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Sample records for geysers calistoga region

  1. Mechanics of Old Faithful Geyser, Calistoga, CA

    USGS Publications Warehouse

    Rudolph, M.L.; Manga, M.; Hurwitz, Shaul; Johnston, Malcolm J.; Karlstrom, L.; Wang, Chun-Yong

    2012-01-01

    In order to probe the subsurface dynamics associated with geyser eruptions, we measured ground deformation at Old Faithful Geyser of Calistoga, CA. We present a physical model in which recharge during the period preceding an eruption is driven by pressure differences relative to the aquifer supplying the geyser. The model predicts that pressure and ground deformation are characterized by an exponential function of time, consistent with our observations. The geyser's conduit is connected to a reservoir at a depth of at least 42 m, and pressure changes in the reservoir can produce the observed ground deformations through either a poroelastic or elastic mechanical model.

  2. Local population impacts of geothermal energy development in the Geysers: Calistoga region

    SciTech Connect

    Haven, K.F.; Berg, V.; Ladson, Y.W.

    1980-09-01

    The country-level population increase implications of two long-term geothermal development scenarios for the Geysers region in California are addressed. This region is defined to include the counties of Lake, Sonoma, Mendocino and Napa, all four in northern California. The development scenarios include two components: development for electrical energy production and direct use applications. Electrical production scenarios are derived by incorporating current development patterns into previous development scenarios by both industry and research organizations. The scenarios are made county-specific, specific to the type of geothermal system constructed, and are projected through the year 2000. Separate high growth rate and low growth rate scenarios are developed, based on a set of specified assumptions. Direct use scenarios are estimated from the nature of the available resource, existing local economic and demographic patterns, and available experience with various separate direct use options. From the composite development scenarios, required numbers of direct and indirect employees and the resultant in-migration patterns are estimated. In-migration patterns are compared to current county level population and ongoing trends in the county population change for each of the four counties. From this comparison, conclusions are drawn concerning the contributions of geothermal resource development to future population levels and the significance of geothermally induced population increase from a county planning perspective.

  3. Workshop on environmental control technology for The Geysers-Calistoga KGRA

    SciTech Connect

    Hill, J.H.; Phelps, P.L.

    1980-01-28

    The proceedings of six work groups that discussed techniques to prevent and abate noise, hydrogen sulfide emissions, and accidental spills of chemicals and geothermal wastes at The Geysers-Calistoga KGRA are reported. Problems associated with well completion and production, and with systems, components, and materials, and their effects on emissions were also discussed. The comments and recommendations of the work groups are included in the proceedings. (MHR)

  4. Geothermal energy and the land resource: conflicts and constraints in The Geysers-Calistoga KGRA

    SciTech Connect

    O'Banion, K.; Hall, C.

    1980-07-14

    This study of potential land-related impacts of geothermal power development in The Geysers region focuses on Lake County because it has most of the undeveloped resource and the least regulatory capability. First, the land resource is characterized in terms of its ecological, hydrological, agricultural, and recreational value; intrinsic natural hazards; and the adequacy of roads and utility systems. Based on those factors, the potential land-use conflicts and constraints that geothermal development may encounter in the region are identified and the availability and relative suitability of land for such development is determined. A brief review of laws and powers germane to geothermal land-use regulation is included.

  5. Geysers.

    ERIC Educational Resources Information Center

    White, Donald E.

    One of a series of general interest publications on science topics, the booklet provides those interested in geysers with a nontechnical introduction to the subject. Separate sections examine the nature and workings of geysers--why geysers erupt, where they occur, the cause of volcanoes and hot springs, the deep circulation of water in geyser…

  6. Tectonic controls on magmatism in the Geysers-Clear Lake region: Evidence from new geophysical models

    USGS Publications Warehouse

    Stanley, W.D.; Benz, H.M.; Walters, M.A.; Villasenor, A.; Rodriguez, B.D.

    1998-01-01

    In order to study magmatism and geothermal systems in The Geysers-Clear Lake region, we developed a detailed three-dimensional tomographic velocity model based on local earthquakes. This high-resolution model resolves the velocity structure of the crust in the region to depths of approximately 12 km. The most significant velocity contrasts in The Geysers-Clear Lake region occur in the steam production area, where high velocities are associated with a Quaternary granitic pluton, and in the Mount Hannah region, where low velocities occur in a 5-km-thick section of Mesozoic argillites. In addition, a more regional tomographic model was developed using traveltimes from earthquakes covering most of northern California. This regional model sampled the whole crust, but at a lower resolution than the local model. The regional model outlines low velocities at depths of 8-12 km in The Geysers-Clear Lake area, which extend eastward to the Coast Range thrust. These low velocities are inferred to be related to unmetamorphosed Mesozoic sedimentary rocks. In addition, the regional velocity model indicates high velocities in the lower crust beneath the Clear Lake volcanic field, which we interpret to be associated with mafic underplating. No large silicic magma chamber is noted in either the local or regional tomographic models. A three-dimensional gravity model also has been developed in the area of the tomographic imaging. Our gravity model demonstrates that all density contrasts can be accounted for in the upper 5-7 km of the crust. Two-dimensional magnetotelluric models of data from a regional, east-west profile indicate high resistivities associated with the granitic pluton in The Geysers production area and low resistivities in the low-velocity section of Mesozoic argillites near Mount Hannah. No indication of midcrustal magma bodies is present in the magnetotelluric data. On the basis of heat flow and geologic evidence, Holocene intrusive activity is thought to have

  7. The impact of H2S emissions on future geothermal power generation - The Geysers region, California

    NASA Technical Reports Server (NTRS)

    Leibowitz, L. P.

    1977-01-01

    The future potential for geothermal power generation in the Geysers region of California is as much as 10 times the current 502 MW(e) capacity. However, environmental factors such as H2S emissions and institutional considerations may play the primary role in determining the rate and ultimate level of development. In this paper a scenario of future geothermal generation capacity and H2S emissions in the Geysers region is presented. Problem areas associated with H2S emissions, H2S abatement processes, plant operations, and government agency resources are described. The impact of H2S emissions on future development and the views of effected organizations are discussed. Potential actions needed to remove these constraints are summarized.

  8. Source Mechanisms of Earthquakes at the Geysers Geothermal Region Using a Hierarchical Bayesian Approach

    NASA Astrophysics Data System (ADS)

    Burky, A.; Mustac, M.; Tkalcic, H.; Dreger, D. S.

    2015-12-01

    The Geysers geothermal region in northern California is a valuable resource for the production of geothermal electric power. Injection of water into the reservoir is necessary to maintain pressure and causes an increase in the number of earthquakes per day, but their source mechanisms are not well understood (Johnson, 2015). Previous studies of source mechanisms for events in the Geysers have identified a large number of events with significant isotropic and compensated linear vector dipole components. These source complexities most likely arise from the presence of pressurized liquids and gases, as well as temperature changes, at depth. The existence of non-double couple components in volcanic and geothermal environments has been extensively documented by previous studies, but it has also been shown that spurious components might occur due to a range of factors such as an inadequate knowledge of Earth structure and earthquake location, or noisy waveform data. Therefore, it is not entirely surprising that non-double-couple components from different source studies, each following a different experimental method and using different data types, do not agree well (e.g. Guilhem et al., 2014). The assessment of the solution robustness is critical for the physical interpretation of source mechanisms.Here, we apply a hierarchical Bayesian approach (Mustac and Tkalcic, 2015) to waveform data from M>4.5 events in the Geysers in order to produce moment tensor "solutions" and simultaneously estimate their robustness. By using a Bayesian inversion, we quantify the uncertainties from an ensemble of probable solutions instead of a single optimized solution and sample solutions at a range of centroid locations. Moreover, the hierarchical approach allows noise in the data to be sampled as a free parameter in the inversion. A rigorous approach in accounting for the data correlated noise covariance matrix prevents "over-interpretation" of noise, thus avoiding erroneous solutions. We

  9. New geophysical models related to heat sources in the geysers-clear lake region, California

    USGS Publications Warehouse

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

    1993-01-01

    We present an updated view of the geological and geophysical complexities of the upper crust in The Geysers-Clear Lake region in order to provide additional information regarding local structures and possible heat sources. New models 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 may be significantly affected by rock-property and physical-state variations in the upper 7 km, and not just to 'magma' at greater depths. We developed the new geophysical models in order to better understand constraints on the location of magma bodies.

  10. Does Geothermal Energy Production Cause Earthquakes in the Geysers Region of Northern California?

    NASA Astrophysics Data System (ADS)

    Grove, K.; Bailey, C.; Sotto, M.; Yu, M.; Cohen, M.

    2003-12-01

    The Geysers region is located in Sonoma County, several hours north of San Francisco. At this location, hot magma beneath the surface heats ground water and creates steam that is used to make electricity. Since 1997, 8 billion gallons of treated wastewater have been injected into the ground, where the water becomes hot and increases the amount of thermal energy that can be produced. Frequent micro-earthquakes (up to magnitude 4.5) occur in the region and seem to be related to the geothermal energy production. The region is mostly uninhabited, except for several small towns such as Anderson Springs, where people have been extremely concerned about potential damage to their property. The energy companies are planning to double the amount of wastewater injected into the ground and to increase their energy production. Geothermal energy is important because it is better for the environment than burning coal, oil, or gas. Air and water pollution, which have negative impacts on living things, are reduced compared to power plants that generate electricity by burning fossil fuels. We have studied the frequency and magnitude of earthquakes that have occurred in the region since the early 1970s and that are occurring today. We used software to analyze the earthquakes and to look for patterns related to water injection and energy production. We are interested in exploring ways that energy production can be continued without having negative impacts on the people in the region.

  11. Using environmental tracers and numerical simulation to investigate regional hydrothermal basins—Norris Geyser Basin area, Yellowstone National Park, USA

    NASA Astrophysics Data System (ADS)

    Gardner, W. Payton; Susong, David D.; Solomon, D. Kip; Heasler, Henry P.

    2013-06-01

    Heat and fluid flow fields are simulated for several conceptual permeability fields and compared to processes inferred from environmental tracers in springs around Norris Geyser Basin, Yellowstone National Park. Large hydrothermal basins require specific permeability distributions in the upper crust. High permeability connections must exist between the land surface and high-temperature environments at depths of up to 5 km. The highest modeled temperatures are produced with a vertical conduit permeability of 10-15m2. Permeability at depths of 3-5 km must be within one order of magnitude of the near-surface permeability and must be ≥10-16m2. Environmental tracers from springs are used to develop a plausible numerical model of the local to regional groundwater flow field for the Norris Geyser Basin area. The model simulations provide insight into the dynamics of heat and fluid flow in a large regional hydrothermal system.

  12. Gravity and magnetic studies of the Geysers-Clear Lake geothermal region, California, USA

    USGS Publications Warehouse

    Isherwood, William F.

    1976-01-01

    Gravity and magnetic fields in The Geysers-Clear Lake region are interpreted in relation to the known geology and other available geophysical data. New gravity data provide additional detail with the area of geothermal steam production. Computer techniques were used for removal of the regional gravity field, anomaly enhancement, and modeling subsurface structures. The gravity field was separated into three components: (1) a regional field presumed to be due to deep crustal structure related to the continental margin; (2) a residual gravity low of approximately 30 mgal centered over Mount Hannah and having an approximate diameter of 20 km, which is caused, according to our model, by a magma chamber whose top lies within 10 km of the surface; and (3) a closed residual low over the original steam production field. This low is probably related to effects within 1.5 km of the surface and was modeled as a steam-saturated reservoir structure. Local magnetic highs correlate with surface outcrops of serpentinite and relief on the volcanic rocks. Upward continuation of the aeromagnetic data suggests that the serpentinite body along the Collayomi fault may extend to a depth of more than 3 km near Boggs Mountain, but that other serpentinite bodies are probably more shallow. A long-wavelength magnetic high (centered at ~39°03'N 122°33'W) and a magnetic low (centered at ~38°:43'N 122°47'W) give half-width depth estimates of about 10 km. The center of the Mount Hannah gravity low lies in an area between these features and appears devoid of deep magnetic expression.

  13. Carbon isotope systematics and CO2 sources in The Geysers-Clear Lake region, northern California, USA

    USGS Publications Warehouse

    Bergfeld, D.; Goff, F.; Janik, C.J.

    2001-01-01

    Carbon isotope analyses of calcite veins, organic carbon, CO2 and CH4 from 96 rock and 46 gas samples show that metamorphic calcite veins and disseminated, organically-derived carbon from Franciscan Complex and Great Valley Sequence rocks have provided a primary carbon source for geothermal fluids during past and present hydrothermal activity across The Geysers-Clear Lake region. The stable isotope compositions of calcite veins vary widely on a regional scale, but overall they document the presence of 13C-poor fluids in early subduction-related vein-precipitating events. ??13C values of calcite veins from the SB-15-D corehole within The Geysers steam field indicate that carbon-bearing fluids in the recent geothermal system have caused the original diverse ??13C values of the veins to be reset. Across The Geysers-Clear Lake region the carbon isotope composition of CO2 gas associated with individual geothermal reservoirs shows a general increasing trend in ??13C values from west to east. In contrast, ??13C values of CH4 do not exhibit any spatial trends. The results from this study indicate that regional variations in ??13C-CO2 values result from differences in the underlying lithologies. Regional CO2 contains significant amounts of carbon related to degradation of organic carbon and dissolution of calcite veins and is not related to equilibrium reactions involving CH4. CO2 from degassing of underlying magma chambers is not recognizable in this region. Published by Elsevier Science Ltd on behalf of CNR.

  14. Sedimentation plan to assess the impact of geothermal activities to the aquatic ecosystem in the Geyers Calistoga KGRA

    SciTech Connect

    Ireland, R.R.

    1981-05-19

    The prevention of sedimentation or siltation in aquatic ecosystems is always a key environmental issue in the development and operation of power plant units. This report describes a field program which will assess the amount of sedimentation in the streams and tributaties of the Geysers-Calistoga Known Geothermal Resource Area (KGRA) due to development-related or other site-specific activities. This sediment plan is one part of a four part venture - the others are water quality, benthic invertebrates and fisheries studies - initiated by the California Energy Commission and involving numerous California organizations. Included in this report are the cost breakdowns for each phase, maps and rationale of the sampling sites, the methodology for the laboratory sample processing, and examples of the type of graphic and tabular output expected.

  15. 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.

  16. Design Study for a Mars Geyser Hopper

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Oleson, Steven J.; McGuire, Melissa

    2012-01-01

    The Mars Geyser Hopper is a design reference missions (DRMs) for a Discovery-class spacecraft using Advanced Stirling Radioisotope Generator (ASRG) power source. The Geyser Hopper is a mission concept that will investigate the springtime carbon-dioxide geysers found in regions around the south pole of Mars. The Geyser Hopper design uses Phoenix heritage systems and approach, but uses a single ASRG as the power source, rather than twin solar arrays, and is designed to last over a one-year stay on the South Pole. The spacecraft will land at a target landing area near the south pole of Mars, and have the ability to "hop" after a summertime landing to reposition itself close to a geyser site, and wait through the winter until the first sunlight of spring to witness first-hand the geyser phenomenon.

  17. The Geysers felsite

    SciTech Connect

    Hulen, J.B.; Nielson, D.L.

    1996-12-31

    The {open_quotes}felsite{close_quotes} is a northwest-trending pluton of batholithic dimensions which underlies and partially hosts The Geysers vapor-dominated geothermal system. It is a composite igneous body with three readily mappable rock types - granite, microgranite porphyry, and late granodiorite. The pluton is affiliated, compositionally and almost certainly in part temporally, with the overlying 1.1 Ma Cobb Mountain volcanic center at the southern margin of the Clear Lake volcanic field, although portions of the intrusive may be at least as old as 1.3-1.4 Ma. Intrusion of the felsite, at the crustal levels explored by drilling, is interpreted to have taken place along periodically reactivated, northwest-trending Cenozoic strike-slip faults. The upper part of the felsite in the central and northwestern Geysers is intensely mineralized with borosilicate (tourmaline plus ferroaxinite), commonly accompanied by potassium metasomatism of the granitic host rocks. These anomalies as well as the geometrically, geochemically, and thermally distinct southeastern and northwestern portions of the steam field are separated by the downward projection of a major northeast-trending regional lineament (the Cobb Creek lineament) which may have formed initially as an antithetic shear in the regional strike-slip fault regime. Steam entries in the felsite are apparently concentrated along the top of and above the granodiorite, and (with notable exceptions) in portions of the pluton relatively impoverished in secondary borosilicates.

  18. Landslide Buries Valley of the Geysers

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Volcanology and Seismology, the new lake appears to be stable and draining gradually through the earthen dam, alleviating fears of a catastrophic flood. Should the new lake drain enough, many of the inundated geysers may restart. Initial reports from the Volcanology and Seismology Institute state this has already happened for some geysers. Geysers outside of the slide region, including the Velikan (Giant) Geyser and a major section of the geyser field known as Vitrazh (Stained Glass) appear to have escaped damage. In addition to destroying a number of geysers, the landslide may have damaged habitats in the Valley of the Geysers. The thermal waters and heated steam jets made this valley warmer than the surrounding landscape, and the warmth supported a unique ecosystem. The loss of a large part of its heat source may alter the ecosystem, but it is not clear what additional longer-term changes might occur. For example, salmon that spawn in the Geyser River will be confined to the lower reaches of the river, and bears, which depended on salmon, will need to shift feeding grounds correspondingly. Thanks to Sergey Chernomorets and Boris Yurchak for information and translation. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  19. Dynamically Triggered Earthquakes in the Geysers Region following the 2014 M6.0 South Napa Earthquake

    NASA Astrophysics Data System (ADS)

    Meng, X.; Peng, Z.; Aiken, C.; Kilb, D.

    2014-12-01

    The 08/24/2014 M6.0 South Napa earthquake is the largest seismic event to strike the San Francisco Bay Area since the 10/17/1989 M6.9 Loma Prieta earthquake. The South Napa event caused severe damage near the epicenter. Based on the Northern California Seismic Network (NCSN) catalog, we find a clear increase of seismicity near the Geysers Geothermal Field following the South Napa event, which is located along its rupture directivity path ~50 km NNW from the hypocenter. Visually inspecting 10 Hz high-pass filtered waveforms at seismic stations near Geysers, we can identify many local earthquakes during the surface waves of the mainshock event that are missing from the NCSN catalog. To obtain a more complete catalog, we apply a recently developed matched filter technique to detect new events within continuous seismic recordings from 74 seismic stations near the Geysers. We use 4000 local earthquakes listed in the NCSN catalog from 06/01/2014 to 09/10/2014 as templates and systematically scan continuous data within ±7 days from the South Napa mainshock. As a result, we detect ~10 times more earthquakes than in the NCSN catalog, and the magnitude of completeness reduces from 0.75 to -0.6. Of the 8091 new events, 28 occurred within the mainshock wavetrain. Depending on the filter used, the first triggered event has an inferred magnitude in the range 3.6-4.0. The intensive seismic activity near the Geysers gradually decays with a p-value of ~0.7 and returns to pre-shock level in about one day. We fit the seismicity rate in the week prior to the South Napa event with the Epidemic Type Aftershock Sequence (ETAS) model and extrapolate to obtain a post-mainshock rate. The observed post-mainshock seismicity rate clearly deviates from the ETAS prediction, which suggests that not all increased seismicity near the Geysers can be explained as aftershocks of the first triggered event. Instead these new events may be associated with stress transients (e.g. creep) or fluid

  20. Geysering in boiling channels

    SciTech Connect

    Aritomi, Masanori; Takemoto, Takatoshi; Chiang, Jing-Hsien

    1995-09-01

    A concept of natural circulation BWRs such as the SBWR has been proposed and seems to be promising in that the primary cooling system can be simplified. The authors have been investigating thermo-hydraulic instabilities which may appear during the start-up in natural circulation BWRs. In our previous works, geysering was investigated in parallel boiling channels for both natural and forced circulations, and its driving mechanism and the effect of system pressure on geysering occurrence were made clear. In this paper, geysering is investigated in a vertical column and a U-shaped vertical column heated in the lower parts. It is clarified from the results that the occurrence mechanism of geysering and the dependence of system pressure on geysering occurrence coincide between parallel boiling channels in circulation systems and vertical columns in non-circulation systems.

  1. Microgravity Propellant Tank Geyser Analysis and Prediction

    NASA Technical Reports Server (NTRS)

    Thornton, Randall J.; Hochstein, John I.; Turner, James E. (Technical Monitor)

    2001-01-01

    An established correlation for geyser height prediction of an axial jet inflow into a microgravity propellant tank was analyzed and an effort to develop an improved correlation was made. The original correlation, developed using data from ethanol flow in small-scale drop tower tests, uses the jet-Weber number and the jet-Bond number to predict geyser height. A new correlation was developed from the same set of experimental data using the jet-Weber number and both the jet-Bond number and tank-Bond number to describe the geyser formation. The resulting correlation produced nearly a 40% reduction in geyser height predictive error compared to the original correlation with experimental data. Two additional tanks were computationally modeled in addition to the small-scale tank used in the drop tower testing. One of these tanks was a 50% enlarged small-scale tank and the other a full-scale 2 m radius tank. Simulations were also run for liquid oxygen and liquid hydrogen. Results indicated that the new correlation outperformed the original correlation in geyser height prediction under most circumstances. The new correlation has also shown a superior ability to recognize the difference between flow patterns II (geyser formation only) and III (pooling at opposite end of tank from the bulk fluid region).

  2. Controls on geyser periodicity.

    PubMed

    Ingebritsen, S E; Rojstaczer, S A

    1993-11-01

    Geyser eruption frequency is not constant over time and has been shown to vary with small (geyser system is approximated as a permeable conduit of intensely fractured rock surrounded by a less permeable rock matrix. Numerical simulation of this conceptual model yields a set of parameters that controls geyser existence and periodicity. Much of the responsiveness to remote seismicity and other small strains in the Earth can be explained in terms of variations in permeability and lateral recharge rates.

  3. Controls on geyser periodicity

    USGS Publications Warehouse

    Ingebritsen, S.E.; Rojstaczer, S.A.

    1993-01-01

    Geyser eruption frequency is not constant over time and has been shown to vary with small (???10-6) strains induced by seismic events, atmospheric loading, and Earth tides. The geyser system is approximated as a permeable conduit of intensely fractured rock surrounded by a less permeable rock matrix. Numerical simulation of this conceptual model yields a set of parameters that controls geyser existence and periodicity. Much of the responsiveness to remote seismicity and other small strains in the Earth can be explained in terms of variations in permeability and lateral recharge rates.

  4. Controls on geyser periodicity.

    PubMed

    Ingebritsen, S E; Rojstaczer, S A

    1993-11-01

    Geyser eruption frequency is not constant over time and has been shown to vary with small (geyser system is approximated as a permeable conduit of intensely fractured rock surrounded by a less permeable rock matrix. Numerical simulation of this conceptual model yields a set of parameters that controls geyser existence and periodicity. Much of the responsiveness to remote seismicity and other small strains in the Earth can be explained in terms of variations in permeability and lateral recharge rates. PMID:17757358

  5. Cumulative biological impacts of The Geysers geothermal development

    SciTech Connect

    Brownell, J.A.

    1981-10-01

    The cumulative nature of current and potential future biological impacts from full geothermal development in the steam-dominated portion of The Geysers-Calistoga KGRA are identified by the California Energy Commission staff. Vegetation, wildlife, and aquatic resources information have been reviewed and evaluated. Impacts and their significance are discussed and staff recommendations presented. Development of 3000 MW of electrical energy will result in direct vegetation losses of 2790 acres, based on an estimate of 11.5% loss per lease-hold of 0.93 acres/MW. If unmitigated, losses will be greater. Indirect vegetation losses and damage occur from steam emissions which contain elements (particularly boron) toxic to vegetation. Other potential impacts include chronic low-level boron exposure, acid rain, local climate modification, and mechanical damage. A potential exists for significant reduction and changes in wildlife from direct habitat loss and development influences. Highly erosive soils create the potential for significant reduction of aquatic resources, particularly game fish. Toxic spills have caused some temporary losses of aquatic species. Staff recommends monitoring and implementation of mitigation measures at all geothermal development stages.

  6. Geysers from the Tiger Stripes of Enceladus

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    Enceladus, the sixth-largest moon of Saturn, is a cold, icy world but its also remarkably active. Recent studies have charted over a hundred geysers venting gas and dust into space from Enceladus south polar region. New research addresses the question of how the moons extreme surface terrain influences the locations and behavior of these geysers.Active PlumesEnceladus orbiting within Saturns E ring. Enceladus plumes probably created this ring. [NASA/JPL/Space Science Institute]A decade ago, scientists discovered that Enceladus south polar region is home to a prominent set of four fractures known as the tiger stripes. This region was found to contain roughly 100 geyser jets, which form plumes of gas and dust venting into space at a combined rate of ~200 kilograms per second! These plumes are probably the source of the material in Saturns E ring, in which Enceladus orbits.Recently, Carolyn Porco (UC Berkeley and CICLOPS Space Science Institute) led a study that analyzed 6.5 years of Cassini data, surveying the locations and orientations of 101 geysers. The outcome was peculiar: the geysers are distributed along the tiger stripes, but their directions are not all pointing vertically from the surface (see the video below!).Now, Paul Helfenstein (Cornell University) has teamed up with Porco to examine whether the surface terrain surrounding the geysers affects where the jets erupt, what direction they point, and even when theyre active.Surface InfluenceHelfenstein and Porco demonstrate that the locations and behavior of the geysers are very likely influenced by Enceladus surface features in this region. In particular, they find:The spacing of the geyser jets on Enceladus is not random.The jets are roughly uniformly distributed along the three most active tiger stripes, spaced about 5 kilometers apart. This fixed spacing might be due to shear fractures produced by fault motion along the tiger stripes cutting across the stripes at regular intervals and providing

  7. Seismic monitoring at the Geysers geothermal field, California

    USGS Publications Warehouse

    Marks, S.M.; Ludwin, R.S.; Louie, K.B.; Bufe, C.G.

    1978-01-01

    Two distinct clusters of microearthquakes have been identified at The Geysers, possibly relating to two independent pressure sinks resulting from steam production described by Lipman, and others (1977). Unlike earthquakes in the Maacama-Rodgers Creek fault zone to the south and west, earthquakes at The Geysers are confined to depths of less than 5 km. The present level of seismicity at The Geysers appears to be higher than the preproduction level and is higher and more continuous than the seismicity in the surrounding region. Earthquakes in the steam production zone at The Geysers resemble earthquakes in the surrounding region with regard to focal plane solutions, source characteristics and magnitude distribution (b slope). Subtle differences in earthquake characteristics may be resolved by analysis of more extensive data now being gathered in the region.

  8. Resource assessment of low- and moderate-temperature geothermal waters in Calistoga, Napa County, California. Report of the second year, 1979-1980

    SciTech Connect

    Youngs, L.G.; Bacon, C.F.; Chapman, R.H.; Chase, G.W.; Higgins, C.T.; Majmundar, H.H.; Taylor, G.C.

    1980-11-10

    Phase I studies included updating and completing the USGS GEOTHERM file for California and compiling all data needed for a California Geothermal Resources Map. Phase II studies included a program to assess the geothermal resource at Calistoga, Napa County, California. The Calistoga effort was comprised of a series of studies involving different disciplines, including geologic, hydrologic, geochemical and geophysical studies.

  9. Enceladus’ Geysers: Relation to Geological Features

    NASA Astrophysics Data System (ADS)

    Helfenstein, Paul; Porco, Carolyn C.

    2015-09-01

    We apply histogram analysis, photogeological methods, and tidal stress modeling to Porco et al.'s survey of 101 Enceladus South Polar Basin geysers and their three-dimensional orientations to test if the jet azimuths are influenced by their placement relative to surface morphology and tectonic structures. Geysers emplaced along the three most active tiger stripe fractures (Damascus Sulcus, Baghdad Sulcus, and Cairo Sulcus) occur in local groupings with relatively uniform nearest-neighbor separation distances (∼5 km). Their placement may be controlled by uniformly spaced en echelon Riedel-type shear cracks originating from left-lateral strike-slip fault motion inferred to occur along tiger stripes. The spacing would imply a lithosphere thickness of ∼5 km in the vicinity of the tiger stripes. The orientations of tilted geyser jets are not randomly distributed; rather their azimuths correlate with the directions either of tiger stripes, cross-cutting fractures, or else fine-scale local tectonic fabrics. Diurnal tidal stress modeling suggests that periodic changes of plume activity are significantly affected by cross-cutting fractures that open and close at different times than the tiger stripes that they intersect. We find evidence of sub-kilometer scale morphological modification of surface geological features surrounding geysers from sublimation-aided erosion, and ablation, and scouring. We propose that the simultaneous crushing and shearing action of periodic transpressional tidal stress on ice condensing on the inside walls of geyser conduits is the mechanism that extrudes the peculiar, paired narrow ridges known as “shark fins” that flank the medial tiger stripe fissures. We present a gallery of high-resolution image mosaics showing the placement of all the jets in their source region and consequently their geological context.

  10. Eruption dynamics of CO2-driven cold-water geysers: Crystal, Tenmile geysers in Utah and Chimayó geyser in New Mexico

    NASA Astrophysics Data System (ADS)

    Watson, Z. T.; Han, Weon Shik; Keating, Elizabeth H.; Jung, Na-Hyun; Lu, Meng

    2014-12-01

    The CO2 bubble volume fraction, eruption velocity, flash depth and mass emission of CO2 were determined from multiple wellbore CO2-driven cold-water geysers (Crystal and Tenmile geysers, in Utah and Chimayó geyser in New Mexico). At shallow depths the bubble volume fraction ranges from 0 to 0.8, eruption velocities range from 2 to 20 m/s and flash depths are predominately shallow ranging from 5 to 40 m below the surface. Annual emission of CO2 is estimated to be (4.77 ± 1.92) ×103, (6.17 ± 1.73) ×101, (6.54 ± 0.57) ×101t/yr for Crystal, Tenmile and Chimayó geysers, respectively. These estimates are coherent with Burnside et al. (2013) showing that the rate of CO2 leakage from wellbores is greater than fault-parallel or diffuse CO2 leakage. The geyser plumbing geometry consists of a vertical wellbore which allows for the upward migration of CO2-rich fluids due to artesian conditions. The positive feedback system of a CO2-driven eruption occurs within the well. Active inflow of CO2 into the regional aquifers through faulted bedrock allows geysering to persist for decades. Crystal geyser erupts for over 24 h at a time, highlighting the potential for a wellbore in a natural environment to reach relatively steady-state high velocity discharge. Mitigating high velocity CO2-driven discharge from wellbores will, however, be easier than mitigating diffuse leakage from faults or into groundwater systems.

  11. Geyser periodicity and the response of geysers to deformation

    USGS Publications Warehouse

    Ingebritsen, S.E.; Rojstaczer, S.A.

    1996-01-01

    Numerical simulations of multiphase fluid and heat transport through a porous medium define combinations of rock properties and boundary conditions which lead to geyser-like periodic discharge. Within the rather narrow range of conditions that allow geyser-like behavior, eruption frequency and discharge are highly sensitive to the intrinsic permeabilities of the geyser conduit and the surrounding rock matrix, to the relative permeability functions assumed, and to pressure gradients in the matrix. In theory, heats pipes (concomitant upward flow of steam and downward flow of liquid) can exist under similar conditions, but our simulations suggest that the periodic solution is more stable. Simulated time series of geyser discharge are chaotic, but integrated quantities such as eruption frequency and mass discharge per eruption are free of chaos. These results may explain the observed sensitivity of natural geysers to small strains such as those caused by remote earthquakes, if ground motion is sufficient to induce permeability changes. Changes in geyser behavior caused by minor preseismic deformation, periodic surface loading, and Earth tides are more difficult to explain in the context of our current model. Copyright 1996 by the American Geophysical Union.

  12. Triggering and modulation of geyser eruptions in Yellowstone National Park by earthquakes, earth tides, and weather

    NASA Astrophysics Data System (ADS)

    Hurwitz, Shaul; Sohn, Robert A.; Luttrell, Karen; Manga, Michael

    2014-03-01

    We analyze intervals between eruptions (IBEs) data acquired between 2001 and 2011 at Daisy and Old Faithful geysers in Yellowstone National Park. We focus our statistical analysis on the response of these geysers to stress perturbations from within the solid earth (earthquakes and earth tides) and from weather (air pressure and temperature, precipitation, and wind). We conclude that (1) the IBEs of these geysers are insensitive to periodic stresses induced by solid earth tides and barometric pressure variations; (2) Daisy (pool geyser) IBEs lengthen by evaporation and heat loss in response to large wind storms and cold air; and (3) Old Faithful (cone geyser) IBEs are not modulated by air temperature and pressure variations, wind, and precipitation, suggesting that the subsurface water column is decoupled from the atmosphere. Dynamic stress changes of 0.1-0.2 MPa resulting from the 2002 M-7.9 Denali, Alaska, earthquake surface waves caused a statistically significant shortening of Daisy geyser's IBEs. Stresses induced by other large global earthquakes during the study period were at least an order of magnitude smaller. In contrast, dynamic stresses of >0.5 MPa from three large regional earthquakes in 1959, 1975, and 1983 caused lengthening of Old Faithful's IBEs. We infer that most subannual geyser IBE variability is dominated by internal processes and interaction with other geysers. The results of this study provide quantitative bounds on the sensitivity of hydrothermal systems to external stress perturbations and have implications for studying the triggering and modulation of volcanic eruptions by external forces.

  13. Earth Tremors Generated by Old Faithful Geyser.

    PubMed

    Rinehart, J S

    1965-10-22

    Several types of earth tremors that could be associated with the eruption cycle of Old Faithful Geyser were registered by a seismograph placed a few meters from the geyser's orifice. Each tremor type was indicative of a specific geyser action. A totally unexpected result was an observed bimodal distribution in frequency of the interval between eruptions.

  14. Earth Tremors Generated by Old Faithful Geyser.

    PubMed

    Rinehart, J S

    1965-10-22

    Several types of earth tremors that could be associated with the eruption cycle of Old Faithful Geyser were registered by a seismograph placed a few meters from the geyser's orifice. Each tremor type was indicative of a specific geyser action. A totally unexpected result was an observed bimodal distribution in frequency of the interval between eruptions. PMID:17842756

  15. Drilling Addendum to Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California

    SciTech Connect

    Taylor, Gary C.; Bacon, C. Forrest; Chapman, Rodger H.; Chase, Gordon W.; Majmundar, Hasmukhrai H.

    1981-05-01

    This addendum report presents the results of the California Division of Mines and Geology (CDMG) drilling program at Calistoga, California, which was the final geothermal-resource assessment investigation performed under terms of the second year contract (1979-80) between the U.S. Department of Energy (DOE) and the CDMG under the State Coupled Program. This report is intended to supplement information presented in CDMG's technical report for the project year, ''Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California''. During the investigative phase of the CDMG's Geothermal Project, over 200 well-driller's reports were obtained from the Department of Water Resources (DWR). It was hoped that the interpretation and correlation of these logs would reveal the subsurface geology of the Upper Napa Valley and also provide a check for the various geophysical surveys that were performed in the course of the study. However, these DWR driller logs proved to be inadequate due to the brief, non-technical, and erroneous descriptions contained on the logs. As a result of the lack of useable drill-hole data, and because information was desired from,deeper horizons, it became evident that drilling some exploratory holes would be necessary in order to obtain physical evidence of the stratigraphy and aquifers in the immediate Calistoga area. Pursuant to this objective, a total of twelve sites were selected--four under jurisdiction of Napa County and eight under jurisdiction of the City of Calistoga. A moratorium is currently in existence within Napa County on most geothermal drilling, and environmental and time constraints precluded CDMG from obtaining the necessary site permits within the county. However, a variance was applied for and obtained from the City of Calistoga to allow CDMG to drill within the city limits. With this areal constraint and also funding limits in mind, six drilling sites were selected on the basis of (1

  16. Understanding the Structure of the Subsurface of the El Tatio Geyser field: A Velocity Model of the El Jefe Geyser from Ambient Seismic Noise

    NASA Astrophysics Data System (ADS)

    LongJohn, T.; Kelly, C.; Seats, K.; Lawrence, J.

    2013-12-01

    Hydrothermal system studies are important for geothermal energy exploration and geysers are also believed to be functional analogues of volcanoes. However, the mechanism of eruption and the characteristics of the plumbing system of most geysers are poorly understood given their subsurface location and sparse global distribution. An accurate acoustic velocity model could yield important insight into subsurface density and thermal variations in a geyser system. Passive seismic data was collected at El Jefe geyser in El Tatio Geyser Field, northern Chile during October of 2012. An array of 6 broadband seismometers and 51 high frequency geophones were deployed for ~1 week in a grid array with station spacing of 2-10 meters (geophones) and 3-50 meters (broadbands) centered around El Jefe Geyser. Using ambient seismic noise generated by the geyser system, I constructed a preliminary subsurface velocity model for El Jefe Geyser. As a result of the close station spacing, the seismic signals sampled shallow depths corresponding to high frequency waves. Coherent seismic records from different seismic station pairs were cross correlated to produce noise correlation functions (NCF). Adaptive covariance filtering and stacking techniques were utilized to amplify the signal of the NCFs and one-dimensional velocities between station pairs at varying depths were determined. Next, a tomographic inversion was done to interpolate between the one-dimensional velocities and produce a three-dimensional velocity model for the entire geyser area. From the velocity model, we can identify regions of low and high acoustic velocity that potentially represent water reservoirs and bedrock respectively.

  17. Volume strain within the Geysers geothermal field

    SciTech Connect

    Mossop, Antony; Segall, Paul

    1999-12-10

    During the 1970s and 1980s. The Geysers geothermal region was rapidly developed as a site of geothermal power production. The likelihood that this could cause significant strain within the reservoir, with corresponding surface displacements, led to a series of deformation monitoring surveys. In 1973, 1975, 1977, and 1980, The Geysers region was surveyed using first-order, class I, spirit leveling. In 1994, 1995, and 1996, many of the leveling control monuments were resurveyed using high-precision Global Positioning System receivers. The two survey methods are reconciled using the GEOID96 geoid model. The displacements are inverted to determine volume strain within the reservoir. For the period 1980-1994, peak volume strains in excess of 5x10{sup -4} are imaged. There is an excellent correlation between the observed changes in reservoir steam pressures and the imaged volume strain. If reservoir pressure changes are inducing volume strain, then the reservoir quasi-static bulk modulus K must be <4.6x10{sup 9} Pa. However, seismic velocities indicate a much stiffer reservoir with K=3.4x10{sup 10} Pa. This apparent discrepancy is shown to be consistent with predicted frequency dependence in K for fractured and water-saturated rock. Inversion of surface deformation data therefore appears to be a powerful method for imaging pressure change within the body of the reservoir. Correlation between induced seismicity at The Geysers and volume strain is observed. However, earthquake distribution does not appear to have a simple relationship with volume strain rate. (c) 1999 American Geophysical Union.

  18. Geologic research at The Geysers

    SciTech Connect

    Hulen, J.B.; Moore, J.N.; Nielson, D.L.

    1996-04-10

    Geologic research at The Geysers vapor-dominated geothermal field during the past year has yielded new information on the nature of steam-reservoir porosity and permeability; the origin of the caprock; mechanisms of lateral sealing; the evolution of The Geysers hydrothermal system; and specific reservoir controls in and immediately above {open_quotes}the felsite{close_quotes}, an hypabyssal, batholith-sized pluton largely responsible for The Geysers` existence. Our research has shown that (1) fluid conduits above the felsite may be dominantly vuggy, high-angle hydrothermal veins; (2) latest-stage hydrothermal calcite in such veins may seal them at the margins of the steam reservoir; mixed-layer clays are probably the corresponding seals in the caprock; (3) steam entries in the felsite are concentrated along the top of the youngest intrusive phase in the pluton - a 1 m.y.-old granodiorite; (4) steam entries in the felsite show a negative correlation with massive borosilicate enrichments.

  19. Resource assessment of low- and moderate-temperature geothermal waters in Calistoga, Napa County, California. Report of the second year, 1979 to 1980 of the US Department of Energy-California State-Coupled Program for reservoir assessment and confirmation

    SciTech Connect

    Youngs, L.G.; Bacon, C.F.; Chapman, R.H.; Chase, G.W.; Higgins, C.T.; Majmundar, H.H.; Taylor, G.C.

    1980-11-10

    Statewide assessment studies included updating and completing the USGS GEOTHERM File for California and compiling all data needed for a California Geothermal Resources Map. Site specific assessment studies included a program to assess the geothermal resource at Calistoga, Napa County, California. The Calistoga effort was comprised of a series of studies involving different disciplines, including geologic, hydrologic, geochemical and geophysical studies.

  20. Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA

    USGS Publications Warehouse

    Hurwitz, Shaul; Hunt, Andrew G.; Evans, William C.

    2012-01-01

    Geysers are rare features that reflect a delicate balance between an abundant supply of water and heat and a unique geometry of fractures and porous rocks. Between April 2007 and September 2008, we sampled Old Faithful, Daisy, Grand, Oblong, and Aurum geysers in Yellowstone National Park's Upper Geyser Basin and characterized temporal variations in major element chemistry and water isotopes (δ18O, δD, 3H). We compare these temporal variations with temporal trends of Geyser Eruption Intervals (GEI). SiO2 concentrations and geothermometry indicate that the geysers are fed by waters ascending from a reservoir with temperatures of ∼190 to 210°C. The studied geysers display small and complex chemical and isotopic seasonal variations, and geysers with smaller volume display larger seasonal variations than geysers with larger volumes. Aurum and Oblong Geysers contain detectable tritium concentrations, suggesting that erupted water contains some modern meteoric water. We propose that seasonal GEI variations result from varying degrees of evaporation, meteoric water recharge, water table fluctuations, and possible hydraulic interaction with the adjacent Firehole River. We demonstrate that the concentrations of major dissolved species in Old Faithful Geyser have remained nearly constant since 1884 despite large changes in Old Faithful's eruption intervals, suggesting that no major changes have occurred in the hydrothermal system of the Upper Geyser Basin for >120 years. Our data set provides a baseline for monitoring future changes in geyser activity that might result from varying climate, earthquakes, and changes in heat flow from the underlying magmatic system.

  1. Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA

    NASA Astrophysics Data System (ADS)

    Hurwitz, Shaul; Hunt, Andrew G.; Evans, William C.

    2012-12-01

    Geysers are rare features that reflect a delicate balance between an abundant supply of water and heat and a unique geometry of fractures and porous rocks. Between April 2007 and September 2008, we sampled Old Faithful, Daisy, Grand, Oblong, and Aurum geysers in Yellowstone National Park's Upper Geyser Basin and characterized temporal variations in major element chemistry and water isotopes (δ18O, δD, 3H). We compare these temporal variations with temporal trends of Geyser Eruption Intervals (GEI). SiO2 concentrations and geothermometry indicate that the geysers are fed by waters ascending from a reservoir with temperatures of ˜190 to 210°C. The studied geysers display small and complex chemical and isotopic seasonal variations, and geysers with smaller volume display larger seasonal variations than geysers with larger volumes. Aurum and Oblong Geysers contain detectable tritium concentrations, suggesting that erupted water contains some modern meteoric water. We propose that seasonal GEI variations result from varying degrees of evaporation, meteoric water recharge, water table fluctuations, and possible hydraulic interaction with the adjacent Firehole River. We demonstrate that the concentrations of major dissolved species in Old Faithful Geyser have remained nearly constant since 1884 despite large changes in Old Faithful's eruption intervals, suggesting that no major changes have occurred in the hydrothermal system of the Upper Geyser Basin for >120 years. Our data set provides a baseline for monitoring future changes in geyser activity that might result from varying climate, earthquakes, and changes in heat flow from the underlying magmatic system.

  2. Geyser's Eruptive Activity in Broadband Seismic Records

    NASA Astrophysics Data System (ADS)

    Kugaenko, Yulia; Saltykov, Vadim

    2010-05-01

    A geyser is a spring characterized by intermittent discharge of water ejected turbulently and accompanied by a vapor phase (steam). The formation of geysers is due to particular hydrogeological conditions, which exist in only a few places on Earth, so they are a fairly rare phenomenon. The reasons of geyser periodicity and specifics of the activity for every particular geyser are not completely clear yet. So almost for all known geysers it is necessary to develop the personal model. In given study we first use seismic method for detection of possible hidden feature of geyser's eruptive activity in Kamchatkan Valley of the Geysers. Broadband seismic records of geyser generated signals were obtained in hydrothermal field. The Valley of the Geysers belongs to Kronotskiy State Natural Biosphere Reserve and the UNESCO World Natural Heritage Site "Volcanoes of Kamchatka". Neither seismological nor geophysical investigations were carried out here earlier. In September, 2009 seismic observation was organized in geyser's field by 24-bit digital output broadband seismometers (GURALP CMG-6TD flat velocity response 0.033-50 Hz). Four geysers were surveyed: the fountain type Big and Giant geysers; the cone type Pearl geyser and the short-period Gap geyser. Seismometers were set as possible close to the geyser's surface vent (usually at the distance near 3-5 m). Main parameters of the eruptions for the investigated geysers: - The Giant geyser is the most powerful among the regular active geysers in Kamchatkan Valley of the Geysers. The height of the fountain reaches 30 meters, the mass of water erupted is about 40-60 tons. The main cycle of activity varies significantly: in 1945 the intervals between eruptions was near 3 hours, nowadays it is 5-6 hours. As a geyser of fountain type, the Giant geyser erupts from the 2*3 m2 pool of water. - The Big geyser was flooded by the lake after the natural catastrophe (giant mud-stone avalanche, formed by landslide, bed into Geiyzernaya

  3. INDUCED SEISMICITY MECHANISM AT THE GEYSERS, CALIFORNIA.

    USGS Publications Warehouse

    Oppenheimer, David

    1985-01-01

    Induced microearthquake activity at The Geysers geothermal reservoir is observed in the vicinity of eight geothermal steam power units. The earthquakes do not align with mapped faults but occur adjacent to steam wells. The sense of motion as deduced from focal mechanisms is strike-slip to reverse in the upper 1 km of the reservoir and changes to strike-slip to oblique normal slip at greater depth because of the increased lithostatic load. Below 1 km the reservoir is undergoing horizontal extension. Alignment of P and T axes with the regional stress field suggests that contraction of the reservoir contributes the incremental stress perturbation to the regional stress field and causes microearthquakes.

  4. Geyser Interaction: Two examples from El Tatio, Chile

    NASA Astrophysics Data System (ADS)

    Munoz Saez, Carolina; Namiki, Atsuko; Manga, Michael

    2015-04-01

    Geysers are eruptive hot springs that episodically discharge steam, liquid water, and non-condensable gases. While hot springs are abundant in geothermal areas, geysers are uncommon and they require special conditions of water supply, heat flow, and fractures and/or porous rocks. Despite more than 200 years of study, there are still open questions about how and why geysers erupt: How is geyser cycle influenced by other adjacent and distant thermal sources? Are hot springs and geyser connected through permeable pathways? Why do only a few hot springs erupt as geysers? We conducted two week-long field studies of geyser interactions in the El Tatio geyser field, Chile during Oct. 2012 and Oct. 2014. We found two different cases: geyser-pool interaction and geyser-geyser interaction. In the first case, we documented how the water level of the pool varies as the geyser eruption evolves. Measured temperature in the geyser conduit has a repeatable pattern, when it reaches boiling the eruption occurs. In contrast, the temperature in the adjacent pool is constant and never reaches the boiling point, suggesting that heat is supplied only to the geyser conduit. Pressure in the geyser conduit and pool have a similar evolution over time so that the side pool acts as a barometer for the conduit. The geyser-geyser interaction was documented in 2014. A geyser with long eruption intervals (1-3 hours) changes the behavior of a short-interval geyser (c.a. 10 minutes). When the long-interval geyser erupts, the short-interval geyser stops erupting. When the eruption of the long-interval geyser becomes less vigorous, the short-interval geyser resumes its eruptions with shorter intervals. During the week of measurements in 2012, we did not observe the short-interval geyser erupting. At that time, the eruption of the long-interval geyser was regular (4 hours and 40 minutes, ref 1). We thus infer that the geyser-geyser interaction made the eruption cycle chaotic. Geyser-pool and geyser-geyser

  5. Modeling Geyser Eruptions in the Classroom

    ERIC Educational Resources Information Center

    Mattox, Stephen; Webster, Christine

    2005-01-01

    Watching Old Faithful transform from a smoldering mound to an explosive 50-meter high geyser is enough to generate awe in any observer. Behind this stunning, visual geologic display is a triad of heat, water, and plumbing that rarely unify on our planet. But geologists are not the only scientists drawn to geysers. Biologists have recently…

  6. The Plausibility of Boiling Geysers on Triton

    NASA Technical Reports Server (NTRS)

    Duxbury, N. S.; Brown, R. H.

    1995-01-01

    A mechanism is suggested and modeled whereby there may be boiling geysers on Triton. The geysers would be of nitrogen considering that Voyager detected cryovolcanic activity, that solid nitrogen conducts heat much less than water ice, and that there is internal heat on Triton.

  7. Geyser Valley on the Kamchatka Peninsula

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On June 2, a devastating mudslide in the world-renowned Geyser Valley on the Kamchatka Peninsula virtually obliterated the natural wonder, forcing the emergency evacuation of visitors and national park personnel. The site, which is the Kamchatka Peninsula's main tourist attraction, consists of some 200 thermal pools created by the area's intense volcanic activity, including about 90 geysers covering an area of four square kilometers (2.5 square miles). It is one of only five sites in the world where the impressive eruptions of steam and boiling-hot water can be found. According to witnesses, a powerful mudslide 1.5 kilometers (one mile) long and 200 meters (600 feet) wide buried more than two-thirds of the valley beneath tens of meters of snow, dirt, trees and boulders (right image), and created a temporary lake submerging more geysers.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is

  8. 18.6-year Earth tide regulates geyser activity.

    PubMed

    Rinehart, J S

    1972-07-28

    Over 40 years of records from Yellowstone National Park, Wyoming, show that the 18.6-year tidal component strongly regulates the frequencies of eruption of Grand and Steamboat geysers. The frequency of Grand Geyser increases with increasing tidal force and that of Steamboat Geyser decreases, which suggests that tidal dilatation is one factor affecting heat flow to a geyser.

  9. 18.6-year Earth tide regulates geyser activity.

    PubMed

    Rinehart, J S

    1972-07-28

    Over 40 years of records from Yellowstone National Park, Wyoming, show that the 18.6-year tidal component strongly regulates the frequencies of eruption of Grand and Steamboat geysers. The frequency of Grand Geyser increases with increasing tidal force and that of Steamboat Geyser decreases, which suggests that tidal dilatation is one factor affecting heat flow to a geyser. PMID:17813197

  10. Triggering and modulation of geyser eruptions in Yellowstone National Park by earthquakes, earth tides, and weather

    USGS Publications Warehouse

    Hurwitz, Shaul; Sohn, Robert A.; Luttrell, Karen; Manga, Michael

    2014-01-01

    We analyze intervals between eruptions (IBEs) data acquired between 2001 and 2011 at Daisy and Old Faithful geysers in Yellowstone National Park. We focus our statistical analysis on the response of these geysers to stress perturbations from within the solid earth (earthquakes and earth tides) and from weather (air pressure and temperature, precipitation, and wind). We conclude that (1) the IBEs of these geysers are insensitive to periodic stresses induced by solid earth tides and barometric pressure variations; (2) Daisy (pool geyser) IBEs lengthen by evaporation and heat loss in response to large wind storms and cold air; and (3) Old Faithful (cone geyser) IBEs are not modulated by air temperature and pressure variations, wind, and precipitation, suggesting that the subsurface water column is decoupled from the atmosphere. Dynamic stress changes of 0.1−0.2 MPa resulting from the 2002 M-7.9 Denali, Alaska, earthquake surface waves caused a statistically significant shortening of Daisy geyser's IBEs. Stresses induced by other large global earthquakes during the study period were at least an order of magnitude smaller. In contrast, dynamic stresses of >0.5 MPa from three large regional earthquakes in 1959, 1975, and 1983 caused lengthening of Old Faithful's IBEs. We infer that most subannual geyser IBE variability is dominated by internal processes and interaction with other geysers. The results of this study provide quantitative bounds on the sensitivity of hydrothermal systems to external stress perturbations and have implications for studying the triggering and modulation of volcanic eruptions by external forces.

  11. How and Why Do Geysers Erupt?

    NASA Astrophysics Data System (ADS)

    Manga, M.

    2014-12-01

    Geysers are features that produce episodic eruptions of water, steam and sometimes non-condensable gases. Natural geysers are rare, with fewer than 1,000 worldwide. They are more than curiosities and popular tourist attractions: they offer a direct window into geothermal processes, and may serve as a natural small-scale laboratory to study larger-scale eruptive process such as those at volcanoes, and other self-organized, intermittent processes that result from phase separation and localized input of energy and mass. Despite > 200 years of scientific study, basic questions remain: Do eruptions begin from the bottom or top of the geyser? What controls eruption duration? Why do eruptions end? What are the required special subsurface geometries? Why are some geysers periodic, and others irregular? How and why do they respond to external influences such as weather, tides, and earthquakes? This presentation will review new insights from field studies at Lone Star geyser, Yellowstone National Park, geysers in the El Tatio geyser field, Chile, and laboratory models. At Lone Star we infer that dynamics are controlled by thermal and mechanical coupling between the conduit and a deeper, laterally-offset reservoir (called a "bubble trap" in previous studies). At El Tatio, we measured pressure and temperature within geysers over multiple eruption cycles: this data document the heating of liquid water by steam delivered from below. The laboratory experiments reveal how episodic release of steam from a bubble trap prepares a conduit for eruption and can generate a range of eruption intensities. In all cases, the eruption initiation, duration and termination are controlled by the interaction between the accumulation and transport of steam and liquid, and modulated by the geometry of the geyser's plumbing. Time series of thousands of eruptions confirm that internal processes control eruptions, with only pool geysers showing a sensitivity to air temperature; only very large stress

  12. Seismic monitoring at The Geysers

    SciTech Connect

    Majer, E.L.; Romero, A.; Vasco, D.; Kirkpatrick, A.; Peterson, J.E.; Zucca, J.J.; Hutchings, L.J.; Kasameyer, P.W.

    1993-04-01

    During the last several years Lawrence Berkeley Laboratory (LBL) and Lawrence Livermore National Laboratory (LLNL) have been working with industry partners at The Geysers geothermal field to evaluate and develop methods for applying the results of microearthquake (MEQ) monitoring. It is a well know fact that seismicity at The Geysers is a common occurrence, however, there have been many studies and papers written on the origin and significance of the seismicity. The attitude toward MEQ data ranges from being nothing more than an curious artifact of the production activities, to being a critical tool in evaluating the reservoir performance. The purpose of the work undertaken b y LBL and LLNL is to evaluate the utility, as well as the methods and procedures used in of MEQ monitoring, recommend the most cost effective implementation of the methods, and if possible link physical processes and parameters to the generation of MEQ activity. To address the objectives above the MEQ work can be categorized into two types of studies. The first type is the direct analysis of the spatial and temporal distribution of MEQ activity and studying the nature of the source function relative to the physical or chemical processes causing the seismicity. The second broad area of study is imaging the reservoir/geothermal areas with the energy created by the MEQ activity and inferring the physical and/or chemical properties within the zone of imaging. The two types of studies have obvious overlap, and for a complete evaluation and development require high quality data from arrays of multicomponent stations. Much of the effort to date at The Geysers by both DOE and the producers has concentrated establishing a high quality data base. It is only within the last several years that this data base is being fully evaluated for the proper and cost effective use of MEQ activity. Presented here are the results to date of DOE`s effort in the acquisition and analysis of the MEQ data.

  13. Enceladus' 101 Geysers: Phantoms? Hardly

    NASA Astrophysics Data System (ADS)

    Porco, C.; Nimmo, F.; DiNino, D.

    2015-12-01

    The discovery by the Cassini mission of present-day geysering activity capping the southern hemisphere of Saturn's moon Enceladus (eg, Porco, C. C. et al. Science 311, 1393, 2006) and sourced within a subsurface body of liquid water (eg, Postberg, F. et al. Nature 459, 1098, 2009; Porco, C.C. et al. AJ 148, 45, 2014, hereafter PEA], laced with organic compounds (eg, Waite, J.H. et al. Science 311, 1419, 2006), has been a significant one, with far-reaching astrobiological implications. In an extensive Cassini imaging survey of the moon's south polar terrain (SPT), PEA identified 101 distinct, narrow jets of small icy particles erupting, with varying strengths, from the four major fractures crossing the SPT. A sufficient spread in stereo angles of the 107 images used in that work allowed (in some cases, many) pair-wise triangulations to be computed; precise surface locations were derived for 98 jets. Recently, it has been claimed (Spitale, J.N. et al. Nature 521, 57, 2015) that the majority of the geysers are not true discrete jets, but are "phantoms" that appear in shallow-angle views of a dense continuous curtain of material with acute bends in it. These authors also concluded that the majority of the eruptive material is not in the form of jets but in the form of fissure-style 'curtain' eruptions. We argue below the contrary, that because almost all the moon's geysers were identified by PEA using multiple images with favorable viewing geometries, the vast majority of them, and likely all, are discrete jets. Specifically, out of 98 jets, no fewer than 90 to 95 were identified with viewing geometries that preclude the appearance of phantoms. How the erupting solids (i.e., icy particles) that are seen in Cassini images are partitioned between jets and inter-jet curtains is still an open question.

  14. Understanding the dynamics of a geyser using seismic ambient noise

    NASA Astrophysics Data System (ADS)

    Cros, Estelle; Roux, Philippe; Vandemeulebrouck, Jean; Kedar, Sharon

    2010-05-01

    between all pairs of seismic stations. The processing of the 10 minutes-long record using a velocity model adapted from S. Kedar's results gave a very stable source at 12 m below the orifice. This location is consistent with in-situ observations using a remote camera made by Hutchinson et al. on 1992 and 1993. The MFP output is well focused, with an accuracy of about 2m. The processing of the seismic signals recorded during an eruptive cycle should lead us to monitor the rise of the boiling region and thus to better understand the geyser's dynamics.

  15. "Geyser" leakage on fluorescein angiography.

    PubMed

    Levy, Jaime; Fagan, Xavier J; Lifshitz, Tova; Schneck, Marina

    2013-11-22

    An 82-year-old patient with diabetes was followed up due to moderate nonproliferative diabetic retinopathy with macular edema in the right eye. Visual acuity was 6/36. Focal macular laser was conducted (A). Three years later, the patient presented with blurry vision in the right eye. Visual acuity was 3/60. Vitreous hemorrhage was observed (B), and neovascularization of the disc was suspected (C). Fluorescein angiography (D, mid venous phase; E-F, recirculation phase) confirmed neovascularization of the disc and depicted a striking vertical leakage. Panretinal photocoagulation was started. Possible explanations for the "geyser" leakage may be either a partial posterior vitreous detachment allowing the fluorescein to track upwards but not elsewhere or a pocket of syneretic vitreous allowing the fluorescein passage in which to diffuse, much like the passage the blood would have taken.

  16. "Geyser" leakage on fluorescein angiography.

    PubMed

    Levy, Jaime; Fagan, Xavier J; Lifshitz, Tova; Schneck, Marina

    2013-01-01

    An 82-year-old patient with diabetes was followed up due to moderate nonproliferative diabetic retinopathy with macular edema in the right eye. Visual acuity was 6/36. Focal macular laser was conducted (A). Three years later, the patient presented with blurry vision in the right eye. Visual acuity was 3/60. Vitreous hemorrhage was observed (B), and neovascularization of the disc was suspected (C). Fluorescein angiography (D, mid venous phase; E-F, recirculation phase) confirmed neovascularization of the disc and depicted a striking vertical leakage. Panretinal photocoagulation was started. Possible explanations for the "geyser" leakage may be either a partial posterior vitreous detachment allowing the fluorescein to track upwards but not elsewhere or a pocket of syneretic vitreous allowing the fluorescein passage in which to diffuse, much like the passage the blood would have taken. PMID:24548789

  17. A simple model for Geyser Flat, Whakarewarewa

    SciTech Connect

    Weir, G.J.; Young, R.M.; McGavin, P.N. )

    1992-04-01

    The work presented in this paper is based on records of geyser activity and other data collected at Geyser Flat, Whakarewarewa, New Zealand. The data is used to used to construct a simple quasi-steady mass, heat, and chemical balance model to account for the interactions between the three geysers Pohutu, Prince of Wales Feathers, Waikorohihi, and the non-eruptive Te Horu cauldron. This model has provided order of magnitude estimates for mass and energy flows, and geyser cavern properties. The importance of the west-south-west wind component on the Te Horu waterlevel is established from the data. Te Horu waterlevels are also shown to correlate significantly with geyser performance. High waterlevels are connected with regular geyser behavior, while low waterlevels are associated with rapid irregular eruptions. Cavern temperatures of 118{degrees} C, 107{degrees} C and 109{degrees} C are inferred from the observed full column plume heights of 20, 8 and 8 meters from Pohutu, Prince of Wales Feathers, and Waikorohihi respectively.

  18. Microgravity Geyser and Flow Field Prediction

    NASA Technical Reports Server (NTRS)

    Hochstein, J. I.; Marchetta, J. G.; Thornton, R. J.

    2006-01-01

    Modeling and prediction of flow fields and geyser formation in microgravity cryogenic propellant tanks was investigated. A computational simulation was used to reproduce the test matrix of experimental results performed by other investigators, as well as to model the flows in a larger tank. An underprediction of geyser height by the model led to a sensitivity study to determine if variations in surface tension coefficient, contact angle, or jet pipe turbulence significantly influence the simulations. It was determined that computational geyser height is not sensitive to slight variations in any of these items. An existing empirical correlation based on dimensionless parameters was re-examined in an effort to improve the accuracy of geyser prediction. This resulted in the proposal for a re-formulation of two dimensionless parameters used in the correlation; the non-dimensional geyser height and the Bond number. It was concluded that the new non-dimensional geyser height shows little promise. Although further data will be required to make a definite judgement, the reformulation of the Bond number provided correlations that are more accurate and appear to be more general than the previously established correlation.

  19. Application of digital image analysis techniques to the Geyser's data and topography

    SciTech Connect

    Porch, W.M.

    1980-05-05

    This paper describes the results of digital image analysis and techniques applied to acoustic sounder data and topographic relief in the Geyser's region. The two dimensional fast Fourier transform (2DFFT) represents the spacial variability of a photographic image. The spacial variability of topography in complex terrain can be represented in this way and insight into degree of complexity and dominating spacial wavelengths can be gained. This was performed for a 16 km square digitized topographic map of the Geyser's region with 63.5 m resolution. It was also of interest to compare facsimile recordings of acoustic sounder data to optical turbulence measurements.

  20. Geysers Characteristics before and after Landslide of June 3-rd, 2007 (Geysers Valley, Kamchatka, Russia)

    NASA Astrophysics Data System (ADS)

    Droznin, V. A.; Kiryukhin, A. V.; Muraviev, J. D.

    2007-12-01

    Since 1990 cycling characteristics of five geysers (Maly, Bolshoy, Shel, Velican, Troynoy) were contentiously monitoring using automatic telemetric system (V A Drosnin, http://www.ch0103.emsd.iks.ru/ ). The most powerful geyser Velikan erupted steam clouds at 300 m height. 1:20 UTC June 3-rd, 2007 lower basin of the Geysers Valley was in a few minutes buried under 10 mln m3 of mud, debris, and blocks of rocks. Some indications were found, that landslide triggered by steam eruption in the upstream area of Vodopadny creek. As a result of this three famous geysers (Pervenets, Sakharny,Troynoy) located at lower elevations were sealed under 10-30 m thick caprock as well as Vodopadny hot creek, a rock dumb trap Geysernaya river and lifted water into 20 m deep lake, which flooded three famous geysers (Conus, Bolshoy and Maly) terminating their cycling activity. Nevertheless Bolshoy and Maly activity continues in a form of discharge of water circulated in the former geysers channels and a clear plume at a lake surface above exits observed. Shortly after landslide continuous monitoring of the cycling characteristics of the upper basin geysers, including Velikan and lake level, accomplished by temperature loggers - restarted. There are some indications time periods of the geysers cycling decrease.

  1. Subsurface energy storage and transport for solar-powered geysers on triton.

    PubMed

    Kirk, R L; Brown, R H; Soderblom, L A

    1990-10-19

    The location of active geyser-like eruptions and related features close to the current subsolar latitude on Triton suggests a solar energy source for these phenomena. Solidstate greenhouse calculations have shown that sunlight can generate substantially elevated subsurface temperatures. A variety of models for the storage of solar energy in a sub-greenhouse layer and for the supply of gas and energy to a geyser are examined. "Leaky greenhouse" models with only vertical gas transport are inconsistent with the observed upper limit on geyser radius of approximately 1.5 kilometers. However, lateral transport of energy by gas flow in a porous N(2) layer with a block size on the order of a meter can supply the required amount of gas to a source region approximately 1 kilometer in radius. The decline of gas output to steady state may occur over a period comparable with the inferred active geyser lifetime of five Earth years. The required subsurface permeability may be maintained by thermal fracturing of the residual N2 polar cap. A lower limit on geyser source radius of approximately 50 to 100 meters predicted by a theory of negatively buoyant jets is not readily attained.

  2. Subsurface energy storage and transport for solar-powered geysers on triton.

    PubMed

    Kirk, R L; Brown, R H; Soderblom, L A

    1990-10-19

    The location of active geyser-like eruptions and related features close to the current subsolar latitude on Triton suggests a solar energy source for these phenomena. Solidstate greenhouse calculations have shown that sunlight can generate substantially elevated subsurface temperatures. A variety of models for the storage of solar energy in a sub-greenhouse layer and for the supply of gas and energy to a geyser are examined. "Leaky greenhouse" models with only vertical gas transport are inconsistent with the observed upper limit on geyser radius of approximately 1.5 kilometers. However, lateral transport of energy by gas flow in a porous N(2) layer with a block size on the order of a meter can supply the required amount of gas to a source region approximately 1 kilometer in radius. The decline of gas output to steady state may occur over a period comparable with the inferred active geyser lifetime of five Earth years. The required subsurface permeability may be maintained by thermal fracturing of the residual N2 polar cap. A lower limit on geyser source radius of approximately 50 to 100 meters predicted by a theory of negatively buoyant jets is not readily attained. PMID:17793019

  3. Subsurface energy storage and transport for solar-powered geysers on Triton

    NASA Technical Reports Server (NTRS)

    Kirk, Randolph L.; Soderblom, Laurence A.; Brown, Robert H.

    1990-01-01

    The location of active geyser-like eruptions and related features close to the current subsolar latitude on Triton suggests a solar energy source for these phenomena. Solid-state greenhouse calculations have shown that sunlight can generate substantially elevated subsurface temperatures. A variety of models for the storage of solar energy in a subgreenhouse layer and for the supply of gas and energy to a geyser are examined. 'Leaky greenhouse' models with only vertical gas transport are inconsistent with the observed upper limit on geyser radius of about 1.5 km. However, lateral transport of energy by gas flow in a porous N2 layer with a block size on the order of a meter can supply the required amount of gas to a source region about 1 km in radius. The decline of gas output to steady state may occur over a period comparable with the inferred active geyser lifetime of 5 earth years. The required subsurface permeability may be maintained by thermal fracturing of the residual N2 polar cap. A lower limit on geyser source radius of about 50 to 100 m predicted by a theory of negatively buoyant jets is not readily attained.

  4. Structure and geotechnical characteristics of landslide of Geyser Valley (Kamchatka)

    NASA Astrophysics Data System (ADS)

    Gvozdeva, I. P.; Alifanova, P. S.; Zerkal, O. V.; Samarin, E. N.

    2010-05-01

    Geyser Valley (the valley of the Geyser River) is one of the most unique nature objects in Russia. There are only four geyser zones in the world. In 2007 in the valley of the Geyser River a large landslide was formed; it destroyed influenced more than a half of all thermal objects. Geyser Valley landslide Formation and displacement of the landslide in Geyser Valley took place 3 June 2007 in the upper reaches of the Vodopadniy creek. According to the observers, the main displacement on the landslide body looked like viscoplastic flow of ground masses and lasted 2,5 minutes. As a result of slope deformations a landslide tongue formed (1,2 -1,5 km length and 0,2-0,4 km width). The landslide surface is uneven, the slope dips do not exceed 100. The whole rock volume involved in displacement is around 4,7 mln m3. Presently the upper part of the landslide consists of different tuff blocks rough to porcelain-like fine-grained rocks. In the lower part of the landslide the type of landslide surface changes, as well as the deposits composing the landslide massif. The surface becomes more even due to the bigger quantity of small fragments and the larger extent of big blocks disintegration. There may be at least two possible reasons for the loss of stability. The first reason is high level of fracturing of the basement rock. Another reason for loss of rock stability is a considerable hydrothermal activity in this region. As the fractured zones are the natural channels for the fluid migration, weakened zones appear along them due to hydrothermal conversion of original rock masses. Initially the slope rock masses represented by tuff-sedimentary rocks are subjected to substantial changes. Converted to the dispersed state, they have various chemical and mineral composition. The content of SiO2 changes 57,4 to 72,8%; Al2O3 - 13,0 to 26,6%; Fe2O3 - 3,9 to 8,6%; CaO - 0,1 to 3,8%; MgO - 0,6 to 3,2%. Among minerals composing these rocks there is a group of clay rocks often forming

  5. Permeability-thickness determination from transient production response at the southeast geysers

    SciTech Connect

    Faulder, D.D.

    1996-08-01

    The Fetkovich production decline curve analysis method was extended for application to vapor-dominated geothermal reservoirs for the purpose of estimating the permeability-thickness product (kh) from the transient production response. The analytic dimensionless terms for pressure, production rate, decline rate, and decline time were derived for saturated steam using the real gas potential and customary geothermal production units of pounds-mass per hour. The derived terms were numerically validating using ``Geysers-line`` reservoir properties at initial water saturation of 0 and at permeabilities of 1, 10, and 100 mD. The production data for 48 wells in the Southeast Geysers were analyzed and the permeability-thickness products determined from the transient production response using the Fetkovich production decline type curve. The kh results were in very good agreement with the published range at the Southeast Geysers and show regions of high permeability-thickness.

  6. Hydrogeologic reconnaissance of the beowawe geysers geothermal area, Nevada

    USGS Publications Warehouse

    Olmsted, F.H.; Rush, F.E.

    1987-01-01

    The Beowawe Geysers in north-central Nevada are the discharge from a hydrothermal-convection system in a region of high heat flow. The site of thermal-fluid upflow (at about 18 kg/s before drilling and well testing) appears to be related to the intersection at depth of two major fault zones. Assuming steady-state conditions, recharge within the drainage basin could account for both thermal and nonthermal ground-water discharge. Circulation of thermal fluid to depths exceeding 5 km is required to attain estimated temperatures of more than 220??C. ?? 1987.

  7. Gas geochemistry of the Geysers geothermal field

    SciTech Connect

    Truesdell, A.H.

    1993-04-01

    Increases in gas concentrations in Central and Southeast Geysers steam are related to the decreases in pressure caused by heavy exploitation in the 1980s. When reservoir pressures in the central parts of the field decreased, high-gas steam from undrilled reservoir margins (and possibly from underlying high-temperature zones) flowed into exploited central areas. The Northwest Geysers reservoir probably lacks high-gas marginal steam and a decline in pressure may not cause a significant increase of gas concentrations in produced steam.

  8. Imaging Seismic Source Variations Using Back-Projection Methods at El Tatio Geyser Field, Northern Chile

    NASA Astrophysics Data System (ADS)

    Kelly, C. L.; Lawrence, J. F.

    2014-12-01

    During October 2012, 51 geophones and 6 broadband seismometers were deployed in an ~50x50m region surrounding a periodically erupting columnar geyser in the El Tatio Geyser Field, Chile. The dense array served as the seismic framework for a collaborative project to study the mechanics of complex hydrothermal systems. Contemporaneously, complementary geophysical measurements (including down-hole temperature and pressure, discharge rates, thermal imaging, water chemistry, and video) were also collected. Located on the western flanks of the Andes Mountains at an elevation of 4200m, El Tatio is the third largest geyser field in the world. Its non-pristine condition makes it an ideal location to perform minutely invasive geophysical studies. The El Jefe Geyser was chosen for its easily accessible conduit and extremely periodic eruption cycle (~120s). During approximately 2 weeks of continuous recording, we recorded ~2500 nighttime eruptions which lack cultural noise from tourism. With ample data, we aim to study how the source varies spatially and temporally during each phase of the geyser's eruption cycle. We are developing a new back-projection processing technique to improve source imaging for diffuse signals. Our method was previously applied to the Sierra Negra Volcano system, which also exhibits repeating harmonic and diffuse seismic sources. We back-project correlated seismic signals from the receivers back to their sources, assuming linear source to receiver paths and a known velocity model (obtained from ambient noise tomography). We apply polarization filters to isolate individual and concurrent geyser energy associated with P and S phases. We generate 4D, time-lapsed images of the geyser source field that illustrate how the source distribution changes through the eruption cycle. We compare images for pre-eruption, co-eruption, post-eruption and quiescent periods. We use our images to assess eruption mechanics in the system (i.e. top-down vs. bottom-up) and

  9. On Recurrent/Homologous Coronal Jets Emission: Coronal Geyser Structures

    NASA Astrophysics Data System (ADS)

    Razvan Paraschiv, Alin; Donea, Alina

    2016-05-01

    Active region 11302 has shown a vast display of solar jets during its lifetime. We examine the emission mechanism responsible for multiple coronal jet events occurring at the center-east side of the active region. Identified jet events were detected in extreme-ultraviolet (EUV), hard X-ray (HXR) and radio emissions, observed by dedicated instruments such as SDO's AIA and HMI, STEREO's EUVI and WAVES, and RHESSI, respectively. We report the detection of a base-arch structure in the lower atmosphere. The site was labelled "Coronal Geyser". The structure had emitted jets quasi-periodically for the entire time the AR was visible in SDO'S field of view. The jets expand into the corona with an apparent line of sight velocity of ~200-300$ km/s. To our knowledge the long time-scale behaviour of jet recurrence and base geyser structure was not previously discussed and data analysis of this phenomena will provide new information for theoretical modelling and data interpretation of jets.

  10. Southeast geysers effluent pipeline project. Final report

    SciTech Connect

    Dellinger, M.

    1998-01-15

    The project concept originated in 1990 with the convergence of two problems: (1) a need for augmented injection to mitigate declining reservoir productivity at the Geysers; and (2) a need for a new method of wastewater disposal for Lake County communities near the The Geysers. A public/private partnership of Geysers operators and the Lake County Sanitation District (LACOSAN) was formed in 1991 to conduct a series of engineering, environmental, and financing studies of transporting treated wastewater effluent from the communities to the southeast portion of The Geysers via a 29-mile pipeline. By 1994, these evaluations concluded that the concept was feasible and the stakeholders proceeded to formally develop the project, including pipeline and associated facilities design; preparation of an environmental impact statement; negotiation of construction and operating agreements; and assembly of $45 million in construction funding from the stakeholders, and from state and federal agencies with related program goals. The project development process culminated in the system`s dedication on October 16, 1997. As of this writing, all project components have been constructed or installed, successfully tested in compliance with design specifications, and are operating satisfactorily.

  11. Evolution of Seismic Geyser, Yellowstone National Park

    USGS Publications Warehouse

    Marler, G. D.; White, D. E.

    1977-01-01

    Among the thousands of thermal springs in Yellowstone Park, Seismic Geyser is one of the few that it totally recent in origin. It is not quiescent or dormant spring that was reactivated; rather it is one that had its genesis as a direct result of the earthquake on August 17, 1959/ 

  12. Draft Genome Sequence of Geobacillus icigianus Strain G1w1T Isolated from Hot Springs in the Valley of Geysers, Kamchatka (Russian Federation).

    PubMed

    Bryanskaya, Alla V; Rozanov, Aleksey S; Logacheva, Maria D; Kotenko, Anastasia V; Peltek, Sergey E

    2014-10-23

    The Geobacillus icigianus G1w1(T) strain was isolated from sludge samples of unnamed vaporing hydrothermal (97°С) outlets situated in a geyser in the Troinoy region (Valley of Geysers, Kronotsky Nature Reserve, Kamchatka, Russian Federation; 54°25'51.40″N, 160°7'41.40″E). The sequenced and annotated genome is 3,457,810 bp and encodes 3,342 genes.

  13. Draft Genome Sequence of Geobacillus icigianus Strain G1w1T Isolated from Hot Springs in the Valley of Geysers, Kamchatka (Russian Federation)

    PubMed Central

    Bryanskaya, Alla V.; Logacheva, Maria D.; Kotenko, Anastasia V.; Peltek, Sergey E.

    2014-01-01

    The Geobacillus icigianus G1w1T strain was isolated from sludge samples of unnamed vaporing hydrothermal (97°С) outlets situated in a geyser in the Troinoy region (Valley of Geysers, Kronotsky Nature Reserve, Kamchatka, Russian Federation; 54°25′51.40″N, 160°7′41.40″E). The sequenced and annotated genome is 3,457,810 bp and encodes 3,342 genes. PMID:25342695

  14. Draft Genome Sequence of Geobacillus icigianus Strain G1w1T Isolated from Hot Springs in the Valley of Geysers, Kamchatka (Russian Federation).

    PubMed

    Bryanskaya, Alla V; Rozanov, Aleksey S; Logacheva, Maria D; Kotenko, Anastasia V; Peltek, Sergey E

    2014-01-01

    The Geobacillus icigianus G1w1(T) strain was isolated from sludge samples of unnamed vaporing hydrothermal (97°С) outlets situated in a geyser in the Troinoy region (Valley of Geysers, Kronotsky Nature Reserve, Kamchatka, Russian Federation; 54°25'51.40″N, 160°7'41.40″E). The sequenced and annotated genome is 3,457,810 bp and encodes 3,342 genes. PMID:25342695

  15. Water discharge from Lone Star Geyser, Yellowstone NP, WY

    NASA Astrophysics Data System (ADS)

    Murphy, F.; Randolph-Flagg, N. G.; Hurwitz, S.

    2014-12-01

    During four days in April, 2014 we made a series of measurements at Lone Star Geyser in Yellowstone National Park, WY. This work included the continuous measurement of liquid water discharge from the geyser and some nearby not springs, and concurrent meteorological measurements. The discharge of the geyser and the hot springs was measured in channels that carry the water to the Firehole River. We found that average measured discharge varies from day to night, likely due to melting of geyser-generated and meteoric snow during warmer daylight hours and freezing of erupted liquid and vapor during the night. The nearby hot springs contribute a nearly constant flow of about 3 l/s to the Firehole River, while during eruptions the total discharge increases to a maximum of about 25 l/s. Two small geysers within 5 meters of the Lone Star Geyser cone were observed to erupt during a time when Lone Star Geyser was not erupting. The water discharged from these small geysers is a very small fraction of that from Lone Star Geyser.

  16. Wine Valley Inn: A mineral water spa in Calistoga, California. Geothermal-energy-system conceptual design and economic feasibility

    SciTech Connect

    Not Available

    1981-10-26

    The purpose of this study is to determine the engineering and economic feasibility for utilizing geothermal energy for air conditioning and service water heating at the Wine Valley Inn, a mineral water spa in Calistoga, California. The study evaluates heating, ventilating, air conditioning and water heating systems suitable for direct heat geothermal application. Due to the excellent geothermal temperatures available at this site, the mechanics and economics of a geothermally powered chilled water cooling system are evaluated. The Wine Valley Inn has the resource potential to have one of the few totally geothermal powered air conditioning and water heating systems in the world. This total concept is completely developed. A water plan was prepared to determine the quantity of water required for fresh water well development based on the special requirements of the project. An economic evaluation of the system is included to justify the added capital investment needed to build the geothermally powered mineral spa. Energy payback calculations are presented. A thermal cascade system is proposed to direct the geothermal water through the energy system to first power the chiller, then the space heating system, domestic hot water, the two spas and finally to heat the swimming pool. The Energy Management strategy required to automatically control this cascade process using industrial quality micro-processor equipment is described. Energy Management controls are selected to keep equipment sizing at a minimum, pump only the amount of geothermal water needed and be self balancing.

  17. Subsurface steam sampling in Geysers wells

    SciTech Connect

    Lysne, P.; Koenig, B.; Hirtz, P.; Normann, R.; Henfling, J.

    1997-01-01

    A new downhole sampling tool has been built for use in steam wells at The Geysers geothermal reservoir. The tool condenses specimens into an initially evacuated vessel that is opened down hole at the direction of an on-board computer. The tool makes a temperature log of the well as it is deployed, and the pressure and temperature of collected specimens are monitored for diagnostic purposes. Initial tests were encouraging, and the Department of Energy has funded an expanded effort that includes data gathering needed to develop a three-dimensional model of The Geysers geochemical environment. Collected data will be useful for understanding the origins of hydrogen chloride and non-condensable gases in the steam, as well as tracking the effect of injection on the composition of produced steam. Interested parties are invited to observe the work and to join the program.

  18. A database for the Geysers geothermal field

    SciTech Connect

    Ripperda, M.; Bodvarsson, G.S.

    1988-10-01

    A general use menu driven software package has been developed that stores and retrieves geothermal field data and produces a large variety of graphic displays. These include, for example, production plots, cross-sections, contour plots, base maps and Horner plots. This software package has been applied to the Geysers geothermal field which has open file data for over 200 wells. The data include production histories, directional surveys, lithology logs, wellhead temperatures and pressures, digitized base maps, steam entry locations, casing diagrams, pressure transient tests, heat flow measurements and noncondensible gas concentrations. Although the software was developed for use with data from the Geysers, it can be used with data from any geothermal reservoir. 2 refs., 5 figs.

  19. Physical interpretation of geysering phenomena and periodic boiling instability at low flows

    SciTech Connect

    Duffey, R.B.; Rohatgi, U.S.

    1996-03-01

    Over 30 years ago, Griffith showed that unstable and periodic initial boiling occurred in stagnant liquids in heated pipes coupled to a cooler or condensing plenum volume. This was called ``geysering``, and is a similar phenomenon to the rapid nucleation and voiding observed in tubes filled with superheated liquid. It is also called ``bumping`` when non-uniformly heated water or a chemical suddenly boils in laboratory glassware. In engineering, the stability and predictability has importance to the onset of bulk boiling in a natural and forced circulation loops. The latest available data show the observed stability and periodicity of the onset of boiling flow when there is a plenum, multiple heated channels, and a sustained subcooling in a circulating loop. We examine the available data, both old and new, and develop a new theory to illustrate the simple physics causing the observed periodicity of the flow. We examine the validity of the theory by comparison to all the geysering data, and develop a useful and simple correlation. We illustrate the equivalence of the onset of geysering to the onset of static instability in subcooled boiling. We also derive the stability boundary for geysering, utilizing turbulent transport analysis to determine the effects of pressure and other key parameters. This new result explains the greater stability region observed at higher pressures. The paper builds on the 30 years of quite independent thermal hydraulic work that is still fresh and useful today. We discuss the physical interpretation of geysering onset with a consistent theory, and show where refinements would be useful to the data correlations.

  20. A database for The Geysers geothermal field

    SciTech Connect

    Bodvarsson, G.S.; Cox, B.L.; Fuller, P.; Ripperda, M.; Tulinius, H.; Witherspoon, P.A.; Goldstein, N.; Flexser, S.; Pruess, K. ); Truesdell, A. )

    1989-09-01

    In Fiscal Year 1985-1986 the Earth Sciences Division of Lawrence Berkeley Laboratory (LBL) began a multi-year project for SLC to organize and analyze the field data from The Geysers. In the first year, most of the work concentrated on the development of a comprehensive database for The Geysers, and conventional reservoir engineering analysis of the data. Essentially, all non-proprietary data for wells at The Geysers have been incorporated into the database, as well as proprietary data from wells located on State leases. In following years, a more detailed analysis of The Geysers data has been carried out. This report is a summary of the non- proprietary work performed in FY 1985--1986. It describes various aspects of the database and also includes: review sections on Field Development, Geology, Geophysics, Geochemistry and Reservoir Engineering. It should be emphasized that these background chapters were written in 1986, and therefore only summarize the information available at that time. The appendices contain individual plots of wellhead pressures, degree of superheat, steam flow rates, cumulative mass flows, injection rates and cumulative injection through 1988 for approximately 250 wells. All of the data contained in this report are non-proprietary, from State and non-State leases. The production/injection and heat flow data from the wells were obtained from the California State Division of Oil and gas (DOG) (courtesy of Dick Thomas). Most of the other data were obtained from SLC files in Sacramento (courtesy of Charles Priddy), or DOG files in Santa Rosa (courtesy of Ken Stelling). 159 refs., 23 figs., 3 tabs.

  1. Geysers advanced direct contact condenser research

    SciTech Connect

    Henderson, J.; Bahning, T.; Bharathan, D.

    1997-12-31

    The first geothermal application of the Advanced Direct Contact Condenser (ADCC) technology developed by the National Renewable Energy Laboratory (NREL) is now operational and is being tested at The Geysers Power Plant Unit 11. This major research effort is being supported through the combined efforts of NREL, The Department of Energy (DOE), and Pacific Gas and Electric (PG&E). NREL and PG&E have entered into a Cooperative Research And Development Agreement (CRADA) for a project to improve the direct-contact condenser performance at The Geysers Power Plant. This project is the first geothermal adaptation of an advanced condenser design developed for the Ocean Thermal Energy Conversion (OTEC) systems. PG&E expects this technology to improve power plant performance and to help extend the life of the steam field by using steam more efficiently. In accordance with the CRADA, no money is transferred between the contracting parties. In this case the Department of Energy is funding NREL for their efforts in this project and PG&E is contributing funds in kind. Successful application of this technology at The Geysers will provide a basis for NREL to continue to develop this technology for other geothermal and fossil power plant systems.

  2. Reservoir assessment of The Geysers Geothermal field

    SciTech Connect

    Thomas, R.P.; Chapman, R.H.; Dykstra, H.

    1981-01-01

    Big Sulphur Creek fault zone, in The Geysers Geothermal field, may be part of a deep-seated, wrench-style fault system. Hydrothermal fluid in the field reservoir may rise through conduits beneath the five main anomalies associated with the Big Sulphur Creek wrench trend. Some geophysical anomalies (electrical resistivity and audio-magnetotelluric) evidently are caused by the hot water geothermal field or zones of altered rocks; others (gravity, P-wave delays, and possibly electrical resistivity) probably respresent the underlying heat source, a possible magma chamber; and others (microearthquake activity) may be related to the steam reservoir. A large negative gravity anomaly and a few low-resistivity anomalies suggest areas generally favorable for the presence of steam zones, but these anomalies apparently do not directly indicate the known steam reservoir. At the current generating capacity of 930 MWe, the estimated life of The Geysers Geothermal field reservoir is 129 years. The estimated reservoir life is 60 years for the anticipated maximum generating capacity of 2000 MWe as of 1990. Wells at The Geysers are drilled with conventional drilling fluid (mud) until the top of the steam reservoir is reached; then, they are drilled with air. Usually, mud, temperature, caliper, dual induction, and cement bond logs are run on the wells.

  3. A Multi-Method Experiment to Investigate Geyser Dynamics: Lone Star Geyser, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Hurwitz, S.; Vandemeulebrouck, J.; Johnston, M. J.; Sohn, R. A.; Karlstrom, L.; Rudolph, M. L.; Murphy, F.; McPhee, D. K.; Glen, J. M.; Soule, S. A.; Pontbriand, C.; Meertens, C. M.

    2011-12-01

    Geysers are intermittently discharging hot springs that are driven by steam and non-condensable gas. They provide unique opportunities to study multiphase eruption processes and the geophysical signals they induce. In September 2010 we carried out a four-day experiment at Lone Star Geyser in Yellowstone National Park. The geyser is located about 5 km SSE of Old Faithful Geyser and 75 m north of the Upper Firehole River. Lone Star is a cone geyser that was selected for the experiment because it is isolated from other geysers, its eruptions are vigorous and voluminous, and its eruption intervals are relatively constant and predictable, occurring approximately every 3 hours. We made measurements during 32 eruption cycles using a suite of instruments including a broadband seismometer, 2 microphones, 5 platform tiltmeters, 3 collimating InfraRed sensors, 2 gravimeters, 2 self-potential sensors, 2 Light Detection And Ranging (LiDAR) scanners, a Forward Looking InfraRed (FLIR) camera, high-speed video cameras, and stream gauging. We also integrated meteorological data from nearby weather stations. The large dataset acquired during the experiment allows for the detection of a myriad of processes in the subsurface and in the erupting column at many different frequencies. The analyzed data yield new insights on multiphase eruptive processes that have implications for understanding self-organized, intermittent processes in nature that result from phase separation and localized input of energy and mass. The geophysical signals recorded during the experiment allow comparison with signals recorded in more complex volcanic systems where gas-driven and magma-driven processes are often hard to distinguish.

  4. Bimodal Distribution of Geyser Preplay Eruptions: Lone Star Geyser, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Namiki, A.; Hurwitz, S.; Murphy, F.; Manga, M.

    2014-12-01

    Geyser eruption intervals are determined by rates of water and heat discharge into shallow subsurface reservoirs and the conduit. In some geysers, small amounts of water discharge prior to a main eruption ('Preplay') can affect eruption intervals. Water discharge during preplay reduces the hydrostatic pressure, which in turn, induces boiling of water that is at, or near the critical temperature. Ascending steam slugs from depth can also lead to shorter eruption intervals (Namiki et al., 2014). In April 2014, we carried a five day experiment at Lone Star Geyser, Yellowstone National Park. Eruptions and their preplays were recorded with an infrared sensor that measured temperature variations immediately above the geyser cone (3.4~m high), temperature loggers that measured water temperature at the base of the cone and in the outflow channels, and visual observations. At Lone Star Geyser, during the preplay phase of the eruption, mainly liquid water is erupted, whereas the main phase of the eruption begins with the liquid-water dominated eruption and turns into the steam discharge. The temperature rise in an outflow channel indicates the occurrence of preplays and initiation of the main eruption. The acquired data suggests that the preplay patterns of Lone Star Geyser are vigorous and complex, consistent with previous observations (Karlstrom et al., 2013). Our new observations reveal two typical styles: 1) vigorous preplays with few events (<5) and long intervals (>20~minutes) that last approximately 40~minutes, and 2) less vigorous preplays that include several events (>5) with short intervals (few minutes), and continue approximately for one hour. Probability distributions of preplay durations show two peaks indicating the bimodal activity. The bimodality of Lone Star preplays may be a result of subtle change of temperature distribution in a convecting reservoir which has been observed in laboratory experiments (Toramaru and Maeda, 2013).

  5. Analysis of noise-induced eruptions in a geyser model

    NASA Astrophysics Data System (ADS)

    Alexandrov, Dmitri V.; Bashkirtseva, Irina A.; Ryashko, Lev B.

    2016-03-01

    Motivated by important geophysical applications we study a non-linear model of geyser dynamics under the influence of external stochastic forcing. It is shown that the deterministic dynamics is substantially dependent on system parameters leading to the following evolutionary scenaria: (i) oscillations near a stable equilibrium and a transient tendency of the phase trajectories to a spiral sink or a stable node (pre-eruption regime), and (ii) fast escape from equilibrium (eruption regime). Even a small noise changes the system dynamics drastically. Namely, a low-intensity noise generates the small amplitude stochastic oscillations in the regions adjoining to the stable equilibrium point. A small buildup of noise intensity throws the system over its separatrix and leads to eruption. The role of the friction coefficient and relative pressure in the deterministic and stochastic dynamics is studied by direct numerical simulations and stochastic sensitivity functions technique.

  6. Reservoir Fracturing in the Geysers Hydrothermal System: Fact or Fallacy?

    SciTech Connect

    Hebein, Jeffrey J.

    1986-01-21

    Proper application of proven worldwide fracture determination analyses adequately aids in the detection and enhanced exploitation of reservoir fractures in The Geysers steam field. Obsolete, superficial ideas concerning fracturing in this resource have guided various malformed judgements of the actual elusive trends. Utilizing regional/local tectonics with theoretical rack mechanics and drilling statistics, offers the most favorable method of fracture comprehension. Exploitation philosophies should favor lateral drilling trends along local tensional components and under specific profound drainage/faulting manifestations to enhance high productivities. Drill core observations demonstrate various degrees of fracture filling, brecciation, strain responses, and rock fracture properties, giving the most favorable impression of subsurface reservoir conditions. Considerably more work utilizing current fracturing principles and geologic thought is required to adequately comprehend and economically exploit this huge complex resource.

  7. Testing Geyser Models using Down-vent Data

    NASA Astrophysics Data System (ADS)

    Wang, C.; Munoz, C.; Ingebritsen, S.; King, E.

    2013-12-01

    Geysers are often studied as an analogue to magmatic volcanoes because both involve the transfer of mass and energy that leads to eruption. Several conceptual models have been proposed to explain geyser eruption, but no definitive test has been performed largely due to scarcity of down-vent data. In this study we compare simulated time histories of pressure and temperature against published data for the Old Faithful geyser in the Yellowstone National Park and new down-vent measurements from geysers in the El Tatio geyser field of northern Chile. We test two major types of geyser models by comparing simulated and field results. In the chamber model, the geyser system is approximated as a fissure-like conduit connected to a subsurface chamber of water and steam. Heat supplied to the chamber causes water to boil and drives geyser eruptions. Here the Navier-Stokes equation is used to simulate the flow of water and steam. In the fracture-zone model, the geyser system is approximated as a saturated fracture zone of high permeability and compressibility, surrounded by rock matrix of relatively low permeability and compressibility. Heat supply from below causes pore water to boil and drives geyser eruption. Here a two-phase form of Darcy's law is assumed to describe the flow of water and steam (Ingebritsen and Rojstaczer, 1993). Both models can produce P-T time histories qualitatively similar to field results, but the simulations are sensitive to assumed parameters. Results from the chamber model are sensitive to the heat supplied to the system and to the width of the conduit, while results from the fracture-zone model are most sensitive to the permeability of the fracture zone and the adjacent wall rocks. Detailed comparison between field and simulated results, such as the phase lag between changes of pressure and temperature, may help to resolve which model might be more realistic.

  8. Variability in geyser eruptive timing and its causes: Yellowstone National Park

    USGS Publications Warehouse

    Rojstaczer, S.; Galloway, D.L.; Ingebritsen, S.E.; Rubin, D.M.

    2003-01-01

    Field data from Upper Geyser Basin, Yellowstone, indicate that geyser frequency is less sensitive to elastic deformation than might be surmised from a review of the literature. Earth-tide influences are not identifiable in any of the geysers we monitored. Though atmospheric-pressure influences are observed, only long-period variations on the order of 5 mBars or greater seem to influence geyser frequency. Long-distance interconnections between geysers are common and add to the difficulty of identifying strain influences. Additional variations in geyser periodicity may be governed by the internal dynamics of the geysers rather than external influences.

  9. Monitoring crustal deformation in The Geysers-Clear Lake geothermal area, California

    USGS Publications Warehouse

    Lofgren, Ben Elder

    1978-01-01

    Geodetic surveys since 1972-73 reveal significant crustal deformation in The Geysers-Clear Lake region. Resurveys of precise control networks are measuring both vertical and horizontal ground movement, with most of the change continuing in the area of geothermal fluid withdrawal. Preliminary evidence suggests right-lateral horizontal movement on northwest-trending fault systems and vertical and horizontal compression of the deep geothermal reservoir system. A direct correlation is suggested between ground-surface deformation and subsurface pressure changes in the reservoir system. Although surface changes appear too small to be of environmental concern in The Geysers-Clear Lake region, they indicate hydrodynamic changes in the reservoir of significant import. Two types of vertical changes in The Geysers production area are indicated in the 1973-77 data--(a) a regional subsidence between the Collayomi and Mercuryville fault zones and (b) local subsidence directly related to the area of principal steam production. Maximum subsidence of 13 centimeters in 4? years occurred in the area of most concentrated steam withdrawals and where fluid-pressure declines were near maximum. Subsidence rates throughout the production area from 1973 to 1975 were about half the 1975-77 rates in apparent correlation with pressure changes measured in the reservoir system. Horizontal ground movement as great as 2.0 centimeters per year, generally inward toward the center of production, was measured around the perimeter of the steam production area.

  10. Back-Projecting Volcano and Geyser Seismic Signals to Sources

    NASA Astrophysics Data System (ADS)

    Kelly, C. L.; Lawrence, J. F.; Ebinger, C. J.

    2015-12-01

    Volcanic and hydrothermal systems are generally characterized by persistent, low-amplitude seismic "noise" with no clear onset or end. Outside of active eruptions and earthquakes, which tend to occur only a small fraction of the time, seismic records and spectrograms from these systems are dominated by long-duration "noise" (typically around 1-5Hz) generated by ongoing processes in the systems' subsurface. Although it has been shown that these low-amplitude signals can represent a series of overlapping low-magnitude displacements related to fluid and volatile movement at depth, because of their "noisy" properties compared to typical active or earthquake sources they are difficult to image using traditional seismic techniques (i.e. phase-picking). In this study we present results from applying a new ambient noise back-projection technique to improve seismic source imaging of diffuse signals found in volcanic and hydrothermal systems. Using this new method we show how the distribution of all seismic sources - particularly sources associated with volcanic tremor - evolves during a proposed intrusion in early June 2010 at Sierra Negra Volcano on the Galápagos Archipelago off the coast of Ecuador. We use a known velocity model for the region (Tepp et al., 2014) to correlate and back-project seismic signals from all available receiver-pairs to potential subsurface source locations assuming bending raypaths and accounting for topography. We generate 4D time-lapsed images of the source field around Sierra Negra before, during and after the proposed intrusion and compare the consistency of our observations with previously identified seismic event locations and tomography results from the same time period. Preliminary results from applying the technique to a dense grid of geophones surrounding a periodically erupting geyser at El Tatio Geyser Field in northern Chile (>2000 eruptions recorded) will also be presented.

  11. 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

  12. Theory of the geyser-pump solar collector. Final report

    SciTech Connect

    Haines, E.

    1985-01-01

    The geyser-pump solar collector is a self-controlling, self-pumping active collector having no moving or electronic parts, drawing its mechanical pump energy from boiling in the collector's risers. The only use of the geyser-pump principle reported in patents and the open literature is only for circulating the fluid in the collector plate. Computer simulations show that most design and algorithm parameters have only negligible impact on solar fraction, F. The only parameter which affects F is the length of the storage heat exchanger. Episodic cloud cover does not hamper the geyser-pump collector's ability to restart. Daylong simulations show that the energy cost of geyser-pumping is only about 3% of the absorbed insolation. The geyser-pump collector is found to be as efficient as an electrically pumped collector. Initial costs are estimated to be about the same for the geyser-pump and conventional collectors, but lifetime costs of the geyser-pump are substantially lower, perhaps only half, because of low maintenance.

  13. Statistical analysis of summer winds in Geysers area prior to ASCOT 1979 experiment

    SciTech Connect

    Porch, W.M.; Walton, J.J.

    1980-02-01

    Statistical analytical techniques were tested on 73 days and 16 stations of hourly data for the summer of 1977. These stations were located in the region surrounding the Geysers geothermal area. Principal components analysis (PCA) was used to define typical wind patterns in the region and to determine typical days for each station. Power spectral analysis was used to quantify the temporal variation of winds at Anderson Ridge and Anderson Springs (two stations included in the ASCOT 1979 study in the local region of Anderson Creek with very different terrain exposures). These results will help determine year to year difference in the wind fields in the ASCOT study region of complex terrain.

  14. How the geysers, tidal stresses, and thermal emission across the south polar terrain of enceladus are related

    SciTech Connect

    Porco, Carolyn; DiNino, Daiana; Nimmo, Francis

    2014-09-01

    We present the first comprehensive examination of the geysering, tidal stresses, and anomalous thermal emission across the south pole of Enceladus and discuss the implications for the moon's thermal history and interior structure. A 6.5 yr survey of the moon's south polar terrain (SPT) by the Cassini imaging experiment has located ∼100 jets or geysers erupting from four prominent fractures crossing the region. Comparing these results with predictions of diurnally varying tidal stresses and with Cassini low resolution thermal maps shows that all three phenomena are spatially correlated. The coincidence of individual jets with very small (∼10 m) hot spots detected in high resolution Cassini VIMS data strongly suggests that the heat accompanying the geysers is not produced by shearing in the upper brittle layer but rather is transported, in the form of latent heat, from a sub-ice-shell sea of liquid water, with vapor condensing on the near-surface walls of the fractures. Normal stresses modulate the geysering activity, as shown in the accompanying paper; we demonstrate here they are capable of opening water-filled cracks all the way down to the sea. If Enceladus' eccentricity and heat production are in steady state today, the currently erupting material and anomalous heat must have been produced in an earlier epoch. If regional tidal heating is occurring today, it may be responsible for some of the erupting water and heat. Future Cassini observations may settle the question.

  15. An experimental study of geyser-like flows induced by a pressurized air pocket

    NASA Astrophysics Data System (ADS)

    Elayeb, I. S.; Leon, A.; Choi, Y.; Alnahit, A. O.

    2015-12-01

    Previous studies argues that the entrapment of pressurized air pockets within combined sewer systems can produce geyser flows, which is an oscillating jetting of a mixture of gas-liquid flows. To verify that pressurized air pockets can effectively produce geysers, laboratory experiments were conducted. However, past experiments were conducted in relatively small-scale apparatus (i.e. maximum φ2" vertical shaft). This study conducted a set of experiments in a larger apparatus. The experimental setup consists of an upstream head tank, a downstream head tank, a horizontal pipe (46.5ft long, φ6") and a vertical pipe (10ft long, φ6"). The initial condition for the experiments is constant flow discharge through the horizontal pipe. The experiments are initiated by injecting an air pocket with pre-determined volume and pressure at the upstream end of the horizontal pipe. The air pocket propagates through the horizontal pipe until it arrives to the vertical shaft, where it is released producing a geyser-like flow. Three flow rates in the horizontal pipe and three injected air pressures were tested. The variables measured were pressure at two locations in the horizontal pipe and two locations in the vertical pipe. High resolution videos at two regions in the vertical shaft were also recorded. To gain further insights in the physics of air-water interaction, the laboratory experiments were complemented with numerical simulations conducted using a commercial 3D CFD model, previously validated with experiments.

  16. Seismic monitoring at the Geysers Geothermal Field

    SciTech Connect

    Romero, A.E. Jr.; Kirkpatrick, A.; Majer, E.L.; Peterson, J.E. Jr.

    1994-09-01

    This report summarizes the efforts of LBL to utilize MEQ data in reservoir definition as well as in evaluating its performance. Results of the study indicate that the velocity and attenuation variations correlate with the known geology of the field. At the NW Geysers, high velocity anomalies correspond to metagraywacke and greenstone units while low velocity anomalies seem to be associated with Franciscan melanges. Low Vp/Vs and high attenuation delineate the steam reservoir suggesting undersaturation of the reservoir rocks. Ongoing monitoring of Vp/Vs may be useful in tracking the expansion of the steam zone with time. Spatial and temporal patterns of seismicity exhibit compelling correlation with geothermal exploitation. Clusters of MEQs occur beneath active injection wells and appear to shift with changing injection activities. High resolution MEQ locations hold promise for inferring fluid flow paths, especially in tracking injectate. This study has demonstrated that continuous seismic monitoring may be useful as an active reservoir management tool.

  17. Geologic research at the Geysers -- 1996

    SciTech Connect

    Hulen, J.B.

    1997-12-31

    In response to the onset of field-wide pressure declines at The Geysers geothermal field in northern California the Department of Energy`s Geothermal Division in 1990 inaugurated sponsorship of a dedicated, multiyear research effort designed to mitigate the pressure drop and to allow steamfield operators to make more informed forecasts of steam supply and quality well into the 21st century. EGI and its predecessor, the University of Utah Research Institute, have from the onset been key participants in this important research effort. For example, utilizing fluid-inclusion and stable-isotopic methods, deciphered the field`s intricate magmatic-hydrothermal history. Hulen et al. (1991, 1992) and Hulen and Nielson (1995a) identified major textural and mineralogic differences between the productive steam reservoir and its relatively impermeable caprock.

  18. Strength measurements of The Geysers reservoir rock

    SciTech Connect

    Lockner, D.A.; Byerlee, J.D.

    1980-09-01

    Rock samples taken from two outcrops and cores from well bores at the Geysers geothermal field were tested at temperatures and pressures similar to those found in the field. Both intact cylinders and cylinders containing 30/sup 0/ sawcuts were deformed at confining pressures of 200 to 1000 bars, pore pressure of 30 bars, and temperatures of 150 to 250/sup 0/C. Constant strain rate tests gave a coefficient of friction of 0.68. Friction was independent of rock type, temperature and strain rate. Most cores taken from the producing zone were highly fractured. For this reason, intact samples were rarely 50% stronger than the frictional strength. At 500 bars confining pressure, P wave velocity of 6.2 km/sec was measured for a sample taken from an outcrop. Porosities and permeabilities were also measured.

  19. Oxygen isotope geochemistry of The Geysers reservoir rocks, California

    SciTech Connect

    Gunderson, Richard P.; Moore, Joseph N.

    1994-01-20

    Whole-rock oxygen isotopic compositions of Late Mesozoic graywacke, the dominant host rock at The Geysers, record evidence of a large liquid-dominated hydrothermal system that extended beyond the limits of the present steam reservoir. The graywackes show vertical and lateral isotopic variations that resulted from gradients in temperature, permeability, and fluid composition during this early liquid-dominated system. All of these effects are interpreted to have resulted from the emplacement of the granitic "felsite" intrusion 1-2 million years ago. The {delta}{sup 18}O values of the graywacke are strongly zoned around a northwest-southeast trending low located near the center of and similar in shape to the present steam system. Vertical isotopic gradients show a close relationship to the felsite intrusion. The {delta}{sup 18}O values of the graywacke decrease from approximately 15 per mil near the surface to 4-7 per mil 300 to 600 m above the intrusive contact. The {delta}{sup 18}O values then increase downward to 8-10 per mil at the felsite contact, thereafter remaining nearly constant within the intrusion itself. The large downward decrease in {delta}{sup 18}O values are interpreted to be controlled by variations in temperature during the intrusive event, ranging from 150{degree}C near the surface to about 425{degree}C near the intrusive contact. The upswing in {delta}{sup 18}O values near the intrusive contact appears to have been caused by lower rock permeability and/or heavier fluid isotopic composition there. Lateral variations in the isotopic distributions suggests that the effects of temperature were further modified by variations in rock permeability and/or fluid-isotopic composition. Time-integrated water:rock ratios are thought to have been highest within the central isotopic low where the greatest isotopic depletions are observed. We suggest that this region of the field was an area of high permeability within the main upflow zone of the liquid

  20. Geyser decline and extinction in New Zealand: energy development impacts and implications for environmental management.

    PubMed

    Barrick, Kenneth A

    2007-06-01

    Geysers are rare natural phenomena that represent increasingly important recreation, economic, and scientific resources. The features of geyser basins, including hot springs, mud pots, and fumaroles, are easily damaged by human development. In New Zealand, the extinction of more than 100 geysers provides important lessons for the environmental management of the world's remaining geyser basins. The impacts on New Zealand's geysers are described in sequential "phases," including the following: the first use of geothermal resources by the indigenous people-the Maori; early European-style tourism and spa development; streamside geyser decline caused by river level modification at the Spa geyser basin; multiple geyser basin extinctions caused by industrial-scale geothermal well withdrawal at Wairakei; the drowning of geysers at Orakeikorako after the filling of a hydroelectric reservoir; and geyser decline caused by geothermal well heating systems in Rotorua City. The crisis in Rotorua prompted preservation of the few remaining geysers at Whakarewarewa -- the last major geyser basin in New Zealand. The New Zealand government ordered the geothermal wells within 1.5 km of Pohutu Geyser, Whakarewarewa, to be closed, which was a locally controversial measure. The well closure program resulted in a partial recovery of the Rotorua geothermal reservoir, but no extinct geysers recovered. The implications of recent geothermal computer modeling and future planning are discussed. The New Zealand case suggests that the protection of geysers requires strong regulations that prevent incompatible development at the outset, a prescription that is especially relevant for the future management of the geothermal fields adjacent to the geyser basins of Yellowstone National Park, U.S.A.

  1. Geyser decline and extinction in New Zealand: energy development impacts and implications for environmental management.

    PubMed

    Barrick, Kenneth A

    2007-06-01

    Geysers are rare natural phenomena that represent increasingly important recreation, economic, and scientific resources. The features of geyser basins, including hot springs, mud pots, and fumaroles, are easily damaged by human development. In New Zealand, the extinction of more than 100 geysers provides important lessons for the environmental management of the world's remaining geyser basins. The impacts on New Zealand's geysers are described in sequential "phases," including the following: the first use of geothermal resources by the indigenous people-the Maori; early European-style tourism and spa development; streamside geyser decline caused by river level modification at the Spa geyser basin; multiple geyser basin extinctions caused by industrial-scale geothermal well withdrawal at Wairakei; the drowning of geysers at Orakeikorako after the filling of a hydroelectric reservoir; and geyser decline caused by geothermal well heating systems in Rotorua City. The crisis in Rotorua prompted preservation of the few remaining geysers at Whakarewarewa -- the last major geyser basin in New Zealand. The New Zealand government ordered the geothermal wells within 1.5 km of Pohutu Geyser, Whakarewarewa, to be closed, which was a locally controversial measure. The well closure program resulted in a partial recovery of the Rotorua geothermal reservoir, but no extinct geysers recovered. The implications of recent geothermal computer modeling and future planning are discussed. The New Zealand case suggests that the protection of geysers requires strong regulations that prevent incompatible development at the outset, a prescription that is especially relevant for the future management of the geothermal fields adjacent to the geyser basins of Yellowstone National Park, U.S.A. PMID:17453282

  2. Geyser Decline and Extinction in New Zealand—Energy Development Impacts and Implications for Environmental Management

    NASA Astrophysics Data System (ADS)

    Barrick, Kenneth A.

    2007-06-01

    Geysers are rare natural phenomena that represent increasingly important recreation, economic, and scientific resources. The features of geyser basins, including hot springs, mud pots, and fumaroles, are easily damaged by human development. In New Zealand, the extinction of more than 100 geysers provides important lessons for the environmental management of the world’s remaining geyser basins. The impacts on New Zealand’s geysers are described in sequential “phases,” including the following: the first use of geothermal resources by the indigenous people—the Maori; early European-style tourism and spa development; streamside geyser decline caused by river level modification at the Spa geyser basin; multiple geyser basin extinctions caused by industrial-scale geothermal well withdrawal at Wairakei; the drowning of geysers at Orakeikorako after the filling of a hydroelectric reservoir; and geyser decline caused by geothermal well heating systems in Rotorua City. The crisis in Rotorua prompted preservation of the few remaining geysers at Whakarewarewa—the last major geyser basin in New Zealand. The New Zealand government ordered the geothermal wells within 1.5 km of Pohutu Geyser, Whakarewarewa, to be closed, which was a locally controversial measure. The well closure program resulted in a partial recovery of the Rotorua geothermal reservoir, but no extinct geysers recovered. The implications of recent geothermal computer modeling and future planning are discussed. The New Zealand case suggests that the protection of geysers requires strong regulations that prevent incompatible development at the outset, a prescription that is especially relevant for the future management of the geothermal fields adjacent to the geyser basins of Yellowstone National Park, U.S.A.

  3. A multitracer approach for characterizing interactions between shallow groundwater and the hydrothermal system in the Norris Geyser Basin area, Yellowstone National Park

    USGS Publications Warehouse

    Gardner, W.P.; Susong, D.D.; Solomon, D.K.; Heasler, H.P.

    2011-01-01

    Multiple environmental tracers are used to investigate age distribution, evolution, and mixing in local- to regional-scale groundwater circulation around the Norris Geyser Basin area in Yellowstone National Park. Springs ranging in temperature from 3??C to 90??C in the Norris Geyser Basin area were sampled for stable isotopes of hydrogen and oxygen, major and minor element chemistry, dissolved chlorofluorocarbons, and tritium. Groundwater near Norris Geyser Basin is comprised of two distinct systems: a shallow, cool water system and a deep, high-temperature hydrothermal system. These two end-member systems mix to create springs with intermediate temperature and composition. Using multiple tracers from a large number of springs, it is possible constrain the distribution of possible flow paths and refine conceptual models of groundwater circulation in and around a large, complex hydrothermal system. Copyright 2011 by the American Geophysical Union.

  4. The Geysers Geothermal Field Update1990/2010

    SciTech Connect

    Brophy, P.; Lippmann, M.; Dobson, P.F.; Poux, B.

    2010-10-01

    In this report, we have presented data in four sections: (1) THE GEYSERS HISTORICAL UPDATE 1990-2010 - A historical update of the primary developments at The Geysers between 1990 and 2010 which uses as its start point Section IIA of the Monograph - 'Historical Setting and History of Development' that included articles by James Koenig and Susan Hodgson. (2) THE GEYSERS COMPREHENSIVE REFERENCE LIST 1990-2010 - In this section we present a rather complete list of technical articles and technical related to The Geysers that were issued during the period 1990-2010. The list was compiled from many sources including, but not limited to scientific journals and conference proceedings. While the list was prepared with care and considerable assistance from many geothermal colleagues, it is very possible that some papers could have been missed and we apologize to their authors in advance. The list was subdivided according to the following topics: (1) Field characterization; (2) Drilling; (3) Field development and management; (4) Induced seismicity; (5) Enhanced Geothermal Systems; (6) Power production and related issues; (7) Environment-related issues; and (8) Other topics. (3) GRC 2010 ANNUAL MEETING GEYSERS PAPERS - Included in this section are the papers presented at the GRC 2010 Annual Meeting that relate to The Geysers. (4) ADDITIONAL GEYSERS PAPERS 1990-2010 - Eighteen additional technical papers were included in this publication in order to give a broad background to the development at The Geysers after 1990. The articles issued during the 1990-2010 period were selected by colleagues considered knowledgeable in their areas of expertise. We forwarded the list of references given in Section 2 to them asking to send us with their selections with a preference, because of limited time, to focus on those papers that would not require lengthy copyright approval. We then chose the articles presented in this section with the purpose of providing the broadest possible view across

  5. Dynamics within geyser conduits, and sensitivity to environmental perturbations: insights from a periodic geyser in the El Tatio Geyser Field, Atacama Desert, Chile

    USGS Publications Warehouse

    Munoz-Saez, Carolina; Manga, Michael; Hurwitz, Shaul; Rudolph, Maxwell L.; Namiki, Atsuko; Wang, Chi-Yuen

    2015-01-01

    Despite more than 200 years of scientific study, the internal dynamics of geyser systems remain poorly characterized. As a consequence, there remain fundamental questions about what processes initiate and terminate eruptions, and where eruptions begin. Over a one-week period in October 2012, we collected down-hole measurements of pressure and temperature in the conduit of an exceptionally regular geyser (132 s/cycle) located in the Chilean desert. We identified four stages in the geyser cycle: (1) recharge of water into the conduit after an eruption, driven by the pressure difference between water in the conduit and in a deeper reservoir; (2) a pre-eruptive stage that follows the recharge and is dominated by addition of steam from below; (3) the eruption, which occurs by rapid boiling of a large mass of water at the top of the water column, and decompression that propagates boiling conditions downward; (4) a relaxation stage during which pressure and temperature decrease until conditions preceding the recharge stage are restored. Eruptions are triggered by the episodic addition of steam coming from depth, suggesting that the dynamics of the eruptions are dominated by geometrical and thermodynamic complexities in the conduit and reservoir. Further evidence favoring the dominance of internal processes in controlling periodicity is also provided by the absence of responses of the geyser to environmental perturbations (air pressure, temperature and probably also Earth tides).

  6. Dynamics within geyser conduits, and sensitivity to environmental perturbations: Insights from a periodic geyser in the El Tatio geyser field, Atacama Desert, Chile

    NASA Astrophysics Data System (ADS)

    Munoz-Saez, Carolina; Manga, Michael; Hurwitz, Shaul; Rudolph, Maxwell L.; Namiki, Atsuko; Wang, Chi-Yuen

    2015-02-01

    Despite more than 200 years of scientific study, the internal dynamics of geyser systems remain poorly characterized. As a consequence, there remain fundamental questions about what processes initiate and terminate eruptions, and where eruptions begin. Over a one-week period in October 2012, we collected down-hole measurements of pressure and temperature in the conduit of an exceptionally regular geyser (132 s/cycle) located in the Chilean desert. We identified four stages in the geyser cycle: (1) recharge of water into the conduit after an eruption, driven by the pressure difference between water in the conduit and in a deeper reservoir; (2) a pre-eruptive stage that follows the recharge and is dominated by addition of steam from below; (3) the eruption, which occurs by rapid boiling of a large mass of water at the top of the water column, and decompression that propagates boiling conditions downward; and (4) a relaxation stage during which pressure and temperature decrease until conditions preceding the recharge stage are restored. Eruptions are triggered by the episodic addition of steam coming from depth, suggesting that the dynamics of the eruptions are dominated by geometrical and thermodynamic complexities in the conduit and reservoir. Further evidence favoring the dominance of internal processes in controlling periodicity is also provided by the absence of responses of the geyser to environmental perturbations (air pressure, temperature and probably also Earth tides).

  7. Spacially-averaged and point measurements of wind variability in the Geyser's area

    SciTech Connect

    Porch, W.M.

    1980-05-01

    This paper describes the results of a comparison of wind measurements made with conventional cup-vane tower mounted anemometers and optical space-averaged anemometer techniques. The results described cover the period from 7/17/79 to 7/27/79 during the intensive ASCOT experiment in the Geyser's region. The average height of the laser beam above terrain was about 30 meters. Most of the optical anemometer wind data was obtained using a laser beam system described in detail by Lawrence, et al. Some measurements were also made along the same path using a white light photodiode array system developed at LLL.

  8. Downhole Seismic Monitoring at the Geysers

    SciTech Connect

    Rutledge, J.T.; Anderson, T.D.; Fairbanks, T.D.; Albright, J.N.

    1999-10-17

    A 500-ft length, 6-level, 3-component, vertical geophone array was permanently deployed within the upper 800 ft of Unocal's well GDCF 63-29 during a plug and abandonment operation on April 7, 1998. The downhole array remains operational after a period of 1 year, at a temperature of about 150 C. Continuous monitoring and analysis of shallow seismicity (<4000 ft deep) has been conducted over that same 1-year period. The downhole array was supplemented with 4 surface stations in late-1998 and early-1999 to help constrain locations of shallow seismicity. Locations occurring within about 1 km ({approximately}3000 ft) of the array have been determined for a subset of high-frequency events detected on the downhole and surface stations for the 10-week period January 6 to March 16, 1999. These events are distinct from surface-monitored seismicity at The Geysers in that they occur predominantly above the producing reservoir, at depths ranging from about 1200 to 4000 ft depth (1450 to -1350 ft elevation). The shallow seismicity shows a northeast striking trend, similar to seismicity trends mapped deeper within the reservoir and the strike of the predominant surface lineament observed over the productive field.

  9. Preliminary Geophysical Characterization of a CO2-Driven Geyser in the Rio Grande Rift, New Mexico

    NASA Astrophysics Data System (ADS)

    Feucht, D. W.; Jensen, K. J.; Kelly, C.; Ryan, J. C.; Ferriz, H.; Kanjorski, N.; Ferguson, J. F.; McPhee, D. K.; Pellerin, L.

    2009-12-01

    As part of the Summer of Applied Geophysical Experience (SAGE) a preliminary geophysical investigation was conducted in the vicinity of a cold CO2-driven geyser located at Chimayó, NM, along the eastern margin of the Rio Grand Rift. This geyser is of interest as a possible analog for CO2 leakage from deep saline-aquifer carbon sequestration projects. Observed water chemistry variations can be explained by mixing of a CO2-rich, high salinity brine rising into, and mixing with a shallow freshwater aquifer. Several large, basin bounding faults and numerous smaller normal faults cut the area of the well and may constitute the necessary conduit for the deep water. Geophysical methods were used to characterize the subsurface properties at the Chimayó geyser as well as regional structures that may influence groundwater flow in the area. Shallow transient electromagnetic (TEM) data and capactively-coupled resistivity (CCR) data were acquired in close proximity to the geyser. The CCR shows a near-surface resistive feature, possibly hematite-cemented Tesuque formation sediment, in close proximity to the geyser. A shallow, highly conductive layer delineated through modeling of the TEM data is postulated to be a fluid consistent with high levels of Total Dissolved Solid (TDS) content. The well is located almost directly on the Roberts fault, which is antithetic to the basin bounding Chimayó fault 1.5 km to the east. Previously published hydrogeochemical studies associate this fault with high CO2 and TDS water along its strike. Deeper sounding TEM and audiomagnetotelluric (AMT) data were acquired along the Alamo Arroyo, 3 km to the southwest of the well. The Kelley Federal #1 Well located in this arroyo provides deep stratigraphic control to Pennsylvanian carbonate basement at 740 m. Tesuque formation conglomeritic alluvial fan deposits occur between 230 and 708 m and are overlain by finer grained basin floor deposits. The deep, coarse grained unit is thought to be a good

  10. 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.

  11. Low-Q structure beneath The Geysers area in the northern California

    NASA Astrophysics Data System (ADS)

    Matsubara, M.

    2010-12-01

    A large reservoir is located beneath The Geysers geothermal area, northern California. Seismic tomography revealed high-velocity (high-V) and low-Vp/Vs zones in the reservoir (Julian et al., 1996) and a decrease of Vp/Vs from 1991 to 1998 (Guasekera et al., 2003) due to withdrawal of steam from the reservoir. I build on these earlier studies by performing the attenuation tomography in this region to investigate the Q structure. The target region, 38.5-39.0°N and 122.5-123°W, covers The Geysers area. I use seismographs of Northern California Earthquake Data Center, which recorded 1235 earthquakes with magnitude larger than 2.0 and resolved focal mechanisms from 2002 to 2008. The band-pass filtered seismographs are analyzed for collecting the maximum amplitude data. Three kinds of Butterworth band-pass filters, such as 1-3, 3-7, and 7-15, correspond to the analysis of the Q structure for 2, 5, and 10 Hz, respectively. I use the P- and S-wave maximum amplitudes between the two seconds after the arrival of those waves in order to avoid the effects by coda. A total of 8980 P- and 1086 S-wave amplitude data for 949 earthquakes recorded at 48 stations are available for the analysis using the attenuation tomographic method (Zao et al., 1996). Extremely low-Qp and Qs zones are found at the northwestern (NW) of The Geysers area at sea level. These zones are consistent with the high-Vp and Vs and low-Vp/Vs zones located at the NW part of the reservoir. The low-Qs zone extends to the southeast (SE) and with approximately 15 km length and 5 km width and has another negative peak beneath the SE part of the reservoir. This low-Qs zone is also consistent with the high-Vp and Vs regions of the reservoir characterized by a low-Vp/Vs zone. However, Qp in the SE part is slightly high. Below sea level in The Geysers reservoir, there are a main greywacke layer and a felsite layer. Above sea level, there is a greenstone melange beneath the NW extremely low-Qp and Qs region and a

  12. Microearthquake source mechanism studies at the Geysers geothermal field

    SciTech Connect

    Kirkpatrick, A.; Romero, A. Jr.; Peterson, J. Jr.; Johnson, L.; Majer, E.

    1996-04-01

    In this paper the authors discuss moment tensors obtained from inversion of MEQ waveform data recorded at the Southeast (SE) and Northwest (NW) Geysers geothermal areas by the high-resolution seismic networks operated by Lawrence Berkeley National Laboratory (Berkeley Lab) and the Coldwater Creek Geothermal Company (now CCPA). The network in the SE Geysers consists of 13 high-frequency (4.5 Hz), digital (480 samples), three-component, telemetered stations deployed on the surface in portions of the Calpine, Unocal-NEC-Thermal (U-N-T), and Northern California Power Agency (NCPA) leases. The network in the NW Geysers is a 16-station borehole array of three-component geophones (4.5 Hz), digital at 400 samples/sec, and telemetered to a central site. One of the main objectives of Berkeley Lab`s program at the Geysers is to assess the utility of MEQ monitoring as a reservoir management tool. Discrimination of the mechanisms of these events may aid in the interpretation of MEQ occurrence patterns and their significance to reservoir processes and conditions of interest to reservoir managers. Better understanding of the types of failure deduced from source mechanism studies, and their relations to production parameters, should also lead to a better understanding of the effects of injection and withdrawal.

  13. Microearthquake monitoring and seismic imaging at The Geysers

    SciTech Connect

    Zucca, J.J.; Hutchings, L.; Bonner, B.; Kasameyer, P.; Majer, E.L.; Peterson, J.; Romero, A.; Kirkpatrick, A.

    1994-06-01

    We are monitoring two high-frequency, high-resolution microearthquake networks at The Geysers. The first network consists of 16 stations and is located in the northwest portion of the Geysers. This array is in an area that is representative of a high-temperature, deep, reservoir environment. The second network consists of 13 stations located in the southeast Geysers around the location of the cooperative injection experiment. We are using the data from the networks to compute velocity and attenuation images and earthquake parameters such as precise location and rate and manner of energy release. Our goal is to evaluate the use of this information to manage steam release from geothermal reservoirs. We are supporting this effort with laboratory measurements of velocity and attenuation on Geysers core samples under varying degrees of saturation to help us better interpret our seismic images. To date we find that microearthquake activity follows injection activity, and the dry, low-pressure portions of the reservoir are characterized by low velocity and high attenuation.

  14. 25. LOBBY FIREPLACE. NOTE THE GEYSER DECORATING THE FIREPLACE SCREEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. LOBBY FIREPLACE. NOTE THE GEYSER DECORATING THE FIREPLACE SCREEN AND THE WEIGHTS AND PENDULUM HANGING FROM THE CLOCK DESIGNED BY ARCHITECT ROBERT C. REAMER. - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  15. Thermal and chemical evolution of The Geysers geothermal system, California

    SciTech Connect

    Moore, J.N.

    1992-01-01

    Fluid inclusions and mineral assemblages provide a reward of the thermal and chemical changes that occurred during the evolution of The Geysers geothermal system. The data document the presence of an extensive liquid dominated geothermal system that developed in response to felsite intrusion and its evolution to a vapor-dominated regime. Temperatures within the early liquid-dominated system ranged from 175 C at a distance of 7200 feet from the felsite to more than 350 C near the contact while salinities varied from 5 equivalent weight percent NaCl (at a distance of 5500 feet) to more than 26 weight percent NaCl. As temperatures around the felsite declined, the liquid-dominated system collapsed upon itself. Downward migration of the low salinity waters resulted in dilution of the fluids present in regions now occupied by the caprock and normal vapor-dominated reservoir. In contrast, dilution was minor in rocks now hosting the high-temperature vapor-dominated reservoir. This suggests that low permeabilities are the primary reason for the development of the high-temperature reservoir. Boiling within the caprock produced late-stage veins of calcite and quartz. As the fluid boiled off, condensate was trapped as low salinity fluid inclusions. Within the main body of the reservoir, a liquid phase with salinities of up to 7 equivalent weight percent NaCl persisted to temperatures between 250 and 270 C. However, except for the presence of vapor-rich inclusions, little evidence of boiling within the reservoir rocks was preserved.

  16. Hydrologic Connection Between Geysers and Adjacent Thermal Pools, Two Examples: El Tatio, Chile and Yellowstone, USA

    NASA Astrophysics Data System (ADS)

    Munoz Saez, C.; Fauria, K.; Manga, M.; Hurwitz, S.; Namiki, A.

    2014-12-01

    Geyser eruption cycles can be influenced by adjacent and distant thermals sources, suggesting a hydraulic connection through permeable pathways. Diffusion of fluid pressure can be responsible for the communication between geysers. In this study we examine the processes linking two different geysers with adjacent thermal pools. The first was Vega Rinconada, located at El Tatio geyser field, Chile, where we measured temperature inside the conduit between the ground surface and a depth of seven meters, at one-meter intervals. The second was Lone Star Geyser in Yellowstone National Park, where we measured temperature of the overflow water at the base of the cone. Concurrently, we measured temperature and the water level in pools adjacent to both geysers. We found common elements in both geyser - pool systems: First, water temperature in both adjacent pools was below the boiling point and cooler than water in the geysers. Second, changes in pool water levels were correlated with eruptions of the geysers. During the quiescent period of the geysers, the water level increased in adjacent pools, while water level in the pools deceased during eruptions. Additionally, measurements inside of the conduit in Vega Rinconada Geyser showed that water temperature increased in the deepest part of the conduit during eruptions, while water temperature decreased in the shallow part of the geyser conduit (~1 to 2 m). These drops in temperature in the shallow conduit were coincident with the drop in water level in the adjacent pool. This suggests that after the initiation of an eruption, water may drain from the pool to the geyser. Furthermore, we observed a temperature drop of 3oC in the shallow conduit immediately preceding the end of an eruption. This suggests that flow from the pool to geyser contributes to eruption shut off. Our observations of geyser-pool systems indicate a hydrologic connection between the geysers and their adjacent pools. In the case of Vega Rinconada, cold water

  17. Thermal History of the Felsite Unit, Geysers Geothermal Field, From Thermal Modeling of 40Ar/39Ar Incremental Heating Data

    SciTech Connect

    T. M. Harrison; G. B. Dalrymple; J. B. Hulen; M. A. Lanphere; M. Grove; O. M. Lovera

    1999-08-19

    An Ar-40/Ar-39 and U-Pb study was performed of the Geysers plutonic complex of the Geysers Geothermal Field in California. Sixty-nine ion microprobe spot analyses of zircons from four granite samples from the plutonic complex that underlies the Geysers geothermal field yielded Pb-207/Pb-206 vs. U-238/Pb-206 concordia ages ranging from 1.13 {+-} 0.04 Ma to 1.25 {+-} 0.04 Ma. The U-Pb ages coincide closely with Ar-40/Ar-39 age spectrum plateau and ''terminal'' ages from coexisting K-feldspars and with the eruption ages of overlying volcanic rocks. The data indicate that the granite crystallized at 1.18 Ma and had cooled below 350 C by {approximately}0.9-1.0 Ma. Interpretation of the feldspar Ar-40/Ar-39 age data using multi-diffusion domain theory indicates that post-emplacement rapid cooling was succeeded either by slower cooling from 350-300 C between 1.0 and 0.4 Ma or transitory reheating to 300-350 C at about 0.4-0.6 Ma. Heat flow calculations constrained with K-feldspar thermal histories and the pre sent elevated regional heal flow anomaly demonstrate that appreciable heat input from sources external to the known Geysers plutonic complex is required to maintain the geothermal system. This requirement is satisfied by either a large, underlying, convecting magma chamber (now solidified) emplaced at 1.2 Ma or episodic intrusion of smaller bodies from 1.2-0.6 Ma.

  18. Analysis of Injection-Induced Micro-Earthquakes in a Geothermal Steam Reservoir, The Geysers Geothermal Field, California

    SciTech Connect

    Rutqvist, Jonny; Rutqvist, J.; Oldenburg, C.M.

    2008-05-15

    In this study we analyze relative contributions to the cause and mechanism of injection-induced micro-earthquakes (MEQs) at The Geysers geothermal field, California. We estimated the potential for inducing seismicity by coupled thermal-hydrological-mechanical analysis of the geothermal steam production and cold water injection to calculate changes in stress (in time and space) and investigated if those changes could induce a rock mechanical failure and associated MEQs. An important aspect of the analysis is the concept of a rock mass that is critically stressed for shear failure. This means that shear stress in the region is near the rock-mass frictional strength, and therefore very small perturbations of the stress field can trigger an MEQ. Our analysis shows that the most important cause for injection-induced MEQs at The Geysers is cooling and associated thermal-elastic shrinkage of the rock around the injected fluid that changes the stress state in such a way that mechanical failure and seismicity can be induced. Specifically, the cooling shrinkage results in unloading and associated loss of shear strength in critically shear-stressed fractures, which are then reactivated. Thus, our analysis shows that cooling-induced shear slip along fractures is the dominant mechanism of injection-induced MEQs at The Geysers.

  19. Age and thermal history of the Geysers plutonic complex (felsite unit), Geysers geothermal field, California: A 40Ar/39Ar and U-Pb study

    USGS Publications Warehouse

    Dalrymple, G.B.; Grove, M.; Lovera, O.M.; Harrison, T.M.; Hulen, J.B.; Lanphere, M.A.

    1999-01-01

    Sixty-nine ion microprobe spot analyses of zircons from four granite samples from the plutonic complex that underlies the Geysers geothermal field yield 207Pb/206Pb vs. 238U/206Pb concordia ages ranging from 1.13 ?? 0.04 Ma to 1.25 ?? 0.04 (1??) Ma. The weighted mean of the U/Pb model ages is 1.18 ?? 0.03 Ma. The U-Pb ages coincide closely with 40Ar/39Ar age spectrum plateau and 'terminal' ages from coexisting K-feldspars and with the eruption ages of overlying volcanic rocks. The data indicate that the granite crystallized at 1.18 Ma and had cooled below 350??C by ~0.9-1.0 Ma. Interpretation of the feldspar 40Ar/39Ar age data using multi-diffusion domain theory indicates that post-emplacement rapid cooling was succeeded either by slower cooling from 350??to 300??C between 1.0 and 0.4 Ma or transitory reheating to 300-350??C at about 0.4-0.6 Ma. Subsequent rapid cooling to below 260??C between 0.4 and 0.2 Ma is in agreement with previous proposals that vapor-dominated conditions were initiated within the hydrothermal system at this time. Heat flow calculations constrained with K-feldspar thermal histories and the present elevated regional heat flow anomaly demonstrate that appreciable heat input from sources external to the known Geysers plutonic complex is required to maintain the geothermal system. This requirement is satisfied by either a large, underlying, convecting magma chamber (now solidified) emplaced at 1.2 Ma or episodic intrusion of smaller bodies from 1.2 to 0.6 Ma.

  20. Geyser eruption intervals and interactions: Examples from El Tatio, Atacama, Chile

    NASA Astrophysics Data System (ADS)

    Munoz-Saez, Carolina; Namiki, Atsuko; Manga, Michael

    2015-11-01

    We compare and contrast data collected in 2012 and 2014 from the El Tatio geyser field, Chile. We identify geyser systems that evolve over time, including changes in the interval between eruptions, development of new thermal features, and interactions between geysers. We study three different cases: (a) an isolated geyser, which is periodic and has nearly identical eruptions every cycle; (b) a geyser and coupled noneruptive pool, where the geyser has nonregular cycles and several preplay eruptions before the main eruption; and (c) two geysers and a mud volcano, which have nonregular cycles and are all interacting. Though geysers erupt with different styles, we recognize some common features: the conduit recharges with liquid during the quiescent period, bubbles enter the conduit before eruptions, and eruptions occur when water boils in the upper part of the conduit. The episodic addition of heat may govern the periodicity, while the depth where heat is added dictates the eruption style: conduits with deeper heat input are more likely to show preplay or minor eruptions. The interactions between thermal features can be explained by pressure transmission in subsurface permeable layers between geyser conduits.

  1. Results of weekly chemical and isotopic monitoring of selected springs in Norris Geyser Basin, Yellowstone National Park during June-September, 1995

    USGS Publications Warehouse

    Fournier, R.O.; Weltman, U.; Counce, D.; White, L.D.; Janik, C.J.

    2002-01-01

    Each year at Norris Geyser Basin, generally in August or September, a widespread hydrothermal 'disturbance' occurs that is characterized by simultaneous changes in the discharge characteristics of many springs, particularly in the Back Basin. During the summer season of 1995, water samples from eight widely distributed hot springs and geysers at Norris were collected each week and analyzed to determine whether chemical and isotopic changes also occurred in the thermal waters at the time of the disturbance. In addition, Beryl Spring in Gibbon Canyon, 5.8 km southwest of Norris Geyser Basin, was included in the monitoring program. Waters discharged by four of the monitored hot springs and geysers appear to issue from relatively deep reservoirs where temperatures are at least 270 C and possibly higher than 300 C. At the time of, and for several days after, the onset of the 1995 disturbance, the normally neutral-chloride waters discharged by these four features all picked up an acid-sulfate component and became isotopically heavier. The acid-sulfate component appears to be similar in composition to some waters discharged in 100 Spring Plain that issue from subsurface regions where temperatures are in the range 170-210 C. However, the two monitored springs that discharge acid-chloride-sulfate waters in the 100 Spring Plain region did not show any significant chemical or isotopic response to the annual disturbance. Beryl Spring, and two neutral-chloride hot springs at Norris that appear to draw their water from reservoirs where temperatures are 250 C or less, also did not show any significant chemical or isotopic response to the annual disturbance. After the start of the annual disturbance, chloride concentrations in water sampled from Double Bulger Geyser in the Back Basin increased from about 800 ppm to about 1500 ppm, nearly twice as high as any previously reported chloride concentration in a thermal water at Yellowstone. The isotopic composition of that water

  2. 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.

  3. Energy Sources for Triton's Geyser-Like Plumes.

    PubMed

    Brown, R H; Kirk, R L; Johnson, T V; Soderblom, L A

    1990-10-19

    Four geyser-like plumes were discovered near Triton's south pole in areas now in permanent sunlight. Because Triton's southern hemisphere is nearing a maximum summer solstice, insolation as a driver or a trigger for Triton's geyser-like plumes is an attractive hypothesis. Trapping of solar radiation in a translucent, low-conductivity surface layer (in a solid-state greenhouse), which is subsequently released in the form of latent heat of sublimation, could provide the required energy. Both the classical solid-state greenhouse consisting of exponentially absorbed insolation in a gray, translucent layer of solid nitrogen, and the "super" greenhouse consisting of a relatively transparent solid-nitrogen layer over an opaque, absorbing layer are plausible candidates. Geothermal heat may also play a part if assisted by the added energy input of seasonal cycles of insolation.

  4. Means of protecting cryogenic systems from the geyser effect

    SciTech Connect

    Filina, N.N.

    1986-03-01

    New means of protection, which permit a low fluid boil in the pipeline without proceeding into an avalanchelike process, have been developed on the basis of theoretical and experimental investigations of the geyser effect in cryogenic systems with an end thermal influx from a regulating fitting. An equation is presented for computing the time allowed for the low fluid boil. Pressure increase in the overhead reservoir is discussed and a cryogenic reservoir with concentric pipeline equipped with a hood for vapor elimination is illustrated. Vapor removal from a vertical pipeline is examined. A structural method of protecting cryogenic systems from the geyser effect is discussed; the value of this method consists in its high reliability.

  5. Some considerations on resource evaluation of The Geysers

    SciTech Connect

    Bodvarsson, G.S.; Gaulke, S.; Ripperda, M.

    1989-08-01

    Although large amounts of data have been collected at The Geysers, some reservoir parameters, such as initial liquid saturation, matrix permeability and the fracture network characteristics, are still poorly known. These parameters greatly affect results of resource evaluation and predictions of reservoir behavior. Several two-dimensional fractured porous medium models have been developed for The Geysers; these models differ in assumptions regarding the initial liquid saturation and matrix permeabilities. These models indicate that the permeability-thickness product (kH) of the fracture network ranges from 10 to 75 Dm (30,000 to 225,000 md{center dot}ft) and matrix permeability ranges from 1 to 3 {mu}Darcies ({mu}D). All three models yielded surprisingly similar predictions regarding the future generating capacities of different areas. 17 refs., 6 figs.

  6. Using HDR (Hot Dry Rock) technology to recharge The Geysers

    SciTech Connect

    Brown, D.W.; Robinson, B.A.

    1990-01-01

    The main reason for the productivity decline at The Geysers geothermal field is obvious: more fluid is being withdrawn from the reservoir than is being returned by reinjection and natural recharge. However, there is another factor that may be contributing to this decline --- the method of reinjection. By reinjecting cold condensate directly into the steam dome as is the current practice, the very large pressure difference between the injected condensate and the underpressured reservoir guarantees that the reinjected fluid will fall rapidly to the bottom of the reservoir, with very little residence time for heat transfer. This point is very important since the vast majority of the heat contained in The Geysers geothermal field is stored in the hot rock comprising the reservoir. 10 refs., 4 figs.

  7. Energy sources for Triton's geyser-like plumes

    NASA Technical Reports Server (NTRS)

    Brown, R. H.; Johnson, T. V.; Kirk, R. L.; Soderblom, L. A.

    1990-01-01

    Four geyser-like plumes were discovered near Triton's south pole in areas now in permanent sunlight. Because Triton's southern hemisphere is nearing a maximum summer solstice, insolation as a driver or a trigger for Triton's geyser-like plumes is an attractive hypothesis. Trapping of solar radiation in a translucent, low-conductivity surface layer (in a solid-state greenhouse), which is subsequently released in the form of latent heat of sublimation, could provide the required energy. Both the classical solid-state greenhouse consisting of exponentially absorbed insolation in a gray, translucent layer of solid nitrogen, and the 'super' greenhouse consisting of a relatively transparent solid-nitrogen layer over an opaque, absorbing layer are plausible candidates. Geothermal heat may also play a part if assisted by the added energy input of seasonal cycles of insolation.

  8. Energy Sources for Triton's Geyser-Like Plumes.

    PubMed

    Brown, R H; Kirk, R L; Johnson, T V; Soderblom, L A

    1990-10-19

    Four geyser-like plumes were discovered near Triton's south pole in areas now in permanent sunlight. Because Triton's southern hemisphere is nearing a maximum summer solstice, insolation as a driver or a trigger for Triton's geyser-like plumes is an attractive hypothesis. Trapping of solar radiation in a translucent, low-conductivity surface layer (in a solid-state greenhouse), which is subsequently released in the form of latent heat of sublimation, could provide the required energy. Both the classical solid-state greenhouse consisting of exponentially absorbed insolation in a gray, translucent layer of solid nitrogen, and the "super" greenhouse consisting of a relatively transparent solid-nitrogen layer over an opaque, absorbing layer are plausible candidates. Geothermal heat may also play a part if assisted by the added energy input of seasonal cycles of insolation. PMID:17793021

  9. Energy sources for triton's geyser-like plumes

    USGS Publications Warehouse

    Brown, R.H.; Kirk, R.L.; Johnson, T.V.; Soderblom, L.A.

    1990-01-01

    Four geyser-like plumes were discovered near Triton's south pole in areas now in permanent sunlight. Because Triton's southern hemisphere is nearing a maximum summer solstice, insolation as a driver or a trigger for Triton's geyser-like plumes is an attractive hypothesis. Trapping of solar radiation in a translucent, low-conductivity surface layer (in a solid-state greenhouse), which is subsequently released in the form of latent heat of sublimation, could provide the required energy. Both the classical solid-state greenhouse consisting of exponentially absorbed insolation in a gray, translucent layer of solid nitrogen, and the "super" greenhouse consisting of a relatively transparent solid-nitrogen layer over an opaque, absorbing layer are plausible candidates. Geothermal heat may also play a part if assisted by the added energy input of seasonal cycles of insolation.

  10. Fieldwide Chemical and Isotopic Gradients in Steam from the Geysers

    SciTech Connect

    Truesdell, A.H.; Haizlip, J.R.; Box, W.T. Jr.; D'Amore, F.

    1987-01-20

    Strong fieldwide gradients from southeast to northwest in gas/steam and {delta}{sup 18}O have been found in steam produced from wells at The Geysers. These gradients result from recharge from the southeast that has increased liquid saturation in the southern part of the reservoir and flushed gases and high {delta}{sup 18}O connate waters to the north and out of the system through surface vents. Variations in the steepness of the gradients are probably related to major venting in the Big Geysers area. Although lateral steam flow and condensation subsequent to flushing explain some local gradients in the southern area, these processes cannot explain the fieldwide variations. 1 tab., 24 refs., 5 figs.

  11. Heat-flow mapping at the Geysers Geothermal Field

    SciTech Connect

    Thomas, R.P.

    1986-10-31

    Pertinent data were compiled for 187 temperature-gradient holes in the vicinity of The Geysers Geothermal field. Terrain-correction techniques were applied to most of the temperature-gradient data, and a temperature-gradient map was constructed. Cutting samples from 16, deep, production wells were analyzed for thermal conductivity. From these samples, the mean thermal conductivities were determined for serpentinized ultramafic rock, greenstone, and graywacke. Then, a heat flow map was made. The temperature-gradient and heat-flow maps show that The Geysers Geothermal field is part of a very large, northwesterly-trending, thermal anomaly; the commercially productive portion of the field may be 100 km/sup 2/ in area. The rate that heat energy flows through the surface by thermal conduction is estimated at 1.79 x 10/sup 9/MJ per year. The net heat energy loss from commercial production for 1983 is estimated at 180.14 x 10/sup 9/MJ.

  12. Numerical modeling of injection experiments at The Geysers

    SciTech Connect

    Pruess, K.; Enedy, S.

    1993-01-01

    Data from injection experiments in the southeast Geysers are presented that show strong interference (both negative and positive) with a neighboring production well. Conceptual and numerical models are developed that explain the negative interference (decline of production rate) in terms of heat transfer limitations and water-vapor relative permeability effects. Recovery and over-recovery following injection shut-in are attributed to boiling of injected fluid, with heat of vaporization provided by the reservoir rocks.

  13. Numerical modeling of injection experiments at The Geysers

    SciTech Connect

    Pruess, Karsten; Enedy, Steve

    1993-01-28

    Data from injection experiments in the southeast Geysers are presented that show strong interference (both negative and positive) with a neighboring production well. Conceptual and numerical models are developed that explain the negative interference (decline of production rate) in terms of heat transfer limitations and water-vapor relative permeability effects. Recovery and overrecovery following injection shut-in are attributed to boiling of injected fluid, with heat of vaporization provided by the reservoir rocks.

  14. Arsenic speciation in atmospheric aerosols at The Geysers

    SciTech Connect

    Solomon, P.A.; Altshuler, S.L.; Keller, M.L. )

    1993-05-01

    California's air toxic law (AB 1807), which became effective in January 1984, defines California's air toxic program. Under this legislation, a statutory mandate was created for the identification and control of toxic air contaminants found in California. The California Air Resources Board (ARB) lists inorganic arsenic under Category I: substances that have been identified as toxic air contaminants by the ARB, pursuant to the provisions of AB1807. The enactment of new regulations regarding air toxics and ARB's report entitled [open quotes]Public Exposure to Airborne Inorganic Arsenic in California[close quotes] suggest that geothermal energy producers in California must remain aware of the current atmospheric levels of arsenic at The Geyser. These producers must also be able to provide evidence of the species-specific nature of the airborne arsenic if the regulatory climate changes to include the inorganic species of arsenic in health risk assessment calculations. Preliminary results reported by this paper are useful as a baseline to provide an indication of As(III) and As(V) concentration levels at The Geysers. If species-specific instead of total data on arsenic in the atmosphere are required by regulators, these results could be useful in evaluating future monitoring and assessment needs for arsenic at The Geysers. 12 refs., 1 fig., 1 tab.

  15. Challenges in determining b value in the Northwest Geysers

    SciTech Connect

    Saltiel, S.; Boyle, K.; Majer, E.

    2011-02-01

    Past analyses of the Gutenberg-Richter b-value in the Geysers and other geothermal settings have revealed a deviation from the assumed linear relationship in log space between magnitude and the number of earthquakes. In this study of the Northwest Geysers, we found a gently-sloping discontinuity in the b-value curve. This is especially apparent when comparing the least-squares fit (LSQ) of the curve to the fit obtained by the maximum likelihood estimation (MLE), a widely-respected method of analyzing magnitude-frequency relationships. This study will describe the assumptions made when using each of these two methods and will also explore how they can be used in conjunction to investigate the characteristics of the observed b-value curve. To understand whether slope-fit differences in the LSQR and MLE methods is due to physical properties of the system or due to artifacts from errors in sampling, it is extremely important to consider the catalog completeness, magnitude bin size, number of events, and differences in source mechanisms for the events comprising the study volume. This work will hopefully lead to informative interpretations of frequency-magnitude curves for the Northwest Geysers, a geothermal area of ongoing high-volume coldwater injection and steam production. Through this statistical investigation of the catalog contents, we hope to better understand the dominant source mechanisms and the role of injected fluids in the creation of seismic clustering around nearly 60 wells of varying depths and injection volumes.

  16. Modeling and observations of geyser activity in relation to catastrophic landslides-mudflows (Kronotsky nature reserve, Kamchatka, Russia)

    NASA Astrophysics Data System (ADS)

    Kiryukhin, Alexey

    2016-09-01

    This study reports and interprets observational data of geyser cycling in the Valley of Geysers and Uzon hydrothermal systems between 2007 and 2015. The monitoring of the Velikan and Bolshoy Geysers after the catastrophic landslide on 3.06.2007 (which dammed and created Podprudnoe Lake, drowning some geysers) and before a mudflow on 3.01.2014 (which destroyed the dam and almost completely drained Podprudnoe Lake) shows that the interval between eruptions (IBE) of the Bolshoy Geyser decreased from 108 to 63 min and that the IBE of the Velikan Geyser slowly declined over three years from 379 min to 335 min. The seasonal hydrological cycle of the Velikan Geyser shows an increase in the IBE during winter (average of 41 min). The dilution of the chloride deep components of the Bolshoy (- 23%) and Velikan Geysers (- 12%) is also observed. A local TOUGH2 model of the Velikan Geyser is developed. This model is used to describe the transient thermal hydrodynamic and CO2 changes in a Velikan Geyser conduit during the entire cycling process by using cyclic, time-dependent boundary mass flow conditions (major eruption discharge and sub-cyclically assigned CO2 mass flow recharge into the base of the geyser conduit and water recharge at the mid-height of the geyser conduit) and a constant mass flow of water into the geyser at depth. This model also indicates a seepage element at the conduit's top to allow pre-eruptive discharge and a buffering isothermal reservoir below to compensate for pressure declines from major eruptions at earlier times. A local TOUGH2 model is successfully calibrated against temperature observations at both the mid-height and base of the conduit of the Velikan Geyser, which shows the essential role of the above parameters in describing the functionality of the geyser. A reservoir model of shallow production geysers is also developed. This 2D model is used to describe changes in the thermal hydrodynamic state and evolving chloride concentrations in the

  17. Fracture patterns in graywacke outcrops at The Geysers geothermal field

    SciTech Connect

    Sammis, Charles G.; Lin Ji An; Ershaghi, I.

    1991-01-01

    The Geysers geothermal field covers an area of more than 35,000 acres and represents one of the most significant steam fields in the world. The heterogeneous nature of the reservoir, its fracture network and non-sedimentary rock distinguish it from ordinary sandstone reservoirs in terms of reservoir definition and evaluation (Stockton et al. 1984). Analysis of cuttings, record of steam entries, temperature and pressure surveys and spinner logs have contributed to an understanding of the subsurface geology and rock characteristics of the Geysers. Few conventional electrical log data are available for the main body of the reservoir. It is generally believed that while the fractures are the main conducts for fluid transport through the reservoirs, tight rocks between the major fractures contain the bulk of the fluid reserves. No independent measurement of liquid and vapor saturation can be made from the existing downhole tools. Pressure depletion in The Geysers geothermal field has become a major concern to the operators and utility companies in recent years. Plans for further development activities and future field management are contingent upon accurate computer modeling and definition of the field. The primary issues in reliable characterization of The Geysers field are the role of the rock matrix in holding liquid reserves and providing pressure support, the nature of fracture network, extent of liquid saturation in the reservoirs and injection pattern strategies to maximize heat recovery. Current modeling of The Geysers field is done through the use of general purpose geothermal reservoir simulators. Approaches employed include treating the reservoir as a single porosity equivalent or a dual porosity system. These simulators include formulation to represent transport of heat, steam and water. Heterogeneities are represented by spatial variations in formation or fracture permeability-thickness product, porosity or fluid saturations. Conceptual models based on dual

  18. Depth migration of seasonally induced seismicity at The Geysers geothermal field

    NASA Astrophysics Data System (ADS)

    Johnson, Christopher W.; Totten, Eoghan J.; Bürgmann, Roland

    2016-06-01

    Seismicity from injected fluids provides insight into the hydraulically conductive fracture network at The Geysers (TG), California, geothermal reservoir. Induced earthquakes at TG result from both thermoelastic and poroelastic stresses as injected fluids cool the rocks and increase pore pressure. The spatiotemporal evolution of M ≥ 1.5 seismicity is characterized as a function of depth in the northwest and southeast regions of TG to develop time-dependent earthquake rates using an epidemic-type aftershock sequence model. The seismicity and injection follow an annual cycle that peaks in the winter months and is correlated by depth. The results indicate a time lag of ≤6 months for fluids to migrate >3 km below the injection depth. Water injection is the main cause of seismicity as fluids penetrate into the reservoir. Our results suggest that a steeply dipping fracture network of hydraulically conductive faults allows fluid migration to a few kilometers below the point of injection.

  19. Eruptions at Lone Star geyser, Yellowstone National Park, USA: 2. Constraints on subsurface dynamics

    USGS Publications Warehouse

    Vandemeulebrouck, Jean; Sohn, Robert A.; Rudolph, Maxwell L.; Hurwitz, Shaul; Manga, Michael; Johnston, Malcolm J.S.; Soule, S. Adam; McPhee, Darcy K.; Glen, Jonathan M.G.; Karlstrom, Leif; Murphy, Fred

    2014-01-01

    We use seismic, tilt, lidar, thermal, and gravity data from 32 consecutive eruption cycles of Lone Star geyser in Yellowstone National Park to identify key subsurface processes throughout the geyser's eruption cycle. Previously, we described measurements and analyses associated with the geyser's erupting jet dynamics. Here we show that seismicity is dominated by hydrothermal tremor (~5–40 Hz) attributed to the nucleation and/or collapse of vapor bubbles. Water discharge during eruption preplay triggers high-amplitude tremor pulses from a back azimuth aligned with the geyser cone, but during the rest of the eruption cycle it is shifted to the east-northeast. Moreover, ~4 min period ground surface displacements recur every 26 ± 8 min and are uncorrelated with the eruption cycle. Based on these observations, we conclude that (1) the dynamical behavior of the geyser is controlled by the thermo-mechanical coupling between the geyser conduit and a laterally offset reservoir periodically filled with a highly compressible two-phase mixture, (2) liquid and steam slugs periodically ascend into the shallow crust near the geyser system inducing detectable deformation, (3) eruptions occur when the pressure decrease associated with overflow from geyser conduit during preplay triggers an unstable feedback between vapor generation (cavitation) and mass discharge, and (4) flow choking at a constriction in the conduit arrests the runaway process and increases the saturated vapor pressure in the reservoir by a factor of ~10 during eruptions.

  20. Eruptions at Lone Star geyser, Yellowstone National Park, USA: 2. Constraints on subsurface dynamics

    NASA Astrophysics Data System (ADS)

    Vandemeulebrouck, Jean; Sohn, Robert A.; Rudolph, Maxwell L.; Hurwitz, Shaul; Manga, Michael; Johnston, Malcolm J. S.; Soule, S. Adam; McPhee, Darcy; Glen, Jonathan M. G.; Karlstrom, Leif; Murphy, Fred

    2014-12-01

    We use seismic, tilt, lidar, thermal, and gravity data from 32 consecutive eruption cycles of Lone Star geyser in Yellowstone National Park to identify key subsurface processes throughout the geyser's eruption cycle. Previously, we described measurements and analyses associated with the geyser's erupting jet dynamics. Here we show that seismicity is dominated by hydrothermal tremor (~5-40 Hz) attributed to the nucleation and/or collapse of vapor bubbles. Water discharge during eruption preplay triggers high-amplitude tremor pulses from a back azimuth aligned with the geyser cone, but during the rest of the eruption cycle it is shifted to the east-northeast. Moreover, ~4 min period ground surface displacements recur every 26 ± 8 min and are uncorrelated with the eruption cycle. Based on these observations, we conclude that (1) the dynamical behavior of the geyser is controlled by the thermo-mechanical coupling between the geyser conduit and a laterally offset reservoir periodically filled with a highly compressible two-phase mixture, (2) liquid and steam slugs periodically ascend into the shallow crust near the geyser system inducing detectable deformation, (3) eruptions occur when the pressure decrease associated with overflow from geyser conduit during preplay triggers an unstable feedback between vapor generation (cavitation) and mass discharge, and (4) flow choking at a constriction in the conduit arrests the runaway process and increases the saturated vapor pressure in the reservoir by a factor of ~10 during eruptions.

  1. Statistical Properties of Induced and Triggered Earthquakes at The Geysers, California

    NASA Astrophysics Data System (ADS)

    Hawkins, A. K.; Turcotte, D. L.; Kellogg, L. H.

    2015-12-01

    This study considers the statistics of induced and triggered seismicity at The Geysers geothermal field, California. Data is considered from the regional Northern California Seismic Network (NCSN) and local Lawrence Berkeley National Laboratory Network (LBNLN). Both data sets give good GR data fits for 2009-2014 but NCSN data have b=1.15 and LBNLN data have b=1.36. Comparing 18,000 individual earthquakes we find on average MLBNLN = MNCSN+0.5. Thus care must be taken when both data sets are used. We hypothesize that the strain accumulated due to the plate motions is a balance by the strain released in earthquakes with a maximum upper limit Mmax. We compare the strain associated with seismicity with the tectonic GPS strain being accumulated in the region. Taking the NCSN GR data with an upper magnitude cutoff, we find this cutoff to be Mmax=4.74. This is consistent with an observed upper magnitude limit to The Geysers seismicity at about M=5. We present studies of aftershock statistics of four M = 4.43, 4.16, 4.62, and 4.53 earthquakes. We find both GR and Omori Law statistics to be typical of tectonic earthquakes. We suggest that the four earthquakes release accumulated tectonic stresses but injected fluids reduce the stress required for rupture initiation. We also consider triggered seismicity caused by three remote earthquakes. We obtain excellent data for the 2010 M=7.2 El Mayor-Cucapah and the M=6.0 South Napa earthquakes. In the first case a M=3.37 event was triggered and in the second case a M=4.48 event was triggered. We conclude that the observed seismicity consists primarily of aftershocks of the large triggered earthquakes and that the directly triggered earthquakes do not satisfy GR frequency-magnitude statistics.

  2. 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

  3. Velocity and Attenuation Structure of the Geysers Geothermal Field, California

    SciTech Connect

    Zucca, J. J.; Hutchings, L. J.; Kasameyer, P. W.

    1993-01-01

    The Geysers geothermal field is located in northern California and is one of the world's largest producers of electricity from geothermal energy. The resource consists of primarily dry steam which is produced from a low, porosity fractured graywacke. Over the last several years steam pressure at the Geysers has been dropping. Concern over decline of the resource has prompted research to understand its fundamental nature. A key issue is the distribution of fluid in the matrix of the reservoir rock. In this paper we interpret seismic compressional-wave velocity and attenuation data at the Geysers in terms of the geologic structure and fluid saturation in the reservoir. Our data consist of approximately 300 earthquakes that are of magnitude 1.2 and are distributed in depth between sea level and 2.5 km. Using compressional-wave arrival times, we invert for earthquake location, origin time, and velocity along a three-dimensional grid. Using the initial pulse width of the compressional-wave, we invert for the initial pulse width associated with the source, and the one-dimensional Q structure. We find that the velocity structure correlates with known mapped geologic units, including a velocity high that is correlated with a felsite body at depth that is known from drilling. The dry steam reservoir, which is also known from drilling, is mostly correlated with low velocity. The Q increases with depth to the top of the dry steam reservoir and decreases with depth within the reservoir. The decrease of Q with depth probably indicates that the saturation of the matrix of the reservoir rock increases with depth.

  4. Protecting the geyser basins of Yellowstone National Park: toward a new national policy for a vulnerable environmental resource.

    PubMed

    Barrick, Kenneth A

    2010-01-01

    Geyser basins provide high value recreation, scientific, economic and national heritage benefits. Geysers are globally rare, in part, because development activities have quenched about 260 of the natural endowment. Today, more than half of the world's remaining geysers are located in Yellowstone National Park, northwest Wyoming, USA. However, the hydrothermal reservoirs that supply Yellowstone's geysers extend well beyond the Park borders, and onto two "Known Geothermal Resource Areas"-Island Park to the west and Corwin Springs on the north. Geysers are sensitive geologic features that are easily quenched by nearby geothermal wells. Therefore, the potential for geothermal energy development adjacent to Yellowstone poses a threat to the sustainability of about 500 geysers and 10,000 hydrothermal features. The purpose here is to propose that Yellowstone be protected by a "Geyser Protection Area" (GPA) extending in a 120-km radius from Old Faithful Geyser. The GPA concept would prohibit geothermal and large-scale groundwater wells, and thereby protect the water and heat supply of the hydrothermal reservoirs that support Yellowstone's geyser basins and important hot springs. Proactive federal leadership, including buyouts of private groundwater development rights, can assist in navigating the GPA through the greater Yellowstone area's "wicked" public policy environment. Moreover, the potential impacts on geyser basins from intrusive research sampling techniques are considered in order to facilitate the updating of national park research regulations to a precautionary standard. The GPA model can provide the basis for protecting the world's few remaining geyser basins.

  5. Protecting the geyser basins of Yellowstone National Park: toward a new national policy for a vulnerable environmental resource.

    PubMed

    Barrick, Kenneth A

    2010-01-01

    Geyser basins provide high value recreation, scientific, economic and national heritage benefits. Geysers are globally rare, in part, because development activities have quenched about 260 of the natural endowment. Today, more than half of the world's remaining geysers are located in Yellowstone National Park, northwest Wyoming, USA. However, the hydrothermal reservoirs that supply Yellowstone's geysers extend well beyond the Park borders, and onto two "Known Geothermal Resource Areas"-Island Park to the west and Corwin Springs on the north. Geysers are sensitive geologic features that are easily quenched by nearby geothermal wells. Therefore, the potential for geothermal energy development adjacent to Yellowstone poses a threat to the sustainability of about 500 geysers and 10,000 hydrothermal features. The purpose here is to propose that Yellowstone be protected by a "Geyser Protection Area" (GPA) extending in a 120-km radius from Old Faithful Geyser. The GPA concept would prohibit geothermal and large-scale groundwater wells, and thereby protect the water and heat supply of the hydrothermal reservoirs that support Yellowstone's geyser basins and important hot springs. Proactive federal leadership, including buyouts of private groundwater development rights, can assist in navigating the GPA through the greater Yellowstone area's "wicked" public policy environment. Moreover, the potential impacts on geyser basins from intrusive research sampling techniques are considered in order to facilitate the updating of national park research regulations to a precautionary standard. The GPA model can provide the basis for protecting the world's few remaining geyser basins. PMID:19841971

  6. Triton's geyser-like plumes - Discovery and basic characterization

    NASA Technical Reports Server (NTRS)

    Soderblom, L. A.; Becker, T. L.; Kieffer, S. W.; Brown, R. H.; Hansen, C. J.; Johnson, T. V.

    1990-01-01

    One model for the mechanism driving the plumes of the four active geyser-like eruptions observed by Voyager 2 on Triton is a heating up of nitrogen ice in a subsurface greenhouse environment, where nitrogen gas pressurized by solar heating explosively vents to the surface carrying clouds of ice and dark particles into the atmosphere. A temperature increase of less than 4 K above the ambient surface value of 38 + or - 3 K suffices to drive the plumes to 8-km altitude. Each eruption may last a year or more, over the course of which 0.1 cu km of ice is sublimed.

  7. Core image analysis of matrix porosity in The Geysers reservoir

    SciTech Connect

    Nielson, Dennis L.; Nash, Greg; Hulen, Jeffrey B.; Tripp, Alan C.

    1993-01-28

    Adsorption is potentially an important consideration when calculating reserves at The Geysers. Our investigations of the mineralogical relationships in core samples have shown matrix pore spaces to be largely associated with fractures. Dissolution of calcite from hydrothermal veins increases porosity in the graywacke reservoir. The high relative surface area of secondary alteration phases could promote adsorption. In order to quantify porosity distribution and surface area, Scanning Electron Microscope (SEM) images were analyzed using software developed for the interpretation of satellite imagery, This software classifies the images as either crystal or pore and then accumulates data on pore size, total porosity and surface area of the mineral-pore interface. Review of literature shows that data on thickness of adsorbed water layer does not exist for many of the mineral phases of interest in The Geysers. We have assumed thicknesses of 10, 100, and 5300 Angstroms for the adsorbed layer and calculated the relative proportions of adsorbed water. These calculations show 0.005%, 0.05%, and 2.5% of total water would be adsorbed using the above thicknesses.

  8. Preliminary Fracture Model for The SE Geysers Geothermal Reservoir

    NASA Astrophysics Data System (ADS)

    Furrey, L.; Furrey, L.; Wagoner, J.; Elkibbi, M.; Hutchings, L. J.

    2001-12-01

    In this study we combine interpretation of steam entry points, seismicity, shear-wave splitting, geology, and rock physics to develop a fracture model for the Southeast Geysers reservoir in an attempt to improve understanding of the permeability and steam flow within the reservoir. The Geysers is a dry steam field located approximately 140 km NNW of San Francisco, in Sonoma and Lake Counties in northern California. We developed this model by utilizing three-dimensional coordinates of wellbores and observations of steam entries encountered during drilling in conjunction with the locations of microearthquakes, the orientations of fractures from shear-wave splitting, geologic interpretation, and the result of rock physics interpretations. We utilize earthVision5.1TM visualization software in analyzing this data. We are interested in analyzing the fault, fractures, or fracture sets that appear to have the major control over fluid flow at reservoir depths. Faults offsetting the reservoir graywacke and felsite are generally identified by indirect methods. Fault detection within the reservoir rocks is difficult because the geology is relatively homogeneous and lacks marker horizons. Most high-angle faults mapped at the surface are truncated above the reservoir by thrust faults, and do not project to zones of high permeability within the reservoir. Thus, we utilize steam entry points along with geological formation topography to assist in the identification of faults at depth.

  9. LBL research on The Geysers: Conceptual models, simulation and monitoring studies

    SciTech Connect

    Bodvarsson, G.S.; Lippmann, M.J.; Majer, E.L.; Pruess, K.

    1982-03-01

    As part of The Geysers research activities of DOE`s Geothermal Reservoir Technology Program, LBL, in close co-operation with industry, is performing fundamental and applied studies of vapor- dominated geothermal systems. These studies include the development of new methods for evaluating cold water injection, monitoring of the seismic activity in The Geysers associated with injection and production, interpretation of pressure and geochemical changes measured during well tests and long-term production and injection operations, and improvement of existing models of the geothermal system. A review is given of the latest results of DOE-sponsored LBL reservoir engineering and seismic studies relevant to The Geysers.

  10. LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies

    SciTech Connect

    Bodvarsson, G.S.; Lippmann, M.J.; Majer, E.L.; Pruess, K.

    1992-03-24

    As part of The Geysers research activities of DOE's Geothermal Reservoir Technology Program, LBL, in close cooperation with industry, is performing fundamental and applied studies of vapor-dominated geothermal systems. These studies include the development of new methods for evaluating cold water injection, monitoring of the seismic activity in The Geysers associated with injection and production, interpretation of pressure and geochemical changes measured during well tests and long-term production and injection operations, and improvement of existing models of the geothermal system. A review is given of the latest results of DOE-sponsored LBL reservoir engineering and seismic studies relevant to The Geysers.

  11. LBL research on The Geysers: Conceptual models, simulation and monitoring studies

    SciTech Connect

    Bodvarsson, G.S.; Lippmann, M.J.; Majer, E.L.; Pruess, K.

    1992-03-01

    As part of The Geysers research activities of DOE's Geothermal Reservoir Technology Program, LBL, in close co-operation with industry, is performing fundamental and applied studies of vapor- dominated geothermal systems. These studies include the development of new methods for evaluating cold water injection, monitoring of the seismic activity in The Geysers associated with injection and production, interpretation of pressure and geochemical changes measured during well tests and long-term production and injection operations, and improvement of existing models of the geothermal system. A review is given of the latest results of DOE-sponsored LBL reservoir engineering and seismic studies relevant to The Geysers.

  12. Source mechanisms of microearthquakes at the Southeast Geysers geothermal field, California

    SciTech Connect

    Kirkpatrick, Ann; Peterson, John E., Jr.; Majer, Ernest L.

    1996-01-24

    Source mechanisms of 985 microearthquakes at the Southeast Geysers geothermal field, are investigated using a moment tensor formulation. P- and S-wave amplitude and polarity are utilized to estimate the full, second-order moment tensor, which is then decomposed into isotropic, double-couple, and compensated linear vector dipole components. The moment tensor principal axes are used to infer the directions of principal stress associated with the double-couple component of the source mechanism. Most of the events can be modeled as primarily double-couple; however, a small but significant isotropic component, which can be either positive or negative, is also needed to explain the observed waveforms. Events with positive isotropic components and events with negative isotropic components both occur in areas of steam extraction and in areas of fluid injection. Principal axes of moment tensors with negative isotropic components are aligned with the regional stress field, while those of moment tensors with positive isotropic components differ significantly from the regional stress field. This suggests that two differing inducing mechanisms are required: negative-type events involve local stress perturbations that are small compared to the regional stress, while positive-type events involve stress perturbations which locally dominate over the regional stress.

  13. Failure analysis report geothermal steam muffler diffusers, the Geysers, California

    SciTech Connect

    McAlpin, Ron; Ellis, Peter F.

    1980-04-01

    On 29 January 1980, the Failure Analysis Laboratory at Radian Corporation received portions of the inner and outer diffusers from a geothermal steam discharge silencer-operated by Thermogenics, Incorporated at Unit No.15, The Geysers, California, for determination of the cause of premature failure, This and several other T 304 stainless steel diffusers have failed with numerous cracks evident. This report considers the causes of failure of the inner and outer diffusers. A geothermal discharge silencer with steam input line is shown in Figure 1; Figure 2 shows several failed stainless steel diffusers. This report is part of a continuing DOE effort to gain insight into component materials employed in geothermal energy utilization. The results of these analyses will be incorporated into the next issue of DOE's Material Selection Guidelines for Geothermal Energy Systems. The first commercial production of electricity from geothermal energy in the western hemisphere occurred in 1960 at The Geysers, a vapor-dominated resource located in Sonoma and Lake counties, California. Steam from numerous geothermal wells is supplied to fifteen generating units with a combined capacity of over 900 Mw(e). When a turbine is tripped off-line, steam is discharged through a silencer for noise abatement, as required by environmental regulations. The silencer at Unit 15 consists of two double-walled cylindrical diffusers mounted horizontally in the base of a discharge tower (Figure 1). During a trip, approximately 550,000 lb{sub m}/hr of steam at 350 F is vented through the silencer. The duration of a trip cycle varies from several hours to a full week. Unit No.15 is the only unit at The Geysers to use a stainless steel diffuser type muffler. All other units have successfully operated with a carbon steel distribution header imbedded in a redwood box filled with lava rock. In the stack shown in Figure 1, there are two sets of diffusers, each with an inner and outer diffuser; both have

  14. Gas geyser syndrome: An important preventable cause of disabling neurological events.

    PubMed

    Correia, Pamela; Agrawal, Chandrashekhar; Ranjan, Rajeev

    2013-04-01

    To bring to light the greatly hazardous effects of the use of flue less gas geysers in the domestic setting. Over a period of two years (2008 to 2010) twenty six cases were documented as presenting with unexplained neurological events while bathing in an ill ventilated bathroom with a functional flue less gas geyser. The cases were mainly of three distinct prototypes namely seizure like episodes seen in 11 patients, carbon monoxide intoxication in 13 patients with near cardiac arrest in 4, and as a precipitating factor for epilepsy as seen in 2 cases. Out of the 13 cases presenting as carbon monoxide intoxication 4 had subtle cognitive defects and 2 developed early Parkinsonian features on follow up. To increase awareness regarding gas geyser induced epilepsy and associated carbon monoxide intoxication, both of which are entirely preventable conditions. We also wish to emphasize the importance of stringent and universal implementation of gas geyser usage and installation laws.

  15. Climate-induced variations of geyser periodicity in Yellowstone National Park, USA

    USGS Publications Warehouse

    Hurwitz, S.; Kumar, A.; Taylor, R.; Heasler, H.

    2008-01-01

    The geysers of Yellowstone National Park, United States, attract millions of visitors each year, and their eruption dynamics have been the subject of extensive research for more than a century. Although many of the fundamental aspects associated with the dynamics of geyser eruptions have been elucidated, the relationship between external forcing (Earth tides, barometric pressure, and precipitation) and geyser eruption intervals (GEIs) remains a matter of ongoing debate. We present new instrumental GEI data and demonstrate, through detailed time-series analysis, that geysers respond to both long-term precipitation trends and to the seasonal hydrologic cycle. Responsiveness to long-term trends is reflected by a negative correlation between the annual averages of GEIs and stream flow in the Madison River. This response is probably associated with long-term pressure changes in the underlying hydrothermal reservoir. We relate seasonal GEI lengthening to snowmelt recharge. ?? 2008 The Geological Society of America.

  16. Microbial Biosignature Preservation at Crystal Geyser, Utah: A Potential Analog for Taphonomic Processes on Mars

    NASA Astrophysics Data System (ADS)

    Zaloumis, J.; Farmer, J. D.

    2014-07-01

    Mineralization at Crystal Geyser promotes the capture of cellular remains of microbial communities living in the spring environment. Thin sections show complex biogenic structures. Microscopic photography shows some evidence of fossilized cells.

  17. Development of an Enhanced Two-Phase Production System at the Geysers Geothermal Field

    SciTech Connect

    Steven Enedy

    2001-12-14

    A method was developed to enhance geothermal steam production from two-phase wells at THE Geysers Geothermal Field. The beneficial result was increased geothermal production that was easily and economically delivered to the power plant.

  18. Gas geyser syndrome: An important preventable cause of disabling neurological events.

    PubMed

    Correia, Pamela; Agrawal, Chandrashekhar; Ranjan, Rajeev

    2013-04-01

    To bring to light the greatly hazardous effects of the use of flue less gas geysers in the domestic setting. Over a period of two years (2008 to 2010) twenty six cases were documented as presenting with unexplained neurological events while bathing in an ill ventilated bathroom with a functional flue less gas geyser. The cases were mainly of three distinct prototypes namely seizure like episodes seen in 11 patients, carbon monoxide intoxication in 13 patients with near cardiac arrest in 4, and as a precipitating factor for epilepsy as seen in 2 cases. Out of the 13 cases presenting as carbon monoxide intoxication 4 had subtle cognitive defects and 2 developed early Parkinsonian features on follow up. To increase awareness regarding gas geyser induced epilepsy and associated carbon monoxide intoxication, both of which are entirely preventable conditions. We also wish to emphasize the importance of stringent and universal implementation of gas geyser usage and installation laws. PMID:23956574

  19. 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.

  20. Self-pumping solar heating system with geyser pumping action

    SciTech Connect

    Haines, E.L.; Bartera, R.E.

    1984-10-23

    A self-pumping solar heating system having a collector including a multitude of small diameter riser tubes from which heated liquid is pumped into a header by a geyser action. A vapor condenser assures a header pressure conducive to bubble nucleation in the riser tube upper end segments. The level of liquid within the header or its outlet is higher than the liquid level in the riser tubes to produce a gravity imbalance capable of circulating heated liquid past a storage heat exchanger, below the header, and then upwardly through the closed vapor condenser in the header prior to return to a collector inlet manifold. A modified header utilizes an open vapor condenser in vapor communication with the collector header.

  1. Measurements of water vapor adsorption on The Geysers rocks

    SciTech Connect

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1996-04-01

    One of the goals of this project is to determine the dependence of the water retention capacity of the rocks as a function of temperature. The results show a significant dependence of the adsorption and desorption isotherms on the grain size of the sample. The increase in the amount of water retained with temperature observed previously between 90 and 30{degrees}C for various reservoir rocks from The Geysers may be due to the contribution of slow chemical adsorption and may be dependent on the time allowed for equilibration. In contrast with the results of Shang, some closed and nearly closed hysteresis loops on the water adsorption/desorption isotherms were obtained in this study. In these cases the effects of activated processes were not present, and no increase in water adsorption with temperature was observed.

  2. Caldwell Ranch Exploration and Confirmation Project, Northwest Geysers, CA

    SciTech Connect

    Walters, Mark A.

    2013-04-25

    The purpose of the Caldwell Ranch Exploration and Confirmation Project was to drill, test, and confirm the present economic viability of the undeveloped geothermal reservoir in the 870 acre Caldwell Ranch area of the Northwest Geysers that included the CCPA No.1 steam field. All of the drilling, logging, and sampling challenges were met. Three abandoned wells, Prati 5, Prati 14 and Prati 38 were re-opened and recompleted to nominal depths of 10,000 feet in 2010. Two of the wells required sidetracking. The flow tests indicated Prati 5 Sidetrack 1 (P-5 St1), Prati 14 (P-14) and Prati 38 Sidetrack 2 (P-38 St2) were collectively capable of initially producing an equivalent of 12 megawatts (MWe) of steam using a conversion rate of 19,000 pounds of steam/hour

  3. Model study of historical injection in the southeast Geysers

    SciTech Connect

    Faulder, D.D.

    1992-08-01

    A three component model study of the historical injection of two wells in the Unit 13 area demonstrates that the recovery of injection derived steam is influenced by the geologic structure of the bottom of the reservoir and the relative location of injection wells. The migration of injectate from the first injection well, located up structure from the second, quenched the area around the second injector before it started operation. While both wells had similar cumulative mass injected, nearly five times more injection derived steam is recovered from the first injector than the-second. Sensitivity runs were made to three cases of increasing matrix capillary pressure. The recovery of injection derived steam increases with higher values of capillarity. The interaction of structure at the bottom of the reservoir, injection well locations, and matrix capillarity all influence the recovery efficiency of injected as steam. The model developed in this study will be used to evaluate injection strategies at The Geysers.

  4. Model study of historical injection in the southeast Geysers

    SciTech Connect

    Faulder, D.D.

    1992-01-01

    A three component model study of the historical injection of two wells in the Unit 13 area demonstrates that the recovery of injection derived steam is influenced by the geologic structure of the bottom of the reservoir and the relative location of injection wells. The migration of injectate from the first injection well, located up structure from the second, quenched the area around the second injector before it started operation. While both wells had similar cumulative mass injected, nearly five times more injection derived steam is recovered from the first injector than the-second. Sensitivity runs were made to three cases of increasing matrix capillary pressure. The recovery of injection derived steam increases with higher values of capillarity. The interaction of structure at the bottom of the reservoir, injection well locations, and matrix capillarity all influence the recovery efficiency of injected as steam. The model developed in this study will be used to evaluate injection strategies at The Geysers.

  5. Model study of historical injection in the Southeast Geysers

    SciTech Connect

    Faulder, D.D.

    1992-01-01

    A three component model study of the historical injection of two wells in the Unit 13 area demonstrates that the recovery of injection derived steam is influenced by the geologic structure of the bottom of the reservoir and the relative location of injection wells. the migration of injectate from the first injection well, located up structure from the second, quenched the area around the second injector before it started operation. while both wells had similar cumulative mass injected, nearly five times more injection derived steam is recovered from the first injector than the second. Sensitivity runs were made to three cases of increasing matrix capillary pressure. The recovery of injection derived steam increases with higher values of capillarity. The interaction of structure at the bottom of the reservoir, injection well locations, and matrix capillarity all influence the recovery efficiency of injectate as steam. The model developed in this study will be used to evaluate injection strategies at The Geysers.

  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. Hydrologic characterization of four cores from the Geysers Coring Project

    SciTech Connect

    Persoff, Peter; Hulen, Jeffrey B.

    1996-01-24

    Results of hydrologic tests conducted on four representative core plugs from Geysers Coring Project drill hole SB-15-D have been related to detailed mineralogic and textural characterization of the plugs to yield new information about permeability, porosity, and capillary-pressure characteristics of the uppermost Geysers steam reservoir and its immediately overlying caprock. The core plugs are all fine- to medium-grained, Franciscan-assemblage (late Mesozoic) metagraywacke with sparse Franciscan metamorphic quartz-calcite veins and late Cenozoic, hydrothermal quartz-calcite-pyrite veins. The matrices of three plugs from the caprock are rich in metamorphic mixed-layer illite/smectite and disseminated hydrothermal pyrite; the reservoir plug instead contains abundant illite and only minor pyrite. The reservoir plug and one caprock plug are sparsely disrupted by latest-stage, unmineralized microfractures which both follow and crosscut veinlets but which could be artifacts. Porosities of the plugs, measured by Boyles-law gas expansion, range between 1.9 and 2.5%. Gas permeability and Klinkenberg slip factor were calculated from gas-pressure-pulse-decay measurements using a specially designed permeameter with small (2 mL) reservoirs. Matrix permeabilities in the range 10-21 m² ( = 1 nanodarcy) were measured for two plugs that included mineral-filled veins but no unfilled microfractures. Greater permeabilities were measured on plugs that contained microfractures; at 500 psi net confining pressure, an effective aperture of 1.6 µm was estimated for one plug. Capillary pressure curves were determined for three cores by measuring saturation as weight gain of plugs equilibrated with atmospheres in which the relative humidity was controlled by saturated brines.

  8. Surface and subsurface hydrothermal flow pathways at Norris Geyser Basin, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Graham Wall, B. R.

    2005-12-01

    During summer 2003 at Yellowstone's Norris Geyser Basin notable changes were observed in the discharge of heat and steam, creating new thermal features, dying vegetation, and the consequent closure of trails to protect public safety. In order to interpret data collected from GPS, seismic, and temperature instruments deployed in response to the increased hydrothermal activity, a study has been undertaken to provide a more complete knowledge of the spatial distribution of subsurface fluid conduits. Geologic data, including mapped outcrops, aerial imagery, thermal infrared imagery, and subsurface core, indicate that fracture pathways in the Lava Creek Tuff (LCT) channel flow in the hydrothermal system. These data show clear evidence that NE-SW and NW-SE trending structures provide major flow pathways at Norris. By mapping fracture sets in outcrops of LCT with varied degrees of hydrothermal alteration, one can consistently identify fractures that localize hydrothermal fluid flow, alteration, and the geometry of surface thermal features. Alteration is characterized by acid leaching that quickly alters LCT mafic minerals and glassy groundmass, which in outcrop is recognized by corroded and disaggregated LCT with local secondary mineral deposition. Mapping the sequence from unaltered to altered LCT has identified vertical cooling joints as primary conduits for hydrothermal fluids. These vertical joints correlate with the NE-SW trending geomorphic expression of the LCT in this area, and parallel the adjacent caldera boundary. Horizontal fractures parallel depositional stratigraphy, and in core from drill holes Y-9 (248 m) and Y-12 (332 m) appear to initiate at collapsed vapor-phase cavities or regions of altered fiamme. Vertical fractures in the core show sequences of hydrothermal minerals locally derived from water-rock interaction that line fracture walls, characteristic of mineral deposition associated with repeat reactivation. Although the hydrothermal system is

  9. Temporal Chemical Variations during the Eruption Cycle at Crystal Geyser in Green River, Utah: Inverse Modeling of Fluid Sourcing and Implications to the Geyser Mechanism

    NASA Astrophysics Data System (ADS)

    Watson, Z. T.; Han, W. S.; Kampman, N.; Grundl, T.; Han, K.

    2014-12-01

    The most well-known example of a CO2-driven geyser is Crystal geyser in Green River, Utah. In situ monitoring of pressure and temperature and analysis of the elemental and isotopic composition of the emanating fluids has provided useful proxies for determining the geysering cycle, the source of water/CO2 and furthermore the physical constraints at depth which ultimately control the surficial expressions. Crystal geyser is the first geyser in the world which has been shown to go through repeated systematic chemical variations during its eruption cycle. The eruption cycle at Crystal geyser is comprised of 4 parts which follow the order of: minor eruption period (mEP), major eruption period (MEP), aftershock eruptions (Ae) and recharge period (R). Minor eruption periods are characterized by increasing specific conductivity (19.3 to 21.2 mS/cm), Na and Cl concentrations during the first half which plateau until the MEP. The beginning of the MEP denotes a sharp drop in temperature (17.4 to 16.8 ºC) Na, Cl, specific conductivity (21.2 to 18 mS/cm), and increasing concentrations of Fe, Sr, Ca, Mg and Mn. Downhole fluid sampling of the Entrada Sandstone and Navajo Sandstone provided 1 and 4 samples from the aquifers, respectively. The Entrada Sandstone in comparison to the deeper Navajo Sandstone has elevated concentrations of Sr and Fe and has lower concentrations of Na and Cl. Inverse modeling using the chemical characteristics of the Entrada Sandstone, Navajo Sandstone and brine was executed to determine the fractional inputs which comprise Crystal geyser's fluid. Variances in the fractional contribution are dependent on the depth of the sample chosen to be representative of the Navajo Sandstone because the concentration of Na and Cl, among other elements, changes over depth. During the mEP the Navajo Sandstone, Entrada Sandstone and brine supply 50-55%, 44-48% and 1-3% of the total fluid, respectively. During the MEP the Navajo Sandstone, Entrada Sandstone and brine

  10. Determining the 3-D fracture structure in the Geysers geothermal reservoir

    SciTech Connect

    Sammis, Charles G.; Linji An; Iraj Ershaghi

    1992-01-01

    fracture development in heterogeneous media also produce fractal patterns. However, a physical interpretation of the mechanics which produce the observed fractal geometry remains an active area of current research. Two hypotheses for the physical cause of self-similarity are the Laplacian growth of fractures in a self-organized critical stress field, and the evolution of percolation clusters in a random medium. Each predicts a different, fractal dimension. The more important questions from a reservoir engineering point of view are: (1) is the network of fractures in the Geysers reservoir fractal and if so over what range of fracture sizes is the self-similarity observed and what is its fractal dimension, and (2) do the conventional dual porosity numerical simulation schemes provide an adequate description of flow and heat mining at the Geysers? Other papers in this volume by Acuna, Ershaghi, and Yortsos (1992) and Mukhopodhyoy and Sahimi (1992) address the second question. The primary objective of this paper is to try to answer the first. Toward this goal we have mapped fracture patterns in surface exposures of the graywacke source rock at the outcrop scale (meters), at the road-cut scale (tens of meters) and at the regional scale (kilometers). We have also examined cores collected at depth from the graywacke reservoir rocks, and analyzed drilling logs making use of the pattern of steam entries as well as the fluctuations in drilling rate.

  11. The Mw4.8 Norris Geyser Basin Earthquake of 30 March, 2014 and its Relationship to Crustal Deformation and Seismic Activity of the Yellowstone Volcanic System

    NASA Astrophysics Data System (ADS)

    Farrell, J.; Shelly, D. R.; Smith, R. B.; Puskas, C. M.; Chang, W. L.

    2014-12-01

    The largest earthquake to be recorded in Yellowstone in over 30 years, a magnitude 4.8 earthquake, occurred on March 30, 2014 near the Norris Geyser Basin on the NW side of the 0.64 Ma Yellowstone caldera. The earthquake was felt throughout Yellowstone and the surrounding region. We analyze this unusual event using data from the Yellowstone Seismic and Geodetic networks in the context of active volcanic-tectonic processes of the Yellowstone volcanic system and its relationship to regional swarm seismicity and crustal deformation. Moment tensor analysis of the March 30 earthquake revealed a strike-slip, double-couple source mechanism with no isotropic contribution. This earthquake was part of a larger sequence of earthquake swarm activity in the Norris Geyser Basin area that began in September 2013 and continued into June 2014. During that period, 50-60% of the total seismicity recorded in Yellowstone, including nearly all of the swarm seismicity (earthquakes clustered in time and space), occurred in the Norris Geyser Basin area. In addition, GPS derived deformation data revealed unusually high uplift rates at ~15 cm/yr in the Norris area prior to the MW4.8 event, while a dramatic reversal to subsidence at rates of ~20 cm/yr occurred after the event. Regionally, the much larger Yellowstone caldera had experienced subsidence since January 2010 at rates of ~1.5 cm/yr prior to the MW4.8 event. After March 30, 2014 the caldera reversed to regional uplift at rates of ~10 cm/yr, similar to accelerated uplift rates observed in mid-2004.

  12. Aerometric measurement and modeling of the mass of CO2 emissions from Crystal Geyser, Utah

    SciTech Connect

    Gouveia, F J; Johnson, M R; Leif, R N; Friedmann, S J

    2005-02-07

    Crystal Geyser in eastern Utah is a rare, non-geothermal geyser that emits carbon dioxide gas in periodic eruptions. This geyser is the largest single source of CO{sub 2} originating from a deep reservoir. For this study, the amount of CO{sub 2} emitted from Crystal Geyser is estimated through measurements of downwind CO{sub 2} air concentration applied to an analytical model for atmospheric dispersion. Five eruptions occurred during the 48-hour field study, for a total of almost 3 hours of eruption. Pre-eruption emissions were also timed and sampled. Slow wind during three of the active eruptions conveyed the plume over a grid of samplers arranged in arcs from 25 to 100 m away from the geyser. An analytical, straight-line Gaussian model matched the pattern of concentration measurements. Plume width was determined from least-squares fit of the CO{sub 2} concentrations integrated over time. The CO{sub 2} emission rate was found to be between 2.6 and 5.8 kg/s during the eruption events, and about 0.17 kg/s during the active pre-eruptive events. Our limited field study can be extrapolated to an annual CO{sub 2} emission of 12 kilotonnes from this geyser. As this is the first application of Gaussian dispersion modeling and objective timing to CO{sub 2} emissions from a geyser of any type, the present study demonstrates the feasibility of applying this method more completely in the future.

  13. Geysers Valley, Kamchatka: Why Landslide of 3-June-2007 Took Place and What Happens After

    NASA Astrophysics Data System (ADS)

    Kiryukhin, A. V.; Rychkova, T. V.; Chernykh, E. V.; Vergasova, L. P.

    2008-12-01

    Analysis of the hydrogeological conditions of the landslide, which took place in the Geysers Valley, Kamchatka on June 3-rd, 2007 shows that possible reason of this was a long term steam upflow occurred along slightly inclined bottom of the Geyzernaya pumice tuffs unit, which finally resulted into deep hydrothermal alteration of the pumice to highly silicified zeolites and montmorillonite, with corresponding loosing of the stability. Landslide triggers may associate with different events including plumbing magma system pressure increase, seasons waterfloods or steam explosions. Landslide took place in a few minutes yielded 10 mln m3 of mud, debris, and blocks of rocks. As a result of this - some geysers located at lower elevations were sealed under 10-30 m thick caprock and a rock dumb trap Geysernaya river into 20 m deep Lake. One year monitoring of the two key geysers eruptions cycling (Velikan and Bolshoy), lake level and thermal discharge into the Lake floor yield to the following results: 1. Velikan maintains stable geysers activity cycling with an average time period 372 min (31 July 2007 - 6 July 2008), slightly exceeding time period before landslide - 339 min (17 Aug - 5 Oct 2003). Time period increase after landslide off-load and some response to the barometric pressure maximums - may characterize geyser sensitivity to the stress; 2. Bolshoy maintained geysers activity with average time period 64-84 min during Sept 2007 - May 2008 at low Lake levels, the rest of the time cold water from Lake inflows into the geysers channel, terminating its activity. Note, Bolshoy time period before landslide was estimated as 108 min (17 Aug - 5 Oct 2003); 3. Thermal discharge into the Lake floor is sensitive to the Lake level, significantly increasing in the winter time.

  14. Broadband Seismic Observations of Lone Star Geyser, Yellowstone National Park, Wyoming, USA

    NASA Astrophysics Data System (ADS)

    Nayak, A.; Hurwitz, S.; Johnson, H. E., III; Manga, M.; Gomez, F. G.

    2014-12-01

    Geysers are natural phenomena that episodically erupt water and steam. Geophysical observations at geysers are analyzed to shed light on subsurface multi-phase mass and heat exchange processes and geometries controlling geyser eruptions, which are still are not completely understood. Lone Star Geyser (LSG) in Yellowstone National Park, Wyoming, USA erupts every ~3 hours, with brief episodes (~5-10 min) of water and steam fountaining (preplays) leading up to the main eruption (~28 min), and the discharge evolves from a water-dominated phase to a steam-dominated phase as the main eruption proceeds in time. We describe observations from multiple seismometers deployed around LSG as part of a comprehensive geophysical survey conducted in April 2014. 3-component seismograms were continuously recorded at 250 samples per second by 6 Nanometrics Trillium 120 P/PA broadband seismometers (lower corner frequency at 120 seconds) and Taurus dataloggers at distances ~10 to 25 m from the geyser cone for a period of 3 days. We identify distinct episodes of hydrothermal tremor associated with preplay events and main eruptions. We find that the dominant tremor frequencies during main eruptions are consistently higher (> 10.0 Hz) than those during preplays (> 1.0 Hz) indicating slightly different source locations or processes controlling the two phenomena. Unlike seismic observations at the Old Faithful Geyser, we also observe subtle harmonic tremor and spectral gliding in the frequency range ~1.0-8.0 Hz towards the end of both main eruption and preplay tremor episodes. We interpret long-period pulses on horizontal components of the seismometers located close to the geyser and synchronous with preplays, as pseudo-tilts resulting from deformation of the sinter terrace. We also compare the evolution of hydrothermal tremor in time with synchronous changes in temperature, acoustic emission and discharge for interpretation of the possible tremor source processes.

  15. A vapor-dominated reservoir exceeding 600{degrees}F at the Geysers, Sonoma County, California

    SciTech Connect

    Walters, M.A.; Sternfeld, J.N.; Haizlip, J.R.; Drenick, A.F.; Combs, Jim

    1988-01-01

    A high-temperature vapor-dominated reservoir underlies a portion of the Northwest Geysers area, Sonoma County, California. The high-temperature reservoir (HTR) is defined by flowing fluid temperatures exceeding 500º F, rock temperatures apparently exceeding 600º F and steam enthalpies of about 1320 BTU/lb. Steam from existing wells drilled in the Northwest Geysers is produced from both a “typical” Geysers reservoir and the HTR. In all cases, the HTR is in the lower portion of the wells and is overlain by a “typical” Geysers reservoir. Depth to the high-temperature reservoir is relatively uniform at about -5900 ft subsea. There are no identified lithologic or mineralogic conditions that separate the HTR from the “typical” reservoir, although the two reservoirs are vertically distinct and can be located in most wells to within about 200 ft by the use of downhole temperature-depth measurements. Gas concentrations in steam from the HTR are higher (6 to 9 wt %) than from the “typical” Geysers reservoir (0.85 to 2.6 wt %). Steam from the HTR is enriched in chloride and the heavy isotopes of water relative to the “typical” reservoir. Available static and dynamic measurements show pressures are subhydrostatic in both reservoirs with no anomalous differences between the two: the HTR pressure being near 520 psia at sea level datum. The small observed differences in pressure between the reservoirs appear to vary along a steam density gradient. It is postulated that the Northwest Geysers area evolved more slowly toward vapor-dominated conditions than other parts of The Geysers field because of its poor connection with the surface. In this paper, a model is presented in which the boundary between the HTR and “typical” reservoir is a thermodynamic feature only, resulting from recent deep venting of a liquid-dominated system in which conduction is still an important component of heat transfer.

  16. Convective Troposphere-Stratosphere Transport in the Tropics and Hydration by ice Crystals Geysers

    NASA Astrophysics Data System (ADS)

    Pommereau, J.

    2008-12-01

    Twenty-five years ago the suggestion was made by Danielsen of direct fast convective penetration of tropospheric air in the stratosphere over land convective systems. Although the existence of the mechanism is accepted, it was thought to be rare and thus its contribution to Troposphere-Stratosphere Transport (TST) of chemical species and water vapour at global scale unimportant at global scale. In contrast to this assumption, observations of temperature, water vapour, ice particles, long-lived tropospheric species during HIBISCUS, TROCCINOX and SCOUT-O3 over Brazil, Australia and Africa and more recently CALIPSO aerosols observations suggest that it is a general feature of tropical land convective regions in the summer. Particularly relevant to stratospheric water vapour is the observation of geyser like ice crystals in the TTL over overshooting events which may result in the moistening of the stratosphere. Although such events successfully captured by small scale Cloud-Resolving Models may have a significant impact on stratospheric ozone chemistry and climate, they are currently totally ignored by NWPs, CTMs and CCMs. Several recent balloon and aircraft observations of overshoots and CRM simulations will be shown illustrating the mechanism, as well as observations from a variety of satellites suggesting a significant impact at global scale.

  17. Measurements of water vapor adsorption on the Geysers rocks

    SciTech Connect

    Gruszkiewicz, Miroslaw S.; Horita, Juske; Simonson, John M.; Mesmer, Robert E.

    1996-01-24

    The ORNL high temperature isopiestic apparatus was adapted for adsorption measurements. The quantity of water retained by rock samples taken from three different wells of The Geysers was measured at 150 °C and at 200 °C as a function of pressure in the range 0.00 ≤ p/p0 ≤ 0.98, where p0 is the saturated water vapor pressure. The rocks were crushed and sieved into three fractions of different grain sizes (with different specific surface areas). Both adsorption (increasing pressure) and desorption (decreasing pressure) runs were made in order to investigate the nature and extent of the hysteresis. Additionally, BET surface area analyses were performed by Porous Materials Inc. on the same rock samples using nitrogen or krypton adsorption measurements at 77 K. Specific surface areas and pore volumes were determined. These parameters are important in estimating water retention capability of a porous material. The same laboratory also determined the densities of the samples by helium pycnometry. Their results were then compared with our own density values obtained by measuring the effect of buoyancy in compressed argon. One of the goals of this project is to determine the dependence of the water retention capacity of the rocks as a function of temperature. The results show a significant dependence of the adsorption and desorption isotherms on the grain size of the sample. The increase in the amount of water retained with temperature observed previously (Shang et al., 1994a, 1994b, 1995) between 90 and 130°C for various reservoir rocks from The Geysers may be due to the contribution of slow chemical adsorption and may be dependent on the time allowed for equilibration. In contrast with the results of Shang et al. (1994a, 1994b, 1995), some closed and nearly closed hysteresis loops on the water adsorption/desorption isotherms (with closing points at p/p0 ≈ 0.6) were obtained in this study. In these cases the effects of activated

  18. 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

  19. Dissolved gases in hydrothermal (phreatic) and geyser eruptions at Yellowstone National Park, USA

    USGS Publications Warehouse

    Hurwitz, Shaul; Clor, Laura; McCleskey, R. Blaine; Nordstrom, D Kirk; Hunt, Andrew G.; Evans, William C.

    2016-01-01

    Multiphase and multicomponent fluid flow in the shallow continental crust plays a significant role in a variety of processes over a broad range of temperatures and pressures. The presence of dissolved gases in aqueous fluids reduces the liquid stability field toward lower temperatures and enhances the explosivity potential with respect to pure water. Therefore, in areas where magma is actively degassing into a hydrothermal system, gas-rich aqueous fluids can exert a major control on geothermal energy production, can be propellants in hazardous hydrothermal (phreatic) eruptions, and can modulate the dynamics of geyser eruptions. We collected pressurized samples of thermal water that preserved dissolved gases in conjunction with precise temperature measurements with depth in research well Y-7 (maximum depth of 70.1 m; casing to 31 m) and five thermal pools (maximum depth of 11.3 m) in the Upper Geyser Basin of Yellowstone National Park, USA. Based on the dissolved gas concentrations, we demonstrate that CO2 mainly derived from magma and N2 from air-saturated meteoric water reduce the near-surface saturation temperature, consistent with some previous observations in geyser conduits. Thermodynamic calculations suggest that the dissolved CO2 and N2 modulate the dynamics of geyser eruptions and are likely triggers of hydrothermal eruptions when recharged into shallow reservoirs at high concentrations. Therefore, monitoring changes in gas emission rate and composition in areas with neutral and alkaline chlorine thermal features could provide important information on the natural resources (geysers) and hazards (eruptions) in these areas.

  20. Odorless inhalant toxic encephalopathy in developing countries household: Gas geyser syndrome

    PubMed Central

    Mehta, Anish; Mahale, Rohan; John, Aju Abraham; Abbas, Masoom Mirza; Javali, Mahendra; Acharya, Purushottam; Rangasetty, Srinivasa

    2016-01-01

    Background: Liquefied petroleum gas geysers are used very frequently for heating water in developing countries such as India. However, these gas geysers emit various toxic gases; one among them is colorless, odorless carbon monoxide (CO). In the past few years, there were reports of unexplained loss of consciousness in the bathroom. However, the exact cause for these episodes has been recognized as toxic encephalopathy due to toxic gases inhalation mainly CO. Objective: To analyze the clinical profile and outcome of patients brought with loss of consciousness in the bathroom while bathing using gas geyser. Materials and Methods: Case records of patients with the diagnosis of gas geyser syndrome from 2013 to 2015 were retrieved and analyzed. Twenty-four cases were identified and included in the study. This was a retrospective, descriptive study. Results: Twenty-four patients were brought to our Emergency Department with loss of consciousness in the bathroom while bathing. Twenty-one cases had loss of consciousness during bathing and recovered spontaneously. Two cases were found dead in the bathroom and were brought to the Department of Forensic Medicine for postmortem. One case was brought in deep altered state of consciousness and succumbed to illness within 1 week. Conclusion: Awareness regarding CO intoxication due to usage of ill-fitted, ill-ventilated gas geyser is necessary as they are entirely preventable conditions. PMID:27114653

  1. Triton's Geyser-Like Plumes: Discovery and Basic Characterization.

    PubMed

    Soderblom, L A; Kieffer, S W; Becker, T L; Brown, R H; Cook, A F; Hansen, C J; Johnson, T V; Kirk, R L; Shoemaker, E M

    1990-10-19

    At least four active geyser-like eruptions were discovered in Voyager 2 images of Triton, Neptune's large satellite. The two best documented eruptions occur as columns of dark material rising to an altitude of about 8 kilometers where dark clouds of material are left suspended to drift downwind over 100 kilometers. The radii of the rising columns appear to be in the range of several tens of meters to a kilometer. One model for the mechanism to drive the plumes involves heating of nitrogen ice in a subsurface greenhouse environment; nitrogen gas pressurized by the solar heating explosively vents to the surface carrying clouds of ice and dark partides into the atmosphere. A temperature increase of less than 4 kelvins above the ambient surface value of 38 +/- 3 kelvins is more than adequate to drive the plumes to an 8-kilometer altitude. The mass flux in the trailing clouds is estimated to consist of up to 10 kilograms of fine dark particles per second or twice as much nitrogen ice and perhaps several hundred or more kilograms of nitrogen gas per second. Each eruption may last a year or more, during which on the order of a tenth of a cubic kilometer of ice is sublimed.

  2. Paenibacillus cisolokensis sp. nov., isolated from litter of a geyser.

    PubMed

    Yokota, Akira; Ningsih, Fitria; Nurlaili, Dafina Ghossani; Sakai, Yasuteru; Yabe, Shuhei; Oetari, Ariyanti; Santoso, Iman; Sjamsuridzal, Wellyzar

    2016-08-01

    A Gram-stain-positive, endospore-forming, aerobic and thermophilic bacterium, designated strain LC2-13AT, was isolated from Cisolok geyser, West Java, Indonesia, at 50 °C. The isolate was rod-shaped and motile by means of peritrichous flagella. The major cellular fatty acids were iso-C16 : 0, C16 : 0 and anteiso-C15 : 0 and the major quinone was menaquinone 7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The genomic DNA G+C content was 56.6 mol% and the major diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain LC2-13AT is related most closely to Paenibacillus kobensis DSM 10249T (94.86 % similarity), Paenibacillus tarimensis SA-7-6T (94.77 %) and Paenibacillus barengoltzii SAFN-016T (94.77 %). On the basis of phenotypic, chemotaxonomic and phylogenetic evidence, strain LC2-13AT is affiliated to the genus Paenibacillus, but could be distinguished from recognized species of this genus. A novel species with the name Paenibacillus cisolokensis sp. nov. is thus proposed. The type strain is LC2-13AT (=UICC B-42T=NRRL B-65368T=DSM 101873T).

  3. Mitigation of hydrogen sulfide emissions in The Geysers KGRA

    SciTech Connect

    Buell, R.

    1981-07-01

    Violations of the ambient air quality standard (AAQS) for hydrogen sulfide (H/sub 2/S) are currently being experienced in The Geysers KGRA and could significantly increase in the future. Attainment and maintenance of the H/sub 2/S AAQS is a potential constraint to optimum development of this resource. The availability of reliable H/sub 2/S controls and the development of a validated air dispersion model are critical to alleviating this constraint. The purpose of this report is to assess the performance capabilities for state-of-the-art controls, to identify potential cost-effective alternative controls, and to identify the California Energy Commission (CEC) staff's efforts to develop a validated air dispersion model. Currently available controls (Stretford, Hydrogen Peroxide, and EIC) are capable of abating H/sub 2/S emissions from a proposed facility to five lbs/hr. Alternative controls, such as condensate stripping and condensate pH control, appear to be promising, cost-effective control options.

  4. High temperature water adsorption on The Geysers rocks

    SciTech Connect

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1997-08-01

    In order to measure water retention by geothermal reservoir rocks at the actual reservoir temperature, the ORNL high temperature isopiestic apparatus was adapted for adsorption measurements. The quality of water retained by rock samples taken from three different wells of The Geysers geothermal reservoir was measured at 150{sup degree}C, 200{sup degree}C, and 250{sup degree}C as a function of pressure in the range 0.00 {<=}p/p{sub degree} {<=} 0.98, where p{sub degree} is the saturated water vapor pressure. Both adsorption (increasing pressure) and desorption (decreasing pressure) runs were made in order to investigate the nature and the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were performed on the same rock samples. Nitrogen or krypton adsorption and desorption isotherms at 77 K were used to obtain BET specific surface areas, pore volumes and their distributions with respect to pore sizes. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A correlation is sought between water adsorption, the surface properties, and the mineralogical and petrological characteristics of the solids.

  5. Paenibacillus cisolokensis sp. nov., isolated from litter of a geyser.

    PubMed

    Yokota, Akira; Ningsih, Fitria; Nurlaili, Dafina Ghossani; Sakai, Yasuteru; Yabe, Shuhei; Oetari, Ariyanti; Santoso, Iman; Sjamsuridzal, Wellyzar

    2016-08-01

    A Gram-stain-positive, endospore-forming, aerobic and thermophilic bacterium, designated strain LC2-13AT, was isolated from Cisolok geyser, West Java, Indonesia, at 50 °C. The isolate was rod-shaped and motile by means of peritrichous flagella. The major cellular fatty acids were iso-C16 : 0, C16 : 0 and anteiso-C15 : 0 and the major quinone was menaquinone 7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The genomic DNA G+C content was 56.6 mol% and the major diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain LC2-13AT is related most closely to Paenibacillus kobensis DSM 10249T (94.86 % similarity), Paenibacillus tarimensis SA-7-6T (94.77 %) and Paenibacillus barengoltzii SAFN-016T (94.77 %). On the basis of phenotypic, chemotaxonomic and phylogenetic evidence, strain LC2-13AT is affiliated to the genus Paenibacillus, but could be distinguished from recognized species of this genus. A novel species with the name Paenibacillus cisolokensis sp. nov. is thus proposed. The type strain is LC2-13AT (=UICC B-42T=NRRL B-65368T=DSM 101873T). PMID:27188601

  6. Triton's Geyser-Like Plumes: Discovery and Basic Characterization.

    PubMed

    Soderblom, L A; Kieffer, S W; Becker, T L; Brown, R H; Cook, A F; Hansen, C J; Johnson, T V; Kirk, R L; Shoemaker, E M

    1990-10-19

    At least four active geyser-like eruptions were discovered in Voyager 2 images of Triton, Neptune's large satellite. The two best documented eruptions occur as columns of dark material rising to an altitude of about 8 kilometers where dark clouds of material are left suspended to drift downwind over 100 kilometers. The radii of the rising columns appear to be in the range of several tens of meters to a kilometer. One model for the mechanism to drive the plumes involves heating of nitrogen ice in a subsurface greenhouse environment; nitrogen gas pressurized by the solar heating explosively vents to the surface carrying clouds of ice and dark partides into the atmosphere. A temperature increase of less than 4 kelvins above the ambient surface value of 38 +/- 3 kelvins is more than adequate to drive the plumes to an 8-kilometer altitude. The mass flux in the trailing clouds is estimated to consist of up to 10 kilograms of fine dark particles per second or twice as much nitrogen ice and perhaps several hundred or more kilograms of nitrogen gas per second. Each eruption may last a year or more, during which on the order of a tenth of a cubic kilometer of ice is sublimed. PMID:17793016

  7. A Reservoir Assessment of the Geysers Geothermal Field

    SciTech Connect

    Thomas, Richard P.; Chapman, Rodger H.; Dykstra, Herman; Stockton, A.D.

    1981-01-01

    Big Sulphur Creek fault zone, in The Geysers Geothermal field, may be part of a deep-seated, wrench-style fault system. Hydrothermal fluid reservoir may rise through conduits beneath the five main anomalies associated with the Big Sulphur Creek wrench trend. Upon moderately dipping, fracture network. Condensed steam at the steep reservoir flank drains back to the hot water table. These flanks are defined roughly by marginally-producing geothermal wells. Field extensions are expected to be on the southeast and northwest. Some geophysical anomalies (electrical resistivity and audio-magnetotelluric) evidently are caused by the hot water geothermal field or zones of altered rocks; others (gravity, P-wave delays, and possibly electrical resistivity) probably represent the underlying heat source, a possible magma chamber; and others (microearthquake activity) may be related to the steam reservoir. A large negative gravity anomaly and a few low-resitivity anomalies suggest areas generally favorable for the presence of steam zones, but these anomalies apparently do not directly indicate the known steam reservoir. Monitoring gravity and geodetic changes with time and mapping microearthquake activity are methods that show promise for determining reservoir size, possible recharge, production lifetime, and other characteristics of the known stream field. Seismic reflection data may contribute to the efficient exploitation of the field by identifying fracture zones that serve as conduits for the steam. (DJE-2005)

  8. Triton's geyser-like plumes: Discovery and basic characterization

    USGS Publications Warehouse

    Soderblom, L.A.; Kieffer, S.W.; Becker, T.L.; Brown, R.H.; Cook, A.F.; Hansen, C.J.; Johnson, T.V.; Kirk, R.L.; Shoemaker, E.M.

    1990-01-01

    At least four active geyser-like eruptions were discovered in Voyager 2 images of Triton, Neptune's large satellite. The two best documented eruptions occur as columns of dark material rising to an altitude of about 8 kilometers where dark clouds of material are left suspended to drift downwind over 100 kilometers. The radii of the rising columns appear to be in the range of several tens of meters to a kilometer. One model for the mechanism to drive the plumes involves heating of nitrogen ice in a sub-surface greenhouse environment; nitrogen gas pressurized by the solar heating explosively vents to the surface carrying clouds of ice and dark particles into the atmosphere. A temperature increase of less than 4 kelvins above the ambient surface value of 38 ?? 3 kelvins is more than adequate to drive the plumes to an 8-kilometer altitude. The mass flux in the trailing clouds is estimated to consist of up to 10 kilograms of fine dark particles per second or twice as much nitrogen ice and perhaps several hundred or more kilograms of nitrogen gas per second. Each eruption may last a year or more, during which on the order of a tenth of a cubic kilometer of ice is sublimed.

  9. Hydrologic characterization of four cores from the Geysers Coring Project

    SciTech Connect

    Persoff, P.; Hulen, J.B.

    1996-01-01

    Results of hydrologic tests on 4 representative core plugs from Geysers Coring Project drill hole SB-15-D were related to mineralogy and texture. Permeability measurements were made on 3 plugs from caprock and one plug from the steam reservoir. Late-stage microfractures present in 2 of the plugs contributed to greater permeability, but the values for the 2 other plugs indicate a typical matrix permeability of 1 to 2 {times} 10{sup {minus}21}m{sup 2}. Klinkenberg slip factor b for these plugs is generally consistent with the inverse relation between slip factor and permeability observed by Jones (1972) for plugs of much more permeable material. The caprock and reservoir samples are nearly identical metagraywackes with slight mineralogical differences which appear to have little effect on hydrology. The late stage microfractures are suspected of being artifacts. The capillary pressure curves for 3 cores are fit by power-law relations which can be used to estimate relative permeability curves for the matrix rocks.

  10. The origin of harmonic tremor at Old Faithful geyser

    NASA Astrophysics Data System (ADS)

    Kedar, Sharon; Sturtevant, Bradford; Kanamori, Hiroo

    1996-02-01

    VOLCANIC eruptions are sometimes accompanied by a characteristic type of seismicity known as harmonic tremor, in which the signal is dominated by discrete vibration frequencies1-4. This harmonic structure could reflect resonance behaviour in the excitation source4-6 or filtering of the seismic waves as they propagate through the surrounding rocks7-10 but complexity and variability in the properties of volcanic systems make it difficult to discriminate between such mechanisms. To address this question, we have analysed the source and propagation characteristics of seismicity at Old Faithful geyser (Yellowstone National Park), the cyclic behaviour and accessibility of which make it an ideal natural laboratory for studying harmonic tremor associated with near-surface sources. We find that sharp pressure pulses inside the water column trigger distinct seismic events that give rise to a harmonic ground response whose frequency varies spatially but not temporally. A superposition of these seismic events creates the appearance of continuous harmonic tremor. The absence of resonance within the water column suggests that the harmonic motion must arise from the interaction of the seismic waves with heterogeneities in the surrounding elastic medium-most probably a near-surface soft layer.

  11. Rock Physics Interpretation of P-Wave Q and Velocity Structure, Geology, Fluids and Fractures at the Southeast Portion of The Geysers Geothermal Reservoir

    SciTech Connect

    Berge, P; Hutchings, L; Wagoner, J; Kasameyer, P

    2001-04-06

    We examine how quantitative rock physics models, such as effective medium theories, can improve the interpretation of seismic parameters and material and fluid properties at The Geysers. We use effective medium theories to estimate effects of fractures on velocities for The Geysers rocks. We compare theoretical velocity estimates to laboratory measurements from the literature and our seismic velocity values from 1992 earthquake data. We approximate the reservoir as being homogeneous in mineral composition, with a constant density of fractures whose total void ratio is reduced by lithostatic pressure. Thus, we expect low velocities near the surface, increasing with depth up to the values observed in the lab on intact samples, 5.5 - 5.7 km/sec. We use a one-dimensional inversion of P-waves to obtain an ''expected'' P-wave velocity (Vp) and attenuation (Qp) relation as a function of depth for The Geysers rocks. We then use a three-dimensional Vp and Qp inversion to find anomalous zones within the reservoir. We find portions with ''high'' Vp and Qp, high Vp and low Qp, and low Vp and low Qp. We interpret the regions with high Vp and Qp to be relatively less fractured, and the regions with low Vp and Qp to be significantly fractured. The high V and Q anomaly is centered on the zone of greatest pressure drop, and is mostly within the shallowest part of the felsite. The anomalous zones within the greywacke reservoir are on either side of the felsite, in areas of more moderate pressure depletion. More work is required to interpret the significance of these observations.

  12. Compilation of gas geochemistry and isotopic analyses from The Geysers geothermal field: 1978-1991

    USGS Publications Warehouse

    Lowenstern, Jacob B.; Janik, Cathy; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    We present 45 chemical and isotopic analyses from well discharges at The Geysers geothermal field and summarize the most notable geochemical trends. H2 and H2S concentrations are highest in the Southeast Geysers, where steam samples have δD and δ18O values that reflect replenishment by meteoric water. In the Northwest Geysers, samples are enriched in gas/steam, CO2, CH4, and N2/Ar relative to the rest of the field, and contain steam that is elevated in δD and δ18O, most likely due to substantial contributions from Franciscan-derived fluids. The δ13C of CO2, trends in CH4 vs. N2, and abundance of NH3 indicate that the bulk of the non-condensable gases are derived from thermal breakdown of organic materials in Franciscan meta-sediments.

  13. Current techniques in acid-chloride corrosion control and monitoring at The Geysers

    SciTech Connect

    Hirtz, Paul; Buck, Cliff; Kunzman, Russell

    1991-01-01

    Acid chloride corrosion of geothermal well casings, production piping and power plant equipment has resulted in costly corrosion damage, frequent curtailments of power plants and the permanent shut-in of wells in certain areas of The Geysers. Techniques have been developed to mitigate these corrosion problems, allowing continued production of steam from high chloride wells with minimal impact on production and power generation facilities.The optimization of water and caustic steam scrubbing, steam/liquid separation and process fluid chemistry has led to effective and reliable corrosion mitigation systems currently in routine use at The Geysers. When properly operated, these systems can yield steam purities equal to or greater than those encountered in areas of The Geysers where chloride corrosion is not a problem. Developments in corrosion monitoring techniques, steam sampling and analytical methodologies for trace impurities, and computer modeling of the fluid chemistry has been instrumental in the success of this technology.

  14. Santa Rosa Geysers Recharge Project: GEO-98-001. Final Report

    SciTech Connect

    Brauner, Edwin Jr.; Carlson, Daniel C.

    2002-10-01

    The Geysers steamfields in northern Sonoma County have produced reliable ''green'' power for many years. An impediment to long-term continued production has been the ability to provide a reliable source of injection water to replace water extracted and lost in the form of steam. The steamfield operators have historcially used cooling towers to recycle a small portion of the steam and have collected water during the winter months using stream extraction. These two sources, however, could not by themselves sustain the steamfield in the long term. The Lake County Reclaimed Water Project (SEGEP) was inititated in 1997 and provides another source of steamfield replenishment water. The Santa Rosa Geysers Recharge Project provides another significant step in replenishing the steamfield. In addition, the Santa Rosa Geysers Recharge Project has been built with capacity to potentially meet virtually all injection water requirements, when combined with these other sources. Figure 2.1 graphically depicts the combination of injection sources.

  15. Analysis of cause and mechanism for injection-induced seismicityat the Geysers Geothermal Field, California

    SciTech Connect

    Rutqvist, Jonny; Oldenburg, Curtis

    2007-06-14

    We analyzed relative contributions to the cause andmechanism of injection-induced seismicity at The Geysers geothermalfield, California, using coupled thermal-hydrological-mechanicalmodeling. Our analysis shows that the most important cause forinjection-induced seismicity is injection-induced cooling and associatedthermal-elastic shrinkage that changes the stress state in such a waythat mechanical failure and seismicity can be induced. Specifically, thecooling shrinkage results in unloading and associated loss of shearstrength in critically shear-stressed fractures, which are thenreactivated. Thus, our analysis shows that cooling-induced shear slipalong fractures is the dominant mechanism of injection-induced seismicityat The Geysers.

  16. Heat-flow studies in the northwest geysers geothermal field, California

    USGS Publications Warehouse

    Williams, Colin F.; Galanis, S. Peter; Moses, Thomas H.; Grubb, Frederick V.; ,

    1993-01-01

    Temperature and thermal conductivity data were acquired from 3 idle production wells in the Northwest Geysers. Heat-flow profiles derived from data recorded in the caprock which overlies the steam reservoir reveal a decrease of heat flow with depth in 2 of the 3 wells. These observations contradict the generally accepted theory that conductive heat flow is constant with depth within The Geysers caprock. There are several possible explanations for this, but the available data suggest that these profiles reflect a local recession or cooling of the reservoir top within the past 5000 to 10000 years.

  17. Abnormal P-wave delays in the geysers-clear lake Geothermal Area, California

    USGS Publications Warehouse

    Iyer, H.M.; Oppenheimer, D.H.; Hitchcock, T.

    1979-01-01

    Large teleseismic delays, exceeding 1 second, are found near Mount Hannah in the Clear Lake volcanic field and in the steam-production area at The Geysers. The delays are superimposed on a general delay field of about 0.5 second extending over the volcanic rocks and the steam reservoir. It is postulated that a magma chamber under the surface volcanic rocks with a core of severely molten rock beneath Mount Hannah and a highly fractured steam reservoir probably underlain by partially molten rock at The Geysers are responsible for the observed delays. Both zones extend to depths of 20 kilometers or more. Copyright ?? 1979 AAAS.

  18. Abnormal p-wave delays in the geysers--clear lake geothermal area, california.

    PubMed

    Iyer, H M; Oppenheimer, D H; Hitchcock, T

    1979-05-01

    Large teleseismic delays, exceeding 1 second, are found near Mount Hannah in the Clear Lake volcanic field and in the steam-production area at The Geysers. The delays are superimposed on a general delay field of about 0.5 second extending over the volcanic rocks and the steam reservoir. It is postulated that a magma chamber under the surface volcanic rocks with a core of severely molten rock beneath Mount Hannah and a highly fractured steam reservoir probably underlain by partially molten rock at The Geysers are responsible for the observed delays. Both zones extend to depths of 20 kilometers or more. PMID:17819952

  19. 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.

  20. Laboratory measurements on reservoir rocks from The Geysers geothermal field

    SciTech Connect

    Boitnott, G.N.

    1995-01-26

    A suite of laboratory measurements have been conducted on Geysers metagraywacke and metashale recovered from a drilled depth of 2599 to 2602 meters in NEGU-17. The tests have been designed to constrain the mechanical and water-storage properties of the matrix material. Various measurements have been made at a variety of pressures and at varying degrees of saturation. Both compressional and shear velocities exhibit relatively little change with effective confining pressure. In all of the samples, water saturation causes an increase in the compressional velocity. In some samples, saturation results in a moderate decrease in shear velocity greater in magnitude than would be expected based on the slight increase in bulk density. It is found that the effect of saturation on the velocities can be quantitatively modeled through a modification of Biot-Gassmann theory to include weakening of the shear modulus with saturation. The decrease is attributed to chemo-mechanical weakening caused by the presence of water. The degree of frame weakening of the shear modulus is variable between samples, and appears correlated with petrographic features of the cores. Two related models are presented through which we can study the importance of saturation effects on field-scale velocity variations. The model results indicate that the saturation effects within the matrix are significant and may contribute to previously observed field anomalies. The results help to define ways in which we may be able to separate the effects of variations in rock properties, caused by phenomena such as degree of fracturing, from similar effects caused by variations in matrix saturation. The need for both compressional and shear velocity data in order to interpret field anomalies is illustrated through comparisons of model results with the field observations.

  1. Timing and prediction of CO2 eruptions from Crystal Geyser, UT

    SciTech Connect

    Gouveia, F J; Friedmann, S J

    2006-05-30

    Special instruments were deployed at Crystal Geyser, Utah, in August 2005 creating a contiguous 76-day record of eruptions from this cold geyser. Sensors measured temperature and fluid movement at the base of the geyser. Analysis of the time series that contains the start time and duration of 140 eruptions reveals a striking bimodal distribution in eruption duration. About two thirds of the eruptions were short (7-32 min), and about one third were long (98-113 min). No eruption lasted between 32 and 98 min. There is a strong correlation between the duration of an eruption and the subsequent time until the next eruption. A linear least-squares fit of these data can be used to predict the time of the next eruption. The predictions were within one hour of actual eruption time for 90% of the very short eruptions (7-19 min), and about 45% of the long eruptions. Combined with emission estimates from a previous study, we estimate the annual CO{sub 2} emission from Crystal Geyser to be about 11 gigagrams (11,000 tons).

  2. The geyser sign and torn rotator cuff: clinical significance and pathomechanics.

    PubMed

    Craig, E V

    1984-12-01

    The geyser radiographic sign on shoulder arthrogram is characterized by leakage of dye from the glenohumeral joint into the subdeltoid bursa. The dye outlines the acromioclavicular joint. It is usually an indication of a full-thickness cuff tear of long duration. The clinical occurrence and pathomechanics of this finding indicate that repair is generally difficult.

  3. New evidence for a magmatic origin of some gases in the Geysers geothermal reservoir

    SciTech Connect

    Truesdell, A.H.; Kennedy, B.M.; Walters, M.A.; D'Amore, F.

    1994-01-20

    The Geysers vapor-dominated geothermal reservoir is known to have a wide range of gas concentrations in steam (<100 to >75,000 ppmw), but the variations in gas compositions and the origin of the gases have been little studied. Low gas concentrations and steam isotopes similar to meteoric waters are found in the SE Geysers, but steam high in gas and HCI from a high temperature reservoir (HTR) in the NW Geysers has been thought to be related to metamorphic or magmatic brine. New analyses of noble gas isotopes show that the highest gas steam from the HTR has high {sup 3}He/{sup 4}He (8.3 Ra), and very low {sup 36}Ar and radiogenic {sup 40}Ar/{sup 4}He, indicating a strong magmatic component and essentially no atmospheric or crustal noble gases. Other samples from the HTR show various amounts of atmospheric dilution of the magmatic gas and lower HCI and total gas contents. The occurrence of steam in the NW Geysers highly enriched in heavy isotopes of oxygen and hydrogen supports the indications of remnant magmatic fluid: The existence of this fluid strongly suggests that the HTR was formed by rapid heating and catastrophic boiling resulting from injection of magma.

  4. Mitigation of Hydrogen Sulfide Emissions in the Geysers KGRA (Staff Draft)

    SciTech Connect

    Buell, Richard

    1981-07-01

    Violations of the ambient air quality standard (AAQS) for hydrogen sulfide (H2S) are currently being experienced in The Geysers KGRA and could significantly increase in the future. Attainment and maintenance of the H2S AAQS is a potential constraint to optimum development of this resource. The availability of reliable H2S controls and the development of a validated air dispersion model are critical to alleviating this constraint. The purpose of this report is to assess the performance capabilities for state-of-the-art controls, to identify potential cost-effective alternative controls, and to identify the California Energy Commission (CEC) staffs efforts to develop a validated air dispersion model. Currently available controls (Stretford, Hydrogen Peroxide, and EIC) are capable of abating H2S emissions from a proposed facility to five lbs/hr. Alternative controls, such as condensate stripping and condensate pH control, appear to promising, cost-effective control option. The CEC staff is currently developing a validated air dispersion model for The Geysers KGRA. The CEC staff recommends investigation of retrofit control options for existing units, investigation of alternative control technologies, and dispersion analysis for optimum plant location in order to maximize the development potential of The Geysers KGRA. Energy cost studies suggest that the EIC process would be the most cost-effective for retrofits at The Geysers. (DJE-2005)

  5. 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.

  6. The geyser sign and torn rotator cuff: clinical significance and pathomechanics.

    PubMed

    Craig, E V

    1984-12-01

    The geyser radiographic sign on shoulder arthrogram is characterized by leakage of dye from the glenohumeral joint into the subdeltoid bursa. The dye outlines the acromioclavicular joint. It is usually an indication of a full-thickness cuff tear of long duration. The clinical occurrence and pathomechanics of this finding indicate that repair is generally difficult. PMID:6499313

  7. Predicting Air-Water Geysers and Their Implications on Reducing Combined Sewer Overflows

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Leon, A.; Apte, S.

    2014-12-01

    An air-water geyser in a closed conduit system is characterized by an explosive jetting of a mixture of air and water through drop-shafts. In this study, three scenarios of geysers are numerically simulated using a 3D computational fluid dynamics (CFD) model. The three tested scenarios are comprised of a drop shaft that is closed at its bottom and partially or fully open at the top. Initially, the lower section of the drop shaft is filled with pressurized air, the middle section with stagnant water and the upper section with air at atmospheric pressure. The pressure and volume of the pressurized air, and hence the stored energy, is different for all three test cases. The volume of the stagnant water and the air at atmospheric pressure are kept constant in the tests. The numerical simulations aim to identify the correlation between dimensionless energy stored in the pressurized air pocket and dimensionless maximum pressure reached at the outlet. This dimensionless correlation could be used to determine the energy threshold that does not produce air-water geyser, which in turn could be used in the design of combined sewer systems for minimizing geysers.

  8. High Spatial Density Ambient Noise Tomography at the El Jefe Geyser, Chile

    NASA Astrophysics Data System (ADS)

    Hakso, A. W.; Seats, K.

    2015-12-01

    The El Jefe geyser in the Atacama Desert, Chile has been the subject of study to better understand processes of heat transport and eruption mechanisms in geyser systems (Munoz-Saez et al., 2015). Existing seismological literature on geyser and volcanic systems is predominantly focused on seismicity generated in the eruptive process (Benoit and McNutt, 1997; O'Brien et al., 2011). In contrast, this study leverages seismic noise in the repose period to generate an approximation to the Green's function for each receiver pair, known as noise correlation functions (NCFs). A dense seismic array of 51 geophones spaced at 2-10 meter intervals recorded several days of data at a spatial scale and frequency range approximately two orders of magnitude removed from prior seismic interferometry studies. While eruptions of the El Jefe geyser impose a transient signal on a diffuse background noise, a regular eruption interval of 132.52.5 seconds (Munoz-Saez et al., 2015) allows for reliable removal of seismic energy associated with the eruption, improving the azimuthal distribution of noise across the array. The approach to generating noise correlation functions closely follows the methodology of Seats and Lawrence (2014). Moveout of at least two phases of energy is apparent in the calculated NCFs, suggesting that multiple phases of seismic energy may be present in the noise, moving coherently across the array.

  9. Database for the geologic map of Upper Geyser Basin, Yellowstone National Park, Wyoming

    USGS Publications Warehouse

    Abendini, Atosa A.; Robinson, Joel E.; Muffler, L. J. Patrick; White, D. E.; Beeson, Melvin H.; Truesdell, A. H.

    2015-01-01

    This dataset contains contacts, geologic units, and map boundaries from Miscellaneous Investigations Series Map I-1371, "The Geologic map of upper Geyser Basin, Yellowstone, National Park, Wyoming". This dataset was constructed to produce a digital geologic map as a basis for ongoing studies of hydrothermal processes.

  10. An analysis of CO2-driven cold-water geysers in Green River, Utah and Chimayo, New Mexico

    NASA Astrophysics Data System (ADS)

    Watson, Zach

    The eruption periodicity, CO2 bubble volume fraction, eruption velocity, flash depth and mass emission of CO2 were determined from multiple wellbore CO2-driven cold-water geysers (Crystal and Tenmile geysers, in Utah and Chimayo geyser in New Mexico). Utilizing a suite of temporal water sample datasets from multiple field trips to Crystal geyser, systematic and repeated trends in effluent water chemistry have been revealed. Crystal geyser has a four part eruption cycle composed of a minor eruption period (mEP), major eruption period (MEP), aftershock eruption period (Ae) and recharge (R). Tenmile geyser has a four part eruption cycle composed of MEP, drainage (D), mEP and R. Chimayo geyser has a two part eruption cycle composed of a MEP and R. The MEP at Crystal geyser currently lasts for over 24 hours highlighting the potential for a natural geyser to reach quasi steady state discharge. At shallow depths the bubble volume fraction ranges from 0 to 0.8, eruption velocities range from 2 to 20 m/s and flash depths are predominately shallow ranging from 5 to 40 meters below the surface. Annual emission of CO2 is estimated to be (4.77+/-1.92)x10 3, (6.17+/-1.73)x101, (6.54+/-0.57)x10 1 tonnes/yr for Crystal, Tenmile and Chimayo geysers, respectively. Inverse modeling of endmembers for the mEP at Crystal geyser show that the effluent is comprised of 66%, 33% and 1% the Navajo Sandstone, Entrada Sandstone and Fault Brine, respectively. The range of input for the Navajo, Entrada and Brine during the MEP is 53-57%, 42-45% and 1-2%, respectively. The geyser plumbing geometry consists of a vertical wellbore which allows for the upward migration of CO2-rich fluids due to artesian conditions. The positive feedback system of a CO2-driven eruption occurs within the well. Mitigating high velocity CO2-driven discharge from wellbores will, however, be easier than mitigating diffuse leakage from faults or into groundwater systems.

  11. Environmental controls on methanogen viability in the hydrothermal waters of the El Tatio geyser field, Chile.

    NASA Astrophysics Data System (ADS)

    Franks, M. A.; Bennett, P. C.; Omelon, C.; Engel, A. S.

    2007-12-01

    At the El Tatio geyser field, a unique hydrothermal site located in the Andes Mountains in Chile, methanogenic archaea were found in only two of the hundreds of hydrothermal features. Reported here is an investigation into the environmental and geochemical controls on the distribution of methanogenic archaea. Located in the hyper- arid Atacama Desert, El Tatio waters are characterized by high salinity (95-175mM), Na-Cl type waters and circum-neutral pH (6.5-7), with very low inorganic carbon (0.1-0.5 mM TIC), but very high concentrations of As and Sb (300-700 uM As, 10-30uM Sb). Extensive bacterial mats thrive in most of the shallow run-off streams originating from hydrothermal features. In order to determine geochemical controls on methanogen populations, major and trace elements, including As and Sb speciation and concentrations, were determined using IC and HPLC-ICP-MS methods. The structure of microbial communities was analyzed using MPN enumeration of methanogens, culturing, and phylogenetic analysis using molecular techniques. Here, as in many hydrothermal regions, temperature and geochemical gradients influence the microbial ecology. Results from MPN enumeration indicate methanogen populations are dominated by H2-utilizing (carbonate reducing) archaea at both of the sites, with some acetate-oxidizing archaea present. These sites contain comparatively high DIC concentrations; however, it is unclear whether this is a control or a product of methanogenic archaea. Water quality analyses also show a strong correlation between antimony concentrations and the presence of methanogens; methanogenic archaea being present only at sites with 17 uM Sb concentrations or less.

  12. X-ray tomography of preserved samples from The Geysers scientific corehole

    SciTech Connect

    Bonner, B.P.; Roberts, J.J.; Schneberk, D.J.; Marsh, A.; Ruddle, C.; Updike, E.

    1995-01-26

    Approximately 800 ft. of continuous core was recovered from borehole SB-15 D (on unit 15, near the site of the abandoned Geysers Resort) during a recently completed drilling operation funded by the USDOE. Sections of this core were collected at 50 ft intervals for subsequent examination as drilling proceeded. Five foot sections were not removed at the drill site, but were sealed in the innermost sleeve of a triple tube coring system to minimize drying and disturbance of the core. All cores remained sealed and were radiographed within 72 hours of drilling: the five foot core from near 1400 ft. was scanned within 18 hours of drilling. A third generation x-ray scanner, which uses high energy radiation to penetrate the aluminum sleeve and 3.5 inch cores, was used to make preliminary radiographs and to collect multiple views of the sample as the core is rotated in front of the beam. True three dimensional tomographs are then reconstructed from the data. At present, the images have a spatial resolution of approximately 140 micrometers and can resolve contrast differences of 0.2%. The tomographs clearly show differences in lithology with depth in the reservoir. Partially filled fractures, vein selvage and vuggy porosity are all evident in parts of the core. A principle goal of the imaging effort is to help determine the fluid content of the reservoir. Important questions to investigate include water loss during core recovery, infiltration of drilling fluid, and the heterogeneous distribution of pore fluid. Images show that radial gradients in x-ray attenuation commonly occur in jacketed cores. Regions of excess attenuation extend about halfway into the 3.5 in. core, and are probably caused by mud invasion induced by capillarity of the small scale porosity of the graywacke matrix. X-ray measurements will be coordinated with other independent measurements of fluid content underway in separate studies, particularly NMR spectroscopy of frozen ''pressure core'', and

  13. X-ray tomography of preserved samples from the Geysers scientific corehole

    SciTech Connect

    Bonner, B.P.; Roberts, J.J.; Schneberk, D.J.; Marsh, A.; Ruddle, C.; Updike, E.

    1995-01-23

    Approximately 800 ft. of continuous core was recovered from borehole SB-15 D (on unit 15, near the site of the abandoned Geysers Resort) during a recently completed drilling operation. Sections of this core were collected at 50 ft intervals for subsequent examination as drilling proceeded. Five foot sections were not removed at the drill site, but were sealed in the innermost sleeve of a triple tube coring system to minimize drying and disturbance of the core. All cores remained sealed and were radiographed within 72 hours of drilling: the five foot core from near 1400 ft. was scanned within 18 hours of drilling. A third generation x-ray scanner, which uses high energy radiation to penetrate the aluminum sleeve and 3.5 inch cores, was used to make preliminary radiographs and to collect multiple views of the sample as the core is rotated in front of the beam. True three dimensional tomographs are then reconstructed from the data. The images have a spatial resolution of approximately 140 micrometers and can resolve contrast differences of 0.2%. The tomographs clearly show differences in lithology with depth in the reservoir. Partially filled fractures, vein selvage and vuggy porosity are all evident in parts of the core. A principle goal is to determine the fluid content of the reservoir. Important questions to investigate include water loss during core recovery, infiltration of drilling fluid, and the heterogeneous distribution of pore fluid. Images show that radial gradients in x-ray attenuation commonly occur in jacketed cores. Regions of excess attenuation extend about halfway into the 3.5 in. core, and are probably caused by mud invasion induced by capillarity of the small scale porosity of the graywacke matrix. X-ray measurements will be coordinated with other independent measurements of fluid content underway in separate studies, particularly NMR spectroscopy of frozen `pressure core,` and compressional velocity and electrical resistivity measurements.

  14. Lake Bogoria, Kenya: Hot and warm springs, geysers and Holocene stromatolites

    NASA Astrophysics Data System (ADS)

    McCall, Joseph

    2010-11-01

    I carried out the first regional geological survey of the central Gregory Rift Valley in Kenya in 1958-60, and review here the numerous subsequent specialised studies focused on the unique endoreic Lake Bogoria (formerly Hannington), studies which embraced the sedimentology of the Holocene sediments around the lake shores, the hot-spring and geyser activities and the coring of the sediments beneath the lake. I focus on the occurrences of stromatolites in a hydrothermal environment, both in two closely spaced late Holocene (~ 4500 yr BP) generations at the lake margin, associated with algae and cyanobacteria, which represent a final more humid climatic phase after the several interglacial more humid phases (also represented by stromatolite occurrences in other rift valley lakes); and also at present being formed, at the edge of the now highly saline lake, in the very hot springs in association with thermophilic bacteria and with silica. I briefly mention the older occurrences in Lake Magadi to the south, which are quite different; and form three generations; and also present-day occurrences of stromatolites in a flood-plain environment, unlike the present-day environment at Lake Bogoria. Other stromatolite occurrences are mentioned, around Lake Turkana and the former lake in the Suguta River valley to the north. I suggest that the hot waterfall at Kapedo, at the head of the Suguta River, and the central island of Ol Kokwe (with hot springs, amidst the fresh water Lake Baringo) could well be investigated for stromatolite occurrences. Lake Bogoria, an empty wilderness occupied only by flamingos when I mapped it, is now more accessible and provides a unique open-air laboratory for such researches, but like all the Rift Valley lakes, is unique, sui generis. Results of detailed investigations of the type reviewed here, can only be applied to other occurrences of stromatolites elsewhere in the rift system or beyond the rift system with reservation.

  15. Metagenomic Reconstruction of a Microbial Community from a CO2-driven Geyser

    NASA Astrophysics Data System (ADS)

    Emerson, J. B.; Banfield, J. F.; Thomas, B. C.

    2012-12-01

    Given that only ~1% of microorganisms are cultivable, and because microbes naturally exist in interactive consortia, it is important to include culture-independent analyses of microbial communities as we evaluate the role that microbes may play in geologic carbon sequestration. Through metagenomics, we report near-complete genomes from a microbial community dominated by iron-oxidizing Zetaproteobacteria from a CO2-driven geyser. Our study site, Crystal Geyser (Green River, Utah), is a cold (17 °C), iron-rich geyser that erupts due to pressure from soluble and free-phase CO2 accumulation in an aquifer ~500 m below the surface, and it is an established natural analog for geologic carbon sequestration. We collected 65 L of geyser water as it precipitated during an eruption in November 2009, and we sequentially filtered the water through 3.0 and 0.2 μm. DNA was extracted from the 0.2 μm filter, from which we generated 13 million 150 bp paired-end Illumina sequencing reads. We assembled near-complete genomes of neutrophilic, iron-oxidizing Mariprofundus ferrooxydans and sulfur-oxidizing Thiomicrospira crunogena. Significant genomic reconstruction was also achieved for other chemolithoautotrophic bacteria, for representatives of Candidate Division TM7 (an as yet uncultivable bacterial phylum), and for a small number of low-abundance archaea. We see evidence for a variety of metabolisms, including iron, sulfur, and complex carbon oxidation, carbon and nitrogen fixation, hydrogen metabolism, aerobic and anaerobic respiration (e.g., of sulfate and nitrate), and methanogenesis. Although the geyser community contains only ~20 populations at 0.5% or higher abundance, our results demonstrate that a CO2-saturated solution can be conducive to a thriving microbial community of diverse phylogeny and broad metabolic potential.

  16. Helium isotopes: Lower geyser basin, Yellowstone National Park

    SciTech Connect

    Kennedy, B.M.; Reynolds, J.H.; Smith, S.P.; Truesdell, A.H.

    1987-11-10

    High /sup 3/He//sup 4/He ratios associated with the Yellowstone caldera reflect the presence of a magmatic helium component. This component is ultimately derived from a mantle plume capped by a cooling batholith underlying the caldera. In surface hot springs, fumaroles, etc., the /sup 3/He//sup 4/He ratio varies from approx.1 to 16 tims the air ratio. The variations are produced by varying degrees of dilution of the magmatic component with radiogenic helium. The radiogenic helium is crustal-derived and is thought to be scavenged from aquifers in which the hydrothermal fluids circulate. We determined the helium iosotopic composition in 12 different springs from the Lower Geyser Basin, a large hydrothermal basin with the caldera. The /sup 3/He//sup 4/He ratio was found to vary from approx.2.7 to 7.7 times the air ratio. The variations correlate with variations in water chemistry. Specifically, the /sup 3/He//sup 4/He ratio increased with total bicarbonate concentration. The dissolved bicarbonate is from gas-water-rock interactions involving CO/sub 2/ and Na silicates. The concentration of bicarbonate is a function of the availability of dissolved CO/sub 2/, which, in turn, is a function of deep boiling with phase separation prior to CO/sub 2/-bicarbonate conversion. The correlation of high /sup 3/He//sup 4/He ratios with high bicarbonate is interpreted as the result of deep dilution of a single thermal fluid with cooler water during ascent to the surface. The dilution and cooling deters deep boiling, and therefore both CO/sub 2/ and /sup 3/He are retained in the rising fluid. Fluids that are not diluted with boil to a greater extent, losing a large proportion of /sup 3/He, as well as CO/sub 2/, leaving a helium-poor residual fluid in which the isotopic composition of helium will be strongly affected by the addition of radiogenic helium.

  17. Heat Budget Monitoring in Norris Geyser Basin, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Mohamed, R. A. M.; Neale, C. M. U.; Jaworowski, C.

    2014-12-01

    Frequent estimation of heat flux in active hydrothermal areas are required to monitor the variation in activity. Natural changes in geothermal and hydrothermal features can include rapid significant changes in surface temperature distribution and may be an indication of "re-plumbing" of the systems or potential hydrothermal explosions. Frequent monitoring of these systems can help Park managers make informed decisions on infrastructure development and/or take precautionary actions to protect the public. Norris Geyser Basin (NGB) is one of Yellowstone National Park's hottest and most dynamic basins. Airborne high-resolution thermal infrared remote sensing was used to estimate radiometric temperatures within NGB and allow for the estimation of the spatial and temporal distribution of surface temperatures and the heat flow budget. The airborne monitoring occurred in consecutive years 2008-2012 allowing for the temporal comparison of heat budget in NGB. Airborne thermal infrared images in the 8-12 µm bands with 1-m resolution were acquired using a FLIR SC640 scanner. Digital multispectral images in the green (0.57 μm), red (0.65 μm), and near infrared (0.80 μm) bands were also acquired to classify the terrain cover and support the atmospheric and emissivity correction of the thermal images. The airborne images were taken in the month of September on selected days with similar weather and under clear sky conditions. In the winter of 2012, images were also taken in March to compare the effect of the cold weather and snow cover on the heat budget. Consistent methods were used to acquire and process the images each year to limit the potential variability in the results to only the variability in the hydrothermal system. Data from radiation flux towers installed within the basin were used to compare with airborne radiometric surface temperatures and compensate for residual solar heating in the imagery. The presentation will discuss the different mechanisms involved in

  18. Physicochemical and Biological Zonation of High Temperature Silica and Arsenic-Rich Streams at El Tatio Geyser Field, Chile

    NASA Astrophysics Data System (ADS)

    Myers, K. D.; Engel, A. S.; Omelon, C. R.; Bennett, P.

    2012-12-01

    El Tatio Geyser Field is a geothermal complex comprised of three main basins in the northern Atacama Desert (Region II), Chile. Located at 4400 m elevation in the Andes Mountains it experiences intense solar radiation and a UV flux 33% higher than at Yellowstone National Park (Wyoming). Local boiling point is 86°C, and geothermal waters are Na-Ca-Cl type with circumneutral pH, high dissolved silica, and high dissolved arsenic concentrations (30-50 ppm). Most thermal features contain scant dissolved inorganic carbon (DIC as CO2(aq) + HCO3- + CO3-2). There is a conspicuous lack of microbial mat development in temperature zones where thick mats are seen at other geothermal sites. This investigation focused on understanding the physicochemical controls on microbial diversity that lead to microbial mat colonization and development within specific thermal regions of the geothermal features. Temperature surveys were done at three geothermal features where microbial mats and water chemistry were sampled, and a high-resolution thermal survey was conducted at one geyser orifice through the discharge channel where chemistry and mineralogy have been characterized, and microbial diversity was evaluated from 16S rRNA gene sequences. At the main study geyser, the stream is 0.25 m wide near its source, and for the first 20 m, the discharge stream is constrained by a solid silica bank with a mineralized channel bottom and no obvious microbial mat development. Temperatures decrease from ~86°C to ~67°C. In this zone sparse filaments were observed on rare sediments below the water surface consisting of ~80% Thermus spp. with rare uncultured Chloroflexus spp. and Candidate Division OP1 sequences. At 12 m, visible red-orange mat development starts on the sides of the channel where bulk water temperature is 67°C. Photosynthetic Chloroflexus spp. dominate red-orange filaments that form the first conspicuous mats (between 43-88% of the 16S rRNA sequences from different samples), with

  19. Hydrothermal factors in porosity evolution and caprock formation at the Geysers steam field, California--insight from the Geysers Coring Project

    SciTech Connect

    Hulen, Jeffrey B.; Nielson, Dennis L.

    1995-01-26

    The Department of Energy (DOE)/geothermal industry-sponsored Geysers Coring Project (GCP) has yielded 236.8 m of continuous core apparently spanning the transition between the uppermost Geysers steam reservoir and its caprock. Both zones in the corehole are developed in superficially similar, fractured, complexly veined and locally sericitized, Franciscan (late Mesozoic) graywacke-argillite sequences. However, whereas the reservoir rocks host two major fluid conduits (potential steam entries), the caprock is only sparingly permeable. This discrepancy appears to reflect principally vein texture and mineralogy. Two types of veins are common in the core--randomly-oriented, Franciscan metamorphic quartz-calcite veins; and high-angle, late Cenozoic veins deposited by The Geysers hydrothermal system. The older veins locally contain hydrothermal carbonate-dissolution vugs, which, although concentrated at the larger fluid conduit, are scattered throughout the core. The younger veins, commonly with intercrystalline vugs, consist dominantly of euhedral quartz, calcite, K-feldspar, wairakite, and pyrite--those in the reservoir rock also contain minor epidote and illite. The corresponding caprock veins are devoid of epidote but contain abundant, late-stage, mixed-layer illite/smecite (5-18% smectite interlayers) with minor chlorite/smectite (40-45% smectite interlayers). We suggest that clots of these two expandable clays in the caprock clog otherwise permeable veins and carbonate-dissolution networks at strategic sites to produce or enhance the seal on the underlying steam reservoir. Illite/smectite geothermometry indicates that the SB-15-D caprock clays were precipitated in the approximate temperature range 180-218 C, and those in the reservoir at about 218-238 C. These temperatures, along with occurrence of the clays on commonly etched calcite, K-feldspar, or wairakite, suggest that the clays were precipitated from mildly acidic steam condensate under conditions similar to

  20. The geology and remarkable thermal activity of Norris Geyser Basin, Yellowstone National Park, Wyoming

    SciTech Connect

    White, D.E.; Keith, T.E.C. ); Hutchinson, R.A. )

    1988-01-01

    Norris Geyser Basin is adjacent to the north rim of the Yellowstone Caldera, one of the largest volcanic features of its type in the world. Hydrothermal activity may have been continuous for {gt}100,000 years B.P. Norris Basin includes the highest erupting geyser of recent water types, colors of organisms and inorganic precipitates, frequent changes in activity and chemistry, and very high subsurface temperatures ({gt}240{degrees}C). Norris Basin is only a part of the Norris-Mammoth Corridor that strikes north from the caldera rim to Mammoth Hot Springs. Norris Basin has a heat flow roughly 10 percent of that of the Yellowstone Caldera and requires an estimated 0.01 km{sup 3} of rhyolitic magma per year-a quantity far greater than the corridor's rate of eruption.

  1. Concentrations of arsenic, antimony, and boron in steam and steam condensate at The Geysers, California

    USGS Publications Warehouse

    Smith, C.L.; Ficklin, W.H.; Thompson, J.M.

    1987-01-01

    Studies at The Geysers Geothermal Field, California indicate that under some circumstances elements that are transported in the vapor phase can become enriched in the liquid phase. Waters from two condensate traps (steam traps) on steam lines at The Geysers are enriched with arsenic, antimony, and boron compared to the concentrations of these elements in coexisting steam. Concentrations of boron in condensate-trap waters were as high as 160 mg/L, arsenic as high as 35 mg/L, and antimony as high as 200 ??g/L. Enrichment of arsenic, antimony, and boron is at least partially controlled by the partitioning of these elements into the liquid phase, according to their vapor-liquid distribution coefficients, after they are transported in steam. Several of the elements that are most soluble in steam, including arsenic and antimony, are part of the trace-element suite that characterizes precious-metal epithermal ore deposits. ?? 1987.

  2. Database of the Geology and Thermal Activity of Norris Geyser Basin, Yellowstone National Park

    USGS Publications Warehouse

    Flynn, Kathryn; Graham Wall, Brita; White, Donald E.; Hutchinson, Roderick A.; Keith, Terry E.C.; Clor, Laura; Robinson, Joel E.

    2008-01-01

    This dataset contains contacts, geologic units and map boundaries from Plate 1 of USGS Professional Paper 1456, 'The Geology and Remarkable Thermal Activity of Norris Geyser Basin, Yellowstone National Park, Wyoming.' The features are contained in the Annotation, basins_poly, contours, geology_arc, geology_poly, point_features, and stream_arc feature classes as well as a table of geologic units and their descriptions. This dataset was constructed to produce a digital geologic map as a basis for studying hydrothermal processes in Norris Geyser Basin. The original map does not contain registration tic marks. To create the geodatabase, the original scanned map was georegistered to USGS aerial photographs of the Norris Junction quadrangle collected in 1994. Manmade objects, i.e. roads, parking lots, and the visitor center, along with stream junctions and other hydrographic features, were used for registration.

  3. Public service impacts of geothermal development: cumulative impacts study of the Geysers KGRA. Final staff report

    SciTech Connect

    Matthews, K.M.

    1983-07-01

    The number of workers currently involved in the various aspects of geothermal development in the Geysers are identified. Using two different development scenarios, projections are made for the number of power plants needed to reach the electrical generation capacity of the steam resource in the Geysers. The report also projects the cumulative number of workers needed to develop the steam field and to construct, operate, and maintain these power plants. Although the number of construction workers fluctuates, most are not likely to become new, permanent residents of the KGRA counties. The administrative and public service costs of geothermal development to local jurisdications are examined, and these costs are compared to geothermal revenues accruing to the local governments. Revenues do not cover the immediate fiscal needs resulting from increases in local road maintenance and school enrollment attributable to geothermal development. Several mitigation options are discussed and a framework presented for calculating mitigation costs for school and road impacts.

  4. The hydrogen sulfide emissions abatement program at the Geysers Geothermal Power Plant

    NASA Technical Reports Server (NTRS)

    Allen, G. W.; Mccluer, H. K.

    1974-01-01

    The scope of the hydrogen sulfide (H2S) abatement program at The Geysers Geothermal Power Plant and the measures currently under way to reduce these emissions are discussed. The Geysers steam averages 223 ppm H2S by weight and after passing through the turbines leaves the plant both through the gas ejector system and by air-stripping in the cooling towers. The sulfide dissolved in the cooling water is controlled by the use of an oxidation catalyst such as an iron salt. The H2S in the low Btu ejector off gases may be burned to sulfur dioxide and scrubbed directly into the circulating water and reinjected into the steam field with the excess condensate. Details are included concerning the disposal of the impure sulfur, design requirements for retrofitting existing plants and modified plant operating procedures. Discussion of future research aimed at improving the H2S abatement system is also included.

  5. Siliceous algal and bacterial stromatolites in hot spring and geyser effluents of yellowstone national park.

    PubMed

    Walter, M R; Bauld, J; Brock, T D

    1972-10-27

    Growing algal and bacterial stromatolites composed of nearly amorphous silica occur around hot springs and geysers in Yellowstone National Park, Wyoming. Some Precambrian stromatolites may be bacterial rather than algal, which has important implications in atmospheric evolution, since bacterial photo-synthesis does not release oxygen. Conophyton stromatolites were thought to have become extinct at the end of the Precambrian, but are still growing in hot spring effluents.

  6. Waterfalls and geysers: the development of diversity awareness at Children's Hospital.

    PubMed

    Ratliff, S S

    1999-02-01

    The development of diversity awareness at Children's Hospital in Columbus, Ohio, has been a work in progress since the early 1980s. The interface of administration and individual initiatives ("waterfalls" and "geysers") has resulted in projects ranging from major international exchange programs to noontime Spanish language classes. This article recounts the journey from a parochial focus to a consciousness of multiculturalism in virtually all aspects of hospital interaction. PMID:9926677

  7. Final cost reduction study for the Geysers Recharge Alternative. Volume 1

    SciTech Connect

    1997-11-01

    The purpose of this study is to determine whether or not cost reduction opportunities exist for the Geysers Recharge Alternative as defined in the Santa Rosa Subregional Long-Term Wastewater Project EIR/EIS. The City of Santa Rosa has been directed to have a plan for reclaimed water disposal in place by 1999 which will meet future capacity needs under all weather conditions. A Draft EIR/EIS released in July 1996 and a Final EIR certified in June 1997 examine four primary alternatives plus the No Action Alternative. Two of the primary alternatives involve agricultural irrigation with reclaimed water, either in western or southern Sonoma County. Another involves increased discharge of reclaimed water into the Russian River. The fourth involves using reclaimed water to replenish the geothermal reservoir at the Geysers. The addition of this water source would enable the Geysers operators to produce more steam from the geothermal area and thereby prolong the life and economic production level of the steamfield and the geothermal power plants supplied by the steamfield. This study provides additional refined cost estimates for new scenarios which utilize an alternative pipeline alignment and a range of reclaimed water flows, which deliver less water to the Geysers than proposed in the EIR/EIS (by distributing flow to other project components). Also, electrical power rates were revised to reflect the recent changes in costs associated with deregulation of the power industry. In addition, this report provides information on sources of potential public and private funding available and future environmental documentation required if the cost reduction scenarios were to be selected by the City as part of their preferred alternative.

  8. Siliceous algal and bacterial stromatolites in hot spring and geyser effluents of yellowstone national park.

    PubMed

    Walter, M R; Bauld, J; Brock, T D

    1972-10-27

    Growing algal and bacterial stromatolites composed of nearly amorphous silica occur around hot springs and geysers in Yellowstone National Park, Wyoming. Some Precambrian stromatolites may be bacterial rather than algal, which has important implications in atmospheric evolution, since bacterial photo-synthesis does not release oxygen. Conophyton stromatolites were thought to have become extinct at the end of the Precambrian, but are still growing in hot spring effluents. PMID:17815363

  9. Waterfalls and geysers: the development of diversity awareness at Children's Hospital.

    PubMed

    Ratliff, S S

    1999-02-01

    The development of diversity awareness at Children's Hospital in Columbus, Ohio, has been a work in progress since the early 1980s. The interface of administration and individual initiatives ("waterfalls" and "geysers") has resulted in projects ranging from major international exchange programs to noontime Spanish language classes. This article recounts the journey from a parochial focus to a consciousness of multiculturalism in virtually all aspects of hospital interaction.

  10. Decline curve analysis of production data from The Geysers geothermal field

    SciTech Connect

    Ripperda, M.; Bodvarsson, G.S.

    1987-01-01

    Production data for over two hundred wells at The Geysers geothermal field were compiled and analyzed. Decline curves for groups of wells with 5, 10, and 40 acre spacing are presented and compared to curves published previously by Budd (1972) and Dykstra (1981). Decline curves for several individual wells and leases are discussed to illustrate the effects of well spacing and location, as well as the heterogeneous nature of the reservoir.

  11. Decline Curve Analysis of Production Data from the Geysers Geothermal Field

    SciTech Connect

    Ripperda, M.; Bodvarsson, G.S.

    1987-01-20

    Production data for over two hundred wells at The Geysers geothermal field were compiled and analysed. Decline curves for groups of wells with 5, 10, and 40 acre spacing are presented and compared to curves published previously by Budd (1972) and Dykstra (1981). Decline curves for several individual wells and leases are discussed to illustrate the effects of well spacing and location, as well as the heterogeneous nature of the reservoir. 6 figs., 1 tab., 10 refs.

  12. Eruptions at Lone Star Geyser, Yellowstone National Park, USA, part 1: energetics and eruption dynamics

    USGS Publications Warehouse

    Karlstrom, Leif; Hurwitz, Shaul; Sohn, Robert; Vandemeulebrouck, Jean; Murphy, Fred; Rudolph, Maxwell L.; Johnston, Malcolm J.S.; Manga, Michael; McCleskey, R. Blaine

    2013-01-01

    Geysers provide a natural laboratory to study multiphase eruptive processes. We present results from a four–day experiment at Lone Star Geyser in Yellowstone National Park, USA. We simultaneously measured water discharge, acoustic emissions, infraredintensity, and visible and infrared video to quantify the energetics and dynamics of eruptions, occurring approximately every three hours. We define four phases in the eruption cycle: 1) a 28 ± 3 minute phase with liquid and steam fountaining, with maximum jet velocities of 16–28 m s− 1, steam mass fraction of less than ∼ 0.01. Intermittently choked flow and flow oscillations with periods increasing from 20 to 40 s are coincident with a decrease in jet velocity and an increase of steam fraction; 2) a 26 ± 8 minute post–eruption relaxation phase with no discharge from the vent, infrared (IR) and acoustic power oscillations gliding between 30 and 40 s; 3) a 59 ± 13 minute recharge period during which the geyser is quiescent and progressively refills, and 4) a 69 ± 14 minute pre–play period characterized by a series of 5–10 minute–long pulses of steam, small volumes of liquid water discharge and 50–70 s flow oscillations. The erupted waters ascend froma 160 − 170° C reservoir and the volume discharged during the entire eruptive cycle is 20.8 ± 4.1 m3. Assuming isentropic expansion, we calculate a heat output from the geyser of 1.4–1.5 MW, which is < 0.1% of the total heat output from Yellowstone Caldera.

  13. 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.

  14. Cumulative impacts study of The Geysers KGRA: public-service impacts of geothermal development

    SciTech Connect

    Matthews, K.M.

    1982-05-01

    Geothermal development in The Geysers KGRA has affected local public services and fiscal resources in Sonoma, Lake, Mendocino, and Napa counties. Each of these counties underwent rapid population growth between 1970 and 1980, some of which can be attributed to geothermal development. The number of workers currently involved in the various aspects of geothermal development in The Geysers is identified. Using three different development scenarios, projections are made for the number of power plants needed to reach the electrical generation capacity of the steam resource in The Geysers. The report also projects the cumulative number of workers needed to develop the steam field and to construct, operate, and maintain these power plants. Although the number of construction workers fluctuates, most are not likely to become new, permanent residents of the KGRA counties. The administrative and public service costs of geothermal development to local jurisdictions are examined and compared to geothermal revenues accruing to the local governments. Revenues do not cover the immediate fiscal needs resulting from increases in local road maintenance and school enrollment attributable to geothermal development. Several mitigation options are discussed, and a framework is presented for calculating mitigation costs per unit of public service.

  15. Role of temperature differences between surface and deep reservoirs in geyser dynamics: Insights from laboratory experiments

    NASA Astrophysics Data System (ADS)

    Munoz Saez, C.; Shteinberg, A.; Manga, M.

    2012-12-01

    Geysers are springs that produce episodic eruptions of steam, liquid water, and non-condensable gases. Their eruptions are smaller and more frequent than other eruptive processes (volcanic, or hydrothermal eruptions), providing a feasible natural laboratory to understand eruptive processes. Moreover, the fluid dynamics of geysers probe processes that operate in more inaccessible geothermal systems. We developed laboratory experiments to understand the role of the surface temperature on geyser dynamics. For the experimental model, we followed to model developed by Steinberg et al. (1982), which produced periodic eruptions. In this experimental model, eruptions are driven by the ascent of bubbles. The "explosive" ejection of fluid occurs when bubbles reach the surface of the conduit. The eruption of a bubble influences the nucleation on the next bubble through the pressure changes in the conduit. The experimental apparatus consists of a bottom reservoir and a vertical conduit that opens into an upper chamber that collects and returns liquid to the reservoir after the eruption. The reservoir was heated from below at a constant rate. The fluid used was Freon 113, which has a boiling point of 48°C. Temperature in the upper part of the tube was varied between 0° to 20°C. As we increase the temperature difference between the reservoir and the surface of the tube we find (1) that vapor contained in the upper part of bubble tends condense, impeding its ascent to the surface, (2) an increase the number of bubbles generated during the time between eruptions, (3) that the volume of vapor in the tube remain almost constant during the period between eruptions (4) an increase the frequency of eruptions, (5) an increase the escape speed of fluid from the tube, and (6) an increase in Reynolds number. We interpret these results in terms of heat transport by the rising bubbles. Bubbles transport the heat as latent heat of evaporation. Because the amount of heating was the same in

  16. Synoptically driven down-slope winds and their effects on local nocturnal-drainage air flow in The Geysers Geothermal Resource Area

    SciTech Connect

    Orgill, M.M.; Schreck, R.I.; Whiteman, C.D.

    1981-07-01

    Some of the possible synoptic to local sale interactions are identified and discussed that may have an important influence on the development and persistence of nocturnal drainage (katabatic) winds in the eastern portion of The Geysers geothermal development area. On the basis of the July 1979 ASCOT field data at The Geysers, the interactions identified are summarized.

  17. Systematics of Water Temperature and Flow at Tantalus Creek During Calendar Year 2005, Norris Geyser Basin, Yellowstone National Park, Wyoming

    USGS Publications Warehouse

    Clor, Laura E.; Lowenstern, Jacob B.; Heasler, Henry P.

    2007-01-01

    We analyze data for stream flow and water temperature from Tantalus Creek in the Norris Geyser Basin and their relationship to air temperature, precipitation, and geyser eruptions during calendar year 2005. The creek is of interest because it is the primary drainage of the Norris Geyser Basin and carries a very high proportion of thermal water derived directly from hot springs. Two separate diurnal patterns emerge - (1) a winter pattern where increases in water temperature and stream flow closely track those of air temperature and (2) a summer pattern where water and air temperature are closely aligned but stream flow declines once water temperature reaches its daily maximum. The winter pattern is present when the daily average temperature consistently drops below 0 ?C whereas the summer pattern is recognizable when the daily average temperature regularly exceeds 0 ?C. Spring and fall systematics are much more irregular, although both summer and winter patterns can be discerned occasionally during those seasons. We interpret increases in stream flow associated with the winter pattern to result from addition of locally sourced melt water (both snow and soil-bound ice) that increases in abundance once temperatures increase in the morning. Melting is facilitated by the warm ground temperatures in the geyser basin, which are significantly higher than air temperatures in the winter. The summer pattern appears to be strongly affected by increased evaporation in the afternoon, decreasing flow and cooling the remaining water. Discharge from eruptions at Echinus Geyser are clearly visible as peaks in the hydrograph, and indicate that water from this geyser reach the Tantalus weir in 80 to 90 minutes, reflecting a slug of water that travels about 0.4 m s-1.

  18. Understanding the dynamics of a geyser from temporal monitoring of seismic source

    NASA Astrophysics Data System (ADS)

    Cros, E. C.; Roux, P.; Vandemeulebrouck, J.; Kedar, S.

    2010-12-01

    Old Faithful Geyser is the most popular geyser in Yellowstone National Park. The predictability, the repeatability and the short time lag, ~1 hour, between two eruptions make its study very convenient to apprehend its cycle and to make progress in the understanding of geyser's dynamics. The geyser's edifice is characterized by a diameter of 60 m, a height of 4m, with an opening of approximately 2 m x 1 m, a crack-like aperture. In 1992, Sharon Kedar deployed 96 geophones around the geyser vent in order to continuously record seismic signals during several eruptive cycles. The signal recorded at Old Faithful is characterized by small impulsive events, with durations of ~1s, related to bubble collapse in the boiling water column. We revisited the seismic signals recorded by Sharon Kedar in order to determine the locations of the source of these events during an entire cycle with the objective to monitor the temporal evolution of the system. An analysis of 2 hours of seismic data was performed using Matched Field Processing (MFP) techniques, in order to localize the source of the signal produced by the geyser's activity. The seismic signal recorded on the stations is strongly coherent from a station to another which is a prerequisite to MFP. This method is based on the comparison of the phase delays of real data with the phase delays of synthetic signals (i.e. replica). The synthetic signals correspond to the acoustic field recorded at the geophone locations for a certain position of the candidate source at every node of a search grid. When the correlation of the data with the synthetic signals is maximum, the candidate point source and the true point source are co-located. The MFP can be linear (i.e. Bartlett) or non linear (i.e. Minimum Variance Distorsionless Response). The MFP processor is generally incoherently averaged over the frequency bandwidth of interest but the cross-correlation of the data with a reference station permits to average coherently the signal

  19. Clinics in diagnostic imaging (151). Acromioclavicular joint geyser sign with chronic full-thickness supraspinatus tendon (SST) tear.

    PubMed

    Khor, Andrew Yu Keat; Wong, Steven Bak Siew

    2014-02-01

    An 82-year-old man presented with neck pain, right upper limb radiculopathy and right shoulder pain. Physical examination revealed a soft lump over the right shoulder joint, as well as reduced range of shoulder movements. On magnetic resonance imaging, the soft lump was shown to be a cystic mass over the acromioclavicular joint and was related to a full-thickness supraspinatus tendon tear. This is the classic geyser sign. The pathophysiology and clinical features of the geyser sign, and its imaging features with various imaging modalities, are discussed.

  20. Integrated High Resolution Microearthquake Analysis and Monitoring for Optimizing Steam Production at The Geysers Geothermal Field, California

    SciTech Connect

    Majer, Ernest; Peterson, John; Stark, Mitch; Smith, Bill; Rutqvist, Jonny; Kennedy, Mack

    2004-04-26

    In December of 2003 a large amount of water from the Santa Rosa wastewater project began being pumped to The Geysers for injection. Millions of dollars are being spent on this injection project in the anticipation that the additional fluid will not only extend the life of The Geysers but also greatly increase the net amount of energy extracted. Optimal use of the injected water, however, will require that the water be injected at the right place, in the right amount and at the proper rate. It has been shown that Microearthquake (MEQ) generation is a direct indicator of the effect of fluid injection at The Geysers (Majer and McEvilly 1979; Eberhart-Phillips and Oppenheimer 1984; Enedy et al. 1992; Stark 1992; Kirkpatrick et al. 1999; Smith et al. 2000). It is one of the few, if not only methods, practical to monitor the volumetric effect of water injection at The Geysers. At the beginning of this project there was not a detailed MEQ response, Geysers-wide, to a large influx of water such as will be the case from the Santa Rosa injection project. New technology in MEQ acquisition and analysis, while used in parts of The Geysers for short periods of time had not been applied reservoir-wide to obtain an integrated analysis of the reservoir. Also needed was a detailed correlation with the production and injection data on a site wide basis. Last but not least, needed was an assurance to the community that the induced seismicity is documented and understood such that if necessary, mitigation actions can be undertaken in a timely manner. This project was necessary not only for optimizing the heat recovery from the resource, but for assuring the community that there is no hazard associated with the increased injection activities. Therefore, the primary purpose of this project was to develop and apply high-resolution micro earthquake methodology for the entire Geysers geothermal field such that at the end of this project a monitoring and process definition methodology will

  1. Clinics in diagnostic imaging (151). Acromioclavicular joint geyser sign with chronic full-thickness supraspinatus tendon (SST) tear.

    PubMed

    Khor, Andrew Yu Keat; Wong, Steven Bak Siew

    2014-02-01

    An 82-year-old man presented with neck pain, right upper limb radiculopathy and right shoulder pain. Physical examination revealed a soft lump over the right shoulder joint, as well as reduced range of shoulder movements. On magnetic resonance imaging, the soft lump was shown to be a cystic mass over the acromioclavicular joint and was related to a full-thickness supraspinatus tendon tear. This is the classic geyser sign. The pathophysiology and clinical features of the geyser sign, and its imaging features with various imaging modalities, are discussed. PMID:24570312

  2. Clinics in diagnostic imaging (151). Acromioclavicular joint geyser sign with chronic full-thickness supraspinatus tendon (SST) tear.

    PubMed Central

    Khor, Andrew Yu Keat; Wong, Steven Bak Siew

    2014-01-01

    An 82-year-old man presented with neck pain, right upper limb radiculopathy and right shoulder pain. Physical examination revealed a soft lump over the right shoulder joint, as well as reduced range of shoulder movements. On magnetic resonance imaging, the soft lump was shown to be a cystic mass over the acromioclavicular joint and was related to a full-thickness supraspinatus tendon tear. This is the classic geyser sign. The pathophysiology and clinical features of the geyser sign, and its imaging features with various imaging modalities, are discussed. PMID:24570312

  3. Seismic velocity structure and microearthquake source properties at The Geysers, California, geothermal area

    SciTech Connect

    O'Connell, D.R.

    1986-12-01

    The method of progressive hypocenter-velocity inversion has been extended to incorporate S-wave arrival time data and to estimate S-wave velocities in addition to P-wave velocities. S-wave data to progressive inversion does not completely eliminate hypocenter-velocity tradeoffs, but they are substantially reduced. Results of a P and S-wave progressive hypocenter-velocity inversion at The Geysers show that the top of the steam reservoir is clearly defined by a large decrease of V/sub p//V/sub s/ at the condensation zone-production zone contact. The depth interval of maximum steam production coincides with minimum observed V/sub p//V/sub s/, and V/sub p//V/sub s/ increses below the shallow primary production zone suggesting that reservoir rock becomes more fluid saturated. The moment tensor inversion method was applied to three microearthquakes at The Geysers. Estimated principal stress orientations were comparable to those estimated using P-wave firstmotions as constraints. Well constrained principal stress orientations were obtained for one event for which the 17 P-first motions could not distinguish between normal-slip and strike-slip mechanisms. The moment tensor estimates of principal stress orientations were obtained using far fewer stations than required for first-motion focal mechanism solutions. The three focal mechanisms obtained here support the hypothesis that focal mechanisms are a function of depth at The Geysers. Progressive inversion as developed here and the moment tensor inversion method provide a complete approach for determining earthquake locations, P and S-wave velocity structure, and earthquake source mechanisms.

  4. Real-time Remote Data Online For Norris Geyser Basin in Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Perry, J. E.; Lowenstern, J. B.; Clor, L.; Cervelli, P. F.; Allen, S. T.; Heasler, H.; Moloney, T.

    2010-12-01

    Perry, John, Lowenstern, Jacob, Cervelli, Peter, Clor, Laura, Heasler, Henry, Allen, Scott, Moloney, Tim During June 2010, ten 900MHz wireless temperature data loggers (nodes) were installed around the Norris Geyser Basin to monitor geothermal features, streams and soil temperatures. The loggers can provide near real-time updates on temperature variations within 0.2 deg C due to hydrothermal discharges or subsurface fluid migration. Each sensor node is programmed to measure the temperature every two minutes and automatically upload data to the base station computer daily. The hardware consists of a waterproof case containing an M5 logger (made by Marathon Products, Inc.®) with internal memory, lithium D-cell batteries and a 900 MHz, 1-W-transceiver and 5 meter long Teflon-coated probe with a thermistor sensor. Tethered stub or panel antennas are oriented to optimize signal strength to the base station near the Norris Museum. A 0.61 meter-long base-station antenna located 10m high provides signal to the furthest node over 850 meters away with most being “line-of-sight”. A 20-meter coaxial cable and lightning grounding wire connects the base-station antenna to an Ethernet-radio connected to the YNP local-area network. A server located 26-km north at Mammoth Hot Springs requests data at regular intervals (normally daily), archives the information, and then sends it to the USGS for further archiving and internet distribution. During periods of unusual hydrothermal behavior, data can be requested as needed, and it is possible to set user-programmable alarm limits for notification. The RF network is designed to monitor changes from three different sub-basins at Norris (Gray Lakes, Steamboat-Echinus and Porcelain Basin), the main Tantalus Creek drainage, and five individual thermal features (Constant, Porkchop, Steamboat and Echinus Geysers, and Opalescent Spring). The logger installed in Nuphar Lake provides ambient temperatures controlled solely by local

  5. Cryogenic liquid hydrogen reorientation activated by constant reverse gravity acceleration of geyser initiation

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1990-01-01

    A key objective for cryogenic fluid management in a spacecraft propulsion system is development of the technology necessary for acquisition or positioning of liquid outflow or vapor venting. Numerical simulation of positive liquid acquisition is attempted by introducing a reverse gravity acceleration from the propulsive thrust of auxiliary engines which exceeds critical value for the initiation of a geyser. Based on the computer simulation of flow fields during the course of fluid reorientation, six dimensionless parameters resulted. These parameters hold near-constant values through the entire range of liquid filled levels, from 30 to 80 percent, during the course of fluid reorientation.

  6. Constant reverse thrust activated reorientation of liquid hydrogen with Geyser initiation

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1992-01-01

    A key objective of the cryogenic fluid management of the spacecraft propulsion system is to develop the technology necessary for acquisition or positioning of liquid outflow or vapor venting. Numerical simulation of positive liquid acquisition is attempted by introducing reverse gravity acceleration, resulting from the propulsive thrust of auxiliary engines, which exceeds critical value for the initiation of geyser. Based on the computer simulation of flowfields during the course of fluid reorientation, six dimensionless parameters resulted in this study. It shows that these parameters hold near-constant values through the entire ranges of liquid filled levels, from 30-80 percent, during the course of fluid reorientation.

  7. Modeling of jet-induced geyser formation in a reduced gravity environment

    NASA Technical Reports Server (NTRS)

    Wendl, M. C.; Hochstein, J. I.; Sasmal, G. P.

    1991-01-01

    Flow patterns predicted by a computational model of jet-induced geyser formation in a reduced gravity environment are presented and comparison is made to patterns predicted by experimentally based correlations. The configuration studied is an idealization of a forthcoming flight experiment to examine cryogenic propellant management issues. A transitional version of the ECLIPSE code used as a computational tool for the analyses is described. It is shown that computationally predicted flow patterns are in qualitative agreement with the correlation-based predictions, and some details of the predicted flow fields are given.

  8. Medium-frequency impulsive-thrust-excited slosh waves during propellant reorientation with a geyser

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.; Lee, C. C.

    1992-01-01

    Slosh wave excitation induced by a resettling flowfield activated by 1.0-Hz impulsive thrust during the course of liquid reorientation with the initiation of geyser for liquid-fill levels of 30, 50, 65, 70, and 80 percent has been studied. Characteristics of slosh waves of various frequencies excited by the resettling flowfield are discussed. Slosh wave excitations shift the fluid mass distribution in the container which imposes time-dependent variations in spacecraft moment of inertia. This information is important for spacecraft control during the course of liquid reorientation.

  9. Geochemical studies of reservoir processes in the NCPA field of The Geysers, a preliminary report

    SciTech Connect

    Truesdell, Alfred; Enedy, Steve; Smith, Bill

    1993-01-28

    Methods of tracing reservoir processes will be discussed and applied to the NCPA Geysers steam field. The gas and isotope chemistry of produced steam is far from uniform even in a restricted volume of the reservoir. The composition is affected by many factors. Differences in permeability, local existence of gas pockets or perched liquid and the pattern of fracture connection can cause neighboring wells to produce steam of different compositions. This study attempts to separate local effects from general influences by viewing the data across the field and over a period of time. The fits of the trend lines to the data are far from perfect but present a reasonably consistent picture.

  10. Arsenite oxidase gene diversity among Chloroflexi and Proteobacteria from El Tatio Geyser Field, Chile.

    PubMed

    Engel, Annette Summers; Johnson, Lindsey R; Porter, Megan L

    2013-03-01

    Arsenic concentrations (450-600 μmol L(-1)) at the El Tatio Geyser Field in northern Chile are an order of magnitude greater than at other natural geothermal sites, making El Tatio an ideal location to investigate unique microbial diversity and metabolisms associated with the arsenic cycle in low sulfide, > 50 °C, and circumneutral pH waters. 16S rRNA gene and arsenite oxidase gene (aioA) diversities were evaluated from biofilms and microbial mats from two geyser-discharge stream transects. Chloroflexi was the most prevalent bacterial phylum at flow distances where arsenite was converted to arsenate, corresponding to roughly 60 °C. Among aioA-like gene sequences retrieved, most had homology to whole genomes of Chloroflexus aurantiacus, but others were homologous to alphaproteobacterial and undifferentiated beta- and gammaproteobacterial groups. No Deinococci, Thermus, Aquificales, or Chlorobi aioA-like genes were retrieved. The functional importance of amino acid sites was evaluated from evolutionary trace analyses of all retrieved aioA genes. Fifteen conserved residue sites identified across all phylogenetic groups highlight a conserved functional core, while six divergent sites demonstrate potential differences in electron transfer modes. This research expands the known distribution and diversity of arsenite oxidation in natural geothermal settings, and provides information about the evolutionary history of microbe-arsenic interactions.

  11. Characterization of Fracture Patterns in the Geysers Geothermal Reservoir by Shear-wave Splitting

    SciTech Connect

    D. Erten; J. A. Rial

    1999-09-15

    The authors have analyzed the splitting of shear waves from microearthquakes recorded by a 16-station three-component seismic network at the Northwest Geysers geothermal field, Geysers, California, to determine the preferred orientation of subsurface fractures and cracks. Average polarization crack directions with standard deviation were computed for each station. Also, graphical fracture characterizations in the form of equal-area projections and rose diagrams were created to depict the results. The main crack orientations within the steam field are predominantly in the N10{degree}E to N50{degree}E direction, consistent with expected fracture directions in a pull-apart basin created by sub-parallel right-lateral strike-slip faults related to the San Andreas fault system. Time delays range from 15--60 ms, similar to the time delays from previous studies at geothermal reservoirs. They have detected a significant increase in time delays between 1988 and 1994, which they attribute to widening of the cracks or filling of the cracks with fluid. Increase in production activities during this time also could have influenced this widening.

  12. Geology and remarkable thermal activity of Norris Geyser Basin, Yellowstone National Park, Wyoming

    SciTech Connect

    White, D.E.; Hutchinson, R.A.; Keith, T.E.C.

    1988-01-01

    Norris Geyser Basin is adjacent to the north rim of the Yellowstone caldera at the common intersection of the caldera rim and the Norris-Mammoth Corridor, a zone of faults, volcanic vents, and thermal activity that strikes north from the caldera rim to Mammoth Hot Springs. The dominant quartz sand is hydrothermally cemented by chalcedony and is extremely hard, thereby justifying the term hydrothermal quartzite. The fundamental water type in Norris Basin is nearly neutral in pH and high in Cl and SiO/sub 2/. Another common type of water in Norris Basin is high in SO/sub 4/ and moderately high in Cl, with Cl/SO/sub 4/ ratios differing considerably. This study provides no new conclusive data on an old problem, the source or sources of rare dissolved constitutents. An important part of this paper consists of examples of numerous changes in behavior and chemical composition of most springs and geysers, to extents not known elsewhere in the park and perhaps in the world. Hydrothermal mineralogy in core samples from three research holes drilled entirely in Lava Creek Tuff to a maximum depth of -331.6 m permits an interpretation of the hydrothermal alteration history. A model for large, long-lived, volcanic-hydrothermal activity is also suggested, involving all of the crust and upper mantle and using much recent geophysical data bearing on crust-mantle interrelations.

  13. Final Report: Natural State Models of The Geysers Geothermal System, Sonoma County, California

    SciTech Connect

    T. H. Brikowski; D. L. Norton; D. D. Blackwell

    2001-12-31

    Final project report of natural state modeling effort for The Geysers geothermal field, California. Initial models examined the liquid-dominated state of the system, based on geologic constraints and calibrated to match observed whole rock delta-O18 isotope alteration. These models demonstrated that the early system was of generally low permeability (around 10{sup -12} m{sup 2}), with good hydraulic connectivity at depth (along the intrusive contact) and an intact caprock. Later effort in the project was directed at development of a two-phase, supercritical flow simulation package (EOS1sc) to accompany the Tough2 flow simulator. Geysers models made using this package show that ''simmering'', or the transient migration of vapor bubbles through the hydrothermal system, is the dominant transition state as the system progresses to vapor-dominated. Such a system is highly variable in space and time, making the rock record more difficult to interpret, since pressure-temperature indicators likely reflect only local, short duration conditions.

  14. The MRI geyser sign: acromioclavicular joint cysts in the setting of a chronic rotator cuff tear.

    PubMed

    Cooper, H John; Milillo, Ralph; Klein, Devon A; DiFelice, Gregory S

    2011-06-01

    We present the case of a 71-year-old man with a large acromioclavicular (AC) joint cyst successfully managed with surgical excision. AC joint cysts are soft tissue masses generally signifying underlying rotator cuff pathology. Traditionally, these cysts were identified with shoulder arthrography as a "geyser" of fluid escaping through the AC joint. Magnetic resonance imaging (MRI) is today's preferred imaging modality; we describe the MRI equivalent of the "geyser sign," signifying synovial fluid escaping through the cuff defect, across the subacromial bursa, and decompressing superiorly through a degenerated AC joint. Surgical management is preferred for symptomatic cysts. Based on a review of limited retrospective case series, recommendations for management of these lesions are as follows. Repair of the rotator cuff is preferable whenever possible. In the case of an irreparable defect, good results can be achieved through excisional AC joint arthroplasty and resection of the cyst base. Aspiration of these cysts should not be attempted, due to the high recurrence rate and potential for a draining sinus. Hemiarthroplasty also may be effective in indirectly decompressing these cysts; but given the invasive nature of this procedure, it should be reserved for patients who are also symptomatic from cuff arthropathy.

  15. TRACKING THE GEYSERS OF ENCELADUS INTO SATURN’S E RING

    SciTech Connect

    Mitchell, C. J.; Porco, C. C.; Weiss, J. W.

    2015-05-15

    We examine Cassini Imaging Science Subsystem images of the E ring taken over a period of almost 7 yr, from 2006 September to 2013 July, in which long, sinuous structures dubbed tendrils are present. We model these structures by numerically integrating the trajectories of particles launched from the sources of the most active geysers recently located along the four main fractures crossing the south polar terrain of the moon, and producing from these integrations synthetic images that we then compare to the real ones. We include the effects of charging and the electromagnetic forces on the particles in addition to the gravity of Saturn and Enceladus. We demonstrate that these structures are produced by the highest velocity particles erupting from the most active geysers and entering Saturn’s orbit, and not perturbations of E ring particles by Enceladus. The detailed structures of the tendrils change with the orbital position of Enceladus, a finding likely to be the result of the diurnal variability in the source activity.

  16. Sedimentology, stratigraphy, and depositional environment of the Crystal Geyser Dinosaur Quarry, east-central Utah

    USGS Publications Warehouse

    Suarez, M.B.; Suarez, C.A.; Kirkland, J.I.; Gonzalez, Luis A.; Grandstaff, D.E.; Terry, D.O.

    2007-01-01

    The Crystal Geyser Dinosaur Quarry, near Green River, Utah, is located at the base of the Lower Cretaceous (Barremian) Yellow Cat Member of the Cedar Mountain Formation. The quarry preserves a nearly monospecific accumulation of a new basal therizinosauroid, Falcarius utahensis. We used field descriptions and petrographic analysis to determine the depositional environment and development of the quarry strata. Results of these analyses suggest that the quarry represents multiple episodes of bone accumulation buried by spring and overbank flood deposits. Evidence for these previously undescribed spring deposits includes calcite macroscopic structures within the quarry strata - such as pisolites and travertine fragments - and calcite micromorphologies - including radial-fibrous, feather, and scandulitic dendrite morphologies and tufa clasts. At least two episodes of bone incorporation are preserved in the quarry based on their stratigraphic position and lithologic associations. The unique depositional setting in and around the Crystal Geyser Dinosaur Quarry appears to have been favorable for the preservation of vertebrate fossils and provides insight into early Cretaceous environments in North America. Copyright ?? 2007, SEPM (Society for Sedimentary Geology).

  17. Arsenite oxidase gene diversity among Chloroflexi and Proteobacteria from El Tatio Geyser Field, Chile.

    PubMed

    Engel, Annette Summers; Johnson, Lindsey R; Porter, Megan L

    2013-03-01

    Arsenic concentrations (450-600 μmol L(-1)) at the El Tatio Geyser Field in northern Chile are an order of magnitude greater than at other natural geothermal sites, making El Tatio an ideal location to investigate unique microbial diversity and metabolisms associated with the arsenic cycle in low sulfide, > 50 °C, and circumneutral pH waters. 16S rRNA gene and arsenite oxidase gene (aioA) diversities were evaluated from biofilms and microbial mats from two geyser-discharge stream transects. Chloroflexi was the most prevalent bacterial phylum at flow distances where arsenite was converted to arsenate, corresponding to roughly 60 °C. Among aioA-like gene sequences retrieved, most had homology to whole genomes of Chloroflexus aurantiacus, but others were homologous to alphaproteobacterial and undifferentiated beta- and gammaproteobacterial groups. No Deinococci, Thermus, Aquificales, or Chlorobi aioA-like genes were retrieved. The functional importance of amino acid sites was evaluated from evolutionary trace analyses of all retrieved aioA genes. Fifteen conserved residue sites identified across all phylogenetic groups highlight a conserved functional core, while six divergent sites demonstrate potential differences in electron transfer modes. This research expands the known distribution and diversity of arsenite oxidation in natural geothermal settings, and provides information about the evolutionary history of microbe-arsenic interactions. PMID:23066664

  18. Tracking the Geysers of Enceladus into Saturn’s E Ring

    NASA Astrophysics Data System (ADS)

    Mitchell, C. J.; Porco, C. C.; Weiss, J. W.

    2015-05-01

    We examine Cassini Imaging Science Subsystem images of the E ring taken over a period of almost 7 yr, from 2006 September to 2013 July, in which long, sinuous structures dubbed tendrils are present. We model these structures by numerically integrating the trajectories of particles launched from the sources of the most active geysers recently located along the four main fractures crossing the south polar terrain of the moon, and producing from these integrations synthetic images that we then compare to the real ones. We include the effects of charging and the electromagnetic forces on the particles in addition to the gravity of Saturn and Enceladus. We demonstrate that these structures are produced by the highest velocity particles erupting from the most active geysers and entering Saturn’s orbit, and not perturbations of E ring particles by Enceladus. The detailed structures of the tendrils change with the orbital position of Enceladus, a finding likely to be the result of the diurnal variability in the source activity.

  19. The MRI geyser sign: acromioclavicular joint cysts in the setting of a chronic rotator cuff tear.

    PubMed

    Cooper, H John; Milillo, Ralph; Klein, Devon A; DiFelice, Gregory S

    2011-06-01

    We present the case of a 71-year-old man with a large acromioclavicular (AC) joint cyst successfully managed with surgical excision. AC joint cysts are soft tissue masses generally signifying underlying rotator cuff pathology. Traditionally, these cysts were identified with shoulder arthrography as a "geyser" of fluid escaping through the AC joint. Magnetic resonance imaging (MRI) is today's preferred imaging modality; we describe the MRI equivalent of the "geyser sign," signifying synovial fluid escaping through the cuff defect, across the subacromial bursa, and decompressing superiorly through a degenerated AC joint. Surgical management is preferred for symptomatic cysts. Based on a review of limited retrospective case series, recommendations for management of these lesions are as follows. Repair of the rotator cuff is preferable whenever possible. In the case of an irreparable defect, good results can be achieved through excisional AC joint arthroplasty and resection of the cyst base. Aspiration of these cysts should not be attempted, due to the high recurrence rate and potential for a draining sinus. Hemiarthroplasty also may be effective in indirectly decompressing these cysts; but given the invasive nature of this procedure, it should be reserved for patients who are also symptomatic from cuff arthropathy. PMID:21869946

  20. 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.

  1. Laboratory measurements of reservoir rock from the Geysers geothermal field, California

    USGS Publications Warehouse

    Lockner, D.A.; Summers, R.; Moore, D.; Byerlee, J.D.

    1982-01-01

    Rock samples taken from two outcrops, as well as rare cores from three well bores at the Geysers geothermal field, California, were tested at temperatures and pressures similar to those found in the geothermal field. Both intact and 30?? sawcut cylinders were deformed at confining pressures of 200-1000 bars, pore pressure of 30 bars and temperatures of 150?? and 240??C. Thin-section and X-ray analysis revealed that some borehole samples had undergone extensive alteration and recrystallization. Constant strain rate tests of 10-4 and 10-6 per sec gave a coefficient of friction of 0.68. Due to the highly fractured nature of the rocks taken from the production zone, intact samples were rarely 50% stronger than the frictional strength. This result suggests that the Geysers reservoir can support shear stresses only as large as its frictional shear strength. Velocity of p-waves (6.2 km/sec) was measured on one sample. Acoustic emission and sliding on a sawcut were related to changes in pore pressure. b-values computed from the acoustic emissions generated during fluid injection were typically about 0.55. An unusually high b-value (approximately 1.3) observed during sudden injection of water into the sample may have been related to thermal cracking. ?? 1982.

  2. Statistical Studies of Induced and Triggered Seismicity at The Geysers, California

    NASA Astrophysics Data System (ADS)

    Hawkins, Angela

    This study considers the statistics of induced and triggered seismicity at The Geysers geothermal field, California. Little seismicity was reported before steam extraction began in 1960. In 1980 the residual water associated with power generation was re-injected, producing induced seismicity. Beginning in 1997 large-scale injections of cold water began in order to enhance the generation of steam. This led to an increase in M < 1.2 earthquakes from approximately five per month to twenty. The induced seismicity satisfies Gutenberg- Richter (GR) scaling to a good approximation with b ≈ 1.3. This study demonstrates that aftershocks of the larger induced earthquakes also satisfy GR scaling as well as Omori's law for their time dependence. Statistics of triggered seismicity at the Geysers are also presented. The 8/24/14 Mw = 6.02 South Napa earthquake triggered a M ≈ 4.38 event as well as some 80 other M > 1.25 events. The GR and decay statistics will be given. However, in order to separate second-order aftershocks from triggered aftershocks, an additional triggered sequence is studied. The M = 7.2 4/4/10 Baja earthquake had some 34 M >1.25 triggered events in the first hour including a M = 3.37 event.

  3. Nature and use of bimodalism in spectral images of the Geysers steam field, California

    SciTech Connect

    Gabelman, J.W.

    1996-08-01

    Bimodalism in remotely sensed images is expressed as a brightness gradient perpendicular to flight path, rendering overbright and overdark halves. It results from Mie scattering by molecular-size and larger atmospheric particles of aerosols, moisture, and dust. It becomes significant at low ratios of sensor height to sweep angle (essentially confined to the atmosphere). Airborne Daedalus Thematic Mapper Simulator images of The Geysers field are bimodal in all bands except 8. Atmospheric scattering normally is insignificant at infragreen (Band 3) wavelengths. Its strength in higher (numbered) bands at The Geysers suggests unusually large and abundant particles, most likely water vapor. Relative intensities of bimodalism, determined by rationing adjacent bands, show broadly Gaussian curves on either side of Band 8. Over the steam field the bright-dark boundary at midgradient is bowed into general conformation with the field center and axis. In bands 1-7 the boundary remains generally parallel to flight path, but in 9-12 is it perpendicular to structural grain and steam field axis. The gradient also is segmented into brightness steps, the boundaries of which coincide with major fractures across the field axis. Bimodalism is further distorted by overwhelming reflectance from intensely argillized portions of the field cap.

  4. Physical and Geochemical Controls on the Structure and Function of Microbial Mat Communities at El Tatio Geyser Field, Chile

    NASA Astrophysics Data System (ADS)

    Myers, K. D.; Omelon, C. R.; Bennett, P.

    2013-12-01

    Cyanobacteria are important primary producers that form the basis of most hot spring microbial mat communities in waters between 30-73°C. Primary producers shape microbial mat communities by fixing the dissolved inorganic carbon (DIC) pool to organic carbon and providing nutrients for diverse microorganisms that perform a broad range of biogeochemical transformations. This study compares the microbial community structure and net primary productivity of cyanobacterially-based and non-cyanobacterially based microbial mats collected from the El Tatio Geyser Field, a high elevation geyser complex in the Andes Mountains in Region II, Chile. In addition to extreme conditions imparted by high elevation and its location in the Atacama Desert, El Tatio has a suite of extreme geochemical stressors for life, including high arsenic as As(III) and As(V) (0.4-0.6 mM). El Tatio also has unusually low concentrations of DIC in some streams (0.1-0.3 mM), low enough to severely limit primary production in microbial mats. In contrast to other geothermal sites around the world where microbial diversity is controlled primarily by temperature, observations of unusual patterns in microbial mat composition in low-DIC streams at El Tatio suggest alternate controls their distribution. For instance, we observe less biomass in low-DIC streams compared to nearby high DIC streams, and less biomass in high temperature regions of low-DIC streams, compared to low-temperature locations that are dominated by cyanobacteria. To further investigate these patterns, a field assay was conducted to compare carbon assimilation, the relative importance of photo- and chemoautotrophy, and bacterial 16S rRNA sequence abundance at two distinct sites along a low-DIC stream. Water temperature at the upstream site measured 60°C, is dominated by high As(III), and is composed of sparse, red-colored mat material, whereas the downstream site measured a water temperature of 40°C, is dominated by high As(V), and is

  5. Park Visitors' Understandings, Values and Beliefs Related to Their Experience at Midway Geyser Basin, Yellowstone National Park, USA.

    ERIC Educational Resources Information Center

    Brody, Michael; Tomkiewicz, Warren

    2002-01-01

    Investigates the development of park visitors' knowledge, values, and beliefs during their visit to the Midway Geyser Basin. Draws on prior work in the areas of museum and informal education, and public understanding of science and cognitive psychology. Interprets the results in terms of park visitors' knowledge systems, how the experience…

  6. Characterizing Fractures in Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy

    SciTech Connect

    Aminzadeh, Fred; Sammis, Charles; Sahimi, Mohammad; Okaya, David

    2015-04-30

    The ultimate objective of the project was to develop new methodologies to characterize the northwestern part of The Geysers geothermal reservoir (Sonoma County, California). The goal is to gain a better knowledge of the reservoir porosity, permeability, fracture size, fracture spacing, reservoir discontinuities (leaky barriers) and impermeable boundaries.

  7. Archaeal and bacterial communities in three alkaline hot springs in Heart Lake Geyser Basin, Yellowstone National Park.

    PubMed

    Bowen De León, Kara; Gerlach, Robin; Peyton, Brent M; Fields, Matthew W

    2013-01-01

    The Heart Lake Geyser Basin (HLGB) is remotely located at the base of Mount Sheridan in southern Yellowstone National Park (YNP), Wyoming, USA and is situated along Witch Creek and the northwestern shore of Heart Lake. Likely because of its location, little is known about the microbial community structure of springs in the HLGB. Bacterial and archaeal populations were monitored via small subunit (SSU) rRNA gene pyrosequencing over 3 years in 3 alkaline (pH 8.5) hot springs with varying temperatures (44°C, 63°C, 75°C). The bacterial populations were generally stable over time, but varied by temperature. The dominant bacterial community changed from moderately thermophilic and photosynthetic members (Cyanobacteria and Chloroflexi) at 44°C to a mixed photosynthetic and thermophilic community (Deinococcus-Thermus) at 63°C and a non-photosynthetic thermophilic community at 75°C. The archaeal community was more variable across time and was predominantly a methanogenic community in the 44 and 63°C springs and a thermophilic community in the 75°C spring. The 75°C spring demonstrated large shifts in the archaeal populations and was predominantly Candidatus Nitrosocaldus, an ammonia-oxidizing crenarchaeote, in the 2007 sample, and almost exclusively Thermofilum or Candidatus Caldiarchaeum in the 2009 sample, depending on SSU rRNA gene region examined. The majority of sequences were dissimilar (≥10% different) to any known organisms suggesting that HLGB possesses numerous new phylogenetic groups that warrant cultivation efforts.

  8. Archaeal and bacterial communities in three alkaline hot springs in Heart Lake Geyser Basin, Yellowstone National Park.

    PubMed

    Bowen De León, Kara; Gerlach, Robin; Peyton, Brent M; Fields, Matthew W

    2013-01-01

    The Heart Lake Geyser Basin (HLGB) is remotely located at the base of Mount Sheridan in southern Yellowstone National Park (YNP), Wyoming, USA and is situated along Witch Creek and the northwestern shore of Heart Lake. Likely because of its location, little is known about the microbial community structure of springs in the HLGB. Bacterial and archaeal populations were monitored via small subunit (SSU) rRNA gene pyrosequencing over 3 years in 3 alkaline (pH 8.5) hot springs with varying temperatures (44°C, 63°C, 75°C). The bacterial populations were generally stable over time, but varied by temperature. The dominant bacterial community changed from moderately thermophilic and photosynthetic members (Cyanobacteria and Chloroflexi) at 44°C to a mixed photosynthetic and thermophilic community (Deinococcus-Thermus) at 63°C and a non-photosynthetic thermophilic community at 75°C. The archaeal community was more variable across time and was predominantly a methanogenic community in the 44 and 63°C springs and a thermophilic community in the 75°C spring. The 75°C spring demonstrated large shifts in the archaeal populations and was predominantly Candidatus Nitrosocaldus, an ammonia-oxidizing crenarchaeote, in the 2007 sample, and almost exclusively Thermofilum or Candidatus Caldiarchaeum in the 2009 sample, depending on SSU rRNA gene region examined. The majority of sequences were dissimilar (≥10% different) to any known organisms suggesting that HLGB possesses numerous new phylogenetic groups that warrant cultivation efforts. PMID:24282404

  9. Surface deformation and seismic signatures associated with the eruption cycle of Lone Star Geyser, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Gomez, F. G.; Johnson, H. E., III; LeWinter, A. L.; Finnegan, D. C.; Sandvol, E. A.; Nayak, A.; Hurwitz, S.

    2014-12-01

    Geysers are important subjects for studying processes involved with multi-phase eruptions. As part of a larger field effort, this study applies imaging geodesy and seismology to study eruptive cycles of the Lone Star Geyser in Yellowstone National Park. Lone Star Geyser is an ideal candidate for such study, as it erupts with a nearly regular period of approximately 3 hours. The geyser includes a 5 m diameter cone that rises 2 meters above the sinter terrace, and the entire system can be viewed from a nearby hillside. Fieldwork was accomplished during April 2014. Ground-based interferometric radar (GBIR) and terrestrial laser scanning (TLS) were used to image possible surface deformations associated with Lone Star Geyer's eruption cycles. Additional observations were provided by global positioning system (GPS) measurements and six broad-band seismometers deployed in the immediate vicinity of the geyser. The GBIR and TLS were deployed approximately 65 meters from the sinter cone of the geyser. The GBIR involves a ku-band radar (1.7 cm wavelength) that is sensitive to approximately half-millimeter changes in the line-of-sight distance. Radar images were acquired every minute for 3 or more eruptions per day. Temporally redundant, overlapping interferograms were used to improve the sensitivity and interpolate a minute-wise time series of line-of-sight displacement, and efforts were made to account for possible path-delay effects resulting from water vapor around the geyser cone. Repeat (every minute) high-speed TLS scans were acquired for multiple eruption cycles over the course of two-days. Resulting measurement point spacing on the sinter cone was ~3cm. The TLS point-clouds were geo-referenced using static surveyed reflectors and scanner positions. In addition to measuring ground deformation, filtering and classification of the TLS point cloud was used to construct a mask that allows radar interferometry to exclude non-ground areas (vegetation, snow, sensors

  10. Preliminary analysis of the use of electrical resistance tomography for injectate tracking at the Geysers geothermal field

    SciTech Connect

    Creed, Bob; Daily, Bill

    1996-01-24

    Current geochemical and geophysical injectate tracking methods are useful reservoir management techniques but do not track injectate movement quick enough to maximize injection efficiency or avoid negative impacts on nearby steam production wells. A preliminary analysis indicates that two dimensional electrical resistance tomography (ERT) may be useful for imaging plume movement resulting from Geysers/Lake County Effluent Pipeline injectate in near real time. ERT models comparing an injection plume resistivity of 50 Ohm-m with background resistivities of 10, 100 (typical Geysers greywacke), and 500 Ohm-m (typical Geysers felsite) indicate that liquid plumes can be imaged at depths of 6,000 feet to 8,000 feet or greater for resistivity contrasts of 2 to 1 or greater. Further refinement of the ERT model could be accomplished with more data on porosity in the vicinity of the borehole, resistivity measurements, and reservoir engineering estimates of plume temperature and saturation. Based on the results of this analysis and previous successes in using ERT to map shallow subsurface steam and water movement in porous media it is likely, but not certain, that ERT will prove to be an additional reservoir management tool to be used in conjunction with additional geochemical, geophysical, and reservoir engineering techniques. A field scale test at The Geysers is required to verify the utility of ERT for injectate tracking. The goal of this paper is to stimulate discussion among geothermal researchers regarding use of the ERT technique for injectate tracking at The Geysers and get some input on the appropriateness and utility of the assumptions used.

  11. Intermittent control procedures for the Geysers hydrogen sulfide emission abatement

    SciTech Connect

    Buick, B.D.; Mooney, M.L.

    1984-01-01

    Pacific Gas and Electric Company (PG and E) operates the world's largest geothermal steam electric power generation facility, currently about 1.140 megawatts (Mw). This facility is located about 80 miles north of San Francisco, California and is within a region referred to as the Known Geothermal Resource Area (KGRA). Pollutants resulting from this method of electric power generation are due to impurities in the geothermal steam. A major contaminate in the steam is hydrogen sulfide (H/sub 2/S), a regulated pollutant in California. The ambient air quality standard (AAQS) for this pollutant in California is 0.03 parts per million (ppM) averaged over one hour. H/sub 2/S is an invisible, unpleasant smelling gas present in varying concentrations in the geothermal steam. Its odor has been compared to the smell of rotten eggs. Since PG and E is increasingly relying on this source of electrical power generation, it has committed millions of dollars to the development, testing, acquisition, and installation of abatement equipment to reduce H/sub 2/S emissions during the past ten years. In order to reduce the number of exceeds of the AAQS during this developmental period, a predictive model was needed for interim abatement purposes. Most of the high hourly H/sub 2/S values occur with meteorological conditions having poor ventilation resulting from a combination of low wind speed and reduced mixing layer depths. This weather condition is most common during the months of June through October in California. A predictive model was developed from three years of hourly H/sub 2/S measurements of 0.03 ppM or greater in populated areas downwind of the generation facility and from observations of associated meteorological data.

  12. Three-dimensional seismic image of a geothermal reservoir: The Geysers, California

    USGS Publications Warehouse

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

    1996-01-01

    Three-dimensional seismic travel-time tomography of The Geysers geothermal area, in the coast ranges of northern California, shows a strong (-9%) anomaly in VP/VS, the ratio of the compressional and shear wave speeds, that is not evident in Vp alone and corresponds closely to the most intensively exploited part of the geothermal reservoir. This anomaly probably indicates low pore pressure and relatively dry conditions, caused partly by boiling of pore water as steam is extracted. Steam pressure decreases over the last decade have probably caused seismologically measurable changes in wave speeds. Tomographic measurement of Vp/Vs is a promising technique both for identifying geothermal resources and for monitoring them during exploitation.

  13. Method and apparatus for enhancing the pumping action of a geyser pumped tube

    SciTech Connect

    Bartera, R.E.

    1987-06-30

    This patent describes a geyser pump system comprising: a riser tube having upper and lower ends; means for heating the riser tube; a liquid medium column filling the tube to near the upper end; bubble generating means in the riser tube below the liquid level near the upper end for generating vapor bubbles when the riser tube is heated; the bubble generating means comprising a cavity to isolate a volume of the liquid medium; the cavity having at least one aperature in communication with the bulk of the liquid medium for generating vapor bubbles when the isolated volume of liquid in the cavity is heated. A temperature rise in the isolated volume of liquid causes formation of bubbles at least one aperature.

  14. 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.

  15. 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.

  16. Liquid hydrogen slosh waves excited by constant reverse gravity acceleration of geyser initiation

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.; Lee, C. C.

    1992-01-01

    The requirement to settle or to position liquid fuel over the outlet end of the spacecraft propellant tank before main engine restart poses a microgravity fluid behavior problem. Resettlement or reorientation of liquid propellant can be accomplished by providing the optimal acceleration to the spacecraft such that the propellant is reoriented over the tank outlet. In this study slosh wave excitation induced by the resettling flowfield during the course of liquid reorientation with the initiation of geyser for liquid-filled levels of 30, 50, 65, 70, and 80 percent have been studied. Characteristics of slosh waves with various frequencies excited are discussed. Slosh wave excitations will affect the fluid stress distribution exerted on the container wall and shift the fluid mass distribution inside the container, which imposes the time-dependent variations in the moment of inertia of the container. This information is important for the spacecraft control during the course of liquid reorientation.

  17. 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.

  18. Conceptual Schematic Geologic Cross-Sections of the Geysers Steam Field

    SciTech Connect

    Hebein, Jeffrey J.

    1986-01-21

    While formerly studied in terms of ancient Franciscan stratigraphy, The Geysers Steam Field now offers new views and interpretations on the deeper structure and importance of the lithocap, main metagraywacke, and felsic intrusive basement units with respect to the huge fractured reservoir. The Big Sulphur Creek enhanced tectonic disruption area provides the best situation for shallow felsite injection, shallow reservoir top, metasomatism transformation, and profound fracture permeability. Steam cells commonly extend to great depths and laterally drop off sharply, with relatively flat lateral continuance in some resource areas. Injectate ponding may offer a third fluid interface for reservoir steam reserves. A possible boiled down residuum of complex evaporates and hematite has been viewed in one area of the field where the reservoir (proper) bottom was encountered. Such a deposit may exist along all reservoir cell(s) bottoms, where in numerous cases the reservoir proper has been seen to pass into a somewhat mysterious ultra-superheated reservoir.

  19. Hydrothermal Alteration Minerals of the Geysers Steam Field, California and their Potential Use in Exploration

    SciTech Connect

    Moore, Diane

    1980-12-16

    Little information has been published on the hydrothermal alteration minerals occurring at depth in the Geysers steam field, California. Steiner (1958) reported the occurrence of wairakite from a well; McNitt (1964) identified pyrite, sericite, calcite, quartz, siderite, apatite and chlorite in cores of Franciscan graywacke and greenstone. Recently, Union Oil Geothermal Division furnished a set of well cores from the cap rock overlying the steam reservoir for geophysical studies (Lockner -e t -a l . , 1980). Cores of metagraywacke and greenstone from 4 wells were compared to unaltered Franciscan metagraywacke from surface exposures. Several previously unreported alteration minerals were found in the cored rocks, including epidote, tremolite-actinolite, prehnite and tourmaline. This note describes the observed alteration minerals and some of the factors that controlled their growth.

  20. Coupled variations in helium isotopes and fluid chemistry: Shoshone Geyser Basin, Yellowstone National Park

    SciTech Connect

    Hearn, E.H.; Kennedy, B.M. ); Truesdell, A.H. )

    1990-11-01

    Early studies of {sup 3}He/{sup 4}He variations in geothermal systems have generally attributed these fluctuations to either differences in the source of the magmatic {sup 3}He-rich helium or to local differences in the deep flux of magmatic {sup 3}He-rich helium. Kennedy et al, however, show that near-surface processes such as boiling and dilution may also drastically affect {sup 3}He/{sup 4}He ratios of geothermal vapors. Helium isotope ratios were determined for several hot springs at Shoshone Geyser Basin of Yellowstone National Park for this study, along with other noble gas data. Stable isotope data and water and gas chemistry data for each spring were also compiled. The water chemistry indicates that there is one deep, hot thermal water in the area which is mixing with dilute meteoric water that has entered the system at depth. Spring HCO{sub 3}{sup {minus}} concentrations correlate with {sup 3}He/{sup 4}He values, as in nearby Lower Geyser Basin. This correlation is attributed to variable amounts of deep dilution of thermal waters with a relatively cool water that inhibits boiling at depth, thus preventing the loss of CO{sub 2} and magmatic He in the most diluted samples. Oxygen and hydrogen isotope data also support a boiling and dilution model, but to produce the observed fractionations, the boiling event would have to be extensive, with steam loss at the surface, whereas the boiling that affected the helium isotope ratios was probably a small scale event with steam loss at depth. It is possible that deep boiling occurred in the basin and that small amounts of steam escaped along fractures at about 500 m below the surface while all subsequently produced steam was lost near or at the surface.

  1. Generation and evolution of hydrothermal fluids at Yellowstone: Insights from the Heart Lake Geyser Basin

    USGS Publications Warehouse

    Lowenstern, J. B.; Bergfeld, D.; Evans, William C.; Hurwitz, S.

    2012-01-01

    We sampled fumaroles and hot springs from the Heart Lake Geyser Basin (HLGB), measured water and gas discharge, and estimated heat and mass flux from this geothermal area in 2009. The combined data set reveals that diverse fluids share an origin by mixing of deep solute-rich parent water with dilute heated meteoric water, accompanied by subsequent boiling. A variety of chemical and isotopic geothermometers are consistent with a parent water that equilibrates with rocks at 205°C ± 10°C and then undergoes 21% ± 2% adiabatic boiling. Measured diffuse CO2 flux and fumarole compositions are consistent with an initial dissolved CO2 concentration of 21 ± 7 mmol upon arrival at the caldera boundary and prior to southeast flow, boiling, and discharge along the Witch Creek drainage. The calculated advective flow from the basin is 78 ± 16 L s−1 of parent thermal water, corresponding to 68 ± 14 MW, or –1% of the estimated thermal flux from Yellowstone. Helium and carbon isotopes reveal minor addition of locally derived crustal, biogenic, and meteoric gases as this fluid boils and degasses, reducing the He isotope ratio (Rc/Ra) from 2.91 to 1.09. The HLGB is one of the few thermal areas at Yellowstone that approaches a closed system, where a series of progressively boiled waters can be sampled along with related steam and noncondensable gas. At other Yellowstone locations, steam and gas are found without associated neutral Cl waters (e.g., Hot Spring Basin) or Cl-rich waters emerge without significant associated steam and gas (Upper Geyser Basin).

  2. Coupled variations in helium isotopes and fluid chemistry: Shoshone Geyser Basin, Yellowstone National Park

    USGS Publications Warehouse

    Hearn, E.H.; Kennedy, B.M.; Truesdell, A.H.

    1990-01-01

    Early studies of 3He/4He variations in geothermal systems have generally attributed these fluctuations to either differences in the source of the magmatic 3He-rich helium or to local differences in the deep flux of magmatic 3He-rich helium. Kennedy et al. (1987), however, show that near-surface processes such as boiling and dilution may also drastically affect 3He 4He ratios of geothermal vapors. Helium isotope ratios were determined for several hot springs at Shoshone Geyser Basin of Yellowstone National Park for this study, along with other noble gas data. Stable isotope data and water and gas chemistry data for each spring were also compiled. The water chemistry indicates that there is one deep, hot thermal water in the area which is mixing with dilute meteoric water that has entered the system at depth. Spring HCO3- concentrations correlate with 3He 4He values, as in nearby Lower Geyser Basin. This correlation is attributed to variable amounts of deep dilution of thermal waters with a relatively cool water that inhibits boiling at depth, thus preventing the loss of CO2 (and therefore HCO3-) and magmatic He in the most diluted samples. Oxygen and hydrogen isotope data also support a boiling and dilution model, but to produce the observed fractionations, the boiling event would have to be extensive, with steam loss at the surface, whereas the boiling that affected the helium isotope ratios was probably a small scale event with steam loss at depth. It is possible that deep boiling occurred in the basin and that small amounts of steam escaped along fractures at about 500 m below the surface while all subsequently produced steam was lost near or at the surface. ?? 1990.

  3. Determining the in situ water content of the Geysers Graywacke of Northern California

    SciTech Connect

    Marsh, A.

    1994-12-01

    The water content, porosity and permeability measurements of the Northern California Geysers rocks are used to predict the lifetime of the geothermal resource, which provides 10% of Northern California`s electricity. The Geysers rock was drilled from defunct well SB-15-D, and some cores wee sealed in aluminum tubes to preserve the in situ water content. These cores were sent to the Lawrence Livermore Laboratory to measure the water content. Humidity measurements were taken of the air around a one and a half foot encased core, recovered from a depth of 918.9 feet. Over a seven day period, the humidity reached almost 100% indicating that the air around the core was saturated in water vapor. We believe the sealing method is effective, preserving the in-situ water content. To measure water content, I will use Archimede`s principle to determine the density of the core before and after drying in an oven. Ultrasonic measurements will be taken of the core upon removal from aluminum tube to determine the change of p-wave velocity with change in water content. Water in the pores increases the effective compressibility of the rock therefore increasing the p-velocity. The measured p-wave velocities can then be used in the field to determine in-situ water content. Three dimensional x-ray images will be used to determine the deviations from average density within individual cores. Since the density depends on water content as well as mineralogy, images can show the location of pore fluid and drilling mud. Archimede`s principle, humidity detection, ultrasonics and x-ray scanning are viable methods to measure the in-situ water content and pore water distribution in the graywacke.

  4. Detection and Isolation Techniques for Methanogens from Microbial Mats (in the El Tatio Geyser Field, Chile)

    NASA Astrophysics Data System (ADS)

    Pearson, E. Z.; Franks, M. A.; Bennett, P.

    2010-12-01

    Isolating methanogenic archea from an extreme environment such as El Tatio (high altitude, arid climate) gives insight to the methanogenic taxas able to adapt and grow under extreme conditions. The hydrothermal waters at El Tatio geyser field demonstrate extreme geochemical conditions, with discharge water from springs and geysers at local boiling temperature (85° C) with high levels of arsenic and low DIC levels. Despite these challenges, many of El Tatio’s hundred plus hydrothermal features host extensive microbial mat communities, many showing evidence of methanogenesis. When trying to isolate methanogens unique to this area, various approaches and techniques were used. To detect the presence of methanogens in samples taken from the field, dissolved methane concentrations were determined via gas chromatography (GC) analysis. Samples were then selected for culturing and most probable number (MPN) enumeration, where growth was assessed using both methane production and observations of fluorescence under UV light. PCR was used to see if the archeal DNA was apparent directly from the field, and shotgun cloning was done to determine phylogenetic affiliation. Several culturing techniques were carried out in an attempt to isolate methanogens from samples that showed evidence of methanogenesis. The slant culturing method was used because of the increased surface area for colonization combined with the relative ease of keeping anaerobic. After a few weeks, when colonies were apparent, some were aseptically selected and inoculated to observe growth in a liquid media containing ampicillin to inhibit bacterial growth. Culturing techniques proved successful after inoculation, showing a slow growth of methanogens via GC and autofluorescence. Further PCR tests and subsequent sequencing were done to confirm and identify isolates.

  5. Monitoring and Characterizing the Geysering and Seismic Activity at the Lusi Mud Eruption Site, East Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Karyono, Karyono; Obermann, Anne; Mazzini, Adriano; Lupi, Matteo; Syafri, Ildrem; Abdurrokhim, Abdurrokhim; Masturyono, Masturyono; Hadi, Soffian

    2016-04-01

    The Lusi eruption began on May 29, 2006 in the northeast of Java Island, Indonesia, and to date is still active. Lusi is a newborn sedimentary-hosted hydrothermal system characterized by continuous expulsion of liquefied mud and breccias and geysering activity. Lusi is located upon the Watukosek fault system, a left lateral wrench system connecting the volcanic arc and the bakarc basin. This fault system is still periodically reactivated as shown by field data. In the framework of the Lusi Lab project (ERC grant n° 308126) we conducted several types of monitoring. Based on camera observations, we characterized the Lusi erupting activity by four main behaviors occurring cyclically: (1) Regular activity, which consists in the constant emission of water and mud breccias (i.e. viscous mud containing clay, silt, sand and clasts) associated with the constant expulsion of gas (mainly aqueous vapor with minor amounts of CO2 and CH4) (2) Geysering phase with intense bubbling, consisting in reduced vapor emission and more powerful bursting events that do not seem to have a regular pattern. (3) Geysering phase with intense vapor and degassing discharge and a typically dense plume that propagates up to 100 m height. (4) Quiescent phase marking the end of the geysering activity (and the observed cycle) with no gas emissions or bursts observed. To investigate the possible seismic activity beneath Lusi and the mechanisms controlling the Lusi pulsating behaviour, we deployed a network of 5 seismic stations and a HD camera around the Lusi crater. We characterize the observed types of seismic activity as tremor and volcano-tectonic events. Lusi tremor events occur in 5-10 Hz frequency band, while volcano tectonic events are abundant in the high frequencies range from 5 Hz until 25 Hz. We coupled the seismic monitoring with the images collected with the HD camera to study the correlation between the seismic tremor and the different phases of the geysering activity. Key words: Lusi

  6. 27 CFR 9.209 - Calistoga.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... the North Fork of Crystal Springs Road), which lies in the Carne Humana Land Grant approximately 1,400... Canyon in section 28, T9N/R6W, and Simmons Canyon in section 29, T9N/R6W, to the contour line's first... 880-foot contour line across the two forks of Horns Creek and through Hoisting Works Canyon in...

  7. 27 CFR 9.209 - Calistoga.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the North Fork of Crystal Springs Road), which lies in the Carne Humana Land Grant approximately 1,400... Canyon in section 28, T9N/R6W, and Simmons Canyon in section 29, T9N/R6W, to the contour line's first... 880-foot contour line across the two forks of Horns Creek and through Hoisting Works Canyon in...

  8. 27 CFR 9.209 - Calistoga.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... the North Fork of Crystal Springs Road), which lies in the Carne Humana Land Grant approximately 1,400... Canyon in section 28, T9N/R6W, and Simmons Canyon in section 29, T9N/R6W, to the contour line's first... 880-foot contour line across the two forks of Horns Creek and through Hoisting Works Canyon in...

  9. 27 CFR 9.209 - Calistoga.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... the North Fork of Crystal Springs Road), which lies in the Carne Humana Land Grant approximately 1,400... Canyon in section 28, T9N/R6W, and Simmons Canyon in section 29, T9N/R6W, to the contour line's first... 880-foot contour line across the two forks of Horns Creek and through Hoisting Works Canyon in...

  10. 27 CFR 9.209 - Calistoga.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the North Fork of Crystal Springs Road), which lies in the Carne Humana Land Grant approximately 1,400... Canyon in section 28, T9N/R6W, and Simmons Canyon in section 29, T9N/R6W, to the contour line's first... 880-foot contour line across the two forks of Horns Creek and through Hoisting Works Canyon in...

  11. Time-dependent Induced Seismicity Rates Described with an Epidemic Type Aftershock Sequence Model at The Geysers Geothermal Field, California

    NASA Astrophysics Data System (ADS)

    Johnson, C. W.; Totten, E. J.; Burgmann, R.

    2015-12-01

    To improve understanding of the link between injection/production activity and seismicity, we apply an Epidemic Type Aftershock Sequence (ETAS) model to an earthquake catalog from The Geysers geothermal field (GGF) between 2005-2015 using >140,000 events and Mc 0.8 . We partition the catalog along a northeast-southwest trending divide, which corresponds to regions of high and low levels of enhanced geothermal stimulation (EGS) across the field. The ETAS model is fit to the seismicity data using a 6-month sliding window with a 1-month time step to determine the background seismicity rate. We generate monthly time series of the time-dependent background seismicity rate in 1-km depth intervals from 0-5km. The average wellhead depth is 2-3 km and the background seismicity rates above this depth do not correlate well with field-wide injected masses over the time period of interest. The auto correlation results show a 12-month period for monthly time series proximal to the average wellhead depths (2-3km and 3-4km) for northwest GGF strongly correlates with field-wide fluid injection masses, with a four-month phase shift between the two depth intervals as fluid migrates deeper. This periodicity is not observed for the deeper depth interval of 4-5 km, where monthly background seismicity rates reduce to near zero. Cross-correlation analysis using the monthly time series for background seismicity rate and the field-wide injection, production and net injection (injection minus production) suggest that injection most directly modulates seismicity. Periodicity in the background seismicity is not observed as strongly in the time series for the southeast field. We suggest that the variation in background seismicity rate is a proxy for pore-pressure diffusion of injected fluids at depth. We deduce that the contrast between the background seismicity rates in the northwest and southeast GGF is a result of reduced EGS activity in the southeast region.

  12. A Comprehensive Study of Fracture Patterns and Densities in The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography

    SciTech Connect

    Peter E. Malin; Eylon Shalev; Min Lou; Silas M. Simiyu; Anastasia Stroujkova; Windy McCausland

    2004-02-24

    In this project we developed a method for using seismic S-wave data to map the patterns and densities of sub-surface fractures in the NW Geysers Geothermal Field/ (1) This project adds to both the general methods needed to characterize the geothermal production fractures that supply steam for power generation and to the specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be possible to reduce the cost of geothermal power development with the targeting of high production geothermal wells. (3) The results of the project having been transferred to both US based and international geothermal research and exploration agencies and concerns by several published papers and meeting presentations, and through the distribution of the data handling and other software codes we developed.

  13. Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

    USGS Publications Warehouse

    Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    The Geysers geothermal field in northern California, with about 2000-MW electrical capacity, is the largest geothermal field in the world. Despite its importance as a resource and as an example of a vapor-dominated reservoir, very few complete geochemical analyses of the steam have been published (Allen and Day, 1927; Truesdell and others, 1987). This report presents data from 90 steam, gas, and condensate samples from wells in The Geysers geothermal field in northern California. Samples were collected between 1978 and 1991. Well attributes include sampling date, well name, location, total depth, and the wellhead temperature and pressure at which the sample was collected. Geochemical characteristics include the steam/gas ratio, composition of noncondensable gas (relative proportions of CO2, H2S, He, H2, O2, Ar, N2, CH4, and NH3), and isotopic values for deltaD and delta18O of H2O, delta13C of CO2, and delta34S of H2S. The compilation includes 81 analyses from 74 different production wells, 9 isotopic analyses of steam condensate pumped into injection wells, and 5 complete geochemical analyses on gases from surface fumaroles and bubbling pools. Most samples were collected as saturated steam and plot along the liquid-water/steam boiling curve. Steam-togas ratios are highest in the southeastern part of the geothermal field and lowest in the northwest, consistent with other studies. Wells in the Northwest Geysers are also enriched in N2/Ar, CO2 and CH4, deltaD, and delta18O. Well discharges from the Southeast Geysers are high in steam/gas and have isotopic compositions and N2/Ar ratios consistent with recharge by local meteoric waters. Samples from the Central Geysers show characteristics found in both the Southeast and Northwest Geysers. Gas and steam characteristics of well discharges from the Northwest Geysers are consistent with input of components from a high-temperature reservoir containing carbonrich gases derived from the host Franciscan rocks. Throughout the

  14. Abrupt physical and chemical changes during 1992-1999, Anderson Springs, SE Geyser Geothermal Field, California

    USGS Publications Warehouse

    Janik, Cathy J.; Goff, Fraser; Walter, Stephen R.; Sorey, Michael L.; Counce, Dale; Colvard, Elizabeth M.

    2000-01-01

    The Anderson Springs area is located about 90 miles (145 kilometers) north of San Francisco, California, in the southwestern part of Lake County. The area was first developed in the late 1800s as a health resort, which was active until the 1930s. Patrons drank a variety of cool to hot mineral waters from improved springs, swam in various baths and pools, and hiked in the rugged hills flanking Anderson Creek and its tributaries. In the bluffs to the south of the resort were four small mercury mines of the eastern Mayacmas quicksilver district. About 1,260 flasks of mercury were produced from these mines between 1909 and 1943. By the early 1970s, the higher ridges south and west of Anderson Springs became part of the southeast sector of the greater Geysers geothermal field. Today, several electric power plants are built on these ridges, producing energy from a vapor-dominated 240 °C reservoir. Only the main hot spring at Anderson Springs has maintained a recognizable identity since the 1930s. The hot spring is actually a cluster of seeps and springs that issue from a small fault in a ravine southwest of Anderson Creek. Published and unpublished records show that the maximum temperature (Tm) of this cluster fell gradually from 63°C in 1889 to 48°C in 1992. However, Tm of the cluster climbed to 77°C in 1995 and neared boiling (98°C) in 1998. A new cluster of boiling vents and small fumaroles (Tm = 99.3°C) formed in 1998 about 30 m north of the old spring cluster. Several evergreen trees on steep slopes immediately above these vents apparently were killed by the new activity. Thermal waters at Anderson Hot Springs are mostly composed of near-surface ground waters with some added gases and condensed steam from The Geysers geothermal system. Compared to gas samples from Southeast Geysers wells, the hot spring gases are higher in CO2 and lower in H2S and NH3. As the springs increased in temperature, however, the gas composition became more like the mean composition

  15. G.R.I.P.S activities in the development of direct use of geothermal resources and small scale geothermal power development

    NASA Astrophysics Data System (ADS)

    1981-10-01

    The activities of the geothermal research information and planning services (G.R.I.P.S.) in the four Geysers-Calistoga KGRA counties (i.e., Lake, Mendocino, Napa, Sonoma) in California are reported. Activities in the G.R.I.P.S. information and outreach program, workshop presentations, pilot project development, permit processing improvements and Department of Energy reporting are described.

  16. A comprehensive study of fracture patterns and densities in the Geysers geothermal reservoir using microearthquake shear-wave splitting tomography. [Quarterly progress report 03/16/1998 - 06/15/1998

    SciTech Connect

    Malin, P.E.; Shalev, E.

    1999-03-17

    We completed the process of identifying shear-wave splitting in the Geyser area. A total of 2700 observations were recorded with about 1700 observations from the 1988 data and about 1000 observations from 1994. Fast polarization direction map in Figure 1 shows that most of the stations in the Geyser area display consistent direction throughout the main field, between 0{degree} azimuth to 40{degree} azimuth. Some exemptions to the consistent crack alignment (fast polarization direction) can be seen in stations 9 and station 3, and also in stations 13 and 14 outside the field. Since the stations are in boreholes it is possible that some of the station orientations, calculated using P-wave arrivals from located events, are erroneous. If we treat measurements of polarization direction as a statistical process, same as deep of layer measurement, we can say that in the small area of the station we have aligned cracks. Figures 2 and 3 show results of the crack density inversion assuming regional crack azimuth of 20{degree}. Almost 2400 raypaths were used to perform this tomographic inversion. There is weak dependency of the results on the regional crack direction, but the main areas of high and low crack density are the same. The changes are mainly in the size of the anomalies. Since the amplitudes of those anomalies depend mainly on the damping parameter we use in the inversion, exact regional crack direction is not a critical parameter of the inversion. The map in figure 2 and cross-sections in Figure 3 show two areas of high crack density at the top 1 km one at station 8 and the other between stations 6 and 5. At greater depth of 1 to 2 km those two area converge to one high crack density anomaly between stations 3, 4, 11, and 10.

  17. Three-dimensional numerical reservoir simulation of the EGS Demonstration Project at The Geysers geothermal field

    NASA Astrophysics Data System (ADS)

    Borgia, Andrea; Rutqvist, Jonny; Oldenburg, Curt M.; Hutchings, Lawrence; Garcia, Julio; Walters, Mark; Hartline, Craig; Jeanne, Pierre; Dobson, Patrick; Boyle, Katie

    2013-04-01

    The Enhanced Geothermal System (EGS) Demonstration Project, currently underway at the Northwest Geysers, California, aims to demonstrate the feasibility of stimulating a deep high-temperature reservoir (up to 400 °C) through water injection over a 2-year period. On October 6, 2011, injection of 25 l/s started from the Prati 32 well at a depth interval of 1850-2699 m below sea level. After a period of almost 2 months, the injection rate was raised to 63 l/s. The flow rate was then decreased to 44 l/s after an additional 3.5 months and maintained at 25 l/s up to August 20, 2012. Significant well-head pressure changes were recorded at Prati State 31 well, which is separated from Prati 32 by about 500 m at reservoir level. More subdued pressure increases occur at greater distances. The water injection caused induced seismicity in the reservoir in the vicinity of the well. Microseismic monitoring and interpretation shows that the cloud of seismic events is mainly located in the granitic intrusion below the injection zone, forming a cluster elongated SSE-NNW (azimuth 170°) that dips steeply to the west. In general, the magnitude of the events increases with depth and the hypocenter depth increases with time. This seismic cloud is hypothesized to correlate with enhanced permeability in the high-temperature reservoir and its variation with time. Based on the existing borehole data, we use the GMS™ GUI to construct a realistic three-dimensional (3D) geologic model of the Northwest Geysers geothermal field. This model includes, from the top down, a low permeability graywacke layer that forms the caprock for the reservoir, an isothermal steam zone (known as the normal temperature reservoir) within metagraywacke, a hornfels zone (where the high-temperature reservoir is located), and a felsite layer that is assumed to extend downward to the magmatic heat source. We then map this model onto a rectangular grid for use with the TOUGH2 multiphase, multicomponent, non

  18. The Northwest Geysers EGS Demonstration Project, California. Pre-stimulation Modeling and Interpretation of the Stimulation

    DOE PAGES

    Rutqvist, Jonny; Dobson, Patrick F.; Garcia, Julio; Hartline, Craig; Jeanne, Pierre; Oldenburg, Curtis M.; Vasco, Donald W.; Walters, Mark

    2013-10-17

    The Northwest Geysers Enhanced Geothermal System (EGS) demonstration project aims to create an EGS by directly and systematically injecting cool water at relatively low pressure into a known High Temperature (280–400 °C) Zone (HTZ) located under the conventional (240 °C) geothermal steam reservoir at The Geysers geothermal field in California. Here we report that , the results of coupled thermal, hydraulic, and mechanical (THM) analyses made using a model developed as part of the pre-stimulation phase of the EGS demonstration project is presented. The model simulations were conducted in order to investigate injection strategies and the resulting effects of cold-watermore » injection upon the EGS system; in particular to predict the extent of the stimulation zone for a given injection schedule. The actual injection began on October 6, 2011, and in this paper a comparison of pre-stimulation model predictions with micro-earthquake (MEQ) monitoring data over the first few months of a one-year injection program is presented. The results show that, by using a calibrated THM model based on historic injection and MEQ data at a nearby well, the predicted extent of the stimulation zone (defined as a zone of high MEQ density around the injection well) compares well with observed seismicity. The modeling indicates that the MEQ events are related to shear reactivation of preexisting fractures, which is triggered by the combined effects of injection-induced cooling around the injection well and small changes in steam pressure as far as half a kilometer away from the injection well. Pressure-monitoring data at adjacent wells and satellite-based ground-surface deformation data were also used to validate and further calibrate reservoir-scale hydraulic and mechanical model properties. The pressure signature monitored from the start of the injection was particularly useful for a precise back-calculation of reservoir porosity. Ultimately, the first few months of reservoir

  19. The Northwest Geysers EGS Demonstration Project, California. Pre-stimulation Modeling and Interpretation of the Stimulation

    SciTech Connect

    Rutqvist, Jonny; Dobson, Patrick F.; Garcia, Julio; Hartline, Craig; Jeanne, Pierre; Oldenburg, Curtis M.; Vasco, Donald W.; Walters, Mark

    2013-10-17

    The Northwest Geysers Enhanced Geothermal System (EGS) demonstration project aims to create an EGS by directly and systematically injecting cool water at relatively low pressure into a known High Temperature (280–400 °C) Zone (HTZ) located under the conventional (240 °C) geothermal steam reservoir at The Geysers geothermal field in California. Here we report that , the results of coupled thermal, hydraulic, and mechanical (THM) analyses made using a model developed as part of the pre-stimulation phase of the EGS demonstration project is presented. The model simulations were conducted in order to investigate injection strategies and the resulting effects of cold-water injection upon the EGS system; in particular to predict the extent of the stimulation zone for a given injection schedule. The actual injection began on October 6, 2011, and in this paper a comparison of pre-stimulation model predictions with micro-earthquake (MEQ) monitoring data over the first few months of a one-year injection program is presented. The results show that, by using a calibrated THM model based on historic injection and MEQ data at a nearby well, the predicted extent of the stimulation zone (defined as a zone of high MEQ density around the injection well) compares well with observed seismicity. The modeling indicates that the MEQ events are related to shear reactivation of preexisting fractures, which is triggered by the combined effects of injection-induced cooling around the injection well and small changes in steam pressure as far as half a kilometer away from the injection well. Pressure-monitoring data at adjacent wells and satellite-based ground-surface deformation data were also used to validate and further calibrate reservoir-scale hydraulic and mechanical model properties. The pressure signature monitored from the start of the injection was particularly useful for a precise back-calculation of reservoir porosity. Ultimately, the first few months of reservoir pressure and

  20. Temporal changes in noble gas compositions within the Aidlinsector ofThe Geysers geothermal system

    SciTech Connect

    Dobson, Patrick; Sonnenthal, Eric; Kennedy, Mack; van Soest,Thijs; Lewicki, Jennifer

    2006-05-03

    The use of nonreactive isotopic tracers coupled to a full thermal-hydrological reservoir simulation allows for an improved method of investigating how reservoir fluids contained within matrix and fractures contribute over time to fluids produced from geothermal systems. A combined field and modeling study has been initiated to evaluate the effects of injection, production, and fracture-matrix interaction on produced noble gas contents and isotopic ratios. Gas samples collected periodically from the Aidlin steam field at The Geysers, California, between 1997 and 2006 have been analyzed for their noble gas compositions, and reveal systematic shifts in abundance and isotopic ratios over time. Because of the low concentrations of helium dissolved in the injection waters, the injectate itself has little impact on the helium isotopic composition of the reservoir fluids over time. However, the injection process may lead to fracturing of reservoir rocks and an increase in diffusion-controlled variations in noble gas compositions, related to gases derived from fluids within the rock matrix.

  1. Biogenicity of silica precipitation around geysers and hot-spring vents, North Island, New Zealand

    SciTech Connect

    Jones, B.; Renaut, R.W.; Rosen, M.R.

    1997-01-01

    Before anthropogenic modifications, Ohaaki Pool (Broadlands-Ohaaki) and Dragon`s Mouth Geyser (Wairakei) emitted waters at temperatures of 93--98 C. The siliceous sinter that precipitated around their vents has the characteristics of geyserite, a dense laminated deposit of presumed abiogenic origin, that was precipitated from waters too hot (>73C) to support microbes other than thermophilic bacteria. Petrographic and SEM examinations of the sinters show that they incorporate columnar stromatolites and silicified, laminated stromatolitic mats that contain well-preserved filamentous microbes. At both localities the microbes lack evidence of desiccation or shrinkage, which implies that they were silicified rapidly at or shortly after their death. Although boiling and very hot (>90 C) waters were discharged, temperatures at many sites surrounding the vents remained sufficiently low and moist to support a microbial community that included thermophilic bacteria and cyanobacteria. In these cooler niches, the microbes and their biofilms served as highly favorable templates for the nucleation and growth of amorphous silica, and collectively provided a microbial framework for the laminated accretionary sinter. Some columnar, spicular, and stratiform geyserites are probably not abiotic precipitates, but are true silica stromatolites.

  2. Downhole measurements and fluid chemistry of a castle rock steam well, the Geysers, Lake County, California

    USGS Publications Warehouse

    Truesdell, A.H.; Nathenson, M.; Frye, G.A.

    1981-01-01

    Wellbore and reservoir processes in a steam well in the Castle Rock field of The Geysers have been studied by means of down-hole pressure and temperature measurements and analyses of ejected water and steam produced under bleed and full flow. Down-hole measurements show that below a vapor zone there is liquid water in the well in pressure equilibrium with reservoir steam at a depth of 2290 m. The progressive decreases, from 1973 to 1977, of pressure and temperature in the vapor zone indicate that wellbore heat loss is high enough to condense a large fraction of the steam inflow. The chemical composition of water ejected from the well is consistent with an origin from wellbore condensation of steam. Calculations using the differences in gas and isotopic compositions between bleed and full-flow steam show that about half of the full-flow steam originated as liquid water in the reservoir and that about 30% of the steam entering the well under bleed was condensed in the wellbore and drained downward. Heat loss calculations are also consistent with this amount of condensation. ?? 1981.

  3. Evolution of the Geysers (US) - Data From Fluid-Inclusion Microthermometry and Gas Geochemistry

    SciTech Connect

    Moore, J.N.; Hulen, J.B.; Norman, D.I.

    1995-01-01

    The Geysers, California, is the site of an active hydrothermal system that initially developed between about 1.5 and 2 Ma in response to intrusion of a hypabyssal granitic pluton. Mineralogic and fluid-inclusion data demonstrate that the present vapor-dominated regime evolved from an earlier and more extensive, liquid-dominated hydrothermal system. Circulation of these early fluids produced veins characterized by tourmaline and/or biotite {+-} actinolite {+-} clinopyroxene within the pluton and adjacent biotite-rich hornfels, actinolite {+-} ferroaxinite {+-} epidote, and epidote {+-} chlorite {+-} wairakite within the intermediate parts of the thermal system, and calcite in the outer parts. Potassium feldspar and quartz are present in all assemblages. Maximum pressure-corrected homogenization temperatures and apparent salinities of fluid-inclusions in these veins range from 440 C and 44 weight percent NaCl equivalent within the hornfels (<600 m from the pluton) to 325 C and 5 weight percent NaCl equivalent at approximately 1500 m from the intrusion. We suggest that the shallow, moderate-salinity fluids are crustal waters modified by water-rock interactions and that the high-salinity fluids are magmatic brines. The formation of vapor-dominated conditions is reflected in the abrupt appearance of low salinity (0.0 to 0.4 weight percent NaCl equivalent) fluid inclusions with homogenization temperatures near 265 C. These inclusion fluids are thought to represent steam condensate formed as the liquid-dominated system boiled off.

  4. Status of the S.E. Geysers effluent pipeline & injection project

    SciTech Connect

    Dellinger, M.

    1997-12-31

    A unique public/private partnership of local, state, federal, and corporate stakeholders is constructing the world`s first wastewater-to-electricity system in Lake County, California. A rare example of a genuinely {open_quotes}sustainable{close_quotes} system, three Lake County communities will recycle their treated wastewater effluent through the Geysers geothermal steamfield to produce an estimated 625,000 MWh of electricity annually from six existing geothermal power plants. The concept is shown schematically. Construction was initiated in October 1995, and as of this writing, the system is approximately 85% complete. Operational start-up is expected in October 1997. The key to the project`s success thus far has been its emphasis on cooperative action among affected stakeholders; and a broad, community-based view of solving problems rather than the traditional, narrower view of engineering-driven technical solutions. Special attention has been given to environmentally-responsive engineering design to avoid or minimize adverse environmental impacts.

  5. Effects of boiling on electrical resistivity of microporous rocks from the Geysers

    SciTech Connect

    Roberts, J.; Duba, A.; Bonner, B.; Kasameyer, P.

    1997-12-31

    In a laboratory study of cores from borehole SB-15-D in The Geysers geothermal area, we measured the electrical resistivity of metashale with and without pore-pressure control, with confining pressures up to 100 bars and temperatures between 20 and 150{degrees}C, to determine how the pore-size distribution and capillarity affected boiling. We observed a gradual increase in resistivity when the downstream pore pressure or confining pressure decreased below the phase boundary of free water. For the conditions of this experiment, boiling, as indicated by an increase in resistivity, is initiated at pore pressures of approximately 0.5 to 1 bar (0.05 to 0.1 MPa) below the free-water boiling curve, and it continues to increase gradually as pressure is lowered to atmospheric. A simple model of the effects of capillarity suggests that at 145{degrees}C, less than 15% of the pore water can boil in these rocks. If subsequent experiments bear out these preliminary observations, then boiling within a geothermal reservoir is controlled not just by pressure and temperature but also by pore-size distribution. Thus, it may be possible to determine reservoir characteristics by monitoring changes in electrical resistivity as reservoir conditions change.

  6. Water adsorption at high temperature on core samples from The Geysers geothermal field

    SciTech Connect

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1998-06-01

    The quantity of water retained by rock samples taken from three wells located in The Geysers geothermal reservoir, California, was measured at 150, 200, and 250 C as a function of pressure in the range 0.00 {le} p/p{sub 0} {le} 0.98, where p{sub 0} is the saturated water vapor pressure. Both adsorption (increasing pressure) and desorption (decreasing pressure) runs were made in order to investigate the nature and the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were performed on the same rock samples. Nitrogen or krypton adsorption and desorption isotherms at 77 K were used to obtain BET specific surface areas, pore volumes and their distributions with respect to pore sizes. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A qualitative correlation was found between the surface properties obtained from nitrogen adsorption and the mineralogical and petrological characteristics of the solids. However, there is in general no proportionality between BET specific surface areas and the capacity of the rocks for water adsorption at high temperatures. The results indicate that multilayer adsorption rather than capillary condensation is the dominant water storage mechanism at high temperatures.

  7. Water adsorption at high temperature on core samples from The Geysers geothermal field

    SciTech Connect

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1998-06-01

    The quantity of water retained by rock samples taken from three wells located in The Geysers geothermal field, California, was measured at 150, 200, and 250 C as a function of steam pressure in the range 0.00 {le} p/p{sub 0} {le} 0.98, where p{sub 0} is the saturated water vapor pressure. Both adsorption and desorption runs were made in order to investigate the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were made on the same rock samples. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A qualitative correlation was found between the surface properties obtained from nitrogen adsorption and the mineralogical and petrological characteristics of the solids. However, there was no direct correlation between BET specific surface areas and the capacity of the rocks for water adsorption at high temperatures. The hysteresis decreased significantly at 250 C. The results indicate that multilayer adsorption, rather than capillary condensation, is the dominant water storage mechanism at high temperatures.

  8. Excitation of slosh waves associated with low frequency impulsive reverse gravity acceleration of geyser initiation

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1992-01-01

    The objective of the cryogenic fluid management of the spacecraft propulsion system is to develop the technology necessary for acquisition or positioning of liquid and vapor within a tank in reduced gravity to enable liquid outflow or vapor venting. The requirement to settle or to position liquid fuel over the outlet end of the spacecraft propellant tank prior to main engine restart poses a microgravity fluid behavior problem. The purpose of the present study is to investigate the stability of the most efficient technique for propellant resettling through the minimization of propellant usage and weight penalties. In this study slosh wave excitation induced by the resettling flow field activated by 0.1 Hz low frequency, impulsive reverse gravity acceleration, during reorientation with the initiation of geyser for liquid fill levels of 30, 50, 65, 70 and 80 percent, have been studied. Characteristics of slosh waves with various frequencies excited are discussed. Slosh wave excitation shift the fluid mass distribution in the container which impose time dependent variations in spacecraft moment of inertia. This information is important for the spacecraft control during the course of liquid reorientation.

  9. Slosh wave and geyser excitations due to liquid hydrogen shut-off during draining in microgravity

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1995-01-01

    The dynamical behavior of liquid hydrogen shut-off during draining, and shut-off at the moment of the incipience of a suction dip have been investigated. It shows that a large amplitude surge is observed for liquid in the container at the moment of liquid hydrogen shut-off in reduced gravity. It also shows that slosh waves accompanied by a strong geyser are developed for surge-related flow fields induced by liquid hydrogen shut-off at the incipience of a suction dip. In the slosh wave excitation, both a lower gravity environment and higher flow rate before the shut-off of liquid draining are resonsible for the initiation of greater amplitude slosh waves. Slosh wave excitation, due to shut-off during liquid hydrogen draining, shift the fluid mass distribution in the container which imposes time-dependent variation in the spacecraft moment of inertia. This provides important information necessary for on-orbit guidance and attitude control of spacecraft.

  10. Geodetic analysis of reservoir depletion at the Geyser steam field in northern California.

    USGS Publications Warehouse

    Denlinger, R.P.; Isherwood, W.F.; Kovach, R.L.

    1981-01-01

    Reservoir depletion at the Geysers from 1974 to 1977 is evident in measured changes in gravity, surface strain, and pore pressure drainage. The drainage area increased about 20%, the maximum gravity decrease was about -120 mu Gal, and the maximum elevation change was about 6 cm during this period. Since the net mass withdrawal is known, it may be combined with the gravity change to estimate a drainage volume. The maximum drainage volume is 25 km3. Because the depth of the caprock and extent of the pore pressure drainage is known, this volume limit implies that no significant mass withdrawal occurs below a depth of 4 km. The ratios of surface elevation changes to horizontal contraction coinciding with the drainage area imply an equant drainage geometry, assuming that fluid production produces negative dilatation. Using the same cylindrical geometry used to model the gravity, negative dilatational strain rates of 4 to 5 X 10-5/yr were found to produce the observed surface displacements. The likelihood of boiling in the system to produce steam combined with apparent large bulk moduli (from seismic velocities) and small pore pressure declines suggest that most of the reservoir contraction is due to cooling. -Authors

  11. X-ray evidence for capillary pressure driven flow in preserved core from The Geysers

    SciTech Connect

    Bonner, B.P.; Roberts, J.J.; Schneberk, D.J.

    1997-03-01

    Improved understanding of fluid storage and transport mechanisms relevant to The Geysers reservoir is fundamental to efficient and economic long term production of steam. X-ray computed tomographs of core from research borehole SB-15D made within 72 hours of drilling show characteristic x-ray attenuation profiles that can only be explained by imbibition of drilling fluid at reservoir conditions. The shape of the profile is highly diagnostic. Early time scans, when interpreted taking into account independent measurements of pore size distribution, permeabilities and capillary pressures for the rock matrix sampled by SB-15D, are consistent with strong capillary suctions for the recovered rocks. This indirect indication of imbibition under reservoir conditions, along with detailed analysis of x-ray attenuation in recovered core, suggests that water content was low in much of the preserved core. These measurements are part of a series of laboratory experiments monitored by x-ray methods intended to evaluate movement of various fluids to determine the relative importance capillarity, Darcy flow and vapor phase diffusion.

  12. Chemical stimulation treatment, The Geysers: Ottoboni State 22. Geothermal-reservoir well-stimulation program

    SciTech Connect

    Not Available

    1981-02-01

    Experiment No. 6 of the Geothermal Reservoir Well Stimulation Program (GRWSP) was performed at The Geysers Field in Sonoma County, California. This well had low productivity (46,000 lb/hr), probably because it did not intersect the primary natural fracture system of the reservoir. Surrounding production wells are considered to be good wells with an average flow rate of about 100,000 lb/hr. The stimulation technique selected was an acid etching treatment (Halliburton Services' MY-T-ACID). A small water prepad was used to provide tubular cooling and fluid loss control. Following the water prepad were 500 to 750 bbl of high viscosity crosslinked gel fluid and 400 to 500 bbl of a hydrofluoric-hydrochloric (HF-HCl) acid solution. The frac fluids were expected to enter only a single or limited fracture zone within the open interval. Frac rates of 20 to 40 BPM and surface pressures of 3000 psig were estimated for this treatment. During the job, however, no significant surface pressure was recorded, and all fluids flowed easily into the interval. Subsequent evaluation of the well performance showed that no noticeable stimulation had been achieved even though the frac fluids were properly injected. Temperature and gamma ray surveys along with tracer studies indicated that the frac fluids entered natural fracture channels over a 650-foot zone of the open interval, which probably prevented the staged acid etching treatment from functioning as designed.

  13. Formation of jets in Comet 19P/Borrelly by subsurface geysers

    USGS Publications Warehouse

    Yelle, R.V.; Soderblom, L.A.; Jokipii, J.R.

    2004-01-01

    Observations of the inner coma of Comet 19P/Borrelly with the camera on the Deep Space 1 spacecraft revealed several highly collimated dust jets emanating from the nucleus. The observed jets can be produced by acceleration of evolved gas from a subsurface cavity through a narrow orifice to the surface. As long as the cavity is larger than the orifice, the pressure in the cavity will be greater than the ambient pressure in the coma and the flow from the geyser will be supersonic. The gas flow becomes collimated as the sound speed is approached and dust entrainment in the gas flow creates the observed jets. Outside the cavity, the expanding gas loses its collimated character, but the density drops rapidly decoupling the dust and gas, allowing the dust to continue in a collimated beam. The hypothesis proposed here can explain the jets seen in the inner coma of Comet 1P/Halley as well, and may be a primary mechanism for cometary activity. ?? 2003 Published by Elsevier Inc.

  14. Characterization of rock for constraining reservoir scale tomography at the Geysers geothermal field

    SciTech Connect

    Boitnott, G.N.; Bonner, B.P.

    1994-01-20

    A suite of laboratory measurements are being conducted on Geysers graywacke recovered from a drilled depth of 2599 meters in NEGU-17. The tests are being conducted to characterize the effect of pressure and fluid saturation on the seismic properties of the graywacke matrix. The measurements indicate that the graywacke is an unusual rock in many respects. Both compressional and shear velocities exhibit relatively little change with pressure. Water saturation causes a slight increase in the compressional velocity, quantitatively consistent with predictions from the Biot-Gassmann equations. Shear velocity decreases with water saturation by an amount greater than that predicted by the Biot-Gassmann equations. This decrease is attributed to chemomechanical weakening caused by the presence of water. Measurements of Q, from torsion experiments on room dry samples at seismic frequencies indicate unusually high Q, (~500). Water saturation decreases the shear modulus by 12 percent, again indicative of chemomechanical weakening. Q, is lower for the water saturated condition, but still relatively high for rock at low stress. Results of ultrasonic pulse propagation experiments on partially saturated samples are typical of low porosity rocks, being characterized by a monotonic decrease in compressional and shear velocity with decrease in saturation. An increase in shear velocity and low frequency shear modulus after vacuum drying indicates the presence of chemo-mechanical weakening resulting from the presence of small amounts of water.

  15. Adsorption characteristics of rocks from vapor-dominated geothermal reservoir at the Geysers, CA

    SciTech Connect

    Satik, Cengiz; Walters, Mark; Horne, Roland N.

    1996-01-24

    This paper reports on a continuing experimental effort to characterize the adsorption behavior of rocks from The Geysers steam field in California. We show adsorption results obtained for 36 rock samples. All of the adsorption isotherms plotted on the same graph exhibit an envelope of isotherms. The minimum and the maximum values of the slope (or rate of adsorption) and of the magnitude within this envelope of isotherms belonged to the UOC-1 (felsite) and NCPA B-5 (serpentine) samples. The values of surface area and porosity, and pore size distribution for 19 of the samples indicated a very weak correlation with adsorption. An interpretation of the pore size distributions and the liquid saturation isotherms suggests that the change in the slope and the magnitude of the adsorption isotherms within the envelope is controlled primarily by the physical adsorption mechanism instead of capillary condensation. Grain-size and framework grain to matrix ratio are found to be insufficient to characterize this adsorption behavior. An accurate identification of the mineralogy of the samples will be essential to complete this analysis.

  16. Isolation and Characterization of a Novel CO2-Tolerant Lactobacillus Strain from Crystal Geyser, UT

    NASA Astrophysics Data System (ADS)

    Santillan, E. U.; Major, J. R.; Omelon, C. R.; Shanahan, T. M.; Bennett, P.

    2013-12-01

    Capnophiles are microbes that grow in CO2 enriched environments. Cultured capnophiles generally, grow in 2 to 25% CO2, or 0.02 to 0.25 atm. When CO2 is sequestered in deep saline aquifers, the newly created high CO2 environment may select for capnophlic organisms. In this study, a capnophile was isolated from Crystal Geyser, a CO2 spring along the Little Grand Wash Fault, UT, a site being investigated as an analogue to CO2 sequestration. Crystal Geyser periodically erupts with CO2 charged water, indicating the presence of very high CO2 pressures below the subsurface, similar to sequestration conditions. Biomass was sampled by pumping springwater from approximately 10 m below the surface through filters. Filters were immediately placed in selective media within pressure vessels where they were pressurized to 10 atm in the field. Subsequent recultures produced an isolate, designated CG-1, that is most closely (99%) related to Lactobacillus casei on the strain level. CG-1 grows in tryptic soy broth, in PCO2 ranging from 0 atm to 10 atm, 40 times higher than pressures of previously cultured capnophiles. At 25 atm, growth is inhibited though survival can be as long as 5 days. At 50 atm, survival is poor, with sterilization occurring by 24 hours. Growth is optimal between pH values of 6 to 8, though sluggish if no CO2 is present. Its optimal salinity is 0.25 M NaCl though growth is observed ranging from 0 to 1 M NaCl. Growth is observed between 25o to 45o C, but optimal at 25oC. It consumes long-chained carbon molecules such as glucose, sucrose, and crude oil, and exhibits poor growth when supplied with lactate, acetate, formate, and pyruvate. The organism likely performs lactic acid fermentation as it requires no electron acceptors for growth and produces no acid, gas, and sulfide in triple sugar iron agar slants. CG-1 also expresses a variety of lipids, most notably cyclopropyl C19 (cycC19), or lactobacillic acid, characteristic of organisms belonging to the

  17. Hydrothermal alteration in research drill hole Y-2, Lower Geyser Basin, Yellowstone National Park, Wyoming

    SciTech Connect

    Bargar, K.E.; Beeson, M.H.

    1981-05-01

    Y-2, a US Geological Survey research diamond-drill hole in Lower Geyser Basin, Yellowstone National Park, was drilled to a depth of 157.4 meters. The hole penetrated interbedded siliceous sinter and travertine to 10.2 m, glacial sediments of the Pinedale Glaciation interlayered with pumiceous tuff from 10.2 to 31.7 m, and rhyolitic lavas of the Elephant Back flow of the Central Plateau Member and the Mallard Lake Member of the Pleistocene Plateau Rhyolite from 31.7 to 157.4 m. Hydrothermal alteration is pervasive in most of the nearly continuous drill core. Rhyolitic glass has been extensively altered to clay and zeolite minerals (intermediate heulandite, clinoptilolite, mordenite, montmorillonite, mixed-layer illite-montmorillonite, and illite) in addition to quartz and adularia. Numerous veins, vugs, and fractures in the core contain these and other minerals: silica minerals (opal, ..beta..-cristobalite, ..cap alpha..-cristobalite, and chalcedony), zeolites (analcime, wairakite, dachiardite, laumontite, and yugawaralite), carbonates (calcite and siderite), clay (kaolinite and chlorite), oxides (hematite, goethite, manganite, cryptomelane, pyrolusite, and groutite), and sulfides (pyrhotite and pyrite) along with minor aegirine, fluorite, truscottite, and portlandite. Interbedded travertine and siliceous sinter in the upper part of the drill core indicate that two distinct types of thermal water are responsible for precipitation of the surficial deposits, and further that the water regime has alternated between the two thermal waters more than once since the end of the Pinedale Glaciation (approx. 10,000 years B.P.). Alternation of zones of calcium-rich and sodium- and potassium-rich hydrothermal minerals also suggests that the calcium-rich and sodium- and potassium-rich hydrothermal minerals also suggests that the water chemistry in this drill hole varies with depth.

  18. 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.

  19. Stress/strain changes and triggered seismicity at The Geysers, California

    USGS Publications Warehouse

    Gomberg, J.; Davis, S.

    1996-01-01

    The principal results of this study of remotely triggered seismicity in The Geysers geothermal field are the demonstration that triggering (initiation of earthquake failure) depends on a critical strain threshold and that the threshold level increases with decreasing frequency or equivalently, depends on strain rate. This threshold function derives from (1) analyses of dynamic strains associated with surface waves of the triggering earthquakes, (2) statistically measured aftershock zone dimensions, and (3) analytic functional representations of strains associated with power production and tides. The threshold is also consistent with triggering by static strain changes and implies that both static and dynamic strains may cause aftershocks. The observation that triggered seismicity probably occurs in addition to background activity also provides an important constraint on the triggering process. Assuming the physical processes underlying earthquake nucleation to be the same, Gomberg [this issue] discusses seismicity triggered by the MW 7.3 Landers earthquake, its constraints on the variability of triggering thresholds with site, and the implications of time delays between triggering and triggered earthquakes. Our results enable us to reject the hypothesis that dynamic strains simply nudge prestressed faults over a Coulomb failure threshold sooner than they would have otherwise. We interpret the rate-dependent triggering threshold as evidence of several competing processes with different time constants, the faster one(s) facilitating failure and the other(s) inhibiting it. Such competition is a common feature of theories of slip instability. All these results, not surprisingly, imply that to understand earthquake triggering one must consider not only simple failure criteria requiring exceedence of some constant threshold but also the requirements for generating instabilities.

  20. Hydrothermal alteration in research drill hole Y-3, Lower Geyser Basin, Yellowstone National Park, Wyoming

    USGS Publications Warehouse

    Bargar, Keith E.; Beeson, Melvin H.

    1985-01-01

    Y-3, a U.S. Geological Survey research diamond-drill hole in Lower Geyser Basin, Yellowstone National Park, Wyoming, reached a depth of 156.7 m. The recovered drill core consists of 42.2 m of surficial (mostly glacial) sediments and two rhyolite flows (Nez Perce Creek flow and an older, unnamed rhyolite flow) of the Central Plateau Member of the Pleistocene Plateau Rhyolite. Hydrothermal alteration is fairly extensive in most of the drill core. The surficial deposits are largely cemented by silica and zeolite minerals; and the two rhyolite flows are, in part, bleached by thermal water that deposited numerous hydrothermal minerals in cavities and fractures. Hydrothermal minerals containing sodium as a dominant cation (analcime, clinoptilolite, mordenite, Na-smectite, and aegirine) are more abundant than calcium-bearing minerals (calcite, fluorite, Ca-smectite, and pectolite) in the sedimentary section of the drill core. In the volcanic section of drill core Y-3, calcium-rich minerals (dachiardite, laumontite, yugawaralite, calcite, fluorite, Ca-smectite, pectolite, and truscottite) are predominant over sodium-bearing minerals (aegirine, mordenite, and Na-smectite). Hydrothermal minerals that contain significant amounts of potassium (alunite and lepidolite in the sediments and illitesmectite in the rhyolite flows) are found in the two drill-core intervals. Drill core y:.3 also contains hydrothermal silica minerals (opal, [3-cristobalite, chalcedony, and quartz), other clay minerals (allophane, halloysite, kaolinite, and chlorite), gypsum, pyrite, and hematite. The dominance of calcium-bearing hydrothermal minerals in the lower rhyolitic section of the y:.3 drill core appears to be due to loss of calcium, along with potassium, during adiabatic cooling of an ascending boiling water.

  1. Monitoring deformation at The Geysers geothermal field, California using C-band and X-band Interferometric Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Vasco, D. W.; Rutqvist, J.; Dobson, P. F.; Oldenburg, C. M.; Ferretti, A.; Rucci, A.; Novali, F.; Garcia, J.; Walters, M.; Hartline, C.

    2012-12-01

    Using two distinct sets of interferometric synthetic aperture radar (InSAR) data and permanent scatterer analysis we are able to resolve deformation at The Geysers geothermal field. The first set of observations utilize archived European Space Agency (ESA) C-band synthetic aperture radar (SAR) data from 1992 through 1999 to image the long-term and large-scale subsidence in the geothermal field. The peak subsidence rate of 51.5 mm/year agrees with previous estimates from leveling and global positioning system observations. Data from a second set of measurements, acquired by a recently tasked TerraSar-X satellite, extend from May 2011 until April 2012 and overlap the C-band data spatially but not temporally. The higher frequency X-band data provides a much higher density of permanent scatters (1122 per square kilometer) than the lower frequency C-band data (12 per square kilometer) over the area surrounding an enhanced geothermal system (EGS) injection well. The EGS injection well is part of an EGS demonstration project in the northern portion of The Geysers field. The X-band InSAR observations are sensitive to some 1 to 2 cm of deformation induced by water injected into the EGS well starting in October 2011. The temporal variation of the deformation is compatible with the displacement history calculated using coupled numerical modeling of the water injection.

  2. A comprehensive study of fracture patterns and densities in the Geysers geothermal reservoir using microearthquake shear-wave splitting tomography. Quarterly report for Sep-Dec 1998

    SciTech Connect

    Malin, Peter E.; Shalev, Eylon

    1999-03-31

    We start organizing the computer programs needed for crack density inversion into an easy to follow scripts. These programs were collection of bits and pieces from many sources and we want to organize those separate programs into coherent product. We also gave a presentation (enclosed) in the Twenty-Fourth Workshop on Geothermal Reservoir Engineering in Stanford University on our Geyser and Mammoth results.

  3. Ground Penetrating Radar Investigation of Sinter Deposits at Old Faithful Geyser and Immediately Adjacent Hydrothermal Features, Yellowstone National Park, Wyoming, USA

    NASA Astrophysics Data System (ADS)

    Foley, D.; Lynne, B. Y.; Jaworowski, C.; Heasler, H.; Smith, G.; Smith, I.

    2015-12-01

    Ground Penetrating Radar (GPR) was used to evaluate the characteristics of the shallow subsurface siliceous sinter deposits around Old Faithful Geyser. Zones of fractures, areas of subsurface alteration and pre-eruption hydrologic changes at Old Faithful Geyser and surrounding hydrothermal mounds were observed. Despite being viewed directly by about 3,000,000 people a year, shallow subsurface geologic and hydrologic conditions on and near Old Faithful Geyser are poorly characterized. GPR transects of 5754 ft (1754m) show strong horizontal to sub-horizontal reflections, which are interpreted as 2.5 to 4.5 meters of sinter. Some discontinuities in reflections are interpreted as fractures in the sinter, some of which line up with known hydrothermal features and some of which have little to no surface expression. Zones with moderate and weak amplitude reflections are interpreted as sinter that has been hydrothermally altered. Temporal changes from stronger to weaker reflections are correlated with the eruption cycle of Old Faithful Geyser, and are interpreted as post-eruption draining of shallow fractures, followed by pre-eruption fracture filling with liquid or vapor thermal fluids.

  4. Exploration, Drilling and Development Operations in the Bottle Rock Area of the Geysers Steam Field, With New Geologic Insights and Models Defining Reservoir Parameters

    SciTech Connect

    Hebein, Jeffrey J.

    1983-12-15

    MCR Geothermal Corporation pioneered successful exploratiory drilling the Bottle Rock area of the Geysers Steam Field in 1976. The wellfield is characterized by a deep reservoir with varied flowrates, temperatures, pressures, and stem chemistries being quite acceptable. More detailed reservoir engineering tests will follow as production commences.

  5. Anoxybacillus kamchatkensis sp. nov., a novel thermophilic facultative aerobic bacterium with a broad pH optimum from the Geyser valley, Kamchatka.

    PubMed

    Kevbrin, Vadim V; Zengler, Karsten; Lysenko, Anatolii M; Wiegel, Juergen

    2005-10-01

    A facultative aerobic, moderately thermophilic, spore forming bacterium, strain JW/VK-KG4 was isolated from an enrichment culture obtained from the Geyser valley, a geo-thermally heated environment located in the Kamchatka peninsula (Far East region of Russia). The cells were rod shaped, motile, peritrichous flagellated stained Gram positive and had a Gram positive type cell wall. Aerobically, the strain utilized a range of carbohydrates including glucose, fructose, trehalose, proteinuous substrates, and pectin as well. Anaerobically, only carbohydrates are utilized. When growing on carbohydrates, the strain required yeast extract and vitamin B(12). Anaerobically, glucose was fermented to lactate as main product and acetate, formate, ethanol as minor products. Aerobically, even in well-aerated cultures (agitated at 500 rpm), glucose oxidation was incomplete and lactate and acetate were found in culture supernatants as by-products. Optimal growth of the isolate was observed at pH(25 C) 6.8-8.5 and 60 degrees C. The doubling times on glucose at optimal growth conditions were 34 min (aerobically) and 40 min (anaerobically). The G+C content was 42.3 mol% as determined by T(m) assay. Sequence analysis of the 16S rRNA gene indicated an affiliation of strain JW/VK-KG4 with Anoxybacillus species. Based on its morphology, physiology, phylogenetic relationship and its low DNA-DNA homology with validly published species of Anoxybacillus, it is proposed that strain JW/VK-KG4 represents a new species in the genus Anoxybacillus as A. kamchatkensis sp. nov. The type strain for the novel species is JW/VK-KG4(T) (=DSM 14988, =ATCC BAA-549). The GenBank accession number for the 16S rDNA sequence is AF510985.

  6. Anoxybacillus kamchatkensis sp. nov., a novel thermophilic facultative aerobic bacterium with a broad pH optimum from the Geyser valley, Kamchatka.

    PubMed

    Kevbrin, Vadim V; Zengler, Karsten; Lysenko, Anatolii M; Wiegel, Juergen

    2005-10-01

    A facultative aerobic, moderately thermophilic, spore forming bacterium, strain JW/VK-KG4 was isolated from an enrichment culture obtained from the Geyser valley, a geo-thermally heated environment located in the Kamchatka peninsula (Far East region of Russia). The cells were rod shaped, motile, peritrichous flagellated stained Gram positive and had a Gram positive type cell wall. Aerobically, the strain utilized a range of carbohydrates including glucose, fructose, trehalose, proteinuous substrates, and pectin as well. Anaerobically, only carbohydrates are utilized. When growing on carbohydrates, the strain required yeast extract and vitamin B(12). Anaerobically, glucose was fermented to lactate as main product and acetate, formate, ethanol as minor products. Aerobically, even in well-aerated cultures (agitated at 500 rpm), glucose oxidation was incomplete and lactate and acetate were found in culture supernatants as by-products. Optimal growth of the isolate was observed at pH(25 C) 6.8-8.5 and 60 degrees C. The doubling times on glucose at optimal growth conditions were 34 min (aerobically) and 40 min (anaerobically). The G+C content was 42.3 mol% as determined by T(m) assay. Sequence analysis of the 16S rRNA gene indicated an affiliation of strain JW/VK-KG4 with Anoxybacillus species. Based on its morphology, physiology, phylogenetic relationship and its low DNA-DNA homology with validly published species of Anoxybacillus, it is proposed that strain JW/VK-KG4 represents a new species in the genus Anoxybacillus as A. kamchatkensis sp. nov. The type strain for the novel species is JW/VK-KG4(T) (=DSM 14988, =ATCC BAA-549). The GenBank accession number for the 16S rDNA sequence is AF510985. PMID:16142505

  7. Site Specific Probabilistic Seismic Hazard and Risk Analysis for Surrounding Communities of The Geysers Geothermal Development Area

    NASA Astrophysics Data System (ADS)

    Miah, M.; Hutchings, L. J.; Savy, J. B.

    2014-12-01

    We conduct a probabilistic seismic hazard and risk analysis from induced and tectonic earthquakes for a 50 km radius area centered on The Geysers, California and for the next ten years. We calculate hazard with both a conventional and physics-based approach. We estimate site specific hazard. We convert hazard to risk of nuisance and damage to structures per year and map the risk. For the conventional PSHA we assume the past ten years is indicative of hazard for the next ten years from M<4.5 earthquakes. Larger earthquakes are added from evaluation of b-values. For the physics-based appraoch, we utilize computations (Heidbach and Altmann, 2013) to calculate pressure as a function of position throughout The Geysers for the next 10 years. We then use another geo-mechanical modeling code (Bachmann et al., 2012) to calculate the number of earthquakes that will occur. We identify amplification factors for specific sites within each geologic unit from recordings of noise. Then, we interpolate within each geologic unit in finely gridded points. All grid points within a unit are weighted by distance from each data collection point. The entire process is repeated for all of the other types of geologic units until the entire area is gridded and assigned a hazard value for every grid points. We found that nuisance and damage risks calculated by both conventional and physics-based approaches provided almost identical results. This is very surprising since they were calculated by completely independent means. The conventional approach used the actual catalog of the past ten years of earthquakes to estimate the hazard for the next ten year. While the physics-based approach used geotechnical modeling to calculate the catalog for the next ten years. Similarly, for the conventional PSHA, we utilized attenuation relations from past earthquakes recorded at the Geysers to translate the ground motion from the source to the site. While for the physics-based approach we calculated ground

  8. Hydrologic model based on deep test data from the Walker O No. 1 well, Terminal Geyser, California

    SciTech Connect

    Beall, J.J.

    1981-10-01

    The Shasta Forest No. 1 Well (renamed Walker O No. 1) at Terminal Geyser, California, was reentered and deepened from 1258 to 4008 feet. Temperature logs indicate the well penetrated a laterally flowing thermal aquifer between 1400 and 2200 feet. Large amounts of drilling fluids were lost in that zone. Maximum temperature in the well (10 months after drilling) was 348/sup 0/F at 2000 feet. A large reversed temperature gradient zone occurs below 2400 feet. Bottom hole temperature is 256/sup 0/F. After completion, the well was flowed for about five hours with nitrogen injection at 2000 feet. Samples taken throughout the flow indicate that fluids lost during drilling were not completely recovered. Salinity increased steadily during the flow period. Ratios of Na, K, and Ca were nearly constant, however, and application of Na-K and Na-K-Ca geothermometers indicate these fluids were in equilibrium with rocks at a temperature of 448-449/sup 0/F.

  9. Initiation of geyser during the resettlement of cryogenic liquid under impulsive reverse gravity acceleration in microgravity environment

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1991-01-01

    The requirement to settle or to position liquid fluid over the outlet end of spacecraft propellant tank prior to main engine restart poses a microgravity fluid behavior problem. Resettlement or reorientation of liquid propellant can be accomplished by providing optimal acceleration to the spacecraft such that the propellant is reoriented over the tank outlet without any vapor entrainment, any excessive geysering, or any other undesirable fluid motion for the space fluid management under microgravity environment. The purpose of present study is to investigate most efficient technique for propellant resettling through the minimization of propellant usage and weight penalties. Comparison between the constant reverse gravity acceleration and impulsive reverse gravity acceleration to be used for the activation of propellant resettlement, it shows that impulsive reverse gravity thrust is superior to constant reverse gravity thrust for liquid reorientation in a reduced gravity environment.

  10. Liquid draining shut-off induced geyser and slosh wave excitation at suction dip during draining in microgravity

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1992-01-01

    The dynamical behavior of vapor ingestion, liquid residual at the incipience of suction dip, liquid hydrogen shut-off at the incipience of suction dip, and slosh wave excitation under normal and various reduced gravity environments and different flow rates of liquid during draining have been investigated. It shows that the liquid residual at the incipience of suction dip increases as the values of gravity environment decrease from normal gravity to lower reduced gravity, and also that the liquid residual increases as the flow rates of liquid increase during the courses of liquid hydrogen draining. It also shows that slosh waves accompanied by strong geyser are developed for surge-related flowfields at the moment of liquid hydrogen shut-off. Slosh wave excitation, during the liquid hydrogen shut-off, shift the fluid mass distribution in the container which imposes time-dependent variation in spacecraft moment of inertia.

  11. Seismicity at Old Faithful Geyser: an isolated source of geothermal noise and possible analogue of volcanic seismicity

    USGS Publications Warehouse

    Kieffer, S.W.

    1984-01-01

    Old Faithful Geyser in Yellowstone National Park, U.S.A., is a relatively isolated source of seismic noise and exhibits seismic behavior similar to that observed at many volcanoes, including "bubblequakes" that resemble B-type "earthquakes", harmonic tremor before and during eruptions, and periods of seismic quiet prior to eruptions. Although Old Faithful differs from volcanoes in that the conduit is continuously open, that rock-fracturing is not a process responsible for seismicity, and that the erupting fluid is inviscid H2O rather than viscous magma, there are also remarkable similarities in the problems of heat and mass recharge to the system, in the eruption dynamics, and in the seismicity. Water rises irregularly into the immediate reservoir of Old Faithful as recharge occurs, a fact that suggests that there are two enlarged storage regions: one between 18 and 22 m (the base of the immediate reservoir) and one between about 10 and 12 m depth. Transport of heat from hot water or steam entering at the base of the recharging water column into cooler overlying water occurs by migration of steam bubbles upward and their collapse in the cooler water, and by episodes of convective overturn. An eruption occurs when the temperature of the near-surface water exceeds the boiling point if the entire water column is sufficiently close to the boiling curve that the propagation of pressure-release waves (rarefactions) down the column can bring the liquid water onto the boiling curve. The process of conversion of the liquid water in the conduit at the onset of an eruption into a two-phase liquid-vapor mixture takes on the order of 30 s. The seismicity is directly related to the sequence of filling and heating during the recharge cycle, and to the fluid mechanics of the eruption. Short (0.2-0.3 s), monochromatic, high-frequency events (20-60 Hz) resembling unsustained harmonic tremor and, in some instances, B-type volcanic earthquakes, occur when exploding or imploding

  12. A comparison of long-term changes in seismicity at The Geysers, Salton Sea, and Coso geothermal fields

    NASA Astrophysics Data System (ADS)

    Trugman, Daniel T.; Shearer, Peter M.; Borsa, Adrian A.; Fialko, Yuri

    2016-01-01

    Geothermal energy is an important source of renewable energy, yet its production is known to induce seismicity. Here we analyze seismicity at the three largest geothermal fields in California: The Geysers, Salton Sea, and Coso. We focus on resolving the temporal evolution of seismicity rates, which provides important observational constraints on how geothermal fields respond to natural and anthropogenic loading. We develop an iterative, regularized inversion procedure to partition the observed seismicity rate into two components: (1) the interaction rate due to earthquake-earthquake triggering and (2) the smoothly varying background rate controlled by other time-dependent stresses, including anthropogenic forcing. We apply our methodology to compare long-term changes in seismicity to monthly records of fluid injection and withdrawal. At The Geysers, we find that the background seismicity rate is highly correlated with fluid injection, with the mean rate increasing by approximately 50% and exhibiting strong seasonal fluctuations following construction of the Santa Rosa pipeline in 2003. In contrast, at both Salton Sea and Coso, the background seismicity rate has remained relatively stable since 1990, though both experience short-term rate fluctuations that are not obviously modulated by geothermal plant operation. We also observe significant temporal variations in Gutenberg-Richter b value, earthquake magnitude distribution, and earthquake depth distribution, providing further evidence for the dynamic evolution of stresses within these fields. The differing field-wide responses to fluid injection and withdrawal may reflect differences in in situ reservoir conditions and local tectonics, suggesting that a complex interplay of natural and anthropogenic stressing controls seismicity within California's geothermal fields.

  13. Analysis of Seismic Moment Tensor and Finite-Source Scaling During EGS Resource Development at The Geysers, CA

    NASA Astrophysics Data System (ADS)

    Boyd, O. S.; Dreger, D. S.; Gritto, R.

    2015-12-01

    Enhanced Geothermal Systems (EGS) resource development requires knowledge of subsurface physical parameters to quantify the evolution of fracture networks. We investigate seismicity in the vicinity of the EGS development at The Geysers Prati-32 injection well to determine moment magnitude, focal mechanism, and kinematic finite-source models with the goal of developing a rupture area scaling relationship for the Geysers and specifically for the Prati-32 EGS injection experiment. Thus far we have analyzed moment tensors of M ≥ 2 events, and are developing the capability to analyze the large numbers of events occurring as a result of the fluid injection and to push the analysis to smaller magnitude earthquakes. We have also determined finite-source models for five events ranging in magnitude from M 3.7 to 4.5. The scaling relationship between rupture area and moment magnitude of these events resembles that of a published empirical relationship derived for events from M 4.5 to 8.3. We plan to develop a scaling relationship in which moment magnitude and corner frequency are predictor variables for source rupture area constrained by the finite-source modeling. Inclusion of corner frequency in the empirical scaling relationship is proposed to account for possible variations in stress drop. If successful, we will use this relationship to extrapolate to the large numbers of events in the EGS seismicity cloud to estimate the coseismic fracture density. We will present the moment tensor and corner frequency results for the micro earthquakes, and for select events, finite-source models. Stress drop inferred from corner frequencies and from finite-source modeling will be compared.

  14. The Geology and Remarkable Thermal Activity of Norris Geyser Basin, Yellowstone National Park, Wyoming

    USGS Publications Warehouse

    White, Donald Edward; Hutchinson, Roderick A.; Keith, Terry E.C.

    1988-01-01

    Norris Geyser Basin, normally shortened to Norris Basin, is adjacent to the north rim of the Yellowstone caldera at the common intersection of the caldera rim and the Norris-Mammoth Corridor, a zone of faults, volcanic vents, and thermal activity that strikes north from the caldera rim to Mammoth Hot Springs. An east-west fault zone terminates the Gallatin Range at its southern end and extends from Hebgen Lake, west of the park, to Norris Basin. No local evidence exists at the surface in Norris Basin for the two oldest Yellowstone volcanic caldera cycles (~2.0 and 1.3 m.y.B.P.). The third and youngest cycle formed the Yellowstone caldera, which erupted the 600,000-year-old Lava Creek Tuff. No evidence is preserved of hydrothermal activity near Norris Basin during the first 300,000.years after the caldera collapse. Glaciation probably removed most of the early evidence, but erratics of hot-spring sinter that had been converted diagenetically to extremely hard, resistant chalcedonic sinter are present as cobbles in and on some moraines and till from the last two glacial stages, here correlated with the early and late stages of the Pinedale glaciation <150,000 years B.P.). Indirect evidence for the oldest hydrothermal system at Norris Basin indicates an age probably older than both stages of Pinedale glaciation. Stream deposits consisting mainly of rounded quartz phenocrysts of the Lava Creek Tuff were subaerial, perhaps in part windblown and redeposited by streams. A few small rounded pebbles are interpreted as chalcedonic sinter of a still older cycle. None of these are precisely dated but are unlikely to be more than 150,000 to 200,000 years old. ...Most studies of active hydrothermal areas have noted chemical differences in fluids and alteration products but have given little attention to differences and models to explain evolution in types. This report, in contrast, emphasizes the kinds of changes in vents and their changing chemical types of waters and then

  15. Vp/Vs ratios in the Yellowstone National Park region, Wyoming

    USGS Publications Warehouse

    Chatterjee, S.N.; Pitt, A.M.; Iyer, H.M.

    1985-01-01

    In this paper we study the variation of Vp/Vs and Poisson's ratio (??) in the Yellowstone National Park region, using earthquakes which were well recorded by a local seismic network. We find that the average Vp/Vs value within the geothermally active Yellowstone caldera is about 7% lower than in the area outside the caldera. Within the caldera itself there may be a further 2-7% reduction of Vp/Vs in the hydrothermally active Norris Geyser Basin, the Upper and Lower Geyser Basins, and the Yellowstone Lake and Mud Volcano regions. After considering various possible causes for Vp/Vs changes, such as geologic and structural differences, thermal effects, partial melting, and hydrothermal activity, we conclude that the most plausible explanation for the observed Vp/Vs reduction is the presence of hot-water at temperatures and pore-pressures near the water steam transition in the caldera geothermal reservoirs. ?? 1985.

  16. Draft Genome Sequence of Chloroflexus sp. Strain isl-2, a Thermophilic Filamentous Anoxygenic Phototrophic Bacterium Isolated from the Strokkur Geyser, Iceland.

    PubMed

    Gaisin, Vasil A; Ivanov, Timophey M; Kuznetsov, Boris B; Gorlenko, Vladimir M; Grouzdev, Denis S

    2016-07-21

    We report here the draft genome sequence of the thermophilic filamentous anoxygenic phototrophic bacterium Chloroflexus sp. strain isl-2, which was isolated from the Strokkur geyser, Iceland, and contains 5,222,563 bp with a G+C content of 59.65%. The annotated genome sequence offers the genetic basis for understanding the strain's ecological role as a phototrophic bacterium within the bacterial community.

  17. Draft Genome Sequence of Chloroflexus sp. Strain isl-2, a Thermophilic Filamentous Anoxygenic Phototrophic Bacterium Isolated from the Strokkur Geyser, Iceland

    PubMed Central

    Gaisin, Vasil A.; Ivanov, Timophey M.; Kuznetsov, Boris B.; Gorlenko, Vladimir M.

    2016-01-01

    We report here the draft genome sequence of the thermophilic filamentous anoxygenic phototrophic bacterium Chloroflexus sp. strain isl-2, which was isolated from the Strokkur geyser, Iceland, and contains 5,222,563 bp with a G+C content of 59.65%. The annotated genome sequence offers the genetic basis for understanding the strain’s ecological role as a phototrophic bacterium within the bacterial community. PMID:27445390

  18. Draft Genome Sequence of Chloroflexus sp. Strain isl-2, a Thermophilic Filamentous Anoxygenic Phototrophic Bacterium Isolated from the Strokkur Geyser, Iceland.

    PubMed

    Gaisin, Vasil A; Ivanov, Timophey M; Kuznetsov, Boris B; Gorlenko, Vladimir M; Grouzdev, Denis S

    2016-01-01

    We report here the draft genome sequence of the thermophilic filamentous anoxygenic phototrophic bacterium Chloroflexus sp. strain isl-2, which was isolated from the Strokkur geyser, Iceland, and contains 5,222,563 bp with a G+C content of 59.65%. The annotated genome sequence offers the genetic basis for understanding the strain's ecological role as a phototrophic bacterium within the bacterial community. PMID:27445390

  19. Water-chemistry data for selected springs, geysers, and streams in Yellowstone National Park, Wyoming, 2006-2008

    USGS Publications Warehouse

    Ball, James W.; McMleskey, R. Blaine; Nordstrom, D. Kirk

    2010-01-01

    Water analyses are reported for 104 samples collected from numerous thermal and non-thermal features in Yellowstone National Park (YNP) during 2006-2008. Water samples were collected and analyzed for major and trace constituents from 10 areas of YNP including Apollinaris Spring and Nymphy Creek along the Norris-Mammoth corridor, Beryl Spring in Gibbon Canyon, Norris Geyser Basin, Lower Geyser Basin, Crater Hills, the Geyser Springs Group, Nez Perce Creek, Rabbit Creek, the Mud Volcano area, and Washburn Hot Springs. These water samples were collected and analyzed as part of research investigations in YNP on arsenic, antimony, iron, nitrogen, and sulfur redox species in hot springs and overflow drainages, and the occurrence and distribution of dissolved mercury. Most samples were analyzed for major cations and anions, trace metals, redox species of antimony, arsenic, iron, nitrogen, and sulfur, and isotopes of hydrogen and oxygen. Analyses were performed at the sampling site, in an on-site mobile laboratory vehicle, or later in a U.S. Geological Survey laboratory, depending on stability of the constituent and whether it could be preserved effectively. Water samples were filtered and preserved on-site. Water temperature, specific conductance, pH, emf (electromotive force or electrical potential), and dissolved hydrogen sulfide were measured on-site at the time of sampling. Dissolved hydrogen sulfide was measured a few to several hours after sample collection by ion-specific electrode on samples preserved on-site. Acidity was determined by titration, usually within a few days of sample collection. Alkalinity was determined by titration within 1 to 2 weeks of sample collection. Concentrations of thiosulfate and polythionate were determined as soon as possible (generally a few to several hours after sample collection) by ion chromatography in an on-site mobile laboratory vehicle. Total dissolved iron and ferrous iron concentrations often were measured on-site in the

  20. Micro-digitate Silica Structures on Earth and Mars: Potential Biosignatures Revealed in the Geyser Field of El Tatio, Chile

    NASA Astrophysics Data System (ADS)

    Ruff, S. W.; Farmer, J. D.

    2015-12-01

    Opaline silica outcrops and soil identified by the Spirit rover adjacent to "Home Plate" in Gusev crater are associated with a suite of geologic features that demonstrates that they are the products of a volcanic hydrothermal system, the first such example verified on Mars [1]. Fumarolic acid-sulfate leaching of basaltic precursor materials was suggested as the origin of the opaline silica, based largely on geochemical arguments. A more complete analysis by Ruff et al. [2] included stratigraphic and textural observations of the outcrops to advance the hypothesis of a hot spring and/or geyser-related origin under alkaline-neutral conditions; acid-sulfate leaching appears much less tenable. But the nodular expression of many of the outcrops and sub-cm-scale "digitate protrusions" they contain remained enigmatic, precluding a complete explanation for the silica. Now, new observations of silica deposits produced in small discharge channels from hot springs and geysers in a high elevation geothermal field known as El Tatio in the Atacama Desert of northern Chile reveal remarkably similar features, including infrared spectral characteristics and what we describe here as micro-digitate silica structures. We hypothesize that these structures at El Tatio arise through microbial mediation of silica precipitation, i.e., that they are microstromatolites and that they provide favorable environments for the capture and preservation of microbial biosignatures. Similar features have been identified among hot spring silica deposits in Yellowstone National Park, the Taupo Volcanic Zone of New Zealand, and Iceland [e.g., 3; 4; 5]. Our ongoing field and lab studies are intended provide a robust assessment of the biogenicity of the micro-digitate silica structures and other aspects of El Tatio silica sinter deposits and test their viability as direct analogs to similar features found among the Home Plate silica deposits on Mars. [1] Squyres, S. W., et al. (2008), Science, 320, 1063

  1. Radiocarbon dating of silica sinter deposits in shallow drill cores from the Upper Geyser Basin, Yellowstone National Park

    USGS Publications Warehouse

    Lowenstern, Jacob B.; Hurwitz, Shaul; McGeehin, John

    2016-01-01

    To explore the timing of hydrothermal activity at the Upper Geyser Basin (UGB) in Yellowstone National Park, we obtained seven new accelerator mass spectrometry (AMS) radiocarbon 14C ages of carbonaceous material trapped within siliceous sinter. Five samples came from depths of 15–152 cm within the Y-1 well, and two samples were from well Y-7 (depths of 24 cm and 122 cm). These two wells, at Black Sand and Biscuit Basins, respectively, were drilled in 1967 as part of a scientific drilling program by the U.S. Geological Survey (White et al., 1975). Even with samples as small as 15 g, we obtained sufficient carbonaceous material (a mixture of thermophilic mats, pollen, and charcoal) for the 14C analyses. Apparent time of deposition ranged from 3775 ± 25 and 2910 ± 30 14C years BP at the top of the cores to about 8000 years BP at the bottom. The dates are consistent with variable rates of sinter formation at individual sites within the UGB over the Holocene. On a basin-wide scale, though, these and other existing 14C dates hint that hydrothermal activity at the UGB may have been continuous throughout the Holocene.

  2. Degradation of the mechanical properties imaged by seismic tomography during an EGS creation at The Geysers (California) and geomechanical modeling

    NASA Astrophysics Data System (ADS)

    Jeanne, Pierre; Rutqvist, Jonny; Hutchings, Lawrence; Singh, Ankit; Dobson, Patrick F.; Walters, Mark; Hartline, Craig; Garcia, Julio

    2015-03-01

    Using coupled thermal-hydro-mechanical (THM) modeling, we evaluated new seismic tomography results associated with stimulation injection at an EGS demonstration project at the Northwest Geysers geothermal steam field, California. We studied high resolution seismic tomography images built from data recorded during three time periods: a period of two months prior to injection and during two consecutive one month periods after injection started in October 2011. Our analysis shows that seismic velocity decreases in areas of most intense induced microseismicity and this is also correlated with the spatial distribution of calculated steam pressure changes. A detailed analysis showed that shear wave velocity decreases with pressure in areas where pressure is sufficiently high to cause shear reactivation of pre-existing fractures. The analysis also indicates that cooling in a liquid zone around the injection well contributes to reduced shear wave velocity. A trend of reducing compressional wave velocity with fluid pressure was also found, but at pressures much above the pressure required for shear reactivation. We attribute the reduction in shear wave velocity to softening in the rock mass shear modulus associated with shear dislocations and associated changes in fracture surface properties. Also, as the rock mass become more fractured and more deformable this favors reservoir expansion caused by the pressure increase, and so the fracture porosity increases leading to a decrease in bulk density, a decrease in Young modulus and finally a decrease in Vp.

  3. Resistivity During Boiling in the SB-15-D Core from the Geysers Geothermal Field: The Effects of Capillarity

    SciTech Connect

    Roberts, J.; Duba, A.; Bonner, B.; Kasameyer, P.

    1997-01-01

    In a laboratory study of cores from borehole SB-15-D in The Geysers geothermal area, we measured the electrical resistivity of metashale with and without pore-pressure control, with confining pressures up to 100 bars and temperatures between 20 and 150 C, to determine how the pore-size distribution and capillarity affected boiling. We observed a gradual increase in resistivity when the downstream pore pressure or confining pressure decreased below the phase boundary of free water. For the conditions of this experiment, boiling, as indicated by an increase in resistivity, is initiated at pore pressures of approximately 0.5 to 1 bar (0.05 to 0.1 MPa) below the free-water boiling curve, and it continues to increase gradually as pressure is lowered to atmospheric. A simple model of the effects of capillarity suggests that at 145 C, less than 15% of the pore water can boil in these rocks. If subsequent experiments bear out these preliminary observations, then boiling within a geothermal reservoir is controlled not just by pressure and temperature but also by pore-size distribution. Thus, it may be possible to determine reservoir characteristics by monitoring changes in electrical resistivity as reservoir conditions change.

  4. Radiocarbon dating of silica sinter deposits in shallow drill cores from the Upper Geyser Basin, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Lowenstern, Jacob B.; Hurwitz, Shaul; McGeehin, John P.

    2016-01-01

    To explore the timing of hydrothermal activity at the Upper Geyser Basin (UGB) in Yellowstone National Park, we obtained seven new accelerator mass spectrometry (AMS) radiocarbon 14C ages of carbonaceous material trapped within siliceous sinter. Five samples came from depths of 15-152 cm within the Y-1 well, and two samples were from well Y-7 (depths of 24 cm and 122 cm). These two wells, at Black Sand and Biscuit Basins, respectively, were drilled in 1967 as part of a scientific drilling program by the U.S. Geological Survey (White et al., 1975). Even with samples as small as 15 g, we obtained sufficient carbonaceous material (a mixture of thermophilic mats, pollen, and charcoal) for the 14C analyses. Apparent time of deposition ranged from 3775 ± 25 and 2910 ± 30 14C years BP at the top of the cores to about 8000 years BP at the bottom. The dates are consistent with variable rates of sinter formation at individual sites within the UGB over the Holocene. On a basin-wide scale, though, these and other existing 14C dates hint that hydrothermal activity at the UGB may have been continuous throughout the Holocene.

  5. Predicting the spatial extent of injection-induced zones of enhanced permeability at the Northwest Geysers EGS Demonstration Project

    SciTech Connect

    Rutqvist, J.; Oldenburg, C.M.; Dobson, P.F.

    2010-02-01

    We present the results of coupled thermal, hydraulic, and mechanical (THM) modeling of a proposed stimulation injection associated with an Enhanced Geothermal System (EGS) demonstration project at the northwest part of The Geysers geothermal field, California. The project aims at creating an EGS by directly and systematically injecting cool water at relatively low pressure into a known High Temperature (about 280 to 350 C) Zone (HTZ) located under the conventional (240 C) steam reservoir at depths below 3 km. Accurate micro-earthquake monitoring from the start of the injection will be used as a tool for tracking the development of the EGS. We first analyzed historic injection and micro-earthquake data from an injection well (Aidlin 11), located about 3 miles to the west of the new EGS demonstration area. Thereafter, we used the same modeling approach to predict the likely extent of the zone of enhanced permeability for a proposed initial injection in two wells (Prati State 31 and Prati 32) at the new EGS demonstration area. Our modeling indicates that the proposed injection scheme will provide additional steam production in the area by creating a zone of permeability enhancement extending about 0.5 km from each injection well which will connect to the overlying conventional steam reservoir.

  6. The nature of faults and hydrothermal veins in corehole SB-15-D, The Geysers Steam Field, California

    SciTech Connect

    Hulen, J.B.; Nielson, D.L.

    1995-12-31

    Porosity in The Geysers Coring Project corehole SB-15-D is concentrated along vuggy, steeply-dipping, hydrothermal calcite-quartz {plus_minus} adularia veins. There is little difference in the texture and abundance of these veins between the upper two thirds of the core, interpreted as caprock, and the lower two-thirds, in which two, vein-controlled, fluid-loss zones (probable steam entries) were encountered. However, vugs in the caprock veins are locally choked with mixed-layer clay, whereas those in the deeper steam-reservoir veins generally lack this clay but contain calc-silicate minerals. Steeply-dipping, concordant faults concentrated in argillite throughout the core show predominantly strike-slip displacement. Although movement was predominantly along argillites, the lithology appears to have deformed in a ductile manner, and porosity development was minimal. High-angle dilational fractures were developed contemporaneously in the graywackes. These fractures in the graywacke were only partially filled by secondary minerals, and are potential steam conduits in the vapor-dominated geothermal system.

  7. 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.

  8. 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).

  9. Water-Chemistry Data for Selected Springs, Geysers, and Streams in Yellowstone National Park, Wyoming, 2003-2005

    USGS Publications Warehouse

    Ball, James W.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Holloway, JoAnn M.

    2008-01-01

    Water analyses are reported for 157 samples collected from numerous hot springs, their overflow drainages, and Lemonade Creek in Yellowstone National Park (YNP) during 2003-2005. Water samples were collected and analyzed for major and trace constituents from ten areas of YNP including Terrace and Beryl Springs in the Gibbon Canyon area, Norris Geyser Basin, the West Nymph Creek thermal area, the area near Nymph Lake, Hazle Lake, and Frying Pan Spring, Lower Geyser Basin, Washburn Hot Springs, Mammoth Hot Springs, Potts Hot Spring Basin, the Sulphur Caldron area, and Lemonade Creek near the Solfatara Trail. These water samples were collected and analyzed as part of research investigations in YNP on arsenic, antimony, and sulfur redox distribution in hot springs and overflow drainages, and the occurrence and distribution of dissolved mercury. Most samples were analyzed for major cations and anions, trace metals, redox species of antimony, arsenic, iron, nitrogen, and sulfur, and isotopes of hydrogen and oxygen. Analyses were performed at the sampling site, in an on-site mobile laboratory vehicle, or later in a U.S. Geological Survey laboratory, depending on stability of the constituent and whether it could be preserved effectively. Water samples were filtered and preserved onsite. Water temperature, specific conductance, pH, Eh (redox potential relative to the Standard Hydrogen Electrode), and dissolved hydrogen sulfide were measured onsite at the time of sampling. Acidity was determined by titration, usually within a few days of sample collection. Alkalinity was determined by titration within 1 to 2 weeks of sample collection. Concentrations of thiosulfate and polythionate were determined as soon as possible (generally minutes to hours after sample collection) by ion chromatography in an on-site mobile laboratory vehicle. Total dissolved-iron and ferrous-iron concentrations often were measured onsite in the mobile laboratory vehicle. Concentrations of dissolved

  10. Seismic and aseismic deformations and impact on reservoir permeability: The case of EGS stimulation at The Geysers, California, USA

    NASA Astrophysics Data System (ADS)

    Jeanne, Pierre; Rutqvist, Jonny; Rinaldi, Antonio Pio; Dobson, Patrick F.; Walters, Mark; Hartline, Craig; Garcia, Julio

    2015-11-01

    In this paper, we use the Seismicity-Based Reservoir Characterization approach to study the spatiotemporal dynamics of an injection-induced microseismic cloud, monitored during the stimulation of an enhanced geothermal system, and associated with the Northwest Geysers Enhanced Geothermal System (EGS) Demonstration project (California). We identified the development of a seismically quiet domain around the injection well surrounded by a seismically active domain. Then we compare these observations with the results of 3-D Thermo-Hydro-Mechanical simulations of the EGS, which accounts for changes in permeability as a function of the effective normal stress and the plastic strain. The results of our modeling show that (1) the aseismic domain is caused by both the presence of the injected cold water and by thermal processes. These thermal processes cause a cooling-stress reduction, which prevent shear reactivation and favors fracture opening by reducing effective normal stress and locally increasing the permeability. This process is accompanied by aseismic plastic shear strain. (2) In the seismic domain, microseismicity is caused by the reactivation of the preexisting fractures, resulting from an increase in injection-induced pore pressure. Our modeling indicates that in this domain, permeability evolves according to the effective normal stress acting on the shear zones, whereas shearing of preexisting fractures may have a low impact on permeability. We attribute this lack of permeability gain to the fact that the initial permeabilities of these preexisting fractures are already high (up to 2 orders of magnitude higher than the host rock) and may already be fully dilated by past tectonic straining.

  11. Effects of Long-Term Fluid Injection on Maximum Magnitude and Induced Seismicity Parameters at Northwestern The Geysers Geothermal Field

    NASA Astrophysics Data System (ADS)

    Bohnhoff, M.; Kwiatek, G.; Martínez-Garzón, P.; Dresen, G. H.; Sone, H.; Hartline, C. S.

    2015-12-01

    The long-term temporal and spatial changes in statistical, source and stress characteristics of one cluster of induced seismicity recorded at The Geysers geothermal field (US) are analyzed in relation to the field operations, fluid migration and constraints on the maximum likely magnitude. Two injection wells, Prati-9 and Prati-29, located in the northwestern part of the field and their associated seismicity composed of 1,776 events recorded throughout a seven-year period were analyzed. The seismicity catalog was relocated and the source characteristics including focal mechanisms and static source parameters were refined using first-motion polarity, spectral fitting and mesh spectral ratio techniques. The source characteristics together with statistical parameters (b-value) and cluster dynamics were used to investigate and understand the details of fluid migration scheme in the vicinity of injection wells. The observed temporal, spatial and source characteristics were clearly attributed to fluid injection and fluid migration towards greater depths, involving increasing pore pressure in the reservoir. Increasing poroelastic stresses at greater depths affect the kinematic properties of the seismicity in that at reservoir depths normal faulting mechanism events dominate, whereas at larger depths the contribution of strike-slip events are is significantly increasing. The seasonal changes of injection rates were found to directly impact the shape and spatial extent of the seismic cloud. A tendency of larger seismic events to occur closer to injection wells and a correlation between the spatial extent of the seismic cloud and source sizes of the largest events was observed suggesting geometrical constraints on the maximum likely magnitude. The observed maximum magnitude was found to be clearly correlated to the dimensions of seismic cloud which is related to the volume of formation weakened by fluid injection and injection rate, and the average pore pressure change in

  12. Geology, alteration, and magmatic-hydrothermal history of The Geysers felsite -- potential applications for exploration and development

    SciTech Connect

    Hulen, J.B.; Nielson, D.L. )

    1993-01-01

    The [open quotes]felsite[close quotes] is a shallow, young, granitic intrusive body centrally located within and beneath. The Geysers steam field. The field and the felsite are coaxial, and hydrothermal alteration effected by hot-water dominated geothermal systems antedating the modern steam reservoir shows systematic vertical zonation with respect to the pluton. The research summarized in this communication was undertaken both to clarify the role of the pluton in reservoir evolution, and to characterize critical felsite-specific controls on the fields's deep porosity and permeability. The felsite comprises at least three major intrusive phases. Two are high-silica granites probably older than 1.3 Ma. The third is granodiorite (1 Ma), temporally and chemically equivalent to overlying extrusive dacites of the Clear Lake volcanic field. All three intrusive phases are too old to be heat sources for the modern steam field, but probably were the heat engines for the prior liquid-dominant systems. Younger, deeper magmatic heat sources are strongly implied for the current vapor-dominated regime. Porosity in the felsite is provided by: (1) Extensively mineralized fractures and breccias, probably of both tectonic and high-temperature hydrothermal origin; and (2) miarolitic cavities in the upper levels of the pluton. The latter could be analogous to calcite-dissolution cavities in overlying metagraywacke -- they could serve as storage sites for the fields's liquid water reserves. Porosity in these fractures, breccias, and vugs in partially occluded by hydrothermal vein minerals deposited in prior hotwater-dominated systems --tourmaline, ferroaxinite, quartz, potassium feldspar, epidote, actinolite, prehnite, and many others. Such secondary mineralization conceptually could serve as an excellent exploration guide to potentially productive portions of the felsite beyond the field's present boundaries.

  13. The Northwest Geysers EGS Demonstration Project Phase 1: Pre-stimulation coupled geomechanical modeling to guide stimulation and monitoring plans

    SciTech Connect

    Rutqvist, J.; Dobson, P.F.; Oldenburg, C.M.; Garcia, J.; Walters, M.

    2010-10-20

    This paper presents activities and results associated with Phase 1 (pre-stimulation phase) of an Enhanced Geothermal System (EGS) demonstration project at the northwest part of The Geysers geothermal field, California. The paper presents development of a 3-D geological model, coupled thermal-hydraulic-mechanical (THM) modeling of proposed stimulation injection as well as current plans for stimulation and monitoring of the site. The project aims at creating an EGS by directly and systematically injecting cool water at relatively low pressure into a known High Temperature (about 280 to 350 C) Zone (HTZ) located under the conventional (240 C) steam reservoir at depths of {approx}3 km. Accurate micro-earthquake monitoring initiated before the start of the injection will be used as a tool for tracking the development of the EGS and monitoring changes in microseismicity. We first analyzed historic injection and micro-earthquake data from an injection well (Aidlin 11) located about 3 miles to the west of the new EGS demonstration area. Thereafter, we used the same modeling approach to predict the likely extent of the zone of enhanced permeability for a proposed initial injection in two wells (Prati State 31 and Prati 32) at the new EGS demonstration area. Our modeling indicates that the proposed injection scheme will provide additional steam production in the area by creating a zone of permeability enhancement extending about 0.5 km from each injection well which will connect to the overlying conventional steam reservoir, in agreement with the conclusions of Nielson and Moore (2000).

  14. Tidal interaction: A possible explanation for geysers and other fluid phenomena in the Neptune-Triton system

    NASA Astrophysics Data System (ADS)

    Kelly, W. D.; Wood, C. L.

    1993-03-01

    Discovery of geyser-like plumes on the surface of Triton was a highlight of Voyager 2's passage through the Neptune planetary system. Remarkable as these observations were, they were not entirely without precedent. Considering the confirmed predictions for the 1979 Voyager Jovian passage, it was logical to consider other solar system bodies beside Io where tidal effects could be a significant factor in surface processes. It was our intuition that the Neptune-Triton gravitational bond acting at high inclination to the Neptune equator and the fact that Neptune was a fluid body was significant oblateness would produce tidal and mechanical forces that could be transformed into thermal energy vented on Triton's surface. Prior to the Voyager flyby, others have noted that capture and evolution of Triton's orbit from extreme eccentricity to near circular state today would have resulted in significant tidal heating, but these analysts disregard current day forces. Our calculations indicate that the time varying forces between Neptune-Triton fall midway between those exerted in the Earth-Moon and Jupiter-Io systems, and considering the low level of other energy inputs, this source of internal energy should not be ignored when seeking an explanation for surface activity. In each planet-satellite case, residual or steady-state eccentricity causes time-varying stresses on internal satellite strata. In the case of Jupiter the residual eccentricity is due largely to Galilean satellite interactions, particularly Io-Europa, but in the case of Neptune-Triton, it is the effect of Triton's inclined orbit about an oblate primary.

  15. Tidal interaction: A possible explanation for geysers and other fluid phenomena in the Neptune-Triton system

    NASA Technical Reports Server (NTRS)

    Kelly, W. D.; Wood, C. L.

    1993-01-01

    Discovery of geyser-like plumes on the surface of Triton was a highlight of Voyager 2's passage through the Neptune planetary system. Remarkable as these observations were, they were not entirely without precedent. Considering the confirmed predictions for the 1979 Voyager Jovian passage, it was logical to consider other solar system bodies beside Io where tidal effects could be a significant factor in surface processes. It was our intuition that the Neptune-Triton gravitational bond acting at high inclination to the Neptune equator and the fact that Neptune was a fluid body was significant oblateness would produce tidal and mechanical forces that could be transformed into thermal energy vented on Triton's surface. Prior to the Voyager flyby, others have noted that capture and evolution of Triton's orbit from extreme eccentricity to near circular state today would have resulted in significant tidal heating, but these analysts disregard current day forces. Our calculations indicate that the time varying forces between Neptune-Triton fall midway between those exerted in the Earth-Moon and Jupiter-Io systems, and considering the low level of other energy inputs, this source of internal energy should not be ignored when seeking an explanation for surface activity. In each planet-satellite case, residual or steady-state eccentricity causes time-varying stresses on internal satellite strata. In the case of Jupiter the residual eccentricity is due largely to Galilean satellite interactions, particularly Io-Europa, but in the case of Neptune-Triton, it is the effect of Triton's inclined orbit about an oblate primary.

  16. Isolation and characterization of a CO2-tolerant Lactobacillus strain from Crystal Geyser, Utah, U.S.A.

    NASA Astrophysics Data System (ADS)

    Santillan, Eugenio Felipe; Shanahan, Timothy; Omelon, Christopher; Major, Jonathan; Bennett, Philip

    2015-07-01

    When CO2 is sequestered into the deep subsurface, changes to the subsurface microbial community will occur. Capnophiles, microorganisms that grow in CO2-rich environments, are some organisms that may be selected for under the new environmental conditions. To determine whether capnophiles comprise an important part of CO2-rich environments, an isolate from Crystal Geyser, Utah, U.S.A., a CO2- rich spring considered a carbon sequestration analogue, was characterized. The isolate was cultured under varying CO2, pH, salinity, and temperature, as well as different carbon substrates and terminal electron acceptors (TEAs) to elucidate growth conditions and metabolic activity. Designated CG-1, the isolate is related (99%) to Lactobacillus casei in 16S rRNA gene identity, growing at PCO2 between 0 to 1.0 MPa. Growth is inhibited at 2.5 MPa, but stationary phase cultures exposed to this pressure survive beyond 5 days. At 5.0 MPa, survival is at least 24 hours. CG-1 grows in neutral pH, 0.25 M NaCl, and between 25° to 45°C andconsumes glucose, lactose, sucrose, or crude oil, likely performing lactic acid fermentation. Fatty acid profiles between 0.1 MPa to 1.0 MPa suggests decreases in cell size and increases in membrane rigidity. Transmission electron microscopy reveals rod shaped bacteria at 0.1 MPa. At 1.0 MPa, cells are smaller, amorphous, and produce abundant capsular material. Its ability to grow in environments regardless of the presence of CO2 suggests we have isolated an organism that is more capnotolerant than capnophilic. Results also show that microorganisms are capable of surviving the stressful conditions created by the introduction of CO2 for sequestration. Furthermore, our ability to culture an environmental isolate indicates that organisms found in CO2 environments from previous genomic and metagenomics studies are viable, metabolizing, and potentially affecting the surrounding environment.

  17. Geothermal policy development program. Geothermal issues that cross county lines

    SciTech Connect

    Not Available

    1981-07-01

    The principal issues related to geothermal resources for the production of electricity, which cross county lines, as well as issues which may not cross county lines but which are of common concern to the four counties in The Geysers-Calistoga KGRA are identified and described briefly. As this compilation makes clear, the generation of electricity at The Geysers does not occur in a trouble-free environment - rather, it occurs under difficult circumstances componded by jurisdictional fragmentation. These factors are recognized by grouping the issues according to whether they are Environmental, Administrative, or Planning in nature.

  18. Initial Characterization of Carbon Metabolism in Iron Oxidizing Microbial Communities of Acidic Hot Springs in Norris Geyser Basin, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Kreuzer, H. W.; Jennings, R. D.; Whitmore, L.; Inskeep, W. P.; Moran, J.

    2012-12-01

    Norris Geyser Basin in Yellowstone National Park is home to several acidic, sulfidic hot springs. Visual inspection of the springs reveals distinct geochemical regions starting with a sulfur deposition zone followed by a transition to iron oxide deposition downstream. The microbial communities in the iron oxidation zones are dominated by Archaea, including several members that appear to define previously unrecognized taxa. Abiotic iron oxidation rates are very slow at these temperatures (typically ~ 65-70 oC) and pH's (typically ~3). Therefore, the relatively rapid iron oxide deposition rate strongly suggests the process is microbially mediated, and an organism previously isolated from these springs, Metallosphaera yellowstonensis, has been shown to oxide iron in culture. M. yellowstonensis has been observed in the all microbial communities analyzed in the iron oxidizing zones of these springs, though metagenomic profiling suggests it constitutes only ~20% of the community membership. When we began our studies of C flow in the iron-oxidizing community, no C source had been demonstrated. Observed potential carbon sources in the springs include dissolved inorganic carbon, dissolved organic carbon, and methane, as well as random inputs of heterotrophic carbon in the forms of insect carcasses, pine needles, and animal scat. The temperatures in the iron oxidation zones are above the photosynthetic upper temperature limit, thus precluding photosynthetic-based autotrophy within the community itself. We are employing geochemical and stable isotope techniques to assess carbon inventories in the system. We have demonstrated that M. yellowstonensis as well as excised samples of iron oxide mat communities can fix CO2, and our estimated isotopic fractionation factor is consistent with the 3-hydroxypropionate 4-hydroxybutyrate pathway. Genes of this pathway have been identified in the M. yellowstonensis genome. We have tentatively identified small amounts of organic compounds

  19. Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park.

    PubMed

    Moran, James J; Whitmore, Laura M; Isern, Nancy G; Romine, Margaret F; Riha, Krystin M; Inskeep, William P; Kreuzer, Helen W

    2016-05-01

    The Norris Geyser Basin in Yellowstone National Park contains a large number of hydrothermal systems, which host microbial populations supported by primary productivity associated with a suite of chemolithotrophic metabolisms. We demonstrate that Metallosphaera yellowstonensis MK1, a facultative autotrophic archaeon isolated from a hyperthermal acidic hydrous ferric oxide (HFO) spring in Norris Geyser Basin, excretes formaldehyde during autotrophic growth. To determine the fate of formaldehyde in this low organic carbon environment, we incubated native microbial mat (containing M. yellowstonensis) from a HFO spring with (13)C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilated by members of the community. Autotrophy, formaldehyde oxidation, and formaldehyde assimilation displayed different sensitivities to chemical inhibitors, suggesting that distinct sub-populations in the mat selectively perform these functions. Our results demonstrate that electrons originally resulting from iron oxidation can energetically fuel autotrophic carbon fixation and associated formaldehyde excretion, and that formaldehyde is both oxidized and assimilated by different organisms within the native microbial community. Thus, formaldehyde can effectively act as a carbon and electron shuttle connecting the autotrophic, iron oxidizing members with associated heterotrophic members in the HFO community. PMID:26995682

  20. Using noble gases measured in spring discharge to trace hydrothermal processes in the Norris Geyser Basin, Yellowstone National Park, U.S.A.

    USGS Publications Warehouse

    Gardner, W.P.; Susong, D.D.; Solomon, D.K.; Heasler, H.P.

    2010-01-01

    Dissolved noble gas concentrations in springs are used to investigate boiling of hydrothermal water and mixing of hydrothermal and shallow cool water in the Norris Geyser Basin area. Noble gas concentrations in water are modeled for single stage and continuous steam removal. Limitations on boiling using noble gas concentrations are then used to estimate the isotopic effect of boiling on hydrothermal water, allowing the isotopic composition of the parent hydrothermal water to be determined from that measured in spring. In neutral chloride springs of the Norris Geyser Basin, steam loss since the last addition of noble gas charged water is less than 30% of the total hydrothermal discharge, which results in an isotopic shift due to boiling of ?? 2.5% ??D. Noble gas concentrations in water rapidly and predictably change in dual phase systems, making them invaluable tracers of gas-liquid interaction in hydrothermal systems. By combining traditional tracers of hydrothermal flow such as deuterium with dissolved noble gas measurements, more complex hydrothermal processes can be interpreted. ?? 2010 Elsevier B.V.

  1. Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park.

    PubMed

    Moran, James J; Whitmore, Laura M; Isern, Nancy G; Romine, Margaret F; Riha, Krystin M; Inskeep, William P; Kreuzer, Helen W

    2016-05-01

    The Norris Geyser Basin in Yellowstone National Park contains a large number of hydrothermal systems, which host microbial populations supported by primary productivity associated with a suite of chemolithotrophic metabolisms. We demonstrate that Metallosphaera yellowstonensis MK1, a facultative autotrophic archaeon isolated from a hyperthermal acidic hydrous ferric oxide (HFO) spring in Norris Geyser Basin, excretes formaldehyde during autotrophic growth. To determine the fate of formaldehyde in this low organic carbon environment, we incubated native microbial mat (containing M. yellowstonensis) from a HFO spring with (13)C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilated by members of the community. Autotrophy, formaldehyde oxidation, and formaldehyde assimilation displayed different sensitivities to chemical inhibitors, suggesting that distinct sub-populations in the mat selectively perform these functions. Our results demonstrate that electrons originally resulting from iron oxidation can energetically fuel autotrophic carbon fixation and associated formaldehyde excretion, and that formaldehyde is both oxidized and assimilated by different organisms within the native microbial community. Thus, formaldehyde can effectively act as a carbon and electron shuttle connecting the autotrophic, iron oxidizing members with associated heterotrophic members in the HFO community.

  2. Crump Geyser Exploration and Drilling Project. High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling

    SciTech Connect

    Fairbank, Brian D.; Smith, Nicole

    2015-06-10

    The Crump Geyser Exploration and Drilling Project – High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling ran from January 29, 2010 to September 30, 2013. During Phase 1 of the project, collection of all geophysical surveys was completed as outlined in the Statement of Project Objectives. In addition, a 5000-foot full sized exploration well was drilled by Ormat, and preexisting drilling data was discovered for multiple temperature gradient wells within the project area. Three dimensional modeling and interpretation of results from the geophysical surveys and drilling data gave confidence to move to the project into Phase 2 drilling. Geological and geophysical survey interpretations combined with existing downhole temperature data provided an ideal target for the first slim-hole drilled as the first task in Phase 2. Slim-hole 35-34 was drilled in September 2011 and tested temperature, lithology, and permeability along the primary range-bounding fault zone near its intersection with buried northwest-trending faults that have been identified using geophysical methods. Following analysis of the results of the first slim-hole 35-34, the second slim hole was not drilled and subsequent project tasks, including flowing differential self-potential (FDSP) surveys that were designed to detail the affect of production and injection on water flow in the shallow aquifer, were not completed. NGP sold the Crump project to Ormat in August 2014, afterwards, there was insufficient time and interest from Ormat available to complete the project objectives. NGP was unable to continue managing the award for a project they did not own due to liability issues and Novation of the award was not a viable option due to federal award timelines. NGP submitted a request to mutually terminate the award on February 18, 2015. The results of all of the technical surveys and drilling are included in this report. Fault interpretations from surface geology, aeromag

  3. Strategies for steam handling and H/sub 2/S abatement at geothermal power plants in The Geysers area of northern California

    SciTech Connect

    Morris, W.F.; Stephens, F.B.

    1981-08-05

    Strict limitations on the emission of H/sub 2/S from new geothermal power plants in The Geysers area of northern California have been imposed by Lake and Northern Sonoma County Air Pollution Control Districts. Lake County, under new source review rules, has stipulated that specific technologies shall be utilized to limit H/sub 2/S emissions to 5 lb/h as a condition for determination of compliance. The status of these technologies as well as other ongoing technology development efforts to conserve steam and abate H/sub 2/S are evaluated. Although projections indicate that it may be possible to meet the 5 lb/h limit, there is no firm assurance of achievement at this time because of the unproven, full-scale performance status of some key technologies specified by the air pollution control districts.

  4. High-resolution in-situ thermal imaging of microbial mats at El Tatio Geyser, Chile shows coupling between community color and temperature

    NASA Astrophysics Data System (ADS)

    Dunckel, Anne E.; Cardenas, M. Bayani; Sawyer, Audrey H.; Bennett, Philip C.

    2009-12-01

    Microbial mats have spatially heterogeneous structured communities that manifest visually through vibrant color zonation often associated with environmental gradients. We report the first use of high-resolution thermal infrared imaging to map temperature at four hot springs within the El Tatio Geyser Field, Chile. Thermal images with millimeter resolution show drastic variability and pronounced patterning in temperature, with changes on the order of 30°C within a square decimeter. Paired temperature and visual images show that zones with specific coloration occur within distinct temperature ranges. Unlike previous studies where maximum, minimum, and optimal temperatures for microorganisms are based on isothermally-controlled laboratory cultures, thermal imaging allows for mapping thousands of temperature values in a natural setting. This allows for efficiently constraining natural temperature bounds for visually distinct mat zones. This approach expands current understanding of thermophilic microbial communities and opens doors for detailed analysis of biophysical controls on microbial ecology.

  5. Water-Chemistry Data for Selected Springs, Geysers, and Streams in Yellowstone National Park, Wyoming, 1999-2000

    USGS Publications Warehouse

    Ball, James W.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Holloway, JoAnn M.; Verplanck, Philip L.; Sturtevant, Sabin A.

    2002-01-01

    Sixty-seven water analyses are reported for samples collected from 44 hot springs and their overflow drainages and two ambient-temperature acid streams in Yellowstone National Park (YNP) during 1990-2000. Thirty-seven analyses are reported for 1999, 18 for June of 2000, and 12 for September of 2000. These water samples were collected and analyzed as part of research investigations in YNP on microbially mediated sulfur oxidation in stream water, arsenic and sulfur redox speciation in hot springs, and chemical changes in overflow drainages that affect major ions, redox species, and trace elements. Most samples were collected from sources in the Norris Geyser Basin. Two ambient-temperature acidic stream systems, Alluvium and Columbine Creeks and their tributaries in Brimstone Basin, were studied in detail. Analyses were performed at or near the sampling site, in an on-site mobile laboratory truck, or later in a USGS laboratory, depending on stability of the constituent and whether or not it could be preserved effectively. Water temperature, specific conductance, pH, Eh, dissolved oxygen (D.O.), and dissolved H2S were determined on-site at the time of sampling. Alkalinity, acidity, and F were determined within a few days of sample collection by titration with acid, titration with base, and ion-selective electrode or ion chromatography (IC), respectively. Concentrations of S2O3 and SxO6 were determined as soon as possible (minutes to hours later) by IC. Concentrations of Br, Cl, NH4, NO2, NO3, SO4, Fe(II), and Fe(total) were determined within a few days of sample collection. Densities were determined later in the USGS laboratory. Concentrations of Li and K were determined by flame atomic absorption spectrometry. Concentrations of Al, As(total), B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe(total), K, Li, Mg, Mn, Na, Ni, Pb, Se, Si, Sr, V, and Zn were determined by inductively-coupled plasma-optical emission spectrometry. Trace concentrations of Cd, Cr, Cu, Pb, and Sb were

  6. Geysers Unit 18

    SciTech Connect

    Finney, John P.

    1980-12-01

    The geothermal user's viewpoint in this case is somewhat unique. San Diego Gas & Electric Company, by virtue of its activity in geothermal exploration and development since 1972, is in a position to be considered not only a user of geothermal, but a producer as well through the activities of its wholly-owned subsidiary, New Albion Resources Co. As the Supervisor of Fuel Development of SDG&E and the General Manager of NARCO, I can speak from experience on both sides of the negotiating table. I have given advice from the user's point of view to SDG&E's fuel acquisitions people as they labored to negotiate a contract to buy from a geothermal producer of hot water. As General Manager of NARCO, I am in the position of developing geothermal resources and negotiating contracts to sell some of NARCO's heat to third parties. So much for the introduction--How does a utility, such as SDG&E, view risk in today's business climate? The answer to that question is very simple. SDG&E has an allowed rate of return of 10.59%. This is based upon 48% debt, having an imbedded interest cost of 8.1%; 14% preferred stock, at a cost of 8.2% and 42% equity. Out rates are supposed to return 14-112% on this equity. Let me put these numbers in perspective. In early March SDG&E sold $50 million of mortgage bonds which bear an interest rate of 16%. In mid-March we sold 2-112 million shares of common stock for $11.50 per share. The current dividend of $1.52 will yield 13.2% and those dividends are paid after taxes. When money borrowed to build a project costs more than you can earn on the project, there is no incentive to build that project and certainly no incentive to take any risk associated with the project. How does SDG&E view risks? Simple--don't take any risks which can be avoided. Is this attitude likely to change? My forecast is, there is no change in sight. Does this take SDG&E out of contention as a possible market for producers of geothermal energy? Not likely. For all of its risk aversion, SDG&E still remains one of the best potential markets for any energy producer. A recent article in FORBES MAGAZINE found that SDG&E had the third highest price per kilowatt of any utility in the country--5.9{cents} per kilowatt hour for commercial customers. That was in March, 1980. Energy cost adjustment clause increases resulted in an average commercial price per kilowatt hour of 7.2{cents} in May. In July it is expected to climb to 9.2{cents}. SDG&E's rate territory continues to expand at the rate of 5% annually and it is located just over 100 miles from a major source of geothermal heat in the Imperial Valley. But today, SDG&E has no commercial geothermal heat or power purchase contracts with domestic producers. You may ask, ''Why not?'' With no incentive to spend its own money and with a high growth rate, what is SDG&E doing to obtain capacity for its existing and future customers? At the present time, most of SDG&E's capital expenditure for generation is going to the construction of San Onofre Units 2 and 3 , a nuclear project which has been under way for ten years and which is expected to start generating commercial power in 1982 and 1983. San Onofre 2 and 3 will add 440 MW of capacity from a reliable, proven generating technology to SDG&E's system.

  7. Geothermal policy development program: expediting the local geothermal permitting process

    SciTech Connect

    Not Available

    1981-07-01

    For a number of years, concerns have been raised about the length of time and the complexity involved in obtaining required permits in order to develop the geothermal resource at the Geysers. Perhaps the most important factor is jurisdiction. At the Geysers, all three levels of government - local, state, and federal - exercise significant authority over various aspects of geothermal development. In addition, several agencies within each governmental level play an active role in the permitting process. The present study is concerned primarily with the local permitting process, and the ways in which this process could be expedited. This report begins by looking at the local role in the overall permitting process, and then reviews the findings and conclusions that have been reached in other studies of the problem. This is followed by a case study evaluation of recent permitting experience in the four Geysers-Calistoga KGRA counties, and the report concludes by outlining several approaches to expediting the local permitting process.

  8. Effects of long-term fluid injection on induced seismicity parameters and maximum magnitude in northwestern part of The Geysers geothermal field

    NASA Astrophysics Data System (ADS)

    Kwiatek, Grzegorz; Martínez-Garzón, Patricia; Dresen, Georg; Bohnhoff, Marco; Sone, Hiroki; Hartline, Craig

    2015-10-01

    The long-term temporal and spatial changes in statistical, source, and stress characteristics of one cluster of induced seismicity recorded at The Geysers geothermal field (U.S.) are analyzed in relation to the field operations, fluid migration, and constraints on the maximum likely magnitude. Two injection wells, Prati-9 and Prati-29, located in the northwestern part of the field and their associated seismicity composed of 1776 events recorded throughout a 7 year period were analyzed. The seismicity catalog was relocated, and the source characteristics including focal mechanisms and static source parameters were refined using first-motion polarity, spectral fitting, and mesh spectral ratio analysis techniques. The source characteristics together with statistical parameters (b value) and cluster dynamics were used to investigate and understand the details of fluid migration scheme in the vicinity of injection wells. The observed temporal, spatial, and source characteristics were clearly attributed to fluid injection and fluid migration toward greater depths, involving increasing pore pressure in the reservoir. The seasonal changes of injection rates were found to directly impact the shape and spatial extent of the seismic cloud. A tendency of larger seismic events to occur closer to injection wells and a correlation between the spatial extent of the seismic cloud and source sizes of the largest events was observed suggesting geometrical constraints on the maximum likely magnitude and its correlation to the average injection rate and volume of fluids present in the reservoir.

  9. Regional-scale advective, diffusive, and eruptive dynamics of CO2 and brine leakage through faults and wellbores

    NASA Astrophysics Data System (ADS)

    Jung, Na-Hyun; Han, Weon Shik; Han, Kyungdoe; Park, Eungyu

    2015-05-01

    Regional-scale advective, diffusive, and eruptive transport dynamics of CO2 and brine within a natural analogue in the northern Paradox Basin, Utah, were explored by integrating numerical simulations with soil CO2 flux measurements. Deeply sourced CO2 migrates through steeply dipping fault zones to the shallow aquifers predominantly as an aqueous phase. Dense CO2-rich brine mixes with regional groundwater, enhancing CO2 dissolution. Linear stability analysis reveals that CO2 could be dissolved completely within only ~500 years. Assigning lower permeability to the fault zones induces fault-parallel movement, feeds up-gradient aquifers with more CO2, and impedes down-gradient fluid flow, developing anticlinal CO2 traps at shallow depths (<300 m). The regional fault permeability that best reproduces field spatial CO2 flux variation is estimated 1 × 10-17 ≤ kh < 1 × 10-16 m2 and 5 × 10-16 ≤ kv < 1 × 10-15 m2. The anticlinal trap serves as an essential fluid source for eruption at Crystal Geyser. Geyser-like discharge sensitively responds to varying well permeability, radius, and CO2 recharge rate. The cyclic behavior of wellbore CO2 leakage decreases with time.

  10. Effects of fault-controlled CO2 alteration on mineralogical and geomechanical properties of reservoir and seal rocks, Crystal Geyser, Green River, Utah

    NASA Astrophysics Data System (ADS)

    Major, J. R.; Eichhubl, P.; Urquhart, A.; Dewers, T. A.

    2012-12-01

    An understanding of the coupled chemical and mechanical properties of reservoir and seal units undergoing CO2 injection is critical for modeling reservoir behavior in response to the introduction of CO2. The implementation of CO2 sequestration as a mitigation strategy for climate change requires extensive risk assessment that relies heavily on computer models of subsurface reservoirs. Numerical models are fundamentally limited by the quality and validity of their input parameters. Existing models generally lack constraints on diagenesis, failing to account for the coupled geochemical or geomechanical processes that affect reservoir and seal unit properties during and after CO2 injection. For example, carbonate dissolution or precipitation after injection of CO2 into subsurface brines may significantly alter the geomechanical properties of reservoir and seal units and thus lead to solution-enhancement or self-sealing of fractures. Acidified brines may erode and breach sealing units. In addition, subcritical fracture growth enhanced by the presence of CO2 could ultimately compromise the integrity of sealing units, or enhance permeability and porosity of the reservoir itself. Such unknown responses to the introduction of CO2 can be addressed by laboratory and field-based observations and measurements. Studies of natural analogs like Crystal Geyser, Utah are thus a critical part of CO2 sequestration research. The Little Grand Wash and Salt Wash fault systems near Green River, Utah, host many fossil and active CO2 seeps, including Crystal Geyser, serving as a faulted anticline CO2 reservoir analog. The site has been extensively studied for sequestration and reservoir applications, but less attention has been paid to the diagenetic and geomechanical aspects of the fault zone. XRD analysis of reservoir and sealing rocks collected along transects across the Little Grand Wash Fault reveal mineralogical trends in the Summerville Fm (a siltstone seal unit) with calcite and

  11. Spatial and temporal variability of biomarkers and microbial diversity reveal metabolic and community flexibility in Streamer Biofilm Communities in the Lower Geyser Basin, Yellowstone National Park.

    PubMed

    Schubotz, F; Meyer-Dombard, D R; Bradley, A S; Fredricks, H F; Hinrichs, K-U; Shock, E L; Summons, R E

    2013-11-01

    Detailed analysis of 16S rRNA and intact polar lipids (IPLs) from streamer biofilm communities (SBCs), collected from geochemically similar hot springs in the Lower Geyser Basin, Yellowstone National Park, shows good agreement and affirm that IPLs can be used as reliable markers for the microbial constituents of SBCs. Uncultured Crenarchaea are prominent in SBS, and their IPLs contain both glycosidic and mixed glyco-phospho head groups with tetraether cores, having 0-4 rings. Archaeal IPL contributions increase with increasing temperature and comprise up to one-fourth of the total IPL inventory at >84 °C. At elevated temperatures, bacterial IPLs contain abundant glycosidic glycerol diether lipids. Diether and diacylglycerol (DAG) lipids with aminopentanetetrol and phosphatidylinositol head groups were identified as lipids diagnostic of Aquificales, while DAG glycolipids and glyco-phospholipids containing N-acetylgycosamine as head group were assigned to members of the Thermales. With decreasing temperature and concomitant changes in water chemistry, IPLs typical of phototrophic bacteria, such as mono-, diglycosyl, and sulfoquinovosyl DAG, which are specific for cyanobacteria, increase in abundance, consistent with genomic data from the same samples. Compound-specific stable carbon isotope analysis of IPL breakdown products reveals a large isotopic diversity among SBCs in different hot springs. At two of the hot springs, 'Bison Pool' and Flat Cone, lipids derived from Aquificales are enriched in (13) C relative to biomass and approach values close to dissolved inorganic carbon (DIC) (approximately 0‰), consistent with fractionation during autotrophic carbon fixation via the reversed tricarboxylic acid pathway. At a third site, Octopus Spring, the same Aquificales-diagnostic lipids are 10‰ depleted relative to biomass and resemble stable carbon isotope values of dissolved organic carbon (DOC), indicative of heterotrophy. Other bacterial and archaeal lipids show

  12. Spatial and temporal variability of biomarkers and microbial diversity reveal metabolic and community flexibility in Streamer Biofilm Communities in the Lower Geyser Basin, Yellowstone National Park.

    PubMed

    Schubotz, F; Meyer-Dombard, D R; Bradley, A S; Fredricks, H F; Hinrichs, K-U; Shock, E L; Summons, R E

    2013-11-01

    Detailed analysis of 16S rRNA and intact polar lipids (IPLs) from streamer biofilm communities (SBCs), collected from geochemically similar hot springs in the Lower Geyser Basin, Yellowstone National Park, shows good agreement and affirm that IPLs can be used as reliable markers for the microbial constituents of SBCs. Uncultured Crenarchaea are prominent in SBS, and their IPLs contain both glycosidic and mixed glyco-phospho head groups with tetraether cores, having 0-4 rings. Archaeal IPL contributions increase with increasing temperature and comprise up to one-fourth of the total IPL inventory at >84 °C. At elevated temperatures, bacterial IPLs contain abundant glycosidic glycerol diether lipids. Diether and diacylglycerol (DAG) lipids with aminopentanetetrol and phosphatidylinositol head groups were identified as lipids diagnostic of Aquificales, while DAG glycolipids and glyco-phospholipids containing N-acetylgycosamine as head group were assigned to members of the Thermales. With decreasing temperature and concomitant changes in water chemistry, IPLs typical of phototrophic bacteria, such as mono-, diglycosyl, and sulfoquinovosyl DAG, which are specific for cyanobacteria, increase in abundance, consistent with genomic data from the same samples. Compound-specific stable carbon isotope analysis of IPL breakdown products reveals a large isotopic diversity among SBCs in different hot springs. At two of the hot springs, 'Bison Pool' and Flat Cone, lipids derived from Aquificales are enriched in (13) C relative to biomass and approach values close to dissolved inorganic carbon (DIC) (approximately 0‰), consistent with fractionation during autotrophic carbon fixation via the reversed tricarboxylic acid pathway. At a third site, Octopus Spring, the same Aquificales-diagnostic lipids are 10‰ depleted relative to biomass and resemble stable carbon isotope values of dissolved organic carbon (DOC), indicative of heterotrophy. Other bacterial and archaeal lipids show

  13. Mine-Mouth Geyser Problem.

    ERIC Educational Resources Information Center

    de Nevers, Noel

    1982-01-01

    An oilwell drilling rig accidentally drilled into an underground salt mine, draining a lake and filling the mine, with water jetting out of the mine 400 feet into the air. An explanation of the jetting phenomenon is offered in terms of the laws of fluid dynamics, with supporting diagrams and calculations. (Author/JN)

  14. Heat flow and hot dry rock geothermal resources of the Clearlake Region, northern California

    SciTech Connect

    Burns, K.L.

    1996-08-01

    The Geysers-Clear Lake geothermal anomaly is an area of high heat flow in northern California. The anomaly is caused by abnormally high heat flows generated by asthenospheric uplift and basaltic magmatic underplating at a slabless window created by passage of the Mendocino Triple Junction. The Clear Lake volcanic field is underlain by magmatic igneous bodies in the form of a stack of sill-form intrusions with silicic bodies generally at the top and basic magmas at the bottom. The tabular shape and wide areal extent of the heat sources results in linear temperature gradients and near-horizontal isotherms in a broad region at the center of the geothermal anomaly. The Hot Dry Rock (HDR) portion of The Geysers-Clear Lake geothermal field is that part of the geothermal anomaly that is external to the steamfield, bounded by geothermal gradients of 167 mW/m2 (4 heat flow units-hfu) and 335 mW/m2 (8 hfu). The HDR resources, to a depth of 5 km, were estimated by piece-wise linear summation based on a sketch map of the heat flow. Approximately, the geothermal {open_quotes}accessible resource base{close_quotes} (Qa) is 1.68E+21 J; the {open_quotes}HDR resource base{close_quotes} (Qha) is 1.39E+21 J; and the {open_quotes}HDR power production resource{close_quotes} (Qhp) is 1.01E+21 J. The HDR power production resource (Qhp) is equivalent to 2.78E+ 11 Mwht (megawatt hours thermal), or 1.72E+11 bbls of oil.

  15. Modeling of local steam condensation on walls in presence of non-condensable gases. Application to a loca calculation in reactor containment using the multidimensional geyser/tonus code

    SciTech Connect

    Benet, L.V.; Caroli, C.; Cornet, P.

    1995-09-01

    This paper reports part of a study of possible severe pressurized water reactor (PWR) accidents. The need for containment modeling, and in particular for a hydrogen risk study, was reinforced in France after 1990, with the requirement that severe accidents must be taken into account in the design of future plants. This new need of assessing the transient local hydrogen concentration led to the development, in the Mechanical Engineering and Technology Department of the French Atomic Energy Commission (CEA/DMT), of the multidimensional code GEYSER/TONUS for containment analysis. A detailed example of the use of this code is presented. The mixture consisted of noncondensable gases (air or air plus hydrogen) and water vapor and liquid water. This is described by a compressible homogeneous two-phase flow model and wall condensation is based on the Chilton-Colburn formula and the analogy between heat and mass transfer. Results are given for a transient two-dimensional axially-symmetric computation for the first hour of a simplified accident sequence. In this there was an initial injection of a large amount of water vapor followed by a smaller amount and by hydrogen injection.

  16. Regional three-dimensional seismic velocity model of the crust and uppermost mantle of northern California

    USGS Publications Warehouse

    Thurber, C.; Zhang, H.; Brocher, T.; Langenheim, V.

    2009-01-01

    We present a three-dimensional (3D) tomographic model of the P wave velocity (Vp) structure of northern California. We employed a regional-scale double-difference tomography algorithm that incorporates a finite-difference travel time calculator and spatial smoothing constraints. Arrival times from earthquakes and travel times from controlled-source explosions, recorded at network and/or temporary stations, were inverted for Vp on a 3D grid with horizontal node spacing of 10 to 20 km and vertical node spacing of 3 to 8 km. Our model provides an unprecedented, comprehensive view of the regional-scale structure of northern California, putting many previously identified features into a broader regional context and improving the resolution of a number of them and revealing a number of new features, especially in the middle and lower crust, that have never before been reported. Examples of the former include the complex subducting Gorda slab, a steep, deeply penetrating fault beneath the Sacramento River Delta, crustal low-velocity zones beneath Geysers-Clear Lake and Long Valley, and the high-velocity ophiolite body underlying the Great Valley. Examples of the latter include mid-crustal low-velocity zones beneath Mount Shasta and north of Lake Tahoe. Copyright 2009 by the American Geophysical Union.

  17. Regional three-dimensional seismic velocity model of the crust and uppermost mantle of northern California

    NASA Astrophysics Data System (ADS)

    Thurber, Clifford; Zhang, Haijiang; Brocher, Thomas; Langenheim, Victoria

    2009-01-01

    We present a three-dimensional (3D) tomographic model of the P wave velocity (Vp) structure of northern California. We employed a regional-scale double-difference tomography algorithm that incorporates a finite-difference travel time calculator and spatial smoothing constraints. Arrival times from earthquakes and travel times from controlled-source explosions, recorded at network and/or temporary stations, were inverted for Vp on a 3D grid with horizontal node spacing of 10 to 20 km and vertical node spacing of 3 to 8 km. Our model provides an unprecedented, comprehensive view of the regional-scale structure of northern California, putting many previously identified features into a broader regional context and improving the resolution of a number of them and revealing a number of new features, especially in the middle and lower crust, that have never before been reported. Examples of the former include the complex subducting Gorda slab, a steep, deeply penetrating fault beneath the Sacramento River Delta, crustal low-velocity zones beneath Geysers-Clear Lake and Long Valley, and the high-velocity ophiolite body underlying the Great Valley. Examples of the latter include mid-crustal low-velocity zones beneath Mount Shasta and north of Lake Tahoe.

  18. Regional odontodysplasia.

    PubMed

    Mehta, D N; Bailoor, D; Patel, B

    2011-01-01

    Regional odontodysplasia is an unusual developmental anomaly in which ectodermal and mesodermal tooth components are affected. We present a rare case of a developmental anomaly called regional odontodysplasia or 'ghost teeth' in a 12-year-old Indian girl. The anomaly affected right maxillary permanent teeth. The mandibular teeth were unaffected. The clinical, radiographic and histological features are reviewed. The management of affected patients is discussed.

  19. Regional Mapping and Spectral Analysis of Mounds in Acidalia Planitia, Mars

    NASA Technical Reports Server (NTRS)

    Amador, E. S.; Allen, Carlton; Oehler, D. Z.

    2010-01-01

    Acidalia Planitia is a approx.3000 km diameter planum located in the northern plains of Mars. It is believed to be a sedimentary basin containing an accumulation of sediments brought by Hesperian outflow channels that drained the Highlands. A large number of high-albedo mounds have been identified across this basin [1-2] and understanding the process that formed them should help us understand the history of this region. Farrand et al. [2] showed that the mounds are dark in THEMIS (Thermal Emission Imaging System) nighttime IR (infrared) image data. This implies that the mounds have a lower thermal inertia than the surrounding plains (Fig. 1), suggesting that the material of the mounds is fine-grained or unconsolidated. Farrand et al. [2] also reviewed potential analogs for the mounds and concluded that a combination of mud volcanoes with evaporites around geysers or springs is most consistent with all the data. We have built on this work by creating regional maps of the features and analyzing CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) data to see if there are mineralogical differences between the mounds and surrounding plains.

  20. The role of extremophile in the redox reaction of Fe and As relating with the formation of secondary phase mineral in extreme environment, Norris Geyser Basin, Yellowstone National Park, USA

    NASA Astrophysics Data System (ADS)

    Koo, T. H.; Kim, J. Y.; Park, K. R.; Jung, D. H.; Geesey, G. G.; Kim, J. W.

    2015-12-01

    Redox reaction associated with microbial elemental respiration is a ubiquitous process in sediments and suspended particles at various temperatures or pH/Eh conditions. Particularly, changes in elemental redox states (structural or dissolved elemental form) induced by microbial respiration result in the unexpected biogeochemical reactions in the light of biotic/abiotic mineralization. The objective of the present study is, therefore to investigate the secondary phase mineralization through a-/biogeochemical Fe and As redox cycling in the acido-hyperhtermal Norris Geyser Basin (NGB) in Yellowstone National Park, USA, typical of the extreme condition. X-ray diffraction, scanning electron microscope with energy dispersive x-ray spectroscopy, X-ray absorption near edge structure, inductively coupled plasma-atomic emission spectrometer and liquid chromatography with ICP-mass spectroscopy with filtrated supernatant were performed for the mineralogical and hydro-geochemical analysis. The clay slurry collected from the active hot-spring of the NGB area (pH=3.5 and Temperature=78 ℃) was incubated with ("enrichment") or without the growth medium ("natural"). The control was prepared in the same condition except adding the glutaraldehyde to eliminate the microbial activity. The secondary phase mineral formation of the oxidative phase of Fe and As, and K identified as 'Pharmacosiderite' only appeared in the enrichment set suggesting a role of extremophiles in the mineral formation. The considerable population of Fe-oxidizer (Metallosphera yellowstonensis MK-1) and As-oxidizer (Sulfurihydrogenibium sp.) was measured by phylogenetic analysis in the present study area. The inhibition of As-oxidation in the low pH conditions was reported in the previous study, however the As-redox reaction was observed and consequently, precipitated the Pharmacosiderite only in the enrichment set suggesting a biotic mineralization. The present study collectively suggests that the microbial

  1. Geothermal policy development program analysis of county general plans, specific plans and zoning

    SciTech Connect

    Not Available

    1981-07-01

    This study evaluates the local geothermal permitting practices of the four Geysers-Calistoga KGRA counties (i.e. Lake, Mendocino, Napa and Sonoma), in California, and the ways in which these processes could be expedited. The detailed analysis of local permitting processes undertaken in the course of this project revealed great variation in procedural approach, types of conditions imposed, phrasing of conditions and length of time it takes to process use permits; and these variations are described in the report. The analysis also revealed a number of interesting techniques employed by one or the other of the counties, or by Imperial County, to improve the process. These techniques are also described. Finally, four alternative approaches to expediting the local geothermal permitting process are identified.

  2. Returning "Region" to World Regional Geography

    ERIC Educational Resources Information Center

    Rees, Peter W.; Legates, Margaret

    2013-01-01

    World regional geography textbooks rarely focus on the process of region formation, despite frequent calls to reincorporate a regional approach to teaching global geography. An instructional strategy using problem-based learning in a small honors section of a large world regional geography course is described. Using a hypothetical scenario…

  3. Ionospheric research. [E region, F region, D region

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Progress is reported in the following areas: D-region theory; E and F-region; wave propagation; mass spectrometer measurements; and atmospheric reactions. Various supporting operations are included: design and construction of instrumentation; and programming.

  4. Ephemeral regions versus pseudo ephemeral regions

    NASA Technical Reports Server (NTRS)

    Martin, S. F.; Livi, S. H. B.; Wang, J.; Shi, Z.

    1985-01-01

    New studies of the quiet Sun reveal that ephemeral active regions constitute minority rather than a majority of all the short lived, small scale bipolar features on the Sun. In contrast to the recognized patterns of growth and decay of ephemeral regions, various examples of the creation of other temporary bipoles nicknamed pseudo ephemeral regions are illustrated. The pseudo ephemeral regions are the consequence of combinations of small scale dynamic processes of the quiet Sun including: (1) fragmentation of network magnetic fields, (2) the separation of opposite polarity halves of ephemeral regions as they grow and evolve, and (3) the coalescence of weak network or intranetwork magnetic fields. New observations offer the possibility of resolving the discrepancies that have arisen in the association of ephemeral regions with X-ray bright points. Many X-ray bright points may be related to those pseudo ephemeral regions which have begun to exhibit magnetic flux loss.

  5. Regional Sustainable Environmental Management

    EPA Science Inventory

    Regional sustainable environmental management is an interdisciplinary effort to develop a sufficient understanding of the interactions between ecosystems, the economy, law, and technology to formulate effective long-term management strategies on a regional scale. Regional sustai...

  6. A History of Old Tiger Stripe Fracture Sets in the South-Polar Region of Enceladus

    NASA Astrophysics Data System (ADS)

    Kattenhorn, Simon A.; Patthoff, D. A.

    2009-09-01

    The tiger stripe cracks in the south-polar region of Enceladus are the source of the geyser-like eruptions imaged by the Cassini spacecraft. Although past work has mainly focused on these active cracks, which have fairly consistent orientations, the south-polar terrain (SPT) has been pervasively fractured during a complex tectonic history. Our detailed mapping has revealed three additional relict fracture sets having tiger stripe-like characteristics, but with different orientations. Using crosscutting relationships, relative ages were established for the four systematic fracture sets, which show a counterclockwise progression in orientation through time. They imply the causal SPT stress field created distinct fracture sets at different points in time, gradually rotating 153° counterclockwise relative to the present day surface, culminating in the stress field that produced the tiger stripes. Older fracture sets influenced the development of younger sets. For example, the tiger stripe Alexandria Sulcus inherited a portion of an older set along part of its length, creating a dogleg shape. Intersections between different fracture sets also appear to correlate with eruptive plume locations, suggesting a structural control on sites of eruptions. The systematic nature of the fracture sets, combined with the temporal change in orientations, is compatible with the process of nonsynchronous rotation (NSR) being the primary cause of fracturing, as has been proposed for curvilinear fractures on Europa. If this is the case, it may hint at the presence of a global liquid ocean on Enceladus that decouples a mobile ice shell from the silicate interior. A global ocean has been previously conjectured; however, the SPT fracture history may provide indirect evidence. Although NSR may account for a temporal rotation of the stress field, the localization of activity in the SPT nonetheless points to other factors at work, such as a thermal plume in the ice beneath the south pole.

  7. The question of recharge to the deep thermal reservoir underlying the geysers and hot springs of Yellowstone National Park: Chapter H in Integrated geoscience studies in Integrated geoscience studies in the Greater Yellowstone Area—Volcanic, tectonic, and hydrothermal processes in the Yellowstone geoecosystem

    USGS Publications Warehouse

    Rye, Robert O.; Truesdell, Alfred Hemingway; Morgan, Lisa A.

    2007-01-01

    The extraordinary number, size, and unspoiled beauty of the geysers and hot springs of Yellowstone National Park (the Park) make them a national treasure. The hydrology of these special features and their relation to cold waters of the Yellowstone area are poorly known. In the absence of deep drill holes, such information is available only indirectly from isotope studies. The δD-δ18O values of precipitation and cold surface-water and ground-water samples are close to the global meteoric water line (Craig, 1961). δD values of monthly samples of rain and snow collected from 1978 to 1981 at two stations in the Park show strong seasonal variations, with average values for winter months close to those for cold waters near the collection sites. δD values of more than 300 samples from cold springs, cold streams, and rivers collected during the fall from 1967 to 1992 show consistent north-south and east-west patterns throughout and outside of the Park, although values at a given site vary by as much as 8 ‰ from year to year. These data, along with hot-spring data (Truesdell and others, 1977; Pearson and Truesdell, 1978), show that ascending Yellowstone thermal waters are modified isotopically and chemically by a variety of boiling and mixing processes in shallow reservoirs. Near geyser basins, shallow recharge waters from nearby rhyolite plateaus dilute the ascending deep thermal waters, particularly at basin margins, and mix and boil in reservoirs that commonly are interconnected. Deep recharge appears to derive from a major deep thermal-reservoir fluid that supplies steam and hot water to all geyser basins on the west side of the Park and perhaps in the entire Yellowstone caldera. This water (T ≥350°C; δD = –149±1 ‰) is isotopically lighter than all but the farthest north, highest altitude cold springs and streams and a sinter-producing warm spring (δD = –153 ‰) north of the Park. Derivation of this deep fluid solely from present-day recharge is

  8. The question of recharge to the deep thermal reservoir underlying the geysers and hot springs of Yellowstone National Park: Chapter H in Integrated geoscience studies in Integrated geoscience studies in the Greater Yellowstone Area—Volcanic, tectonic, and hydrothermal processes in the Yellowstone geoecosystem

    USGS Publications Warehouse

    Rye, Robert O.; Truesdell, Alfred Hemingway

    2007-01-01

    The extraordinary number, size, and unspoiled beauty of the geysers and hot springs of Yellowstone National Park (the Park) make them a national treasure. The hydrology of these special features and their relation to cold waters of the Yellowstone area are poorly known. In the absence of deep drill holes, such information is available only indirectly from isotope studies. The δD-δ18O values of precipitation and cold surface-water and ground-water samples are close to the global meteoric water line (Craig, 1961). δD values of monthly samples of rain and snow collected from 1978 to 1981 at two stations in the Park show strong seasonal variations, with average values for winter months close to those for cold waters near the collection sites. δD values of more than 300 samples from cold springs, cold streams, and rivers collected during the fall from 1967 to 1992 show consistent north-south and east-west patterns throughout and outside of the Park, although values at a given site vary by as much as 8 ‰ from year to year. These data, along with hot-spring data (Truesdell and others, 1977; Pearson and Truesdell, 1978), show that ascending Yellowstone thermal waters are modified isotopically and chemically by a variety of boiling and mixing processes in shallow reservoirs. Near geyser basins, shallow recharge waters from nearby rhyolite plateaus dilute the ascending deep thermal waters, particularly at basin margins, and mix and boil in reservoirs that commonly are interconnected. Deep recharge appears to derive from a major deep thermal-reservoir fluid that supplies steam and hot water to all geyser basins on the west side of the Park and perhaps in the entire Yellowstone caldera. This water (T ≥350°C; δD = –149±1 ‰) is isotopically lighter than all but the farthest north, highest altitude cold springs and streams and a sinter-producing warm spring (δD = –153 ‰) north of the Park. Derivation of this deep fluid solely from present-day recharge is

  9. Utah: Salt Lake Region

    Atmospheric Science Data Center

    2014-05-15

    article title:  Winter and Summer Views of the Salt Lake Region     View Larger Image Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the ...

  10. [Regional aging in Germany].

    PubMed

    Bucher, H

    1996-01-01

    Elderly people in Germany have a specific regional distribution. Recent regional population projections show that these patterns will change. The most dynamic process of aging will take place in the suburban parts of the large western Germany agglomerations, whereas in eastern Germany aging concentrates in regions with a lower density. There will be a regional deconcentration of elderly people with consequences for the planning of infrastructure.

  11. Learning Regions in Germany

    ERIC Educational Resources Information Center

    Thinesse-Demel, Jutta

    2010-01-01

    In 2000, the German Federal Ministry of Education and Research (BMBF) launched the programme "Learning Regions--Providing Support for Networks'" in cooperation with the Lander. It was co-financed by the European Social Fund (ESF). Some 90 regions were selected and financially supported. After one year, 71 regions continued to build-up their…

  12. Regional flood frequency analysis

    SciTech Connect

    Singh, V.P.

    1987-01-01

    This book, the fourth of a four volume set, contains five sections encompassing major aspects of regional flood frequency analysis. Each section starts usually with an invited state-of-the-art paper followed by contributed papers. The first section provides an assessment of regional flood frequency analysis. Methods for performing regional frequency analysis for ungaged watersheds are presented in Section 2. More discussion on regional frequency analysis is provided in Section 3. Selection and comparison of regional frequency methods are dealt with in Section 4; these are of great interest to the user. Increasing attention is being focused these days on paleohydrologic flood analysis. This topic is covered in Section 5.

  13. Reversed-polarity regions

    NASA Technical Reports Server (NTRS)

    Tang, F.

    1982-01-01

    It is found by a statistical study of 58 reversed-polarity regions (RPRs) covering the 11-year period 1969-1979 that RPRs (1) have a lifespan comparable to normal active regions, (2) do not show a tendency to rotate toward a more normal alignment, and (3) have stable configurations that do not suggest stress due to their anomalous magnetic alignment. As in normal regions, RPR magnetic complexity is found to be the primary factor in flare productivity. Weak-field RPRs produce no flares, and regions with complex spots produce more flares than regions with non-complex spots by a factor of five. The main difference between RPRs and normal regions lies in complex spot frequency, with less that 17% of normal active regions having such spots and fewer than 1.8% having long-lived complex ones, while 41% of RPRs have complex spots and 24% have long-lived complex spots.

  14. The crisis of regionalization.

    PubMed

    Marchildon, Gregory P

    2015-11-01

    Currently in Canada, there is no consensus concerning the efficacy of regionalization, a reversal of the strong commitment in favour only a decade earlier. Instead, provincial governments are either dismantling regional health authorities in favour of highly centralized structures under the control of ministries of health or actively considering more centralized approaches. There is a general feeling among political leaders that regionalization has failed to achieve its original objectives. However, by not including physicians and primary care within regionalized governance, provincial governments have never given regionalization a real chance. Moreover, given the fact that the status quo prior to regionalization was far from an ideal state and would be almost impossible to return to in any event, some provincial governments should consider implementing a more full-blooded version of regionalization before abandoning the approach.

  15. A comprehensive study of fracture patterns and densities in the Geysers geothermal reservoir using microearthquake shear-wave splitting tomography [Quarterly progress report 06/16/1998 - 09/15/1998

    SciTech Connect

    Malin, P.E.; Shalev, E.

    1999-03-26

    We completed the process of locating events and identifying shear-wave splitting in the mammoth area. A total of 2250 split shear wave observations were recorded in the four month period that our network was in place. Fast polarization direction map in Figure 1 shows that most of the stations in the mammoth area display consistent direction throughout the main field, between 300{degree} azimuth to 0{degree} azimuth. Some exemptions to the consistent crack alignment (fast polarization direction) can be seen in station M19, and some stations display inconsistent trend as can be observed in stations M25, M18, and M07. It is possible that station M19 was misaligned during installment. Figure 2 shows the cumulative rose diagram for all observations with a clear preferred direction. Figure 3 also shows that most of the observations of fast split shear wave are in the same direction and that those observation are distributed throughout the target area. If we treat measurements of polarization direction as a statistical process, same as deep of layer measurement, we can say that in the small area of the station we have aligned cracks. Figures 4 and 5 show results of the crack density inversion assuming regional crack azimuth of 340{degree}. Almost 2000 raypaths were used to perform this tomographic inversion. There is weak dependency of the results on the regional crack direction, but the main areas of high and low crack density are the same. The changes are mainly in the size of the anomalies. Since the amplitudes of those anomalies depend mainly on the damping parameter we use in the inversion, exact regional crack direction is not a critical parameter of the inversion. The map in figure 4 and cross-sections in Figure 5 show two areas of high crack density: one northeast of the Casa Diablo area at depth of 1 to 3 km, and one near the Mammoth airport and station 9 at depth of 2 to 3 km.

  16. REGIONAL EMAP PROPOSALS

    EPA Science Inventory

    The US EPA's Environmental Assessment and Monitoring Program (EMAP) annually funds regional EMAP (REMAP) projects through each of the regions to support the improvement of monitoring activities by the states. The last call for proposals emphasized the need to support biological m...

  17. New Lessons in Regionalism.

    ERIC Educational Resources Information Center

    Peirce, Neal R.

    1998-01-01

    From the hierarchical, governmental, industrial, military model of the 20th century, society is moving rapidly toward a globalized, interactive market. This new order is tailor-made for regional development but also challenges regions to think and act strategically in a world of weakened central governments and growing international currency…

  18. Ad Hoc Rural Regionalism

    ERIC Educational Resources Information Center

    Hamin, Elisabeth M.; Marcucci, Daniel J.

    2008-01-01

    A new regionalism has been much documented and researched for metropolitan areas; this article documents that there is a new rural regionalism as well. In the United States, these groups appear most likely to emerge in areas that are challenged by outcomes characterizing globalization's effects on the rural condition: namely, exurban or…

  19. Regional anesthesia for laparoscopy.

    PubMed

    Collins, L M; Vaghadia, H

    2001-03-01

    A variety of laparoscopic procedures can be performed on patients under regional anesthesia. Diagnostic laparoscopy in elective and emergency patients, pain mapping, laparoscopy for infertility, and tubal sterilization are some examples. The key benefits of regional anesthesia include less emesis, less postoperative pain, shorter postoperative stay, improved patient satisfaction, and overall safety. Regional techniques, such as rectus sheath blocks, inguinal blocks, and caudal blocks, are useful adjuncts to general anesthesia and facilitate postoperative analgesia. Other techniques, such as spinal and epidural anesthesia, and combination of the two, are suitable as a sole anesthetic technique for laparoscopy. The physiologic changes during laparoscopy in the awake patient appear to be tolerated well under regional anesthesia. It is reasonable to assume that with advances in instrumentation and surgical techniques, the role of laparoscopy will increase in the future. The benefits conferred by regional anesthesia make it an attractive option to general anesthesia for many patients and procedures. Successful implementation of regional anesthesia is an important determinant of how anesthesiologists, surgeons, and surgical facilities cope with new challenges. In the future, it could be possible to provide "walk-in/walk-out" regional anesthesia with a real possibility of fast tracking patients through the recovery process after ambulatory surgery. For maximal patient safety, however, facilities offering regional anesthesia must have appropriately trained anesthesia personnel and the equipment necessary for monitoring and providing full resuscitation in the event of complications or a need to convert to general anesthesia. PMID:11244919

  20. South Persian Gulf Region

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This oblique view of the south Persian Gulf region (26.0N, 54.0E) was taken over Iran looking west across the south Persian Gulf into the Trucial Coast of the United Arab Emirates and the prominent Qatar peninsula. Rich in petroleum resources, this region supplies much of the world's oil needs from its many ports and off shore loading facilities.

  1. Reversed-polarity regions

    NASA Technical Reports Server (NTRS)

    Tang, F.

    1980-01-01

    The 58 RPRS studied have a lifespan comparable to normal active regions and have no tendency to rotate toward a more normal alignment. They seem to have stable configurations with no apparent evidence suggesting stress due to their anomalous magnetic alignment. Magnetic complexity in RPRs is the key to flare productivity just as it is in normal regions - weak field RPRs produced no flares and regions with complex spots produced more flares than regions with noncomplex spots by a factor of 5. The RPRs however, differ from normal regions in the frequency of having complex spots, particularly the long lived complex spots, in them. Less than 17 percent of normal ARs have complex spots; less than 1.8 percent have long lived complex spots. In contrast, 41 percent of RPRs have complex spots and 24 percent have long lived complex spots.

  2. Modeling the transition region

    NASA Technical Reports Server (NTRS)

    Singer, Bart A.

    1993-01-01

    The current status of transition-region models is reviewed in this report. To understand modeling problems, various flow features that influence the transition process are discussed first. Then an overview of the different approaches to transition-region modeling is given. This is followed by a detailed discussion of turbulence models and the specific modifications that are needed to predict flows undergoing laminar-turbulent transition. Methods for determining the usefulness of the models are presented, and an outlook for the future of transition-region modeling is suggested.

  3. Regional ocean data assimilation.

    PubMed

    Edwards, Christopher A; Moore, Andrew M; Hoteit, Ibrahim; Cornuelle, Bruce D

    2015-01-01

    This article reviews the past 15 years of developments in regional ocean data assimilation. A variety of scientific, management, and safety-related objectives motivate marine scientists to characterize many ocean environments, including coastal regions. As in weather prediction, the accurate representation of physical, chemical, and/or biological properties in the ocean is challenging. Models and observations alone provide imperfect representations of the ocean state, but together they can offer improved estimates. Variational and sequential methods are among the most widely used in regional ocean systems, and there have been exciting recent advances in ensemble and four-dimensional variational approaches. These techniques are increasingly being tested and adapted for biogeochemical applications.

  4. Complex Regional Pain Syndrome

    MedlinePlus

    Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. ... in skin temperature, color, or texture Intense burning pain Extreme skin sensitivity Swelling and stiffness in affected ...

  5. Mercury's South Polar Region

    NASA Video Gallery

    This animation shows 89 wide-angle camera (WAC) images of Mercury’s south polar region acquired by the Mercury Dual Imaging System (MDIS) over one complete Mercury solar day (176 Earth days). Thi...

  6. Regional Instrumentation Centers.

    ERIC Educational Resources Information Center

    Cromie, William J.

    1980-01-01

    Focuses on the activities of regional instrumentation centers that utilize the state-of-the-art instruments and methodology in basic scientific research. The emphasis is on the centers involved in mass spectroscopy, magnetic resonance spectroscopy, lasers, and accelerators. (SA)

  7. On regional geomagnetic charts

    USGS Publications Warehouse

    Alldredge, L.R.

    1987-01-01

    When regional geomagnetic charts for areas roughly the size of the US were compiled by hand, some large local anomalies were displayed in the isomagnetic lines. Since the late 1960s, when the compilation of charts using computers and mathematical models was started, most of the details available in the hand drawn regional charts have been lost. One exception to this is the Canadian magnetic declination chart for 1980. This chart was constructed using a 180 degrees spherical harmonic model. -from Author

  8. Northeast Regional Biomass Program

    SciTech Connect

    Lusk, P.D.

    1992-12-01

    The Northeast Regional Biomass Program has been in operation for a period of nine years. During this time, state managed programs and technical programs have been conducted covering a wide range of activities primarily aim at the use and applications of wood as a fuel. These activities include: assessments of available biomass resources; surveys to determine what industries, businesses, institutions, and utility companies use wood and wood waste for fuel; and workshops, seminars, and demonstrations to provide technical assistance. In the Northeast, an estimated 6.2 million tons of wood are used in the commercial and industrial sector, where 12.5 million cords are used for residential heating annually. Of this useage, 1504.7 mw of power has been generated from biomass. The use of wood energy products has had substantial employment and income benefits in the region. Although wood and woodwaste have received primary emphasis in the regional program, the use of municipal solid waste has received increased emphasis as an energy source. The energy contribution of biomass will increase as potentia users become more familiar with existing feedstocks, technologies, and applications. The Northeast Regional Biomass Program is designed to support region-specific to overcome near-term barriers to biomass energy use.

  9. LAMPF transition region

    SciTech Connect

    Sander, O.R.

    1982-06-01

    After describing the transition region between the LAMPF drift-tube linac and side-coupled linac, we discuss the function of the region, its present shortcomings, and the need for a redesign. Then we present the new design, its advantages, and its expected performance. Included are detailed results of beam-dynamics studies giving the ranges of input- and output-beam shapes that can be successfully matched in the new transition region. To improve the present operation of the two linacs, we suggest small changes that will allow us to easily match the beam between the two linacs. Finally we describe the methods used in our beam-dynamic studies so that effects of future improvements to the new design can be examined.

  10. Turbulence in HII regions

    NASA Astrophysics Data System (ADS)

    O'dell, C. R.

    1986-10-01

    It has been known for many decades that the Reynolds number in HII regions must be very high and that the corresponding fine scale flow must be turbulent. Even though the theoretical relation between turbulent element separation and random velocity was derived by Kolmogoroff over forty years ago, there have been only a few attempts to test this theory and its corresponding assumptions. An attempt by Munch for M42 with marginal velocity resolution lead to ambiguous results, although more recent studies by Jean Rene Roy and his colleagues have been more credible. The internal velocities of a number of HII regions were systematically studied and the theory was tested with considerable certainty. The results should be important for the determination of the energy balance of HII regions and the relation of small scale motion to the process of star formation.

  11. Northeast Regional Biomass Program

    SciTech Connect

    O'Connell, R.A.

    1991-11-01

    The management structure and program objectives for the Northeast Regional Biomass Program (NRBP) remain unchanged from previous years. Additional funding was provided by the Bonneville Power Administration Regional Biomass Program to continue the publication of articles in the Biologue. The Western Area Power Administration and the Council of Great Lakes Governors funded the project Characterization of Emissions from Burning Woodwaste''. A grant for the ninth year was received from DOE. The Northeast Regional Biomass Steering Committee selected the following four projects for funding for the next fiscal year. (1) Wood Waste Utilization Conference, (2) Performance Evaluation of Wood Systems in Commercial Facilities, (3) Wood Energy Market Utilization Training, (4) Update of the Facility Directory.

  12. NV PFA Regional Data

    SciTech Connect

    James Faulds

    2015-10-28

    This project focused on defining geothermal play fairways and development of a detailed geothermal potential map of a large transect across the Great Basin region (96,000 km2), with the primary objective of facilitating discovery of commercial-grade, blind geothermal fields (i.e. systems with no surface hot springs or fumaroles) and thereby accelerating geothermal development in this promising region. Data included in this submission consists of: structural settings (target areas, recency of faulting, slip and dilation potential, slip rates, quality), regional-scale strain rates, earthquake density and magnitude, gravity data, temperature at 3 km depth, permeability models, favorability models, degree of exploration and exploration opportunities, data from springs and wells, transmission lines and wilderness areas, and published maps and theses for the Nevada Play Fairway area.

  13. ORIC central region calculations

    SciTech Connect

    Bailey, J.D.; Dowling, D.T.; Lane, S.N.; Mosko, S.W.; Olsen, D.K.; Tatum, B.A.

    1995-12-31

    The central region for the K = 100 Oak Ridge Isochronous Cyclotron, ORIC, will be modified to provide better orbit centering, focusing of orbits in the axial direction, and phase selection, in order to improve extraction efficiency, and reduce radioactive activation of cyclotron components. The central region is specifically designed for the acceleration of intense light ion beams such as 60 MeV protons and 15--100 MeV alphas. These beams will be used in the production of radioactive atoms in the Radioactive Ion Beam Project at Oak Ridge National Laboratory.

  14. REGIONAL CONFERENCE SUMMARIES, 1966.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    AN AVERAGE OF 200 TEACHER EDUCATORS, STATE DIRECTORS, LAYMEN, AND REPRESENTATIVES OF VARIOUS AGENCIES ATTENDED EACH OF NINE REGIONAL CONFERENCES CONDUCTED THROUGHOUT THE UNITED STATES TO DISCUSS THE INFLUENCE OF SOCIAL AND ECONOMIC CHANGES AND PROBLEMS IN PLANNING AND CONDUCTING VOCATIONAL AND TECHNICAL EDUCATION PROGRAMS. MAJOR SPEECHES PRESENTED…

  15. Recipe for Regional Development.

    ERIC Educational Resources Information Center

    Baldwin, Fred D.

    1994-01-01

    The Ceramics Corridor has created new jobs in New York's Appalachian region by fostering ceramics research and product development by small private companies. Corridor business incubators offer tenants low overhead costs, fiber-optic connections to Alfred University's mainframe computer, rental of lab space, and use of equipment small companies…

  16. Multiethnic Societies and Regions.

    ERIC Educational Resources Information Center

    Stanfield, John H., II

    1996-01-01

    Maintains that sociology must reconceptualize the meaning of multiethnic societies and regions and also advance theories about how such social organizations came into being and transform themselves through conflicting and peaceful processes. Briefly reviews traditional approaches and outlines new areas of study. (MJP)

  17. Regionalism. Clip and Save.

    ERIC Educational Resources Information Center

    Hubbard, Guy

    2002-01-01

    Focuses on the art movement, called Regionalism, discussing the painters involved and describing the characteristics of the art movement. Provides a set of learning activities and background information on John Steuart Curry. Includes a discussion of Curry's painting, "Tornado Over Kansas," and a reproduction of the painting. (CMK)

  18. MISR Regional SAMUM Products

    Atmospheric Science Data Center

    2016-08-24

    ... Regional products:  Radiance ,  Aerosol , and  Land Surface . Each product summarizes selected parameters from one Level 1 or ... the  MISR SAMUM data table . Images available on this web site include the following parameters: Image Description ...

  19. MISR Regional VBBE Products

    Atmospheric Science Data Center

    2016-08-24

    ... Regional products:  Radiance ,  Aerosol , and  Land Surface . Each product summarizes selected parameters from one Level 1 or ... the  MISR VBBE data table . Images available on this web site include the following parameters: Image Description ...

  20. Climatic Concepts and Regions.

    ERIC Educational Resources Information Center

    Thomas, Paul F.

    Designed for students in grades 7 through 12, this teaching unit presents illustrative resource materials depicting concepts related to climate and geographic regions. Emphasis is on giving students an understanding of climatic elements and factors, not as isolated, disjointed entities, but as a dynamic interplay of forces having a very definite…

  1. Australia's Regional Youth Exodus.

    ERIC Educational Resources Information Center

    Gabriel, M.

    2002-01-01

    Examines media coverage of youth outmigration from Tasmania in the context of Australia's regional crisis. Focuses on how young people are constructed by others and positioned in others' visions of their rural home towns. Discusses two recurring narratives: strategies to keep youth at home, and preoccupation with the "best and brightest" young…

  2. Benchmarks: WICHE Region 2012

    ERIC Educational Resources Information Center

    Western Interstate Commission for Higher Education, 2013

    2013-01-01

    Benchmarks: WICHE Region 2012 presents information on the West's progress in improving access to, success in, and financing of higher education. The information is updated annually to monitor change over time and encourage its use as a tool for informed discussion in policy and education communities. To establish a general context for the…

  3. Statistical region merging.

    PubMed

    Nock, Richard; Nielsen, Frank

    2004-11-01

    This paper explores a statistical basis for a process often described in computer vision: image segmentation by region merging following a particular order in the choice of regions. We exhibit a particular blend of algorithmics and statistics whose segmentation error is, as we show, limited from both the qualitative and quantitative standpoints. This approach can be efficiently approximated in linear time/space, leading to a fast segmentation algorithm tailored to processing images described using most common numerical pixel attribute spaces. The conceptual simplicity of the approach makes it simple to modify and cope with hard noise corruption, handle occlusion, authorize the control of the segmentation scale, and process unconventional data such as spherical images. Experiments on gray-level and color images, obtained with a short readily available C-code, display the quality of the segmentations obtained.

  4. Active region seismology

    NASA Technical Reports Server (NTRS)

    Bogdan, Tom; Braun, D. C.

    1995-01-01

    Active region seismology is concerned with the determination and interpretation of the interaction of the solar acoustic oscillations with near-surface target structures, such as magnetic flux concentration, sunspots, and plage. Recent observations made with a high spatial resolution and a long temporal duration enabled measurements of the scattering matrix for sunspots and solar active regions to be carried out as a function of the mode properties. Based on this information, the amount of p-mode absorption, partial-wave phase shift, and mode mixing introduced by the sunspot, could be determined. In addition, the possibility of detecting the presence of completely submerged magnetic fields was raised, and new procedures for performing acoustic holography of the solar interior are being developed. The accumulating evidence points to the mode conversion of p-modes to various magneto-atmospheric waves within the magnetic flux concentration as being the unifying physical mechanism responsible for these diverse phenomena.

  5. Arctic region mapping tool

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-08-01

    An interactive online mapping tool is now available to assist with scientific, environmental, and emergency response needs in the Arctic region, the National Oceanic and Atmospheric Administration (NOAA) announced on 31 July. The Environmental Response Management Application (ERMA®) already has been used in other regions, including in the Gulf of Mexico, as part of the response to the Deepwater Horizon oil spill in 2010. The tool—which is a product of the combined work of NOAA, the U.S. Department of the Interior's Bureau of Safety and Environmental Enforcement (BSEE), the University of New Hampshire, and others—offers near-real time oceanographic observations, weather data, environmental and commercial information, and other data.

  6. Regional Renewable Energy Cooperatives

    NASA Astrophysics Data System (ADS)

    Hazendonk, P.; Brown, M. B.; Byrne, J. M.; Harrison, T.; Mueller, R.; Peacock, K.; Usher, J.; Yalamova, R.; Kroebel, R.; Larsen, J.; McNaughton, R.

    2014-12-01

    We are building a multidisciplinary research program linking researchers in agriculture, business, earth science, engineering, humanities and social science. Our goal is to match renewable energy supply and reformed energy demands. The program will be focused on (i) understanding and modifying energy demand, (ii) design and implementation of diverse renewable energy networks. Geomatics technology will be used to map existing energy and waste flows on a neighbourhood, municipal, and regional level. Optimal sites and combinations of sites for solar and wind electrical generation (ridges, rooftops, valley walls) will be identified. Geomatics based site and grid analyses will identify best locations for energy production based on efficient production and connectivity to regional grids and transportation. Design of networks for utilization of waste streams of heat, water, animal and human waste for energy production will be investigated. Agriculture, cities and industry produce many waste streams that are not well utilized. Therefore, establishing a renewable energy resource mapping and planning program for electrical generation, waste heat and energy recovery, biomass collection, and biochar, biodiesel and syngas production is critical to regional energy optimization. Electrical storage and demand management are two priorities that will be investigated. Regional scale cooperatives may use electric vehicle batteries and innovations such as pump storage and concentrated solar molten salt heat storage for steam turbine electrical generation. Energy demand management is poorly explored in Canada and elsewhere - our homes and businesses operate on an unrestricted demand. Simple monitoring and energy demand-ranking software can easily reduce peaks demands and move lower ranked uses to non-peak periods, thereby reducing the grid size needed to meet peak demands. Peak demand strains the current energy grid capacity and often requires demand balancing projects and

  7. Northwest Regional Climate Assessment

    NASA Technical Reports Server (NTRS)

    Lipschultz, Fred

    2011-01-01

    Objectives are to establish a continuing, inclusive National process that: 1) synthesizes relevant science and information 2) increases understanding of what is known & not known 3) identifies information needs related to preparing for climate variability and change, and reducing climate impacts and vulnerability 4) evaluates progress of adaptation & mitigation activities 5) informs science priorities 6) builds assessment capacity in regions and sectors 7) builds understanding & skilled use of findings

  8. Complex regional pain syndrome.

    PubMed

    Bruehl, Stephen

    2015-07-29

    Complex regional pain syndrome is a chronic pain condition characterized by autonomic and inflammatory features. It occurs acutely in about 7% of patients who have limb fractures, limb surgery, or other injuries. Many cases resolve within the first year, with a smaller subset progressing to the chronic form. This transition is often paralleled by a change from "warm complex regional pain syndrome," with inflammatory characteristics dominant, to "cold complex regional pain syndrome" in which autonomic features dominate. Multiple peripheral and central mechanisms seem to be involved, the relative contributions of which may differ between individuals and over time. Possible contributors include peripheral and central sensitization, autonomic changes and sympatho-afferent coupling, inflammatory and immune alterations, brain changes, and genetic and psychological factors. The syndrome is diagnosed purely on the basis of clinical signs and symptoms. Effective management of the chronic form of the syndrome is often challenging. Few high quality randomized controlled trials are available to support the efficacy of the most commonly used interventions. Reviews of available randomized trials suggest that physical and occupational therapy (including graded motor imagery and mirror therapy), bisphosphonates, calcitonin, subanesthetic intravenous ketamine, free radical scavengers, oral corticosteroids, and spinal cord stimulation may be effective treatments. Multidisciplinary clinical care, which centers around functionally focused therapies is recommended. Other interventions are used to facilitate engagement in functional therapies and to improve quality of life.

  9. Regional Shelter Analysis Methodology

    SciTech Connect

    Dillon, Michael B.; Dennison, Deborah; Kane, Jave; Walker, Hoyt; Miller, Paul

    2015-08-01

    The fallout from a nuclear explosion has the potential to injure or kill 100,000 or more people through exposure to external gamma (fallout) radiation. Existing buildings can reduce radiation exposure by placing material between fallout particles and exposed people. Lawrence Livermore National Laboratory was tasked with developing an operationally feasible methodology that could improve fallout casualty estimates. The methodology, called a Regional Shelter Analysis, combines the fallout protection that existing buildings provide civilian populations with the distribution of people in various locations. The Regional Shelter Analysis method allows the consideration of (a) multiple building types and locations within buildings, (b) country specific estimates, (c) population posture (e.g., unwarned vs. minimally warned), and (d) the time of day (e.g., night vs. day). The protection estimates can be combined with fallout predictions (or measurements) to (a) provide a more accurate assessment of exposure and injury and (b) evaluate the effectiveness of various casualty mitigation strategies. This report describes the Regional Shelter Analysis methodology, highlights key operational aspects (including demonstrating that the methodology is compatible with current tools), illustrates how to implement the methodology, and provides suggestions for future work.

  10. The Pacific Region.

    PubMed

    Tagica, K

    1993-03-01

    Population education in the Pacific region is summarized in terms of awareness and commitment, curriculum and instructional materials development, integration into the school curricula, training programs, and evaluation research. Several population education issues of current concern relate to the increase in chronic diseases such as diabetes and hypertension that are associated with life styles and diet, and the rising incidence of AIDS and teenage pregnancy. In the Pacific region, many countries have advanced population programs and policies, while some still do not even have a population policy. The issue of balancing population and resources is a topic that has not been sufficiently addressed in resource-poor countries. There is wide variance in awareness and commitment to population education in the Pacific region. Commitment and continuous support are crucial to population education projects. Lack of support is sometimes due to changing government personnel and lack of awareness of policy makers. Population education is not the same as family planning or sex education, and traditionally is spread through seminars and workshops by part time project personnel unconnected to the entire educational apparatus. Presently, only 8 population projects are functioning in the region, with 2-3 in the planning stages. Materials development in the Pacific region has been devoted to the secondary school level, yet awareness is increasing that sexuality, family health, and the environment should be introduced at the primary level. A popular strategy is to integrate population issues into the existing curriculum, such as in Fiji, the Marshall Islands, and Kiribati, which also have teacher training curriculum. In most countries sex education is still a controversial topic, and materials are developed by teacher committees working after school rather in a curriculum development unit. AIDS has pushed this topic into the public sector. A chart is provided for each country and

  11. Venus - Eistla Region

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This Magellan image is of an area located in the Eistla Region of Venus in the southern hemisphere and is centered at 5.5 degrees east longitude, 18 degrees south latitude. It is 122 kilometers (76 miles) across east to west and 107 kilometers (66 miles) north to south. North is at the top of the image. Shown is an unusual volcanic edifice unlike all others previously observed. It is approximately 66 kilometers (41 miles) across at the base and has a relatively flat, slightly concave summit 35 kilometers (22 miles) in diameter. The sides of the edifice are characterized by radiating ridges and valleys that impart a fluted appearance. To the west, the rim of the structure appears to have been breached by dark lava flows that emanated from a shallow summit pit approximately 5 kilometers (3 miles) in diameter and traveled west along a channel approximately 5 kilometers wide and 27 kilometers (17 miles) long. A series of coalescing, collapsed pits 2 to 10 kilometers (1.2 to 6.2 miles) in diameter are located 10 kilometers (6 miles) west of the summit. The edifice and western pits are circumscribed by faint, concentric lineaments up to 70 kilometers (43 miles) in diameter. A series of north northwest trending graben are deflected eastward around the edifice; the interplay of these graben and the fluted rim of the edifice produce a distinctive scalloped pattern in the image. Several north northwest trending lineaments cut directly across the summit region. This peculiar volcanic construct is located 25 to 30 kilometers (15 to 19 miles) north of Alpha Regio, a highly deformed region of tessera terrain. A collection of at least six similar volcanoes has been observed near Thetis Regio, a region of tessera within Aphrodite Terra. Thus, these unusual constructs tentatively appear to be spatially associated with regions of tessera. A tessera is a complex, deformed terrain on Venus consisting of at least two sets of intersecting ridges and troughs. The implications of this

  12. 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.

  13. Geothermal steam muffler diffusers: the Geysers, California. Failure analysis report

    SciTech Connect

    McAlpin, R.; Ellis, P.F. II

    1980-04-01

    The primary failure mechanism for the T304 diffusers was chloride induced stress corrosion cracking (sec.) Once SCC had progressed to a certain point, high cycle corrosion/fatigue proceeded to the final fracture. Alteration of the environment to prevent SCC is not feasible. The existing environment will also cause sulfide stress cracking (SSC) in susceptible materials; therefore, alternate materials must resist SSC as well as SCC. The very large amplitude operational stresses make heat treatment to relieve residual fabrication stress questionable for the prevention of SCC. (MHR)

  14. Large scale meteorological influence during the Geysers 1979 field experiment

    SciTech Connect

    Barr, S.

    1980-01-01

    A series of meteorological field measurements conducted during July 1979 near Cobb Mountain in Northern California reveals evidence of several scales of atmospheric circulation consistent with the climatic pattern of the area. The scales of influence are reflected in the structure of wind and temperature in vertically stratified layers at a given observation site. Large scale synoptic gradient flow dominates the wind field above about twice the height of the topographic ridge. Below that there is a mixture of effects with evidence of a diurnal sea breeze influence and a sublayer of katabatic winds. The July observations demonstrate that weak migratory circulations in the large scale synoptic meteorological pattern have a significant influence on the day-to-day gradient winds and must be accounted for in planning meteorological programs including tracer experiments.

  15. Explosive stimulation of a geothermal well at the Geysers

    SciTech Connect

    Hanold, R.J.

    1980-01-01

    The use of an explosive in a vapor-dominated reservoir is discussed. The explosive and the present experimental plan are described. The explosive is HITEX II and some of its properties are listed. (MHR)

  16. Physical properties of preserved core from the Geysers scientific corehole

    SciTech Connect

    Roberts, J.J.; Bonner, B.P.; Duba, A.G.; Schneberk, D.L.

    1996-01-24

    X-ray attenuation, electrical conductivity, and ultrasonic velocity are reported for a segment of preserved core from SB-15D, 918 ft. X-ray tomography and ultrasonic measurements change as the core dries, providing information regarding handling and disturbance of the core. Electrical conductivity measurements at reservoir conditions indicate that pore fluid properties and pore microstructure control bulk conductivity. These data are useful for calibration and interpretation of field geophysical measurements.

  17. Compliance plan for PG and E geysers unit 16

    SciTech Connect

    Not Available

    1981-03-01

    A plan is described to establish a monitoring system to assure that the geothermal power plant is constructed and operated in compliance with air and water quality, public health and safety, and other applicable regulations, guidelines, and conditions of the California Energy Commission. The plan is divided into: a Power Plant Compliance Plan and a Transmission Line Compliance Plan. (MHR)

  18. Geysering discharge of a geothermal wellbore at Zunil, Guatemala

    SciTech Connect

    Michels, Donald E.

    1991-01-01

    Within two hours after discharge began, for a production test in 1989 of well ZCQ-4, pressure variations changed from approximately sinusoidal to a cycle of sudden and complex peak discharge pressures, to 9 bar, separated by irregular pressure declines to 5 bar. Initial cycle periods of 42 minutes evolved to 150 minutes by day 20 of continuous testing, when three of four surge peaks were well separated. Chemical signatures of fluids discharged with pressure surges were distinctive. When combined with downwell pressure measurements, assignments can be made for elevations of fluid entry points. The variety of chemical signatures indicates a scarcity of interzone connectivity. These constrained discharges are suspected to derive from altered rubble zones between layered volcanic rocks.

  19. Regional river sulfur runoff

    NASA Astrophysics Data System (ADS)

    Husar, Rudolf B.; Husar, Janja Djukic

    1985-01-01

    The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as central and eastern North America exceed 8 mg S/L. The sulfur runoff density is also highest in the river basins over these industrialized regions, exceeding 2 g S/m2/yr. However, high sulfur runoff density in excess of 3 g S/m2/yr is also measured over the Pacific islands New Zealand and New Guinea and the archipelagos of Indonesia and the Philippines. The natural background sulfur runoff was estimated by assuming that South America, Africa, Australia, and the Pacific Islands are unperturbed by man and that the average river sulfur concentration is in the range 1-3 mg S/L. Taking these background concentration values, the man-induced sulfur runoff for Europe ranges between 2 and 8 times the natural flow, and over North America, man's contribution ranges between 1 and 5 times the natural runoff. The global sulfur flow from nondesert land to the oceans and the Caspian Sea is estimated as 131 Tg S/yr, of which 46-85 Tg S/yr is attributed to natural causes. The regional river sulfur runoff pattern discussed in this paper does not have enough spatial resolution to be directly applicable to studies of the environmental effects of man-induced sulfur flows. However, it points to the continental-size regions where those perturbations are most evident and to the magnitude of the perturbations as expressed in units of the natural flows.

  20. Regional river sulfur runoff

    SciTech Connect

    Husar, R.B.; Husar, J.D.

    1985-01-20

    The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as central and eastern North America exceed 8 mg S/L. The sulfur runoff density is also highest in the river basins over these industrialized regions, exceeding 2 g S/m/sup 2//yr. However, high sulfur runoff density in excess of 3 g S/m/sup 2//yr is also measured over the Pacific islands New Zealand and New Guinea and the archipelagos of Indonesia and the Philippines. The natural background sulfur runoff was estimated by assuming that South America, Africa, Australia, and the Pacific Islands are unperturbed by man and that the average river sulfur concentration is in the range 1--3 mg S/L. Taking these background concentration values, the man-induced sulfur runoff for Europe ranges between 2 and 8 times the natural flow, and over North America, man's contribution ranges between 1 and 5 times the natural runoff. The global sulfur flow from nondesert land to the oceans and the Caspian Sea is estimated as 131 Tg S/yr, of which 46--85 Tg S/yr is attributed to natural causes. The regional river sulfur runoff pattern discussed in this paper does not have enough spatial resolution to be directly applicable to studies of the environmental effects of man-induced sulfur flows. However, it points to the continental-size regions where those perturbations are most evident and to the magnitude of the perturbations as expressed in units of the natural flows.

  1. Higher Education and Regional Development.

    ERIC Educational Resources Information Center

    Neave, Guy

    1979-01-01

    The effect that the university has upon its region and the issue of regional control of higher education are examined. A definition of regional development is offered and regional planning, relevant research, cultural mobilization, and the Jacobin university are described. (Author/MLW)

  2. Complex regional pain syndrome.

    PubMed

    Sebastin, Sandeep J

    2011-05-01

    Complex regional pain syndrome (CRPS) previously known as reflex sympathetic dystrophy is a chronic neurological disorder involving the limbs characterized by disabling pain, swelling, vasomotor instability, sudomotor abnormality, and impairment of motor function. CRPS is not uncommon after hand surgery and may complicate post-operative care. There is no specific diagnostic test for CRPS and the diagnosis is based on history, clinical examination, and supportive laboratory findings. Recent modifications to diagnostic criteria have enabled clinicians to diagnose this disease more consistently. This review gives a synopsis of CRPS and discusses the diagnosis, pathophysiology, and treatment options based on the limited evidence in the literature. PMID:22022040

  3. Complex regional pain syndrome

    PubMed Central

    Sebastin, Sandeep J

    2011-01-01

    Complex regional pain syndrome (CRPS) previously known as reflex sympathetic dystrophy is a chronic neurological disorder involving the limbs characterized by disabling pain, swelling, vasomotor instability, sudomotor abnormality, and impairment of motor function. CRPS is not uncommon after hand surgery and may complicate post-operative care. There is no specific diagnostic test for CRPS and the diagnosis is based on history, clinical examination, and supportive laboratory findings. Recent modifications to diagnostic criteria have enabled clinicians to diagnose this disease more consistently. This review gives a synopsis of CRPS and discusses the diagnosis, pathophysiology, and treatment options based on the limited evidence in the literature. PMID:22022040

  4. Complex regional pain syndrome.

    PubMed

    Palmer, Greta

    2015-06-01

    Complex regional pain syndrome is an uncommon chronic pain condition. It develops spontaneously or following an injury. The features are limb pain, allodynia, hypersensitivity, hyperalgesia, abnormalities of the vasomotor, sudomotor and motor systems, and trophic changes, with reduced use of the affected limb. The diagnosis is clinical and one of exclusion. The emphasis of therapy is graded rehabilitation and movement of the limb with physiotherapy and occupational therapy. Psychological therapies should be offered if a patient is making no or slow progress in the acute phase, and to all patients in the chronic phase as depression can occur. The goal of pharmacotherapy is to assist functional improvement. The early phase may be managed with simple analgesia. Antineuropathic drugs including tricyclic antidepressants and antiepileptic drugs may be added. Other treatments with some evidence of effectiveness include corticosteroids, calcitonin and bisphosphonates. Vitamin C has been used for primary prevention after wrist fracture and upper and lower limb surgery. There is no evidence that it is effective for treating established complex regional pain syndrome.

  5. Colorado Regional Faults

    SciTech Connect

    Hussein, Khalid

    2012-02-01

    Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Originator: Colorado Geological Survey (CGS) Publication Date: 2012 Title: Regional Faults Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: This layer contains the regional faults of Colorado Spatial Domain: Extent: Top: 4543192.100000 m Left: 144385.020000 m Right: 754585.020000 m Bottom: 4094592.100000 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 ’984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

  6. Regional flood probabilities

    USGS Publications Warehouse

    Troutman, B.M.; Karlinger, M.R.

    2003-01-01

    The T-year annual maximum flood at a site is defined to be that streamflow, that has probability 1/T of being exceeded in any given year, and for a group of sites the corresponding regional flood probability (RFP) is the probability that at least one site will experience a T-year flood in any given year. The RFP depends on the number of sites of interest and on the spatial correlation of flows among the sites. We present a Monte Carlo method for obtaining the RFP and demonstrate that spatial correlation estimates used in this method may be obtained with rank transformed data and therefore that knowledge of the at-site peak flow distribution is not necessary. We examine the extent to which the estimates depend on specification of a parametric form for the spatial correlation function, which is known to be nonstationary for peak flows. It is shown in a simulation study that use of a stationary correlation function to compute RFPs yields satisfactory estimates for certain nonstationary processes. Application of asymptotic extreme value theory is examined, and a methodology for separating channel network and rainfall effects on RFPs is suggested. A case study is presented using peak flow data from the state of Washington. For 193 sites in the Puget Sound region it is estimated that a 100-year flood will occur on the average every 4,5 years.

  7. The Eutherian Pseudoautosomal Region.

    PubMed

    Raudsepp, Terje; Chowdhary, Bhanu P

    2015-01-01

    The pseudoautosomal region (PAR) is a unique segment of sequence homology between differentiated sex chromosomes where recombination occurs during meiosis. Molecular and functional properties of the PAR are distinctive from the autosomes and the remaining regions of the sex chromosomes. These include a higher rate of recombination than genome average, bias towards GC-substitutions and increased interindividual nucleotide divergence and mutations. As yet, the PAR has been physically demarcated in only 28 eutherian species representing 6 mammalian orders. Murid rodents have the smallest, gene-poorest and most diverged PARs. Other eutherian PARs are largely homologous but differ in size and gene content, being the smallest in equids and human/simian primates and much larger in other eutherians. Because pseudoautosomal genes escape X inactivation, their dosage changes with sex chromosome aneuploidies, whereas phenotypic effects of the latter depend on the size and gene content of the PAR. Thus, X monosomy is more viable in mice, humans and horses than in species with larger PARs. Presently, little is known about the functions of PAR genes in individual species, though human studies suggest their involvement in early embryonic development. The PAR is, thus, of evolutionary, genetic and biomedical significance and a 'research hotspot' in eutherian genomes. PMID:26730606

  8. Complex regional pain syndrome.

    PubMed

    Palmer, Greta

    2015-06-01

    Complex regional pain syndrome is an uncommon chronic pain condition. It develops spontaneously or following an injury. The features are limb pain, allodynia, hypersensitivity, hyperalgesia, abnormalities of the vasomotor, sudomotor and motor systems, and trophic changes, with reduced use of the affected limb. The diagnosis is clinical and one of exclusion. The emphasis of therapy is graded rehabilitation and movement of the limb with physiotherapy and occupational therapy. Psychological therapies should be offered if a patient is making no or slow progress in the acute phase, and to all patients in the chronic phase as depression can occur. The goal of pharmacotherapy is to assist functional improvement. The early phase may be managed with simple analgesia. Antineuropathic drugs including tricyclic antidepressants and antiepileptic drugs may be added. Other treatments with some evidence of effectiveness include corticosteroids, calcitonin and bisphosphonates. Vitamin C has been used for primary prevention after wrist fracture and upper and lower limb surgery. There is no evidence that it is effective for treating established complex regional pain syndrome. PMID:26648626

  9. Neptune's south polar region

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This image of Neptune's south polar region was obtained by the NASA Voyager narrow-angle camera on Aug. 23, 1989, when it was at a distance of 25 million kilometers (1.6 million miles). The smallest cloud features are 45 kilometers (28 miles) in diameter. The image shows the discovery of shadows in Neptune's atmosphere, shadows cast onto a deep cloud bank by small elevated clouds. Located at about 68 degrees south latitude, they are the first cloud shadows ever seen by the Voyager on any planet. The dark regions adjacent to the small bright clouds are believed to be shadows, because they are on the side of the cloud that is opposite to the incoming sunlight and because they lengthen in places where the sun lies closer to the horizon. Estimates of the height of these discrete clouds above the underlying cloud bank can be obtained by careful analysis of this data. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  10. Comprehensive air monitoring plan: general monitoring report

    SciTech Connect

    Not Available

    1980-03-31

    Recommendations are provided for general monitoring of hydrogen sulfide (H/sub 2/S) in ambient air in parts of Colusa, Lake, Mendocino, Napa, and Sonoma counties potentially impacted by emissions from geothermal development projects in the Geysers-Calistoga Known Geothermal Resource Area. Recommendations for types, placement, performance guidelines, and criteria and procedure for triggering establishment and termination of CAMP monitoring equipment were determined after examination of four factors: population location; emission sources; meteorological considerations; and data needs of permitting agencies and applicants. Three alternate financial plans were developed. Locations and equipment for immediate installation are recommended for: two air quality stations in communities where the State ambient air quality standard for H/sub 2/S has been exceeded; three air quality trend stations to monitor progress in reduction of H/sub 2/S emissions; two meteorological observation stations to monitor synoptic wind flow over the area; and one acoustic radar and one rawinsonde station to monitor air inversions which limit the depth of the mixing layer.

  11. Staff policy regarding mitigation of school enrollment impacts

    SciTech Connect

    Williams, D.S.

    1983-01-01

    Testimony in recent geothermal power plant siting cases in the Geysers-Calistoga KGRA has established that nine local school districts have reached or exceeded the design which induces immigration into these impacted districts will aggravate the situation. Several power plant applicants have agreed to provide annual mitigation payments to local school districts which can document adverse student enrollment impacts. The Lake County agreements with Occidental Geothermal, Inc. and the California Department of Water Resources require mitigation fees for students having at least one parent who either works directly with the power plant or works indirectly with the geothermal-service industry. An adjustment is made each year so that the applicant only pays a one-time fee for each student. An annual student survey is used to help identify students qualifying for mitigation payments. This paper presents an algorithms which CEC staff will propose to be used in the event that a power plant applicant and an impacted school district are unable to negotiate a mitigation agreement. The algorithm provides a basis for calculating an annual mitigation payment which would be used to help construct new permanent facilities and to purchase additional school buses.

  12. [COMPLEX REGIONAL PAIN SYNDROME].

    PubMed

    Blažeković, Ivan; Bilić, Ervina; Žagar, Marija; Anić, Branimir

    2015-01-01

    Complex regional pain syndrome (CRPS) represents a state of constant and often disabling pain, affecting one region (usually hand) and often occurs after a trauma whose severity does not correlate with the level of pain. The older term for this condition of chronic pain associated with motor and autonomic symptoms is reflex sympathetic dystrophy or causalgia. The aim of this review, based on contemporary literature, is to show the epidemiology and etiology, proposed pathophysiological mechanisms, method of diagnosis and treatment options, prevention and mitigation of this under-recognized disease. CRPS I occurs without known neurological damage, unlike CRPS II, where the history of trauma is present and in some cases damage to the peripheral nervous system can be objectively assessed using electromyoneurography. New diagnostic methods, such as quantitative sensory testing (CST), challenge this division because the CST findings in patients with CRPS I can suggest damage to Adelta peripheral nerve fibers. Except for distinguishing type I and type II disease, it is important to bear in mind the diversity of clinical presentation of CRPS in acute and chronic phase of the disease. This regional pain syndrome typically includes the autonomic and motor signs and thus differs from other peripheral neuropathic pain syndromes. The complexity of the clinical presentation indicates the likely presence of different pathophysiological mechanisms underlying this disease. Previous studies have demonstrated the autonomic dysfunction, neurogenic inflammation and neuroplastic changes. The diagnosis of CRPS is based on anamnesis and clinical examination on the basis of which the disease can be graded according to the Budapest Criteria. A valuable aid in differentiating subtypes of the disease is electromyoneurography. The treatment of CRPS is as complex as the clinical picture and the pathophysiology of the disease and requires interdisciplinary cooperation and individual approach

  13. [COMPLEX REGIONAL PAIN SYNDROME].

    PubMed

    Blažeković, Ivan; Bilić, Ervina; Žagar, Marija; Anić, Branimir

    2015-01-01

    Complex regional pain syndrome (CRPS) represents a state of constant and often disabling pain, affecting one region (usually hand) and often occurs after a trauma whose severity does not correlate with the level of pain. The older term for this condition of chronic pain associated with motor and autonomic symptoms is reflex sympathetic dystrophy or causalgia. The aim of this review, based on contemporary literature, is to show the epidemiology and etiology, proposed pathophysiological mechanisms, method of diagnosis and treatment options, prevention and mitigation of this under-recognized disease. CRPS I occurs without known neurological damage, unlike CRPS II, where the history of trauma is present and in some cases damage to the peripheral nervous system can be objectively assessed using electromyoneurography. New diagnostic methods, such as quantitative sensory testing (CST), challenge this division because the CST findings in patients with CRPS I can suggest damage to Adelta peripheral nerve fibers. Except for distinguishing type I and type II disease, it is important to bear in mind the diversity of clinical presentation of CRPS in acute and chronic phase of the disease. This regional pain syndrome typically includes the autonomic and motor signs and thus differs from other peripheral neuropathic pain syndromes. The complexity of the clinical presentation indicates the likely presence of different pathophysiological mechanisms underlying this disease. Previous studies have demonstrated the autonomic dysfunction, neurogenic inflammation and neuroplastic changes. The diagnosis of CRPS is based on anamnesis and clinical examination on the basis of which the disease can be graded according to the Budapest Criteria. A valuable aid in differentiating subtypes of the disease is electromyoneurography. The treatment of CRPS is as complex as the clinical picture and the pathophysiology of the disease and requires interdisciplinary cooperation and individual approach

  14. Complex Regional Pain Syndrome.

    PubMed

    Ersoy, Hale; Pomeranz, Stephen J

    2016-01-01

    Complex regional pain syndrome (CRPS) is a neurological disorder producing peripheral neurogenic inflammatory process in hands and feet distal to injury, which may lead to severe disability. Symptoms are often out of proportion to the initiating event and not limited to a single peripheral nerve. There is no gold standard in diagnosis of this entity, and a multidisciplinary approach is necessary for proper diagnosis. Magnetic resonance imaging (MRI) is one of the most useful diagnostic modalities in early stages of CRPS (when clinical diagnosis is most difficult), the most desirable time to diagnose this disorder to expedite treatment and improve function. This article discusses MRI findings of CRPS, particularly in the early phase, and differential considerations. PMID:27518298

  15. Venus - Lakshmi Region

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This Magellan image is centered at 55 degrees north latitude, 348.5 degrees longitude, in the eastern Lakshmi region of Venus. This image, which is of an area 300 kilometers (180 miles) in width and 230 kilometers (138 miles) in length, is a mosaic of orbits 458 through 484. The image shows a relatively flat plains region composed of many lava flows. The dark flows mostly likely represent smooth lava flows similar to 'pahoehoe' flows on Earth while the brighter lava flows are rougher flows similar to 'aa' flows on Earth. (The terms 'pahoehoe' and 'aa' refer to textures of lava with pahoehoe a smooth or ropey surface, and aa a rough, clinkery texture). The rougher flows are brighter because the rough surface returns more energy to the radar than the smooth flows. Situated on top of the lava flows are three dark splotches. Because of the thick Venusian atmosphere, the small impactors break up before they reached the surface. Only the fragments from the broken up impactor are deposited on the surface and these fragments produce the dark splotches in this image. The splotch at the far right (east) has a crater centered in it, indicating that the impactor was not completely destroyed during its journey through the atmosphere. The dark splotches in the center and to the far left in this image each represent an impactor that was broken up into small fragments that did not penetrate the surface to produce a crater. The dark splotch at the left has been modified by the wind. A southwest northeast wind flow has moved some of the debris making up the splotch to the northeast where it has piled up against some small ridges.

  16. Moldova. Historic regional conference.

    PubMed

    Moshin, V

    1995-05-01

    The Directorate of Maternal and Child Health and the Family Planning Association of Moldova organized a regional conference, which was held October 18-19, 1994, in Kishinev, Moldova, with the support of the United Nations Population Fund (UNFPA), the World Health Organization (WHO), and the International Planned Parenthood Federation (IPPF). The conference,"Problems of Family Planning in Eastern Europe," was attended by approximately 400 Moldovan delegates of governmental and nongovernmental organizations (NGOs), and by 25 delegates from Romania, Russia, Belarus, the Ukraine, and Georgia. The President of Moldova and the Ministry of Public Health of Moldova gave their approval. The main objectives of the conference were to inform the public about the recommendations of the ICPD, to analyze the status of women's reproductive health and family planning in Eastern Europe, and to find ways of implementing the ICPD Plan of Action. Major problems identified during the conference were: 1) the social and economic problems facing most families; 2) the high rate of morbidity and mortality; 3) the decrease in birth rate; 4) the increase in abortions; 5) the rising incidence of venereal disease; and 6) the absence of an effective family planning system. It was agreed that cooperation between governments and NGOs is essential in designing population programs for each country. The following goals were set: 1) to provide populations with sufficient contraceptives; 2) to actively promote family planning concepts through the mass media; 3) to train specialists and to open family planning offices and centers; 4) to introduce sex education in the curricula of Pedagogical Institutes; and 5) to create national and regional statistical and sociological databases on population issues.

  17. Regional brain hypometabolism is unrelated to regional amyloid plaque burden.

    PubMed

    Altmann, Andre; Ng, Bernard; Landau, Susan M; Jagust, William J; Greicius, Michael D

    2015-12-01

    In its original form, the amyloid cascade hypothesis of Alzheimer's disease holds that fibrillar deposits of amyloid are an early, driving force in pathological events leading ultimately to neuronal death. Early clinicopathological investigations highlighted a number of inconsistencies leading to an updated hypothesis in which amyloid plaques give way to amyloid oligomers as the driving force in pathogenesis. Rather than focusing on the inconsistencies, amyloid imaging studies have tended to highlight the overlap between regions that show early amyloid plaque signal on positron emission tomography and that also happen to be affected early in Alzheimer's disease. Recent imaging studies investigating the regional dependency between metabolism and amyloid plaque deposition have arrived at conflicting results, with some showing regional associations and other not. We extracted multimodal neuroimaging data from the Alzheimer's disease neuroimaging database for 227 healthy controls and 434 subjects with mild cognitive impairment. We analysed regional patterns of amyloid deposition, regional glucose metabolism and regional atrophy using florbetapir ((18)F) positron emission tomography, (18)F-fluordeoxyglucose positron emission tomography and T1-weighted magnetic resonance imaging, respectively. Specifically, we derived grey matter density and standardized uptake value ratios for both positron emission tomography tracers in 404 functionally defined regions of interest. We examined the relation between regional glucose metabolism and amyloid plaques using linear models. For each region of interest, correcting for regional grey matter density, age, education and disease status, we tested the association of regional glucose metabolism with (i) cortex-wide florbetapir uptake; (ii) regional (i.e. in the same region of interest) florbetapir uptake; and (iii) regional florbetapir uptake while correcting in addition for cortex-wide florbetapir uptake. P-values for each setting

  18. Landslides of Palestinian Region

    NASA Astrophysics Data System (ADS)

    Alwahsh, H.

    2013-12-01

    Natural disasters are extreme sudden events caused by environmental and natural actors that take away the lives of many thousands of people each year and damage large amount of properties. They strike anywhere on earth, often without any warning. A risk maps of natural disaster are very useful to identify the places that might be adversely affected in the event of natural disaster. The earthquakes are one of natural disaster that have the greatest hazards and will cause loss of life and properties due to damaging the structures of building, dams, bridges. In addition, it will affect local geology and soil conditions. The site effects play an important role in earthquake risk because of its amplification or damping simulation. Another parameter in developing risk map is landslide, which is also one of the most important topics in site effect hazards. Palestine region has been suffering landslide hazards because of the topographical and geological conditions of this region. Most Palestine consists of mountainous area, which has great steep slopes and the type of soil is mainly grayish to yellowish silty clay (Marl Soil). Due to the above mentioned factors many landslides have been occurred from Negev south to the northern borders of Palestine. An example of huge and destruction landslide in a Palestine authority is the landslide in the White Mountain area in the city of Nablus, which occurred in 1997. The geotechnical and geophysical investigation as well as slope stability analysis should be considered in making landslide maps that are necessary to develop risk levels of the natural disaster. Landslides occurred in slopes that are created naturally or by human beings. Failure of soil mass occurs, and hence landslide of soil mass happen due to sliding of soil mass along a plane or curved surface. In general, the slopes become unstable when the shear stresses (driving force) generated in the soil mass exceed the available shearing resistance on the rupture surface

  19. Sudurnes Regional Heating Corp.

    SciTech Connect

    Lienau, P.J.

    1996-11-01

    The Svartsengi geothermal area is close to the town of Grindavik on the Rekjanes peninsula and is part of an active fissure swarm, lined with crater-rows and open fissures and faults. The high-temperature area has an area of 2 sq. km and shows only limited signs of geothermal activity at the surface. The reservoir, however, contains lots of energy and at least 8 wells supply the Svartsengi Power Plant with steam. The steam is not useable for domestic heating purposes so that heat exchangers are used to heat cold groundwater with the steam. Some steam is also used for producing 16.4 MW{sub e} of electrical power. The article shows the distribution system piping hot water to nine towns and the Keflavik International Airport. The effluent brine from the Svartsengi Plant is disposed of into a surface pond, called the Blue Lagoon, popular to tourists and people suffering from psoriasis and other forms of eczema seeking therapeutic effects from the silica rich brine. This combined power plant and regional district heating system (cogeneration) is an interesting and unique design for the application of geothermal energy.

  20. Active region flows

    NASA Technical Reports Server (NTRS)

    Foukal, Peter

    1987-01-01

    A wide range of observations has shown that active region phenomena in the photospheric, chromospheric and coronal temperature regimes are dynamical in nature. At the photosphere, recent observations of full line profiles place an upper limit of about + or - 20/msec on any downflows at supergranule cell edges. Observations of the full Stokes 5 profiles in the network show no evidence for downflows in magnetic flux tubes. In the area of chromospheric dynamics, several models were put forward recently to reproduce the observed behavior of spicules. However, it is pointed out that these adiabatic models do not include the powerful radiative dissipation which tend to damp out the large amplitude disturbances that produce the spicular acceleration in the models. In the corona, loop flows along field lines clearly transport mass and energy at rates important for the dynamics of these structures. However, advances in understanding the heating and mass balance of the loop structures seem to require new kinds of observations. Some results are presented using a remote sensing diagnostic of the intensity and orientation of macroscopic plasma electric fields predicted by models of reconnective heating and also wave heating.

  1. Regional Kendall test for trend

    USGS Publications Warehouse

    Helsel, D.R.; Frans, L.M.

    2006-01-01

    Trends in environmental variables are often investigated within a study region at more than one site. At each site, a trend analysis determines whether a trend has occurred. Yet often also of interest is whether a consistent trend is evident throughout the entire region. This paper adapts the Seasonal Kendall trend test to determine whether a consistent regional trend occurs in environmental variables.

  2. Regions. [Africa, Middle East].

    PubMed

    1985-03-01

    This discussion of population focuses on the regions of Africa and the Middle East. In South Africa more white women are working but fewer black women work. The overall result is that the percentage of women who work is declining. Marita de Beer, research liaison executive at the South African Advertising Research Foundation, reports that the female population grew by 31% in the past 10 years while the number of working women has grown by only 11%. Among blacks the female population rose by 36%, but the number of workers among them declined by about 1%. Married women are among the fastest growing groups of working women in South Africa. The most recent estimate of the population of Nigeria is 92 million. According to Professor Vremudia Diejomaoh, Nigeria's population will probably reach 155 million by 2000 with 33% living in urban areas. In Saudi Arabia the Pan Arab Research Center recently completed a census of retail outlets in 3 metropolitan areas: Jeddah, Riyadh, and Dammam. The types of outlets surveyed include large supermarkets, small supermarkets, groceries with and without deep freeze, tobacco shops, meat shop/delis, small cafeterias, large restaurants/hotels, cosmetics shops or perfumeries, camera stores, toy shops, pharmacies, watch and gift shop, newsstands, department store, and appliance outlets. Using the Census of Retail Outlets as a base, Pan Arab Research Center also has a new distribution audit system that will cover 500 outlets. By plotting Arab countries according to their population policies and their current growth rates, it is possible to project where the middle class will grow fastest in the Arab world. The countries that have declining growth rates and strong population programs designed to encourage lower fertility rates among women are Egypt, Tunisia, Morocco, Algeria, and Lebanon. The countries most likely to have a better per capita distribution of resources within this decade are those where governments encourage reductions in

  3. Regions. [Africa, Middle East].

    PubMed

    1985-03-01

    This discussion of population focuses on the regions of Africa and the Middle East. In South Africa more white women are working but fewer black women work. The overall result is that the percentage of women who work is declining. Marita de Beer, research liaison executive at the South African Advertising Research Foundation, reports that the female population grew by 31% in the past 10 years while the number of working women has grown by only 11%. Among blacks the female population rose by 36%, but the number of workers among them declined by about 1%. Married women are among the fastest growing groups of working women in South Africa. The most recent estimate of the population of Nigeria is 92 million. According to Professor Vremudia Diejomaoh, Nigeria's population will probably reach 155 million by 2000 with 33% living in urban areas. In Saudi Arabia the Pan Arab Research Center recently completed a census of retail outlets in 3 metropolitan areas: Jeddah, Riyadh, and Dammam. The types of outlets surveyed include large supermarkets, small supermarkets, groceries with and without deep freeze, tobacco shops, meat shop/delis, small cafeterias, large restaurants/hotels, cosmetics shops or perfumeries, camera stores, toy shops, pharmacies, watch and gift shop, newsstands, department store, and appliance outlets. Using the Census of Retail Outlets as a base, Pan Arab Research Center also has a new distribution audit system that will cover 500 outlets. By plotting Arab countries according to their population policies and their current growth rates, it is possible to project where the middle class will grow fastest in the Arab world. The countries that have declining growth rates and strong population programs designed to encourage lower fertility rates among women are Egypt, Tunisia, Morocco, Algeria, and Lebanon. The countries most likely to have a better per capita distribution of resources within this decade are those where governments encourage reductions in

  4. Europa Wedge Region

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This image shows an area of crustal separation on Jupiter's moon, Europa. Lower resolution pictures taken earlier in the tour of NASA's Galileo spacecraft revealed that dark wedge-shaped bands in this region are areas where the icy crust has completely pulled apart. Dark material has filled up from below and filled the void created by this separation.

    In the lower left corner of this image, taken by Galileo's onboard camera on December 16, 1997, a portion of one dark wedge area is visible, revealing a linear texture along the trend of the wedge. The lines of the texture change orientation slightly and reflect the fact that we are looking at a bend in the wedge. The older, bright background, visible on the right half of the image, is criss-crossed with ridges. A large, bright ridge runs east-west through the upper part of the image, cutting across both the older background plains and the wedge. This ridge is rough in texture, with numerous small terraces and troughs containing dark material.

    North is to the top of the picture and the sun illuminates the surface from the northwest. This image, centered at approximately 16.5 degrees south latitude and 196.5 degrees west longitude, covers an area approximately 10 kilometers square (about 6.5 miles square). The resolution of this image is about 26 meters per picture element. This image was taken by the solid state imaging system from a distance of 1250 kilometers (750 miles).

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  5. Emission measure distribution for diffuse regions in solar active regions

    SciTech Connect

    Subramanian, Srividya; Tripathi, Durgesh; Klimchuk, James A.; Mason, Helen E.

    2014-11-01

    Our knowledge of the diffuse emission that encompasses active regions is very limited. In this paper we investigate two off-limb active regions, namely, AR 10939 and AR 10961, to probe the underlying heating mechanisms. For this purpose, we have used spectral observations from Hinode/EIS and employed the emission measure (EM) technique to obtain the thermal structure of these diffuse regions. Our results show that the characteristic EM distributions of the diffuse emission regions peak at log T = 6.25 and the coolward slopes are in the range 1.4-3.3. This suggests that both low- as well as high-frequency nanoflare heating events are at work. Our results provide additional constraints on the properties of these diffuse emission regions and their contribution to the background/foreground when active region cores are observed on-disk.

  6. Callisto's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This mosaic covers part of the equatorial region of Jupiter's moon, Callisto. The mosaic combines six separate image frames obtained by the solid state imaging (CCD) system on NASA's Galileo spacecraft during its ninth orbit around Jupiter. North is to the top of the picture. The mosaic shows several new features and characteristics of the surface revealed by Galileo. These include deposits that may represent landslides in the southern and southwestern floors of many craters. Two such deposits are seen in a 12 kilometer (7.3 mile) crater in the west-central part of the image, and in a 23 kilometer (14 mile) crater just north of the center of the image. Also notable are several sinuous valleys emanating from the southern rims of 10 to 15 kilometer (6.2 to 9.3 mile) irregular craters in the west-central part of the image. The pervasive local smoothing of Callisto's surface is well represented in the plains between the craters in the southeastern part of the image. Possible oblique impacts are suggested by the elongated craters in the northeastern and southeastern parts of the image.

    The mosaic, centered at 7.4 degrees south latitude and 6.6 degrees west longitude, covers an area of approximately 315 by 215 kilometers (192 by 131 miles). The sun illuminates the scene from the west (left). The smallest features that can be seen are about 300 meters (993 feet) across. The images were obtained on June 25, 1997, when the spacecraft was at a range of 15,200 kilometers (8,207 miles) from Callisto.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  7. Regional governance: strategies and disputes in health region management

    PubMed Central

    dos Santos, Adriano Maia; Giovanella, Ligia

    2014-01-01

    OBJECTIVE To analyze the regional governance of the health systemin relation to management strategies and disputes. METHODOLOGICAL PROCEDURES A qualitative study with health managers from 19 municipalities in the health region of Bahia, Northeastern Brazil. Data were drawn from 17 semi-structured interviews of state, regional, and municipal health policymakers and managers; a focus group; observations of the regional interagency committee; and documents in 2012. The political-institutional and the organizational components were analyzed in the light of dialectical hermeneutics. RESULTS The regional interagency committee is the chief regional governance strategy/component and functions as a strategic tool for strengthening governance. It brings together a diversity of members responsible for decision making in the healthcare territories, who need to negotiate the allocation of funding and the distribution of facilities for common use in the region. The high turnover of health secretaries, their lack of autonomy from the local executive decisions, inadequate technical training to exercise their function, and the influence of party politics on decision making stand as obstacles to the regional interagency committee’s permeability to social demands. Funding is insufficient to enable the fulfillment of the officially integrated agreed-upon program or to boost public supply by the system, requiring that public managers procure services from the private market at values higher than the national health service price schedule (Brazilian Unified Health System Table). The study determined that “facilitators” under contract to health departments accelerated access to specialized (diagnostic, therapeutic and/or surgical) services in other municipalities by direct payment to physicians for procedure costs already covered by the Brazilian Unified Health System. CONCLUSIONS The characteristics identified a regionalized system with a conflictive pattern of governance and

  8. Document Delivery Policy. Region 2 [Regional Medical Library Network].

    ERIC Educational Resources Information Center

    Southeastern/Atlantic Regional Medical Library Services, Baltimore, MD.

    Standardized policies and procedures for interlibrary loan and resource sharing in the Southeastern/Atlantic Region of the Regional Medical Library (RML) Network are presented in this policy statement. RML network institutions, which are divided into categories based on their ability and willingness to assume responsibility for interlibrary…

  9. 17 CFR 140.2 - Regional office-regional coordinators.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... direction of a Regional Coordinator who, as a collateral duty, oversees the administration of the office and... parties. Each regional office has delegated authority for the enforcement of the Act and administration of... administration of programs of the Commission in the States of Alabama, Connecticut, Delaware, Florida,...

  10. Statistical relationships between meteorological data stations and implications to diagnostic models in complex terrain

    SciTech Connect

    Porch, W.M.; Lange, R.; Bennett, D.E.

    1984-06-01

    Wind speed and direction measurements taken during field experiments at the Geyser region in northern California were analyzed and characterized for data quality control, representativity, model verification, and improved interpolation. 7 references, 4 figures. (ACR)

  11. About the REL Pacific Region

    ERIC Educational Resources Information Center

    Regional Educational Laboratory Pacific, 2014

    2014-01-01

    REL Pacific is one of ten Regional Educational Laboratories established and funded by the U.S. Department of Education's Institute of Education Sciences. Their region encompasses approximately 4.9 million square miles and serves seven Pacific island entities, including American Samoa; the Commonwealth of the Northern Mariana Islands; the Federated…

  12. Training Teachers for Regional Colleges.

    ERIC Educational Resources Information Center

    Hla Myint; And Others

    This report presents alternative plans for training teachers for the newly-established Regional Colleges in Burma. The Regional Colleges are three-year postsecondary institutions designed to train middle level technicians to help increase the production of goods and services needed in the Burmese economy. Concentrating on the Hawaii Community…

  13. CLIMATE IMPACTS ON REGIONAL WATER

    EPA Science Inventory

    The New England region (including the 6 New England
    states plus upstate New York) offers a very diverse geography,
    matched by an equally diverse economy and human
    population. Livelihoods throughout the region are based
    on service industries that depend heavily on comm...

  14. What's Happening to Regional Policy?

    ERIC Educational Resources Information Center

    Ravenhall, Mark

    2005-01-01

    Back in November, voters in the North East of England overwhelmingly rejected the move towards an elected regional assembly. The scale of the defeat (three to one) of a Government-backed scheme was a rude awakening for the Office of the Deputy Prime Minister and the range of regional agencies created since 1997. After all, it was felt that the…

  15. Adoption Resource Directory: Region X.

    ERIC Educational Resources Information Center

    1983

    State, regional, and national adoption resources are described in this directory for residents of Region X states (Alaska, Idaho, Oregon, and Washington). Emphasizing the adoption of children with special needs, the directory gives organizational contacts for parents in various stages of the adoption process and mentions resources for social…

  16. REGIONAL VULNERABILITY: A CONCEPTUAL FRAMEWORK

    EPA Science Inventory

    Regional vulnerability assessment, or ReVA, is an approach to place-based ecological risk assessment that is currently under development by the Office of Research and Development of the U.S. Environmental Protection Agency (EPA). The assessment is done at the scale of EPA region...

  17. MISR Regional VBBE Imagery Overview

    Atmospheric Science Data Center

    2016-08-24

    ... View Data  |  Download Data About this Web Site: Visualizations of select MISR Level 3 data for special regional ... Regional products are derived from averaging select Level 1 and Level 2 parameters over daily, monthly, seasonal and annual time periods. ...

  18. Regional Early Childhood Policy Review

    ERIC Educational Resources Information Center

    Evans, Judith

    2008-01-01

    The UNESCO-UNICEF joint regional policy review project was launched in September 2006 with the aim to support the countries of Asia-Pacific region in meeting the first goal of Education For All (EFA) on Early Childhood Care and Education (ECCE) by identifying, documenting and sharing good practices as well as constraints and challenges in early…

  19. Global forcing and regional interactions

    USGS Publications Warehouse

    1992-01-01

    The Climate System Modeling Program (CSMP) sponsored a “Global Forcing and Regional Interaction Workshop” from October 21 to 23, 1991, at Colorado State University's Pingree Park campus, to evaluate the relationship between global climate forcing and the response of the land surface on a regional scale. The general aim of the workshop was to develop specific action plans and preliminary science research strategies for regional-global interactions. Each participant was invited to identify tractable, high pay-off science issues related to global forcing and regional interactions. The workshop, with twenty-six participants about evenly split between atmospheric scientists, hydrologists, and ecologists, was also designed to facilitate a network of collaborators to prepare multidisciplinary research proposals. Discussion also focused on regional climate over the last 200 years and included the influence of atmosphere-land surface processes on natural climate variability. Several major recommendations were made on topics discussed.

  20. Disordered regions in transmembrane proteins.

    PubMed

    Tusnády, Gábor E; Dobson, László; Tompa, Peter

    2015-11-01

    The functions of transmembrane proteins in living cells are widespread; they range from various transport processes to energy production, from cell-cell adhesion to communication. Structurally, they are highly ordered in their membrane-spanning regions, but may contain disordered regions in the cytosolic and extra-cytosolic parts. In this study, we have investigated the disordered regions in transmembrane proteins by a stringent definition of disordered residues on the currently available largest experimental dataset, and show a significant correlation between the spatial distributions of positively charged residues and disordered regions. This finding suggests a new role of disordered regions in transmembrane proteins by providing structural flexibility for stabilizing interactions with negatively charged head groups of the lipid molecules. We also find a preference of structural disorder in the terminal--as opposed to loop--regions in transmembrane proteins, and survey the respective functions involved in recruiting other proteins or mediating allosteric signaling effects. Finally, we critically compare disorder prediction methods on our transmembrane protein set. While there are no major differences between these methods using the usual statistics, such as per residue accuracies, Matthew's correlation coefficients, etc.; substantial differences can be found regarding the spatial distribution of the predicted disordered regions. We conclude that a predictor optimized for transmembrane proteins would be of high value to the field of structural disorder. PMID:26275590

  1. Regional strategies for global leadership.

    PubMed

    Ghemawat, Pankaj

    2005-12-01

    The leaders of such global powerhouses as GE, Wal-Mart, and Toyota seem to have grasped two crucial truths: First, far from becoming submerged by the rising tide of globalization, geographic and other regional distinctions may in fact be increasing in importance. Second, regionally focused strategies, used in conjunction with local and global initiatives, can significantly boost a company's performance. The business and economic data reveal a highly regionalized world. For example, trade within regions, rather than across them, drove the surge of international commerce in the second half of the twentieth century. Regionalization is also apparent in foreign direct investment, companies' international sales, and competition among the world's largest multinationals. Harvard Business School Professor Pankaj Ghemawat says that the most successful companies employ five types of regional strategies in addition to--or even instead of--global ones: home base, portfolio, hub, platform, and mandate. Some companies adopt the strategies in sequence, but the most nimble switch from one to another and combine approaches as their markets and businesses evolve. At Toyota, for example, exports from the home base continue to be substantial even as the company builds up an international manufacturing presence. And as Toyota achieves economies of scale and scope with a strong network of hubs, the company also pursues economies of specialization through interregional mandates. Embracing regional strategies requires flexibility and creativity. A company must decide what constitutes a region, choose the most appropriate strategies, and mesh those strategies with the organization's existing structures. In a world that is neither truly global nor truly local, finding ways of coordinating within and across regions can deliver a powerful competitive advantage. PMID:16334585

  2. Regional strategies for global leadership.

    PubMed

    Ghemawat, Pankaj

    2005-12-01

    The leaders of such global powerhouses as GE, Wal-Mart, and Toyota seem to have grasped two crucial truths: First, far from becoming submerged by the rising tide of globalization, geographic and other regional distinctions may in fact be increasing in importance. Second, regionally focused strategies, used in conjunction with local and global initiatives, can significantly boost a company's performance. The business and economic data reveal a highly regionalized world. For example, trade within regions, rather than across them, drove the surge of international commerce in the second half of the twentieth century. Regionalization is also apparent in foreign direct investment, companies' international sales, and competition among the world's largest multinationals. Harvard Business School Professor Pankaj Ghemawat says that the most successful companies employ five types of regional strategies in addition to--or even instead of--global ones: home base, portfolio, hub, platform, and mandate. Some companies adopt the strategies in sequence, but the most nimble switch from one to another and combine approaches as their markets and businesses evolve. At Toyota, for example, exports from the home base continue to be substantial even as the company builds up an international manufacturing presence. And as Toyota achieves economies of scale and scope with a strong network of hubs, the company also pursues economies of specialization through interregional mandates. Embracing regional strategies requires flexibility and creativity. A company must decide what constitutes a region, choose the most appropriate strategies, and mesh those strategies with the organization's existing structures. In a world that is neither truly global nor truly local, finding ways of coordinating within and across regions can deliver a powerful competitive advantage.

  3. LLNL's Regional Seismic Discrimination Research

    SciTech Connect

    Hanley, W; Mayeda, K; Myers, S; Pasyanos, M; Rodgers, A; Sicherman, A; Walter, W

    1999-07-23

    As part of the Department of Energy's research and development effort to improve the monitoring capability of the planned Comprehensive Nuclear-Test-Ban Treaty international monitoring system, Lawrence Livermore Laboratory (LLNL) is testing and calibrating regional seismic discrimination algorithms in the Middle East, North Africa and Western Former Soviet Union. The calibration process consists of a number of steps: (1) populating the database with independently identified regional events; (2) developing regional boundaries and pre-identifying severe regional phase blockage zones; (3) measuring and calibrating coda based magnitude scales; (4a) measuring regional amplitudes and making magnitude and distance amplitude corrections (MDAC); (4b) applying the DOE modified kriging methodology to MDAC results using the regionalized background model; (5) determining the thresholds of detectability of regional phases as a function of phase type and frequency; (6) evaluating regional phase discriminant performance both singly and in combination; (7) combining steps 1-6 to create a calibrated discrimination surface for each stations; (8) assessing progress and iterating. We have now developed this calibration procedure to the point where it is fairly straightforward to apply earthquake-explosion discrimination in regions with ample empirical data. Several of the steps outlined above are discussed in greater detail in other DOE papers in this volume or in recent publications. Here we emphasize the results of the above process: station correction surfaces and their improvement to discrimination results compared with simpler calibration methods. Some of the outstanding discrimination research issues involve cases in which there is little or no empirical data. For example in many cases there is no regional nuclear explosion data at IMS stations or nearby surrogates. We have taken two approaches to this problem, first finding and using mining explosion data when available, and

  4. Future of multistate regional commissions

    SciTech Connect

    Newman, M.

    1980-04-01

    Multistate regional commissions in the United States have been used since 1965. The largest program has been that of the Appalachian Regional Commission (ARC). Institutional and financial barriers have been the most difficult problems encountered by the ARC and other programs (such as Title V commissions). Despite the imperfect performance of the existing regional commissions, they offer a demonstration that some improvement in governmental performance can be achieved. There is virtual unanimity among the nation's governors that this is the route for Federal state relations to follow. Also, the commission route is viewed privately as the most socially acceptable means to have a beneficial impact on government performance. (SAC)

  5. A regional technology transfer program

    NASA Technical Reports Server (NTRS)

    Chenery, P. J.

    1972-01-01

    The activities of the NC/STRC are reported. The background and organization of the regional dissemination center, and marketing methods are discussed along with the services provided, and available information resources.

  6. MISR Regional UAE2 Products

    Atmospheric Science Data Center

    2013-04-29

    ... those familiar with the MISR Level 1 and 2 products, this maps directly to those products; each Regional product summarizes selected ... Theoretical Basis Documents . Images available on this web site include the following parameters: Image Description ...

  7. Active Region Release Two CMEs

    NASA Video Gallery

    Solar material can be seen blowing off the sun in this video captured by NASA’s Solar Dynamics Observatory (SDO) on the night of Feb. 5, 2013. This active region on the sun sent out two coronal ...

  8. Regions.

    ERIC Educational Resources Information Center

    Moulin-Acevedo, Madeleine; And Others

    1993-01-01

    Includes "From School to Jobs: Africa's Dilemma" (Moulin-Acevedo); "Helping Change in Eastern Europe"; "Recognizing the Dignity of Indigenous Peoples"; "An Employment Plan for Pakistan"; and "Around the Continents." (JOW)

  9. Slot Region Radiation Environment Models

    NASA Astrophysics Data System (ADS)

    Sandberg, Ingmar; Daglis, Ioannis; Heynderickx, Daniel; Evans, Hugh; Nieminen, Petteri

    2013-04-01

    Herein we present the main characteristics and first results of the Slot Region Radiation Environment Models (SRREMs) project. The statistical models developed in SRREMs aim to address the variability of trapped electron and proton fluxes in the region between the inner and the outer electron radiation belt. The energetic charged particle fluxes in the slot region are highly dynamic and are known to vary by several orders of magnitude on both short and long timescales. During quiet times, the particle fluxes are much lower than those found at the peak of the inner and outer belts and the region is considered benign. During geospace magnetic storms, though, this region can fill with energetic particles as the peak of the outer belt is pushed Earthwards and the fluxes can increase drastically. There has been a renewed interest in the potential operation of commercial satellites in orbits that are at least partially contained within the Slot Region. Hence, there is a need to improve the current radiation belt models, most of which do not model the extreme variability of the slot region and instead provide long-term averages between the better-known low and medium Earth orbits (LEO and MEO). The statistical models developed in the SRREMs project are based on the analysis of a large volume of available data and on the construction of a virtual database of slot region particle fluxes. The analysis that we have followed retains the long-term temporal, spatial and spectral variations in electron and proton fluxes as well as the short-term enhancement events at altitudes and inclinations relevant for satellites in the slot region. A large number of datasets have been used for the construction, evaluation and inter-calibration of the SRREMs virtual dataset. Special emphasis has been given on the use and analysis of ESA Standard Radiation Environment Monitor (SREM) data from the units on-board PROBA-1, INTEGRAL, and GIOVE-B due to the sufficient spatial and long temporal

  10. Ig Constant Region Effects on Variable Region Structure and Function

    PubMed Central

    Janda, Alena; Bowen, Anthony; Greenspan, Neil S.; Casadevall, Arturo

    2016-01-01

    The adaptive humoral immune response is responsible for the generation of antimicrobial proteins known as immunoglobulin molecules or antibodies. Immunoglobulins provide a defense system against pathogenic microbes and toxins by targeting them for removal and/or destruction. Historically, antibodies have been thought to be composed of distinct structural domains known as the variable and constant regions that are responsible for antigen binding and mediating effector functions such as opsonization and complement activation, respectively. These domains were thought to be structurally and functionally independent. Recent work has revealed however, that in some families of antibodies, the two regions can influence each other. We will discuss the body of work that led to these observations, as well as the mechanisms that have been proposed to explain how these two different antibody regions may interact in the function of antigen binding. PMID:26870003

  11. Regional waveform calibration in the Pamir-Hindu Kush region

    NASA Astrophysics Data System (ADS)

    Zhu, Lupei; Helmberger, Donald V.; Saikia, Chandan K.; Woods, Bradley B.

    1997-10-01

    Twelve moderate-magnitude earthquakes (mb 4-5.5) in the Pamir-Hindu Kush region are investigated to determine their focal mechanisms and to relocate them using their regional waveform records at two broadband arrays, the Kyrgyzstan Regional Network (KNET), and the 1992 Pakistan Himalayas seismic experiment array (PAKH) in northern Pakistan. We use the "cut-and-paste" source estimation technique to invert the whole broadband waveforms for mechanisms and depths, assuming a one-dimensional velocity model developed for the adjacent Tibetan plateau. For several large events the source mechanisms obtained agree with those available from the Harvard centroid moment tensor (CMT) solutions. An advantage of using regional broadband waveforms is that focal depths can be better constrained either from amplitude ratios of Pnl to surface waves for crustal events or from time separation between the direct P and the shear-coupled P wave (sPn + sPmP) for mantle events. All the crustal events are relocated at shallower depths compared with their International Seismological Centre bulletin or Harvard CMT depths. After the focal depths are established, the events are then relocated horizontally using their first-arrival times. Only minor offsets in epicentral location are found for all mantle events and the bigger crustal events, while rather large offsets (up to 30 km) occur for the smaller crustal events. We also tested the performance of waveform inversion using only two broadband stations, one from the KNET array in the north of the region and one from the PAKH array in the south. We found that this geometry is adequate for determining focal depths and mechanisms of moderate size earthquakes in the Pamir-Hindu Kush region.

  12. Regional Transmission Projects: Finding Solutions

    SciTech Connect

    The Keystone Center

    2005-06-15

    The Keystone Center convened and facilitated a year-long Dialogue on "Regional Transmission Projects: Finding Solutions" to develop recommendations that will help address the difficult and contentious issues related to expansions of regional electric transmission systems that are needed for reliable and economic transmission of power within and across regions. This effort brought together a cross-section of affected stakeholders and thought leaders to address the problem with the collective wisdom of their experience and interests. Transmission owners sat at the table with consumer advocates and environmental organizations. Representatives from regional transmission organizations exchanged ideas with state and federal regulators. Generation developers explored common interests with public power suppliers. Together, the Dialogue participants developed consensus solutions about how to begin unraveling some of the more intractable issues surrounding identification of need, allocation of costs, and reaching consensus on siting issues that can frustrate the development of regional transmission infrastructure. The recommendations fall into three broad categories: 1. Recommendations on appropriate institutional arrangements and processes for achieving regional consensus on the need for new or expanded transmission infrastructure 2. Recommendations on the process for siting of transmission lines 3. Recommendations on the tools needed to support regional planning, cost allocation, and siting efforts. List of Dialogue participants: List of Dialogue Participants: American Electric Power American Transmission Company American Wind Energy Association California ISO Calpine Corporation Cinergy Edison Electric Institute Environmental Defense Federal Energy Regulatory Commission Great River Energy International Transmission Company ISO-New England Iowa Public Utility Board Kanner & Associates Midwest ISO National Association of Regulatory Utility Commissioners National Association

  13. Hierarchical probabilistic regionalization of volcanism for Sengan region, Japan.

    SciTech Connect

    Balasingam, Pirahas; Park, Jinyong; McKenna, Sean Andrew; Kulatilake, Pinnaduwa H. S. W.

    2005-03-01

    A 1 km square regular grid system created on the Universal Transverse Mercator zone 54 projected coordinate system is used to work with volcanism related data for Sengan region. The following geologic variables were determined as the most important for identifying volcanism: geothermal gradient, groundwater temperature, heat discharge, groundwater pH value, presence of volcanic rocks and presence of hydrothermal alteration. Data available for each of these important geologic variables were used to perform directional variogram modeling and kriging to estimate geologic variable vectors at each of the 23949 centers of the chosen 1 km cell grid system. Cluster analysis was performed on the 23949 complete variable vectors to classify each center of 1 km cell into one of five different statistically homogeneous groups with respect to potential volcanism spanning from lowest possible volcanism to highest possible volcanism with increasing group number. A discriminant analysis incorporating Bayes theorem was performed to construct maps showing the probability of group membership for each of the volcanism groups. The said maps showed good comparisons with the recorded locations of volcanism within the Sengan region. No volcanic data were found to exist in the group 1 region. The high probability areas within group 1 have the chance of being the no volcanism region. Entropy of classification is calculated to assess the uncertainty of the allocation process of each 1 km cell center location based on the calculated probabilities. The recorded volcanism data are also plotted on the entropy map to examine the uncertainty level of the estimations at the locations where volcanism exists. The volcanic data cell locations that are in the high volcanism regions (groups 4 and 5) showed relatively low mapping estimation uncertainty. On the other hand, the volcanic data cell locations that are in the low volcanism region (group 2) showed relatively high mapping estimation uncertainty

  14. Does regional anaesthesia improve outcome?

    PubMed

    Hopkins, P M

    2015-12-01

    This review examines the recent evidence of an impact of regional anaesthesia on important clinical outcomes. Evidence was obtained from a variety of studies, with increasing numbers of analyses of large databases being prominent. The benefits and limitations of these approaches are considered in order to provide a context for interpretation of the data they generate. There should be little argument that correctly performed and appropriately used regional anaesthetic techniques can provide the most effective postoperative analgesia for the duration of the block, but the majority of studies suggest that this does not translate into improved longer-term surgical outcomes. The evidence for reduced incidence of major complications when regional anaesthesia is compared with, or added to, general anaesthesia is mixed. There appears to be a small effect in reducing blood loss during major joint arthroplasty. Some, but not all, studies demonstrate a reduced incidence of respiratory and infective complications with regional anaesthesia, but the effect on cardiovascular complications is variable. There are even some data consistent with a hypothesis that general anaesthesia may be protective against postoperative cognitive dysfunction. In conclusion, there is probably no generally applicable benefit in long-term outcomes with regional anaesthesia. More likely is an interaction between patient factors, the surgical procedure, and the relative capability of the anaesthetist to manage different types of anaesthesia.

  15. Correlation of regional breath sound with regional ventilation in emphysema

    SciTech Connect

    Ploysongsang, Y.; Pare, J.A.; Macklem, P.T.

    1982-09-01

    We measured regional breath sound intensities (Ib) by a microphone amplifier system in 8 subjects with emphysema. We also measured regional white noise transmissions (Tn) from the same areas in all subjects. The recorded areas were 5, 10, 15, and 20 cm from the apex of the lung just lateral to the right anterior midclavicular line. Xenon ventilation indexes (xenon tidal raw counts, an index of total regional ventilation; xenon equilibration raw counts, an index of ventilating lung volume; xenon ventilation per unit volume (Vr), an index of ventilation per unit volume) were also recorded from the same areas. The Ib, Tn, Ib/Tn (an index of sound generation), and xenon ventilation indexes were all expressed as a fraction of the mean value of all four recorded areas. The Ib and Ib/Tn correlated best with the xenon tidal raw counts, correlated well with the xenon equilibration raw counts, and correlated poorly with Vr. We conclude that Ib and Ib/Tn can be used to quantify regional ventilation in subjects with emphysema.

  16. Satellites monitor Atlanta regional development

    USGS Publications Warehouse

    Todd, William J.; Blackmon, C.C.; Rudasill, R.G.

    1979-01-01

    Since the adoption of a Regional Development Plan in 1975, the Atlanta Regional Commission has investigated methods for monitoring regional development patterns in a periodic, efficient manner. A promising approach appears to be the use of Landsat satellite data. In cooperation with the Earth Resources Observation Systems (EROS) Data Center, the commission used machine processing of digital temporal overlays of Landsat data collected in 1972, 1974 and 1976 to detect land use and land cover changes in the Atlanta metropolitan area. Results of the analysis revealed the conversion of forested and open space areas to residential, commercial and industrial land use in the urban-rural fringe zone from 1972 to 1974 and from 1974 to 1976. The study indicated that a land use and land cover change-detection program may be used to revise small-area forecasts of land use, population and employment made by planning models.

  17. Northeast Regional Biomass Energy Program

    SciTech Connect

    O'Connell, R.A.

    1992-04-01

    The Northeast Regional Biomass Program (NRBP) is entering its ninth year of operation. The management and the objectives have virtually remained unchanged and are stated as follows. The program conducted by NRBP has three basic features: (1) a state grant component that provides funds (with a 50 percent matching requirement) to each of the states in the region to strengthen and integrate the work of state agencies involved in biomass energy; (2) a series of technical reports and studies in areas that have been identified as being of critical importance to the development of biomass energy in the region; and (3) a continuous long range planning component with heavy private sector involvement that helps to identify activities necessary to spur greater development and use of biomass energy in the Northeast.

  18. Desmoid Fibromatosis of Submandibular Region

    PubMed Central

    Ali, Rohana; Parthiban, Nirmalatiban; O’Dwyer, Tadgh

    2014-01-01

    Desmoid fibromatosis is a benign yet locally aggressive tumor with a tendency to recur. It causes considerable morbidity particularly when it arises in a small area in the head and neck region. This tumor is extremely rare in the submandibular region. We report a case of desmoid tumor in the submandibular region in a 32-year-old male who presented with right submandibular swelling postextraction of right lower wisdom tooth. Excision biopsy was carried out initially following inconclusive fine needle aspiration and discussion at multidisciplinary meeting. The tumor recurred 4 months following initial excisional biopsy necessitating a more radical secondary approach involving segmental mandibulectomy. Intraoperatively we also noted that the tumor was originating from the site of previous wisdom tooth extraction, raising the question of surgical trauma as precursor of desmoid tumor. We achieved a negative resection margin and a complete remission for 24 months. PMID:25013548

  19. Parsing surrounding space into regions.

    PubMed

    Franklin, N; Henkel, L A; Zangas, T

    1995-07-01

    Surrounding space is not inherently organized, but we tend to treat it as though it consisted of regions (e.g., front, back, right, and left). The current studies show that these conceptual regions have characteristics that reflect our typical interactions with space. Three experiments examined the relative sizes and resolutions of front, back, left, and right around oneself. Front, argued to be the most important horizontal region, was found to be (a) largest, (b) recalled with the greatest precision, and (c) described with the greatest degree pf detao. Our findings suggest that some of the characteristics of the category model proposed by Huttenlocher, Hedges, and Duncan (1991) regarding memory for pictured circular displays may be generalized to space around oneself. More broadly, our results support and extend the spatial framework analysis of representation of surrounding space (Franklin & Tversky, 1990).

  20. Regional sea level change in the Thailand-Indonesia region

    NASA Astrophysics Data System (ADS)

    Fenoglio-Marc, L.; Becker, M. H.; Buchhaupt, C.

    2013-12-01

    It is expected that the regional sea level rise will strongly affect particular regions with direct impacts including submergence of coastal zones, rising water tables and salt intrusion into groundwaters. It can possibly also exacerbate other factors as floodings, associated to storms and hurricanes, as well as ground subsidence of anthropogenic nature. The Thailand-Vietnam-Indonesian region is one of those zones. On land, the Chao-Praya and Mekong Delta are fertile alluvial zones. The potential for sea level increases and extreme floodings due to global warming makes the Deltas a place where local, regional, and global environmental changes are converging. We investigate the relative roles of regional and global mechanisms resulting in multidecadal variations and inflections in the rate of sea level change. Altimetry and GRACE data are used to investigate the variation of land floodings. The land surface water extent is evaluated at 25 km sampling intervals over fifteen years (1993-2007) using a multisatellite methodology which captures the extent of episodic and seasonal inundations, wetlands, rivers, lakes, and irrigated agriculture, using passive and active (microwaves and visible observations. The regional sea level change is analysed during the period 1993-2012 using satellite altimetry, wind and ocean model data, tide gauge data and GPS. The rates of absolute eustatic sea level rise derived from satellite altimetry through 19-year long precise altimeter observations are in average higher than the global mean rate. Several tide gauge records indicate an even higher sea level rise relative to land. We show that the sea level change is closely linked to the ENSO mode of variability and strongly affected by changes in wind forcing and ocean circulation. We have determined the vertical crustal motion at a given tide gauge location by differencing the tide gauge sea level time-series with an equivalent time-series derived from satellite altimetry and by computing