in the Island Park area has been the subject of widespread publicity over fears of damage to thermal features in Yellowstone Park. At the time of writing this guide, companies have applied for geothermal leases in the Island Park area, but these leases have not yet been granted by the US Forest Service. The Senate is now discussing a bill that would regulate geothermal development in Island Park; outcome of this debate will determine the course of action on the lease applications. The Island Park area was the site of two cycles of caldera activity, with major eruptions at 2.0 and 1.2 million years ago. The US Geological Survey estimates that 16,850 x 10{sup 18} joules of energy may remain in the system. Geothermal resources suitable for direct applications are being sought in the West Yellowstone vicinity by the Montana Bureau of Mines and Geology, under funding from the US Department of Energy. West Yellowstone has a mean annual temperature of 1-2 C. Research thus far suggests that basement rocks in the vicinity are at a depth of about 600 m and are probably similar to the rocks exposed north of Hebgen Lake, where Precambrian, Paleozoic and Mesozoic rocks have been mapped. A few sites with anomalously warm water have been identified near the town. Work is continuing on this project.

  19. 3D characterization of a Great Basin geothermal system: Astor Pass, NV

    SciTech Connect

    Siler, Drew L; Brett, Mayhew; Faulds, James E

    2012-12-03

    The Great Basin exhibits both anomalously high heat flow (~75±5 mWm-2) and active faulting and extension resulting in robust geothermal activity. There are ~430 known geothermal systems in the Great Basin, with evidence suggesting that undiscovered blind geothermal systems may actually represent the majority of geothermal activity. These systems employ discrete fault intersection/interaction areas as conduits for geothermal circulation. Recent studies show that steeply dipping normal faults with step-overs, fault intersections, accommodation zones, horse-tailing fault terminations and transtensional pull-aparts are the most prominent structural controls of Great Basin geothermal systems. These fault geometries produce sub-vertical zones of high fault and fracture density that act as fluid flow conduits. Structurally controlled fluid flow conduits are further enhanced when critically stressed with respect to the ambient stress conditions. The Astor Pass blind geothermal system, northwestern Nevada, lies along the boundary between the Basin and Range to the east and the Walker Lane to the west. Along this boundary, strain is transferred from dextral shear in the Walker Lane to west-northwest directed extension in the Basin and Range. As such, the Astor Pass area lies in a transtensional setting consisting of both northwest-striking, left-stepping dextral faults and more northerly striking normal faults. The Astor Pass tufa tower implies the presence of a blind geothermal system. Previous studies suggest that deposition of the Astor Pass tufa was controlled by the intersection of a northwest-striking dextral normal fault and north-northwest striking normal fault. Subsequent drilling (to ~1200 m) has revealed fluid temperatures of ~94°C, confirming the presence of a blind geothermal system at Astor Pass. Expanding upon previous work and employing additional detailed geologic mapping, interpretation of 2D seismic reflection data and analysis of well cuttings, a 3

  20. 3D characterization of a Great Basin geothermal system: Astor Pass, NV

    NASA Astrophysics Data System (ADS)

    Siler, D. L.; Mayhew, B.; Faulds, J. E.

    2012-12-01

    The Great Basin exhibits both anomalously high heat flow (~75±5 mWm-2) and active faulting and extension resulting in robust geothermal activity. There are ~430 known geothermal systems in the Great Basin, with evidence suggesting that undiscovered blind geothermal systems may actually represent the majority of geothermal activity. These systems employ discrete fault intersection/interaction areas as conduits for geothermal circulation. Recent studies show that steeply dipping normal faults with step-overs, fault intersections, accommodation zones, horse-tailing fault terminations and transtensional pull-aparts are the most prominent structural controls of Great Basin geothermal systems. These fault geometries produce sub-vertical zones of high fault and fracture density that act as fluid flow conduits. Structurally controlled fluid flow conduits are further enhanced when critically stressed with respect to the ambient stress conditions. The Astor Pass blind geothermal system, northwestern Nevada, lies along the boundary between the Basin and Range to the east and the Walker Lane to the west. Along this boundary, strain is transferred from dextral shear in the Walker Lane to west-northwest directed extension in the Basin and Range. As such, the Astor Pass area lies in a transtensional setting consisting of both northwest-striking, left-stepping dextral faults and more northerly striking normal faults. The Astor Pass tufa tower implies the presence of a blind geothermal system. Previous studies suggest that deposition of the Astor Pass tufa was controlled by the intersection of a northwest-striking dextral normal fault and north-northwest striking normal fault. Subsequent drilling (to ~1200 m) has revealed fluid temperatures of ~94°C, confirming the presence of a blind geothermal system at Astor Pass. Expanding upon previous work and employing additional detailed geologic mapping, interpretation of 2D seismic reflection data and analysis of well cuttings, a 3

  1. Advancements in 3D Structural Analysis of Geothermal Systems

    SciTech Connect

    Siler, Drew L; Faulds, James E; Mayhew, Brett; McNamara, David

    2013-06-23

    Robust geothermal activity in the Great Basin, USA is a product of both anomalously high regional heat flow and active fault-controlled extension. Elevated permeability associated with some fault systems provides pathways for circulation of geothermal fluids. Constraining the local-scale 3D geometry of these structures and their roles as fluid flow conduits is crucial in order to mitigate both the costs and risks of geothermal exploration and to identify blind (no surface expression) geothermal resources. Ongoing studies have indicated that much of the robust geothermal activity in the Great Basin is associated with high density faulting at structurally complex fault intersection/interaction areas, such as accommodation/transfer zones between discrete fault systems, step-overs or relay ramps in fault systems, intersection zones between faults with different strikes or different senses of slip, and horse-tailing fault terminations. These conceptualized models are crucial for locating and characterizing geothermal systems in a regional context. At the local scale, however, pinpointing drilling targets and characterizing resource potential within known or probable geothermal areas requires precise 3D characterization of the system. Employing a variety of surface and subsurface data sets, we have conducted detailed 3D geologic analyses of two Great Basin geothermal systems. Using EarthVision (Dynamic Graphics Inc., Alameda, CA) we constructed 3D geologic models of both the actively producing Brady’s geothermal system and a ‘greenfield’ geothermal prospect at Astor Pass, NV. These 3D models allow spatial comparison of disparate data sets in 3D and are the basis for quantitative structu