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.

Tendril-producing Geysers on Enceladus South Polar Terrain

NASA Image and Video Library

2015-04-14

This graphic plots the source locations of geysers scientists have located on Enceladus south polar terrain, with the 36 most active geyser sources marked and color coded by the behavior of the grains erupting from the geysers.

Periodic changes in effluent chemistry at cold-water geyser: Crystal geyser in Utah

DOE PAGES

Han, Weon Shik; Watson, Z. T.; Kampman, Niko; ...

2017-04-20

Crystal geyser is a CO 2-driven cold-water geyser which was originally drilled in the late 1930’s in Green River, Utah. By utilizing a suite of temporal groundwater sample datasets, in situ monitoring of temperature, pressure, pH and electrical conductivity from multiple field trips to Crystal geyser from 2007 to 2014, periodic trends in groundwater chemistry from the geyser effluent were identified. Based on chemical characteristics, the primary sourcing aquifers are characterized to be both the Entrada and Navajo Sandstones with a minor contribution from Paradox Formation brine. The single eruption cycle at Crystal geyser lasted over four days and wasmore » composed of four parts: Minor Eruption (mEP), Major Eruption (MEP), Aftershock Eruption (Ae) and Recharge (R). During the single eruption cycle, dissolved ionic species vary 0–44% even though the degree of changes for individual ions are different. Generally, Na +, K +, Cl -and SO 4 2- regularly decrease at the onset and throughout the MEP. These species then increase in concentration during the mEP. In contrast, Ca 2+, Mg 2+, Fe 2+ and Sr 2+ increase and decrease in concentration during the MEP and mEP, respectively. The geochemical inverse modeling with PHREEQC was conducted to characterize the contribution from three end-members (Entrada Sandstone, Navajo Sandstone and Paradox Formation brine) to the resulting Crystal geyser effluent. Results of the inverse modeling showed that, during the mEP, the Navajo, Entrada and brine supplied 62–65%, 36–33% and 1–2%, respectively. During the MEP, the contribution shifted to 53–56%, 45–42% and 1–2% for the Navajo, Entrada and Paradox Formation brine, respectively. Finally, these changes in effluent characteristics further support the hypothesis by Watson et al. (2014) that the mEP and MEP are driven by different sources and mechanisms.« less

Periodic changes in effluent chemistry at cold-water geyser: Crystal geyser in Utah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Weon Shik; Watson, Z. T.; Kampman, Niko

Crystal geyser is a CO 2-driven cold-water geyser which was originally drilled in the late 1930’s in Green River, Utah. By utilizing a suite of temporal groundwater sample datasets, in situ monitoring of temperature, pressure, pH and electrical conductivity from multiple field trips to Crystal geyser from 2007 to 2014, periodic trends in groundwater chemistry from the geyser effluent were identified. Based on chemical characteristics, the primary sourcing aquifers are characterized to be both the Entrada and Navajo Sandstones with a minor contribution from Paradox Formation brine. The single eruption cycle at Crystal geyser lasted over four days and wasmore » composed of four parts: Minor Eruption (mEP), Major Eruption (MEP), Aftershock Eruption (Ae) and Recharge (R). During the single eruption cycle, dissolved ionic species vary 0–44% even though the degree of changes for individual ions are different. Generally, Na +, K +, Cl -and SO 4 2- regularly decrease at the onset and throughout the MEP. These species then increase in concentration during the mEP. In contrast, Ca 2+, Mg 2+, Fe 2+ and Sr 2+ increase and decrease in concentration during the MEP and mEP, respectively. The geochemical inverse modeling with PHREEQC was conducted to characterize the contribution from three end-members (Entrada Sandstone, Navajo Sandstone and Paradox Formation brine) to the resulting Crystal geyser effluent. Results of the inverse modeling showed that, during the mEP, the Navajo, Entrada and brine supplied 62–65%, 36–33% and 1–2%, respectively. During the MEP, the contribution shifted to 53–56%, 45–42% and 1–2% for the Navajo, Entrada and Paradox Formation brine, respectively. Finally, these changes in effluent characteristics further support the hypothesis by Watson et al. (2014) that the mEP and MEP are driven by different sources and mechanisms.« less

Investigation of Earthquake and Geyser Events in the Upper Geyser Basin of Yellowstone National Park from a Nodal Array

NASA Astrophysics Data System (ADS)

Garcia, S.; Karplus, M. S.; Farrell, J.; Lin, F. C.; Smith, R. B.

2017-12-01

A large seismic nodal array incorporating 133 three-component, 5-Hz geophones deployed for two weeks in early November 2015 in the Upper Geyser Basin recorded earthquake and hydrothermal activity. The University of Utah, the University of Texas at El Paso, and Yellowstone National Park collaborated to deploy Fairfield Nodal ZLand 3-C geophones concentrically centered around the Old Faithful Geyser with an average station spacing of 50 m and an aperture of 1 km. The array provided a unique dataset to investigate wave propagation through various fractures and active geysers in a hydrothermal field located over the Yellowstone hotspot. The complicated sub-surface features associated with the hydrothermal field appear to impact earthquake wave propagation in the Upper Geyser Basin and to generate seismic signals. Previous work using ambient noise cross-correlation has found an intricately fractured sub-surface that provides pathways for water beneath parts of the Upper Geyser Basin that likely feed Old Faithful and other nearby geysers and hot springs. For this study, we used the data to create visualizations of local earthquake, teleseismic earthquake, and hydrothermal events as they propagate through the array. These ground motion visualizations allow observation of wave propagation through the geyser field, which may indicate the presence of anomalous structure impacting seismic velocities and attenuation. Three teleseismic events were observed in the data, two 6.9MW earthquakes that occurred off the coast of Coquimbo, Colombia 9,000km from the array and one 6.5MW near the Aleutian Islands 4,500km from the array. All three teleseismic events observed in the data exhibited strong direct P-wave arrivals and several additional phases. One local earthquake event (2.5ML) 100km from the Upper Geyser Basin was also well-recorded by the array. Time-domain spectrograms show the dominant frequencies present in the recordings of these events. The two 6.9MW earthquakes in Chile

The Geysers Geothermal Field Update1990/2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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, butmore » 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

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).

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…

Enceladus' Geysers and Small-scale Thermal Hot Spots: Spatial Correlations and Implications

NASA Astrophysics Data System (ADS)

Porco, C.; Helfenstein, P.; Goguen, J.

2016-12-01

The geysering south polar terrain (SPT) of Enceladus has been a major focus of the Cassini mission ever since Cassini's first sighting of it in images taken in early 2005 (1). A high resolution imaging survey of the region conducted over the course of seven years resulted in the identification of 100 geysers erupting from the four main fractures crossing the SPT (2). The Cassini Visual and Infrared Mapping Spectrometer (VIMS) detected enhanced thermal emission arising from these fractures and taking the form of small-scale ( ≤ 10 meter) discrete spots (3,4). Four of these hot spot observations have already been spatially associated with four geysers on the Baghdad Sulcus fracture (2). The inferred spatial correlation and small size of each hot spot eliminated shear heating along the near-surface walls of the fractures as the source of the heat and erupting materials. Instead, it was concluded that condensation of vapor (and liquid), and the deposition of latent heat, on the near-surface vent walls, and the subsequent conduction of that heat to the surface, was the source of the observed thermal emission. This indicated that the hot spots are the secondary signature of a geyser eruption process deeply rooted in the moon's sub-surface liquid water reservoir (2). We extend the examination of these relationships to include seven additional VIMS observations of hot spots. At the present time, we have associated a total of 11 VIMS hot spot observations with 13 (maybe 14) geysers distributed over all four tiger stripe fractures. It's not uncommon for the locations of multiple (often two but sometimes three) surveyed geysers to overlap within estimated uncertainties. This can occur when they have different 3D orientations, making them identifiable in our 2014 survey as distinct features; However, the raw, thermally unmodeled VIMS maps, with their (relatively) coarse resolution, may register at that location only one corresponding hot spot. It is also possible that

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

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.

The fascinating and complex dynamics of geyser eruptions

USGS Publications Warehouse

Hurwitz, Shaul; Manga, Michael

2017-01-01

Geysers episodically erupt liquid and vapor. Despite two centuries of scientific study, basic questions persist—why do geysers exist? What determines eruption intervals, durations, and heights? What initiates eruptions? Through monitoring eruption intervals, analyzing geophysical data, taking measurements within geyser conduits, performing numerical simulations, and constructing laboratory models, some of these questions have been addressed. Geysers are uncommon because they require a combination of abundant water recharge, magmatism, and rhyolite flows to supply heat and silica, and large fractures and cavities overlain by low-permeability materials to trap rising multiphase and multicomponent fluids. Eruptions are driven by the conversion of thermal to kinetic energy during decompression. Larger and deeper cavities permit larger eruptions and promote regularity by isolating water from weather variations. The ejection velocity may be limited by the speed of sound of the liquid + vapor mixture.

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

NASA Astrophysics Data System (ADS)

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

2011-05-01

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

"Tepid" Geysers above salt caverns

NASA Astrophysics Data System (ADS)

Bérest, Pierre; Brouard, Benoît; Zakharov, Vassily

2018-06-01

The formation of a brine geyser erupting from the wellhead of a large underground salt cavern is described. In most cases, the brine outflow from an opened cavern is slow; it results from the cavern creep closure and the thermal expansion of the cavern brine. These two processes are smooth; however, the brine outflow often is bumpy, as it is modulated by atmospheric pressure variations that generate an elastic increase (or decrease) of both cavern and brine volumes. In addition, when the flow is fast enough, the brine thermodynamic behavior in the wellbore is adiabatic. The cold brine expelled from the cavern wellhead is substituted with warm brine entering the borehole bottom, resulting in a lighter brine column. The brine outflow increases. In some cases, the flow becomes so fast that inertia terms must be taken into account. A geyser forms, coming to an end when the pressure in the cavern has dropped sufficiently. A better picture is obtained when head losses are considered. A closed-form solution can be reached. This proves that two cases must be distinguished, depending on whether the cold brine initially contained in the wellbore is expelled fully or not. It can also be shown that geyser formation is a rare event, as it requires both that the wellbore be narrow and that the cavern be very compressible. This study stemmed from an actual example in which a geyser was observed. However, scarce information is available, making any definite interpretation difficult. xml:lang="fr"

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.

Southeast geysers effluent pipeline project. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 wasmore » 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.« less

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

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.

Experimental study of geysers through a vent pipe connected to flowing sewers.

PubMed

Huang, Biao; Wu, Shiqiang; Zhu, David Z; Schulz, Harry E

2017-04-01

Geysers of air-water mixtures in urban drainage systems is receiving considerable attention due to public safety concerns. However, the geyser formation process and its relation with air release from pressurized pipes are still relatively little known. A large-scale physical model, that consisted of a main tunnel with a diameter of 270 mm and a length of 25 m connecting two reservoirs and a vertical vent pipe, was established to investigate geyser evolution and pressure transients. Experimental results including dynamic pressure data and high speed videos were analysed in order to characterize geysering flow through the vent pipe. Pressure transients were observed during geysering events. Their amplitudes were found to be about three times the driving pressure head and their periods were close to the classic surge tank predictions. The influence of flow rate and vent pipe size were examined: geyser heights and pressure peaks decreased for small flow rate and large diameter vent pipe. It is suggested that geyser heights are related with the pressure head and the density of the air-water mixture.

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.

Back-Projection Imaging of extended, high-frequency pre-, co-, and post-eruptive seismicity at El Jefe Geyser, El Tatio Geyser Field, Chile

NASA Astrophysics Data System (ADS)

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

2017-12-01

El Tatio Geyser Field in northern Chile is the third largest geyser field in the world. It is comprised of 3 basins that span 10 km x 10 km at an average elevation of 4250 m and contains at least 80 active geysers. Heavy tourist traffic and previous geothermal exploration make the field relatively non-pristine and ideal for performing minimally invasive geophysical experiments. We deployed a dense array of 51 L-28 3-component geophones (1-10 m spacing, corner frequency 4.5 Hz, 1000 Hz sample rate), and 6 Trillium 120 broadband seismometers (2-20 m spacing, long period corner 120 s, 500 Hz sample rate) in a 50 m x 50 m grid in the central Upper Geyser Basin (the largest basin in area at 5 km x 5 km) during October 2012 as part of a collaborative study of hydrothermal systems between Stanford University; U.C. Berkeley; U. of Chile, Santiago; U. of Tokyo; and the USGS. The seismic array was designed to target at El Jefe Geyser (EJG), a columnar geyser (eruption height 1-1.5 m) with a consistent periodic eruption cycle of 132 +/- 3 s. Seismicity at EJG was recorded continuously for 9 days during which 6000 total eruptions occurred. Excluding periods of high anthropogenic noise (i.e. tourist visits, field work), the array recorded 2000 eruptions that we use to create 4D time-lapse images of the evolution of seismic source locations before, during and after EJG eruptions. We use a new back-projection processing technique to locate geyser signals, which tend to be harmonic and diffuse in nature, during characteristic phases of the EJG eruption cycle. We obtain Vp and Vs from ambient-field tomography and estimates of P and S propagation from a hammer source recorded by the array. We use these velocities to back-project and correlate seismic signals from all available receiver-pairs to all potential source locations in a subsurface model assuming straight-line raypaths. We analyze results for individual and concurrent geyser sources throughout an entire EJG eruption cycle

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.

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

Illuminating the Voluminous Subsurface Structures of Old Faithful Geyser, Yellowstone National Park

NASA Astrophysics Data System (ADS)

Hurwitz, Shaul; Shelly, David R.

2017-10-01

Old Faithful geyser in Yellowstone National Park has attracted scientific research for almost a century and a half. Temperature and pressure measurements and video recordings in the geyser's conduit led to proposals of many quantitative eruption models. Nevertheless, information on the processes that initiate the geyser's eruption in the subsurface remained limited. Two new studies, specifically Wu et al. (2017) and Ward and Lin (2017), take advantage of recent developments in seismic data acquisition technology and processing methods to illuminate subsurface structures. Using a dense array of three-component nodal geophones, these studies delineate subsurface structures on a scale larger than previously realized, which exert control on the spectacular eruptions of Old Faithful geyser.

The mathematical model that describes the periodic spouting of a geyser induced by boiling

NASA Astrophysics Data System (ADS)

Kagami, Hiroyuki

2017-04-01

We have derived and modified the dynamical model of a geyser induced by gas inflow and regular or irregular spouting dynamics of geysers induced by gas inflow has been reproduced by the model. On the other hand, though we have derived the dynamical model of a geyser induced by boiling, periodic change between the spouting state and the pause state has not been adequately modeled by the model. In this connection, concerning a geyser induced by gas inflow we have proposed the model as described below. Because pressure in the spouting tube decreases obeying to the Bernoulli's theorem when the spouting state begins and water in the spouting tube begins to flow, inflow of groundwater into the spouting tube occurs. When the amount of this inflow reaches a certain amount, the spouting state transforms to the pause state. In this study, by applying this idea to the dynamical model of a geyser induced by boiling, the periodic change between the spouting state and the pause state could be reappeared. As a result, the whole picture of the spouting mechanism of a geyser induced by boiling became clear. This research results would give hints on engineering repair in order to prevent the weakening or the depletion of the geyser. And this study would be also useful for protection of geysers as tourism and environmental resources.

Geysers advanced direct contact condenser research

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 themore » 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.« less

El Cobreloa: A geyser with two distinct eruption styles

NASA Astrophysics Data System (ADS)

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

2014-08-01

We performed field measurements at a geyser nicknamed "El Cobreloa," located in the El Tatio Geyser Field, Northern Andes, Chile. The El Cobreloa geyser has two distinct eruption styles: minor eruptions and more energetic and long-lived major eruptions. Minor eruptions splash hot water intermittently over an approximately 4 min time period. Major eruptions begin with an eruption style similar to minor eruptions, but then transition to a voluminous liquid water-dominated eruption, and finally end with energetic steam discharge that continues for approximately 1 h. We calculated eruption intervals by visual observations, acoustic measurements, and ground temperature measurements and found that each eruption style has a regular interval: 4 h and 40 min for major eruptions and ˜14 min for minor eruptions. Eruptions of El Cobreloa and geochemical measurements suggest interaction of three water sources. The geyser reservoir, connected to the surface by a conduit, is recharged by a deep, hot aquifer. More deeply derived magmatic fluids heat the reservoir. Boiling in the reservoir releases steam and hot liquid water to the overlying conduit, causing minor eruptions, and heating the water in the conduit. Eventually the water in the conduit becomes warm enough to boil, leading to a steam-dominated eruption that empties the conduit. The conduit is then recharged by a shallow, colder aquifer, and the eruption cycle begins anew. We develop a model for minor eruptions which heat the water in the conduit. El Cobreloa provides insight into how small eruptions prepare the geyser system for large eruptions.

Locating hydrothermal acoustic sources at Old Faithful Geyser using Matched Field Processing

NASA Astrophysics Data System (ADS)

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

2011-10-01

In 1992, a large and dense array of geophones was placed around the geyser vent of Old Faithful, in the Yellowstone National Park, to determine the origin of the seismic hydrothermal noise recorded at the surface of the geyser and to understand its dynamics. Old Faithful Geyser (OFG) is a small-scale hydrothermal system where a two-phase flow mixture erupts every 40 to 100 min in a high continuous vertical jet. Using Matched Field Processing (MFP) techniques on 10-min-long signal, we localize the source of the seismic pulses recorded at the surface of the geyser. Several MFP approaches are compared in this study, the frequency-incoherent and frequency-coherent approach, as well as the linear Bartlett processing and the non-linear Minimum Variance Distorsionless Response (MVDR) processing. The different MFP techniques used give the same source position with better focalization in the case of the MVDR processing. The retrieved source position corresponds to the geyser conduit at a depth of 12 m and the localization is in good agreement with in situ measurements made at Old Faithful in past studies.

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.

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.

The plumbing of Old Faithful Geyser revealed by hydrothermal tremor

NASA Astrophysics Data System (ADS)

Vandemeulebrouck, J.; Roux, P.; Cros, E.

2013-05-01

Faithful Geyser in Yellowstone National Park (USA) has attracted numerous scientific investigations for over two centuries to better understand its geological structure, the physics of its eruptions, and the controls of its intermittency. Using data acquired with a seismic array in 1992, we track the sources of hydrothermal tremor produced by boiling and cavitation inside the geyser. The location of seismic sources identifies a previously unknown lateral cavity at 15 m below the surface, on the SW side of the vent, and connected to the conduit. This reservoir is activated at the beginning of each geyser eruption cycle and plays a major role in the oscillatory behavior of the water level in the conduit before each eruption.

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

Geyser Valley on the Kamchatka Peninsula

NASA Image and Video Library

2007-06-12

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. This image was acquired by NASA Terra spacecraft.

Evolution of Effluent Chemistry at Crystal Geyser, Green River, Utah

NASA Astrophysics Data System (ADS)

Han, W. S.; Park, E.; Choung, S.; Kim, C. Y.; Piao, J.; Han, G.

2016-12-01

Several cold-water geysers and springs are located adjacent to the Green River in Utah where two major east-west faults, the Little Grand Wash and the Salt Wash Graben faults, trend roughly parallel to each other. Among these springs and geysers is Crystal Geyser, located immediately north of the Little Grand Wash fault and approximately 6 km south of the town of Green River. In this study, the fluid mechanics of the regularly erupting Crystal Geyser was investigated by instrumenting its conduit with pressure, temperature, pH, EC, and dissolved oxygen sensors, measuring every 1 minute during and between eruptions. The single eruption cycle at Crystal geyser lasted over four days and was composed of four parts: Minor Eruption (mEP), Major Eruption (MEP), Aftershock Eruption (Ae) and Recharge (R). Current eruption patterns exhibit a bimodal distribution although previous measurements and anecdotal evidence suggests that this pattern was different prior to recent seismic activity. Based on chemical characteristics, the primary sourcing aquifers characterized to be both Entrada and Navajo Sandstones with minor contribution from Paradox Formation brine. Contemporaneously, dissolved ionic species vary 0-44% while transition from mEP, MEP and R even if the degree of changes was different from individual ion. Generally, Na+, K+, Cl- and SO42- regularly decrease at the onset and throughout the MEP. These species then increase in concentration during the mEP. Conversely, Ca2+, Mg2+, Fe2+ and Sr2+ decrease and increase in concentration during the MEP and mEP, respectively. Inverse geochemical modeling was conducted to characterize the contribution of Crystal geyser effluents from endmembers of Entrada Sandstone, Navajo Sandstone and Paradox Formations. Results of inverse modeling show that, during the mEP, the Navajo, Entrada and brine supply 62-65%, 33-36% and 1%, respectively. During the MEP, the contribution shifts to 53-56%, 42-45% and 1% for the Navajo, Entrada and Brine

Protecting the Geyser Basins of Yellowstone National Park: Toward a New National Policy for a Vulnerable Environmental Resource

NASA Astrophysics Data System (ADS)

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.

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

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.

The Time Variability of Individual Geysers in the Plume of Enceladus

NASA Astrophysics Data System (ADS)

Trumbo, S. K.; Ewald, S. P.; Ingersoll, A. P.

2016-12-01

Porco et al. (2014) [1] published the locations of 100 jets along the so-called "tiger stripes" that feed the massive plume of Enceladus. Hedman et al. (2013) [2] observed fluctuations in integrated plume brightness in response to periodic tidal forcing on the orbital timescale of Enceladus, in which the plume is brightest near apocenter and dimmest near pericenter. The thin crack models of Hurford et al. (2007, 2012) [3, 4] suggest that individual jets should respond to the same forces on similar timescales. However, if the jets are produced via vapor and liquid propagation through thin subterranean cracks, then they may also be controlled thermodynamically and dependent on the timescale of ice buildup on the conduit walls. Ingersoll and Ewald (2016) [5] demonstrate that the plume also varies on decadal timescales, perhaps as a result of an eleven-year tide or long-term ice accumulation within source cracks. We examine Cassini ISS Narrow Angle Camera images spanning 2005 - 2012 in order to assess the temporal variability of individual geysers and regional emission in the plume. We observe both the appearance and disappearance of individual jets, as well as visible changes in regional emission. Our observations suggest localized variations on timescales of months to years that are not easily tied to mean anomaly, but that may be indicative of subsurface processes. Theoretical models of the geyser mechanisms and subsurface plumbing predict closure timescales of individual cracks that are dependent on model parameters, such as crack width, crack tortuosity, and water table depth [6, 7, 8]. Thus, we discuss possible implications of these observations for both the mechanism and anatomy of an Enceladus geyser. [1] Porco et al. (2014), AJ, 148, 3. [2] Hedman et al. (2013), Nature, 500, 182 - 184. [3] Hurford et al. (2007), Nature, 447, 292 - 294. [4] Hurford et al. (2012), Icarus, 220, 896 - 903. [5] Ingersoll and Ewald (2016), Icarus, in review. [6] Ingersoll and

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.

Red Geyser: A New Class of Galaxy with Large-scale AGN-driven Winds

NASA Astrophysics Data System (ADS)

Roy, Namrata; Bundy, Kevin; Cheung, Edmond; MaNGA Team

2018-01-01

A new class of quiescent (non-star-forming) galaxies harboring possible AGN-driven winds have been discovered using the spatially resolved optical spectroscopy from the ongoing SDSS-IV MaNGA (Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory) survey. These galaxies named "red geysers" constitute 5%-10% of the local quiescent galaxy population and are characterized by narrow bisymmetric ionized gas emission patterns. These enhanced patterns are seen in equivalent width maps of Hα, [OIII] and other strong emission lines. They are co-aligned with the ionized gas velocity gradients but significantly misaligned with stellar velocity gradients. They also show very high gas velocity dispersions (~200 km/s). Considering these observations in light of models of the gravitational potential, Cheung et al. argued that red geysers host large-scale AGN-driven winds of ionized gas that may play a role in suppressing star formation at late times. In this work, we test the hypothesis that AGN activity is ultimately responsible for the red geyser phenomenon. We compare the nuclear radio activity of the red geysers to a matched control sample of galaxies of similar stellar mass, redshift, rest frame NUV–r color and axis ratio. and additionally, control for the presence of ionized gas. We have used 1.4 GHz radio continuum data from the VLA FIRST Survey to stack the radio flux from the red geyser sample and control sample. We find that the red geysers have a higher average radio flux than the control galaxies at > 3σ significance. Our sample is restricted to rest-frame NUV–r color > 5, thus ruling out possible radio emission due to star formation activity. We conclude that red geysers are associated with more active AGN, supporting a feedback picture in which episodic AGN activity drives large-scale but relatively weak ionized winds in many in many early-type galaxies.

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.

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

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.

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.

The Geysers pipeline project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dellinger, M.; Allen, E.

A unique public/private partnership of local, state, federal and corporate stakeholders are constructing the world`s first wastewater-to-electricity system at The Geysers. A rare example of a genuinely {open_quotes}sustainable{close_quotes} energy system, three Lake County communities will recycle their treated wastewater effluent through the southeast portion of the The Geysers steamfield to produce approximately 625,000 MWh annually from six existing geothermal power plants. In effect, the communities` effluent will produce enough power to indefinitely sustain their electric needs, along with enough extra power for thousands of other California consumers. Because of the project`s unique sponsorship, function and environmental impacts, its implementation hasmore » required: (1) preparation of a consolidated state environmental impact report (EIR) and federal environmental impact statement (EIS), and seven related environmental agreements and management plans; (2) acquisition of 25 local, state, and federal permits; (3) negotiation of six federal and state financial assistance agreements; (4) negotiation of six participant agreements on construction, operation and financing of the project, and (5) acquisition of 163 easements from private land owners for pipeline construction access and ongoing maintenance. The project`s success in efficiently and economically completing these requirements is a model for geothermal innovation and partnering throughout the Pacific Rim and elsewhere internationally.« less

Imaging and structural analysis of the Geyser field, Iceland, from underwater and drone based photogrammetry

NASA Astrophysics Data System (ADS)

Walter, Thomas R.; Jousset, Philippe; Allahbakhshi, Massoud; Witt, Tanja; Gudmundsson, Magnus T.; Pall Hersir, Gylfi

2017-04-01

The Haukadalur thermal area, southwestern Iceland, is composed of a large number of individual thermal springs, geysers and hot pots that are roughly elongated in a north-south direction. The Haukadalur field is located on the eastern slope of a hill, that is structurally delimited by fissures associated with the Western Volcanic Zone. A detailed analysis on the spatial distribution, structural relations and permeability in the Haukadalur thermal area remained to be carried out. By use of high resolution unmanned aerial vehicle (UAV) based optical and radiometric infrared cameras, we are able to identify over 350 distinct thermal spots distributed in distinct areas. Close analysis of their arrangement yields a preferred direction that is found to be consistent with the assumed tectonic trend in the area. Furthermore by using thermal isolated deep underwater cameras we are able to obtain images from the two largest geysers. Geysir, name giving for all geysers in the world, and Strokkur at depths exceeding 20 m. Near to the surface, the conduit of the geysers are near circular, but at a depth the shape changes into a crack-like elongated fissure. In this presentation we discuss the structural relationship of the deeper and shallower parts of these geysers and elaborate on the conditions of geyser and hot pot formations, with general relevance also for other thermal fields elsewhere.

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

Anatomy of Old Faithful From Subsurface Seismic Imaging of the Yellowstone Upper Geyser Basin

NASA Astrophysics Data System (ADS)

Wu, Sin-Mei; Ward, Kevin M.; Farrell, Jamie; Lin, Fan-Chi; Karplus, Marianne; Smith, Robert B.

2017-10-01

The Upper Geyser Basin in Yellowstone National Park contains one of the highest concentrations of hydrothermal features on Earth including the iconic Old Faithful geyser. Although this system has been the focus of many geological, geochemical, and geophysical studies for decades, the shallow (<200 m) subsurface structure remains poorly characterized. To investigate the detailed subsurface geologic structure including the hydrothermal plumbing of the Upper Geyser Basin, we deployed an array of densely spaced three-component nodal seismographs in November of 2015. In this study, we extract Rayleigh wave seismic signals between 1 and 10 Hz utilizing nondiffusive seismic waves excited by nearby active hydrothermal features with the following results: (1) imaging the shallow subsurface structure by utilizing stationary hydrothermal activity as a seismic source, (2) characterizing how local geologic conditions control the formation and location of the Old Faithful hydrothermal system, and (3) resolving a relatively shallow (10-60 m) and large reservoir located 100 m southwest of Old Faithful geyser.

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.

Hydrothermal disturbances at the Norris Geyser Basin, Yellowstone National Park (USA) in 2003

NASA Astrophysics Data System (ADS)

Lowenstern, J. B.; Heasler, H.; Smith, R. B.

2003-12-01

The Norris Geyser Basin in north-central Yellowstone National Park (YNP) experienced a series of notable changes during 2003, including formation of new hot springs and fumaroles, renewed activity of dormant geysers and elevated ground temperatures. This abstract provides a short synopsis of the new hydrothermal activity. In 2000, Yellowstone's tallest geyser, Steamboat, erupted after a dormant period of nearly 9 years. It erupted twice in 2002 and then again on 26 March and 27 April 2003. Surges in flux of thermal water preceding the eruptions (preplay) were recorded by a couplet of temperature data loggers placed in the outlet stream. The data indicated pulses of water flow with 1 and ~3 day intervals. On 10 July 2003, a new thermal feature was reported just west of Nymph Lake, ~ 3.5 km northwest of the Norris Museum. A linear series of vigorous fumaroles, about 75 m long had formed in a forested area, ~ 200 m up a hill on the lake's west shore. Fine particles of rock and mineral fragments coated nearby vegetation. Fumarole temperatures were around the local boiling temperature of water (92° C). After two months, somewhat reduced steam emission was accompanied by discharge of ~ 3-10 gallons per minute of near-neutral thermal water. Trees within 4 meters of the lineament were dead and were being slowly combusted. Porkchop Geyser in Norris' Back Basin had been dormant since it exploded in 1989, littering the nearby area with boulders up to over 1 m in diameter. Since that time, its water had remained well below the boiling temperature of water. From 1 April through 1 July `03, the temperature of waters in Porkchop's vent increased continuously from 67° to 88° C. Each Summer, Norris' Back Basin experiences an "annual disturbance" where individual hot springs and geysers typically show anomalous boiling, and have measurable increases in turbidity, acidity and SO4/Cl ratios. The disturbance has been linked to depressurization of the hydrothermal system as the

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.

Soda Geyser Geochemistry

DOE Data Explorer

Neupane, Ghanashyam; McLing, Travis

2017-04-01

These brine samples are collected from the Soda Geyser (a thermal feature, temperature ~30 C) in Soda Springs, Idaho. These samples also represent the overthrust brines typical of oil and gas plays in western Wyoming. Samples were collected from the source and along the flow channel at different distances from the source. By collecting and analyzing these samples we are able to increase the density and quality of data from the western Wyoming oil and gas plays. Furthermore, the sampling approach also helped determine the systematic variation in REE concentration with the sampling distance from the source. Several geochemical processes are at work along the flow channels, such as degassing, precipitation, sorption, etc.

Induced and triggered earthquakes at The Geysers geothermal reservoir

NASA Astrophysics Data System (ADS)

Johnson, Lane R.; Majer, Ernest L.

2017-05-01

The Geysers geothermal reservoir in northern California is the site of numerous studies of both seismicity induced by injection of fluids and seismicity triggered by other earthquakes. Data from a controlled experiment in the northwest part of The Geysers in the time period 2011 to 2015 are used to study these induced and triggered earthquakes and possible differences between them. Causal solutions to the elastic equations for a porous medium show how fluid injection generates fast elastic and diffusion waves followed by a much slower diffusive wake. Calculations of fluid increment, fluid pressure and elastic stress are used to investigate both when and why seismic failure takes place. Taking into account stress concentrations caused by material heterogeneity leads to the conclusion that fluid injection by itself can cause seismic activity with no need for tectonic forces. Induced events that occur at early times are best explained by changes in stress rate, while those that occur at later times are best explained by changes in stress. While some of the seismic activity is clearly induced by injection of fluids, also present is triggered seismicity that includes aftershock sequences, swarms of seismicity triggered by other earthquakes at The Geysers and clusters of multiple earthquakes. No basic differences are found between the source mechanisms of these different types of earthquakes.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 steammore » 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.« less

Testing for the 'predictability' of dynamically triggered earthquakes in The Geysers geothermal field

NASA Astrophysics Data System (ADS)

Aiken, Chastity; Meng, Xiaofeng; Hardebeck, Jeanne

2018-03-01

The Geysers geothermal field is well known for being susceptible to dynamic triggering of earthquakes by large distant earthquakes, owing to the introduction of fluids for energy production. Yet, it is unknown if dynamic triggering of earthquakes is 'predictable' or whether dynamic triggering could lead to a potential hazard for energy production. In this paper, our goal is to investigate the characteristics of triggering and the physical conditions that promote triggering to determine whether or not triggering is in anyway foreseeable. We find that, at present, triggering in The Geysers is not easily 'predictable' in terms of when and where based on observable physical conditions. However, triggered earthquake magnitude positively correlates with peak imparted dynamic stress, and larger dynamic stresses tend to trigger sequences similar to mainshock-aftershock sequences. Thus, we may be able to 'predict' what size earthquakes to expect at The Geysers following a large distant earthquake.

Testing for the ‘predictability’ of dynamically triggered earthquakes in Geysers Geothermal Field

USGS Publications Warehouse

Aiken, Chastity; Meng, Xiaofeng; Hardebeck, Jeanne L.

2018-01-01

The Geysers geothermal field is well known for being susceptible to dynamic triggering of earthquakes by large distant earthquakes, owing to the introduction of fluids for energy production. Yet, it is unknown if dynamic triggering of earthquakes is ‘predictable’ or whether dynamic triggering could lead to a potential hazard for energy production. In this paper, our goal is to investigate the characteristics of triggering and the physical conditions that promote triggering to determine whether or not triggering is in anyway foreseeable. We find that, at present, triggering in The Geysers is not easily ‘predictable’ in terms of when and where based on observable physical conditions. However, triggered earthquake magnitude positively correlates with peak imparted dynamic stress, and larger dynamic stresses tend to trigger sequences similar to mainshock–aftershock sequences. Thus, we may be able to ‘predict’ what size earthquakes to expect at The Geysers following a large distant earthquake.

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.

Geyser preplay and eruption in a laboratory model with a bubble trap

NASA Astrophysics Data System (ADS)

Adelstein, Esther; Tran, Aaron; Saez, Carolina Muñoz; Shteinberg, Alexander; Manga, Michael

2014-09-01

We present visual observations and temperature measurements from a laboratory model of a geyser. Our model incorporates a bubble trap, a zone in which vapor can accumulate in the geyser's subsurface plumbing, in a vertical conduit connected to a basal chamber. Analogous features have been identified at several natural geysers. We observe three types of eruptions: 1) rising bubbles eject a small volume of liquid in a weak spout (small eruption); 2) boiling occurs in the conduit above the bubble trap (medium eruption); and 3) boiling occurs in the conduit and chamber (large eruption). In the last two cases, boiling in the conduit causes a rapid hydrostatic pressure drop that allows for the rise and eruption of liquid water in a vigorous spout. Boiling initiates at depth rather than propagating downward from the surface. In a single eruption cycle, multiple small eruptions precede every medium and large eruption. At least one eruption cycle that culminates in a medium eruption (i.e., a quiescent period followed by a series of small eruptions leading up to a medium eruption) precedes every eruption cycle that culminates in a large eruption. We find that the transfer of fluid with high enthalpy to the upper conduit during small and medium eruptions is necessary to heat the upper conduit and prepare the system for the full boiling required for a large eruption. The placement of the bubble trap midway up the conduit allows for more efficient heating of the upper conduit. Our model provides insight into the influence of conduit geometry on eruption style and the importance of heat transfer by smaller events in preparing the geyser system for eruption.

Ground penetrating radar documents short-term near-surface hydrological changes around Old Faithful Geyser, Yellowstone National Park, USA

NASA Astrophysics Data System (ADS)

Lynne, Bridget Y.; Heasler, Henry; Jaworowski, Cheryl; Smith, Gary J.; Smith, Isaac J.; Foley, Duncan

2018-04-01

In April 2015, Ground Penetrating Radar (GPR) was used to characterize the shallow subsurface (< 5 m depth) of the western sinter slope immediately adjacent to Old Faithful Geyser and near the north side of an inferred geyser cavity. A series of time-sequence images were collected between two eruptions of Old Faithful Geyser. Each set of time-sequence GPR recordings consisted of four transects aligned to provide coverage near the potential location of the inferred 15 m deep geyser chamber. However, the deepest penetration we could achieve with a 200 MHz GPR antennae was 5 m. Seven time-sequence events were collected over a 48-minute interval to image changes in the near-surface, during pre- and post-eruptive cycles. Time-sequence GPR images revealed a series of possible micro-fractures in a highly porous siliceous sinter in the near-surface that fill and drain repetitively, immediately after an eruption and during the recharge period prior to the next main eruptive event.

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.

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

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

Low-Q structure related to partially saturated pores within the reservoir beneath The Geysers area in the northern California

NASA Astrophysics Data System (ADS)

Matsubara, M.

2011-12-01

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) owing to withdrawal of steam from the reservoir. I perform attenuation tomography in this region to investigate the state of vapor and liquid within the reservoir. The target region, 38.5-39.0°N and 122.5-123°W, covers The Geysers area. I use seismograms of 1,231 events whose focal mechanism are determined among 65,810 events recorded by the Northern California Earthquake Data Center from 2002 to 2008 in the target region. The band-pass filtered seismograms are analyzed for collecting the maximum amplitude data. There are 26 stations that have a three-component seismometer among 47 seismic stations. I use the P- and S-wave maximum amplitudes during the two seconds after the arrival of those waves in order to avoid coda effects. A total of 8,545 P- and 1,168 S-wave amplitude data for 949 earthquakes recorded at 47 stations are available for the analysis using the attenuation tomographic method derived from the velocity tomographic method (Matsubara et al., 2005, 2008) in which spatial velocity correlation and station corrections are introduced to the original code of Zhao et al. (1992). I use 3-D velocity structure obtained by Thurber et al. (2009). The initial Q value is set to 150, corresponding to the average Q of the northern California (Ford et al., 2010). At sea level, low-Q zones are found extending from the middle of the steam reservoir within the main greywacke to the south part of the reservoir. At a depth of 1 km below sea level, a low-Q zone is located solely in the southern part of the reservoir. However, at a depth of 2 km a low-Q zone is located beneath the northern part of the reservoir. At depths of 1 to 3 km a felsite batholith in the deeper portions of the reservoir, and it corresponds

Machine learning reveals cyclic changes in seismic source spectra in Geysers geothermal field.

PubMed

Holtzman, Benjamin K; Paté, Arthur; Paisley, John; Waldhauser, Felix; Repetto, Douglas

2018-05-01

The earthquake rupture process comprises complex interactions of stress, fracture, and frictional properties. New machine learning methods demonstrate great potential to reveal patterns in time-dependent spectral properties of seismic signals and enable identification of changes in faulting processes. Clustering of 46,000 earthquakes of 0.3 < M L < 1.5 from the Geysers geothermal field (CA) yields groupings that have no reservoir-scale spatial patterns but clear temporal patterns. Events with similar spectral properties repeat on annual cycles within each cluster and track changes in the water injection rates into the Geysers reservoir, indicating that changes in acoustic properties and faulting processes accompany changes in thermomechanical state. The methods open new means to identify and characterize subtle changes in seismic source properties, with applications to tectonic and geothermal seismicity.

Machine learning reveals cyclic changes in seismic source spectra in Geysers geothermal field

PubMed Central

Paisley, John

2018-01-01

The earthquake rupture process comprises complex interactions of stress, fracture, and frictional properties. New machine learning methods demonstrate great potential to reveal patterns in time-dependent spectral properties of seismic signals and enable identification of changes in faulting processes. Clustering of 46,000 earthquakes of 0.3 < ML < 1.5 from the Geysers geothermal field (CA) yields groupings that have no reservoir-scale spatial patterns but clear temporal patterns. Events with similar spectral properties repeat on annual cycles within each cluster and track changes in the water injection rates into the Geysers reservoir, indicating that changes in acoustic properties and faulting processes accompany changes in thermomechanical state. The methods open new means to identify and characterize subtle changes in seismic source properties, with applications to tectonic and geothermal seismicity. PMID:29806015

Nowcasting Earthquakes: A Comparison of Induced Earthquakes in Oklahoma and at the Geysers, California

NASA Astrophysics Data System (ADS)

Luginbuhl, Molly; Rundle, John B.; Hawkins, Angela; Turcotte, Donald L.

2018-01-01

Nowcasting is a new method of statistically classifying seismicity and seismic risk (Rundle et al. 2016). In this paper, the method is applied to the induced seismicity at the Geysers geothermal region in California and the induced seismicity due to fluid injection in Oklahoma. Nowcasting utilizes the catalogs of seismicity in these regions. Two earthquake magnitudes are selected, one large say M_{λ } ≥ 4, and one small say M_{σ } ≥ 2. The method utilizes the number of small earthquakes that occurs between pairs of large earthquakes. The cumulative probability distribution of these values is obtained. The earthquake potential score (EPS) is defined by the number of small earthquakes that has occurred since the last large earthquake, the point where this number falls on the cumulative probability distribution of interevent counts defines the EPS. A major advantage of nowcasting is that it utilizes "natural time", earthquake counts, between events rather than clock time. Thus, it is not necessary to decluster aftershocks and the results are applicable if the level of induced seismicity varies in time. The application of natural time to the accumulation of the seismic hazard depends on the applicability of Gutenberg-Richter (GR) scaling. The increasing number of small earthquakes that occur after a large earthquake can be scaled to give the risk of a large earthquake occurring. To illustrate our approach, we utilize the number of M_{σ } ≥ 2.75 earthquakes in Oklahoma to nowcast the number of M_{λ } ≥ 4.0 earthquakes in Oklahoma. The applicability of the scaling is illustrated during the rapid build-up of injection-induced seismicity between 2012 and 2016, and the subsequent reduction in seismicity associated with a reduction in fluid injections. The same method is applied to the geothermal-induced seismicity at the Geysers, California, for comparison.

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.

Searching for the Signature of Wastewater Injection in continuous GPS Data from The Geysers Geothermal Field

NASA Astrophysics Data System (ADS)

Terry, R. L.; Funning, G.; Floyd, M.

2017-12-01

The Geysers geothermal field in California, which provides a large portion of northern California's power, has seen declining steam pressures over the past three decades, accompanied by surface subsidence. Together, these two phenomena are likely the result of the exploitation of the reservoir without adequate time for natural restoration. To combat the decline in steam pressures, The Geysers began injecting imported wastewater into the geothermal reservoir in 1997 and expanded injection in 2003. In 2012 and 2013, we installed three continuously recording GPS stations in The Geysers to closely monitor crustal deformation due to both the extraction of steam and the injection of wastewater. To assess the impact of the current injection and extraction activities on the geothermal reservoir, we analyze the position time-series from these GPS stations alongside wastewater injection and steam extraction data. We use common-mode filtering to remove any regionally-correlated noise from our GPS time series, and also estimate and subtract any seasonal signals present. To predict the effect of injection and production on surface movement, we summed the monthly time series of well data within a rectangular grid framework. We then use an array of Mogi sources based on each grid cell's total volume change to calculate the expected surface deformation due to these volume changes at depth. The temporal resolution provided by GPS allows us to characterize more accurately the properties of the subsurface geothermal reservoir related to forcing. For example, based on a similar spatiotemporal relationship between injection and seismicity, we hypothesize that there may be a delayed deformation response following injection, related to the permeability of the reservoir, and are undertaking detailed comparisons between our time series data to identify this response. Overall changes in the sense and rate of vertical motion in the field due to injection over time are also expected. We

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.

Magnitude and Rupture Area Scaling Relationships of Seismicity at The Northwest Geysers EGS Demonstration Project

NASA Astrophysics Data System (ADS)

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

2017-12-01

Enhanced Geothermal System (EGS) resource development requires knowledge of subsurface physical parameters to quantify the evolution of fracture networks. Spatio-temporal source properties, including source dimension, rupture area, slip, rupture speed, and slip velocity of induced seismicity are of interest at The Geysers geothermal field, northern California to map the coseismic facture density of the EGS swarm. In this investigation we extend our previous finite-source analysis of selected M>4 earthquakes to examine source properties of smaller magnitude seismicity located in the Northwest Geysers Enhanced Geothermal System (EGS) demonstration project. Moment rate time histories of the source are found using empirical Green's function (eGf) deconvolution using the method of Mori (1993) as implemented by Dreger et al. (2007). The moment rate functions (MRFs) from data recorded using the Lawrence Berkeley National Laboratory (LBNL) short-period geophone network are inverted for finite-source parameters including the spatial distribution of fault slip, rupture velocity, and the orientation of the causative fault plane. The results show complexity in the MRF for the studied earthquakes. Thus far the estimated rupture area and the magnitude-area trend of the smaller magnitude Geysers seismicity is found to agree with the empirical relationships of Wells and Coppersmith (1994) and Leonard (2010), which were developed for much larger M>5.5 earthquakes worldwide indicating self-similar behavior extending to M2 earthquakes. We will present finite-source inversion results of the micro-earthquakes, attempting to extend the analysis to sub Mw, and demonstrate their magnitude-area scaling. The extension of the scaling laws will then enable the mapping of coseismic fracture density of the EGS swarm in the Northwest Geysers based on catalog moment magnitude estimates.

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.

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

Triton's Geyser-like Plumes

NASA Astrophysics Data System (ADS)

Brown, Robert H.; Soderblom, Laurence A.

In August of 1989, while flying by Neptune's largest satellite Triton, Voyager 2 made another of its stunning discoveries in its epic journey through the outer solar system. First seen by one of us (LAS) and Tammy Becker (also of the USGS), after stereoscopic examination of a group of images taken very near Voyager's closest approach to the satellite, were at least two, geyser-like plumes spewing almost perfectly vertical columns of material 1-km across roughly 8-km high into Triton's atmosphere; there the columns were sheared by stratospheric winds into 100-km-long, dark clouds thought to composed of condensed nitrogen mixed with organic particles. Triton's plumes may be the most unique of all the manifestations of geologic activity on satellites in the outer solar system in that their energy source may be sunlight trapped below Triton's surface in a so-called "solid-state greenhouse". This talk will focus on the physical characteristics of those plumes, and on the various mechanisms proposed to explain their presence and apparent persistence on Triton.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 shallowmore » 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.« less

Columnar travertines: bio-influenced genesis, Porcelana Geysers, Northern Patagonia, Chile

NASA Astrophysics Data System (ADS)

Ruiz, B. S.; Morata, D.; Díez, B.; Daniele, L.

2017-12-01

Porcelana Geysers are located on the slopes of Barranco Colorado volcano, southern Chile, and is characterized by having a lateral hydrothermal fluid transport and an important CO2 content, having high gas exsolution rates on the surface at temperatures above 80°C. But it does not seem to be enough to explain the genesis of columnar travertines more than 3 meters high, considering that precipitation rates counteracts erosive rates due to rainy climate of the zone and the high slope gradient (>10 mm/h). The presence of extremophilic microbial diversity could explain this exceptional travertine morphology, particularly Phyla Cyanobacteria, Bacteroidetes and Order Thermales, which is evidenced by the vast visible presence of extracellular polymeric substances (EPS), reducing conditions in hot springs waters, microscopic and macroscopic textures and isotopic compositions of travertines, which are lower than the values that thermogenic travertines usually present (δ13C values from -4.85‰ to -3.37‰). These biotic processes would increase total dissolved gas pressure and [CO2]AQ values (over 0.05 mmol/L), and hence making the hydrostatic and bubbling pressure lower in the geysers vent fluids, which increases the amount of bubbles and their size and precipitation total rate of calcium carbonate (about 0.003 mm/h)

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.

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.

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

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.

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

Monitoring deformation at the Geysers Geothermal Field, California using C-band and X-band interferometric synthetic aperture radar

DOE PAGES

Vasco, D. W.; Rutqvist, Jonny; Ferretti, Alessandro; ...

2013-06-07

In this study, we resolve deformation at The Geysers Geothermal Field using two distinct sets of interferometric synthetic aperture radar (InSAR) data. The first set of observations utilize archived European Space Agency C-band synthetic aperture radar data from 1992 through 1999 to image the long-term and large-scale subsidence at The Geysers. The peak range velocity of approximately 50 mm/year agrees with previous estimates from leveling and global positioning system observations. Data from a second set of measurements, acquired by TerraSAR-X satellites, extend from May 2011 until April 2012 and overlap the C-band data spatially but not temporally. These X-band data,more » analyzed using a combined permanent and distributed scatterer algorithm, provide a higher density of scatterers (1122 per square kilometer) than do the C-band data (12 per square kilometer). The TerraSAR-X observations resolve 1 to 2 cm of deformation due to water injection into a Northwest Geysers enhanced geothermal system well, initiated on October 2011. Lastly, the temporal variation of the deformation is compatible with estimates from coupled numerical modeling.« less

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.

Industrially induced changes in Earth structure at the Geysers Geothermal Area, California

NASA Astrophysics Data System (ADS)

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

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.

El Cobreloa: A geyser with two distinct eruption styles

NASA Astrophysics Data System (ADS)

Namiki, A.; Munoz, C.; Manga, M.; Hurwitz, S.; King, E.; Negri, A.; Ortega, P.; Patel, A.; Rudolph, M.

2013-12-01

El Cobreloa geyser has two distinct eruption styles: vigorous major eruptions, and less energetic minor eruptions. Minor eruptions splash hot water intermittently over an approximately 4 minute time period. Major eruptions begin with an eruption style similar to minor eruptions, but then transition to a voluminous and water-dominated eruption, and finally end with energetic steam discharge. The steam discharge continues for approximately 1 hour. We calculated the eruption intervals by visual observations, acoustic measurements, and ground temperature measurements. All of measurements consistently show that each eruption style has a regular interval: 4 hours and 40 minutes for major eruptions, and ~13 minutes for minor eruptions. From these observations, we infer that there are two boiling loci that source each type of eruption, one at the bottom and the other at the top of the conduit. If the bottom of the conduit is hot enough, boiling begins at the bottom of the conduit to make a steam slug. As this slug ascends in the conduit, it heats the surrounding water. If the slug rises fast enough it splashes water when it reaches the surface, creating minor eruptions. Each successive steam slug continues to heat water in the conduit until it eventually reaches the boiling temperature everywhere. Once the top of the conduit begins boiling, the energetic steam discharge begins and the boiling propagates downward. Such a process causes major eruption. Geysers are often studied as an analogue to magmatic volcanoes because it is easier to document how mass and energy transfer lead to eruptions. El Cobreloa provides insight into how the system becomes primed for large eruptions.

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).

A model for internal oscillations in geysers, with application to Old Faithful (Yellowstone, USA)

NASA Astrophysics Data System (ADS)

Rudolph, Maxwell L.; Sohn, Robert A.

2017-09-01

We present a mechanical model for internal oscillations in geysers with "bubble trap" configurations, where ascending gas or vapor becomes trapped beneath the roof of a cavity that is laterally offset from the eruption conduit. We consider two cases, one in which the trapped gas behaves as an isothermal ideal gas, and one where it is treated as isenthalpic steam. In both cases the system behaves as a damped, harmonic oscillator with a resonant frequency that is sensitive to the conduit geometries and fluid volumes. We use the model to predict internal oscillation frequencies for Old Faithful geyser, in Yellowstone, USA, using conduit geometry constraints from the literature, and find that the frequencies predicted by the model are consistent with observations ( 1 Hz). We show that systematic frequency increases during the recharge cycle, when the fluid volume of the system is increasing due to recharge, are consistent with either a decrease in the amount (both volume and mass) of trapped gas or vapor, a decrease in the eruption conduit area, or a combination of both.

Anatomy of Old Faithful hydrothermal system from subsurface seismic imaging of the Yellowstone Upper Geyser Basin

NASA Astrophysics Data System (ADS)

Wu, S. M.; Lin, F. C.; Farrell, J.; Ward, K. M.; Karplus, M. S.; Smith, R. B.

2017-12-01

The Upper Geyser Basin (UGB) in Yellowstone National Park contains one of the highest concentrations of hydrothermal features on Earth including the iconic Old Faithful Geyser (OFG). Although this system has been the focus of many geological, geochemical, and geophysical studies, the shallow (<200 m) subsurface structure and the hydrothermal tremor behavior remain poorly characterized. To probe the detailed structure that relates to the hydrothermal plumbing of the UGB, we deployed dense arrays of 3-C 5-Hz geophones in both November of 2015 and 2016, composed of 133 stations with 50 m spacing, and 519 station locations, with an 20 m spacing, respectively. By applying seismic interferometry techniques, we extracted Rayleigh-wave signals between 1-10 Hz via seismic signals excited by nearby hydrothermal features (e.g. geysers and pools). We observe a clear lateral velocity boundary at 3.3 Hz frequency that delineates a higher phase velocity of 1.6 km/sec in the NE and a lower phase velocity of 1.0 km/sec in the SW corresponding to the local geologic formation of rhyolitic and glacial deposits, respectively. We also image a relatively shallow (20-60 m deep) large reservoir with an estimated porosity 30% located 100 meters southwest of the OFG from the significant spatial-dependent waveform distortions and delays between 5-10 Hz frequency. This reservoir is likely controlled by the local geology with a rhyolitic deposit in the NE acting as a relatively impermeable barrier to vertical fluid ascent. To understand the pre-eruption tremor signals from OFG, we first study the seismic waveforms recorded at the closest station to the OFG cone. Many highly repetitive seismic pulses associated with bubble collapse, which compose the tremor signal, can be identified. Using a reference event template and the cross-correlation method, we can determine the onset of each individual bubbling event using a cross-correlation coefficient threshold of 0.8. Based on the detected timing

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 tomore » 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.« less

Seismic source parameters of the induced seismicity at The Geysers geothermal area, California, by a generalized inversion approach

NASA Astrophysics Data System (ADS)

Picozzi, Matteo; Oth, Adrien; Parolai, Stefano; Bindi, Dino; De Landro, Grazia; Amoroso, Ortensia

2017-04-01

The accurate determination of stress drop, seismic efficiency and how source parameters scale with earthquake size is an important for seismic hazard assessment of induced seismicity. We propose an improved non-parametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for the attenuation and site contributions. Then, the retrieved source spectra are inverted by a non-linear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (ML 2-4.5) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations of the Lawrence Berkeley National Laboratory Geysers/Calpine surface seismic network, more than 17.000 velocity records). We find for most of the events a non-selfsimilar behavior, empirical source spectra that requires ωγ source model with γ > 2 to be well fitted and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes, and that the proportion of high frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with the earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that, in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping fault in the fluid pressure diffusion.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aminzadeh, Fred; Sammis, Charles; Sahimi, Mohammad

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.

Turning community wastes into sustainable geothermal energy: The S.E. Geysers effluent pipeline project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dellinger, M.; Allen, E.

A unique public/private partnership of local, state, federal, and corporate stakeholders are constructing the world`s first wastewater-to-electricity system at The Geysers. A rare example of a genuinely {open_quotes}sustainable{close_quote} energy system, three Lake County communities will recycle their treated wastewater effluent through the southeast portion of The Geysers steamfield to produce approximately 625,000 MWh annually from six existing geothermal power plants. In effect, the communities` effluent will produce enough power to indefinitely sustain their electric needs, along with enough extra power for thousands of other California consumers. Because of the project`s unique sponsorship, function, and environmental impacts, its implementation has required:more » (1) preparation of a consolidated state environmental impact report (EIR) and federal environmental impact statement (EIS), and seven related environmental agreements and management plans; (2) acquisition of 25 local, state, and federal permits; (3) negotiation of six federal and state financial assistance agreements; (4) negotiation of six participant agreements on construction, operation, and financing of the project; and (5) acquisition of 163 easements from private land owners for pipeline construction access and ongoing maintenance. The project`s success in efficiently and economically completing these requirements is a model for geothermal innovation and partnering throughout the Pacific Rim and elsewhere internationally.« less

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

The Variability and Interpretation of Earthquake Source Mechanisms in The Geysers Geothermal Field From a Bayesian Standpoint Based on the Choice of a Noise Model

NASA Astrophysics Data System (ADS)

Mustać, Marija; Tkalčić, Hrvoje; Burky, Alexander L.

2018-01-01

Moment tensor (MT) inversion studies of events in The Geysers geothermal field mostly focused on microseismicity and found a large number of earthquakes with significant non-double-couple (non-DC) seismic radiation. Here we concentrate on the largest events in the area in recent years using a hierarchical Bayesian MT inversion. Initially, we show that the non-DC components of the MT can be reliably retrieved using regional waveform data from a small number of stations. Subsequently, we present results for a number of events and show that accounting for noise correlations can lead to retrieval of a lower isotropic (ISO) component and significantly different focal mechanisms. We compute the Bayesian evidence to compare solutions obtained with different assumptions of the noise covariance matrix. Although a diagonal covariance matrix produces a better waveform fit, inversions that account for noise correlations via an empirically estimated noise covariance matrix account for interdependences of data errors and are preferred from a Bayesian point of view. This implies that improper treatment of data noise in waveform inversions can result in fitting the noise and misinterpreting the non-DC components. Finally, one of the analyzed events is characterized as predominantly DC, while the others still have significant non-DC components, probably as a result of crack opening, which is a reasonable hypothesis for The Geysers geothermal field geological setting.

Potential application of radiogenic isotopes and geophysical methods to understand the hydrothermal dystem of the Upper Geyser Basin, Yellowstone National Park

USGS Publications Warehouse

Paces, James B.; Long, Andrew J.; Koth, Karl R.

2015-01-01

Numerous geochemical and geophysical studies have been conducted at Yellowstone National Park to better understand the hydrogeologic processes supporting the thermal features of the Park. This report provides the first 87Sr/86Sr and 234U/238U data for thermal water from the Upper Geyser Basin (UGB) intended to evaluate whether heavy radiogenic isotopes might provide insight to sources of groundwater supply and how they interact over time and space. In addition, this report summarizes previous geophysical studies made at Yellowstone National Park and provides suggestions for applying non-invasive ground and airborne studies to better understand groundwater flow in the subsurface of the UGB. Multiple samples from Old Faithful, Aurum, Grand, Oblong, and Daisy geysers characterized previously for major-ion concentrations and isotopes of water (δ2H, δ18O, and 3H) were analyzed for Sr and U isotopes. Concentrations of dissolved Sr and U are low (4.3–128 ng g-1 Sr and 0.026–0.0008 ng g-1 U); consequently only 87Sr/86Sr data are reported for most samples. Values of 87Sr/86Sr for most geysers remained uniform between April and September 2007, but show large increases in all five geysers between late October 2007 and early April, 2008. By late summer of 2008, 87Sr/86Sr values returned to values similar to those observed a year earlier. Similar patterns are not present in major-ion data measured on the same samples. Furthermore, large geochemical differences documented between geysers are not observed in 87Sr/86Sr data, although smaller differences between sites may be present. Sr-isotope data are consistent with a stratified hydrologic system where water erupted in spring and summer of 2007 and summer of 2008 equilibrated with local intracaldera rhyolite flows at shallower depths. Water erupted between October 2007 and April 2008 includes greater amounts of groundwater that circulated deep enough to acquire a radiogenic 87Sr/86Sr, most likely from Archean basement

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.

Analysis of induced seismicity at The Geysers geothermal field, California

NASA Astrophysics Data System (ADS)

Emolo, A.; Maercklin, N.; Matrullo, E.; Orefice, A.; Amoroso, O.; Convertito, V.; Sharma, N.; Zollo, A.

2012-12-01

Fluid injection, steam extraction, and reservoir stimulation in geothermal systems lead to induced seismicity. While in rare cases induced events may be large enough to pose a hazard, on the other hand the microseismicity provides information on the extent and the space-time varying properties of the reservoir. Therefore, microseismic monitoring is important, both for mitigation of unwanted effects of industrial operations and for continuous assessment of reservoir conditions. Here we analyze induced seismicity at The Geysers geothermal field in California, a vapor-dominated field with the top of the main steam reservoir some 1-3 km below the surface. Commercial exploitation began in the 1960s, and the seismicity increased with increasing field development. We focus our analyses on induced seismicity recorded between August 2007 and October 2011. Our calibrated waveform database contains some 15000 events with magnitudes between 1.0 and 4.5 and recorded by the LBNL Geysers/Calpine surface seismic network. We associated all data with events from the NCEDC earthquake catalog and re-picked first arrival times. Using selected events with at least 20 high-quality P-wave picks, we determined a minimum 1-D velocity model using VELEST. A well-constrained P-velocity model shows a sharp velocity increase at 1-2 km depth (from 3 to 5 km/s) and then a gradient-like trend down to about 5 km depth, where velocities reach values of 6-7 km/s. The station corrections show coherent, relatively high, positive travel time delays in the NW zone, thus indicating a strong lateral variation of the P-wave velocities. We determined an average Vp-to-Vs ratio of 1.67, which is consistent with estimates from other authors for the same time period. The events have been relocated in the new model using a non-linear probabilistic methods. The seismicity appears spatially diffused in a 15x10 km2 area elongated in NW-SE direction, and earthquake depths range between 0 and 6 km. As in previous

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.

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.

Empirical Green's tensor retrieved from ambient noise cross-correlations at The Geysers geothermal field, Northern California

NASA Astrophysics Data System (ADS)

Nayak, Avinash; Taira, Taka'aki; Dreger, Douglas S.; Gritto, Roland

2018-04-01

We retrieve empirical Green's functions in the frequency range (˜0.2-0.9 Hz) for interstation distances ranging from ˜1 to ˜30 km (˜0.22 to ˜6.5 times the wavelength) at The Geysers geothermal field, Northern California, from coherency of ambient seismic noise being recorded by a variety of sensors (broad-band, short-period surface and borehole sensors, and one accelerometer). The applied methodology preserves the intercomponent relative amplitudes of the nine-component Green's tensor that allows us to directly compare noise-derived Green's functions (NGFs) with normalized displacement waveforms of complete single-force synthetic Green's functions (SGFs) computed with various 1-D and 3-D velocity models using the frequency-wavenumber integration method and a 3-D finite-difference wave propagation method, respectively. These comparisons provide an effective means of evaluating the suitability of different velocity models to different regions of The Geysers, and assessing the quality of the sensors and the NGFs. In the T-Tangential, R-Radial, Z-Vertical reference frame, the TT, RR, RZ, ZR and ZZ components (first component: force direction, second component: response direction) of NGFs show clear surface waves and even body-wave phases for many station pairs. They are also broadly consistent in phase and intercomponent relative amplitudes with SGFs for the known local seismic velocity structure that was derived primarily from body-wave traveltime tomography, even at interstation distances less than one wavelength. We also find anomalous large amplitudes in TR, TZ, RT and ZT components of NGFs at small interstation distances (≲4 km) that can be attributed to ˜10°-30° sensor misalignments at many stations inferred from analysis of longer period teleseismic waveforms. After correcting for sensor misalignments, significant residual amplitudes in these components for some longer interstation distance (≳8 km) paths are better reproduced by the 3-D velocity

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

NASA Astrophysics Data System (ADS)

Lowenstern, J. B.; Bergfeld, D.; Evans, W. 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-1of 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).

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).

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.

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.

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.

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.

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.

Strategies for steam handling and H2S abatement at geothermal power plants in the geysers area of Northern California

NASA Astrophysics Data System (ADS)

Morris, W. F.; Stephens, F. B.

1981-08-01

Strict limitations on the emission of H2S from new geothermal power plants in The Geysers area of northern California were imposed by Lake and Northern Sonoma County Air Pollution Control Districts. Lake County, under new source review rules, stipulated that specific technologies should be utilized to limit H2S 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 H2S are evaluated.

Soils and the soil cover of the Valley of Geysers

NASA Astrophysics Data System (ADS)

Kostyuk, D. N.; Gennadiev, A. N.

2014-06-01

The results of field studies of the soil cover within the tourist part of the Valley of Geysers in Kamchatka performed in 2010 and 2011 are discussed. The morphology of soils, their genesis, and their dependence on the degree of hydrothermal impact are characterized; the soil cover patterns developing in the valley are analyzed. On the basis of the materials provided by the Kronotskii Biospheric Reserve and original field data, the soil map of the valley has been developed. The maps of vegetation conditions, soil temperature at the depth of 15 cm, and slopes of the surface have been used for this purpose together with satellite imagery and field descriptions of reference soil profiles. The legend to the soil map includes nine soil units and seven units of parent materials and their textures. Soil names are given according to the classification developed by I.L. Goldfarb (2005) for the soils of hydrothermal fields. The designation of soil horizons follows the new Classification and Diagnostic System of Russian Soils (2004). It is suggested that a new horizon—a thermometamorphic horizon TRM—can be introduced into this system by analogy with other metamorphic (transformed in situ) horizons distinguished in this system. This horizon is typical of the soils partly or completely transformed by hydrothermal impacts.

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

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.

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

Formaldehyde as a carbon and electron shuttle between autotroph and heterotroph populations in acidic hydrothermal vents of Norris Geyser Basin, Yellowstone National Park

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moran, James J.; Whitmore, Laura M.; Isern, Nancy G.

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 yellowstonesis 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 13C-formaldehyde. Isotopic analysis of incubation-derived CO2 and biomass showed that formaldehyde was both oxidized and assimilatedmore » 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.« less

Long-Term Effect of Fault-Controlled CO2 Alteration on the Weakening and Strengthening of Reservoir and Seal Lithologies at Crystal Geyser, Green River, Utah

NASA Astrophysics Data System (ADS)

Major, J. R.; Eichhubl, P.; Dewers, T. A.

2014-12-01

An understanding of the coupled chemical and mechanical properties and behavior of reservoir and seal rocks is critical for assessing both the short and long term security of sequestered CO2. A combined structural diagenesis approach using observations from natural analogs has great advantages for understanding these properties over longer time scales than is possible using laboratory or numerical experiments. Current numerical models evaluating failure of reservoirs and seals during and after CO2 injection in the subsurface are just beginning to account for such coupled processes. Well-characterized field studies of natural analogs such as Crystal Geyser, Utah, are essential for providing realistic input parameters, calibration, and testing of numerical models across a range of spatial and temporal scales. Fracture mechanics testing was performed on a suite of naturally altered and unaltered reservoir and seal rocks exposed at the Crystal Geyser field site. These samples represent end-products of CO2-related alteration over geologic (>103 yr) time scales. Both the double torsion and short rod test methods yield comparable results on the same samples. Tests demonstrate that CO2-related alteration has weakened one reservoir sandstone lithology by approximately 50%, but the subcritical index is not significantly affected. An altered siltstone sample also shows a reduction in fracture toughness values and lowered subcritical index in comparison to unaltered siltstone. In contrast, elevated calcite content in shales due to CO2 alteration has increased fracture toughness. Similarly, fracture toughness was increased in what is otherwise a weak, poorly cemented sandstone unit due to increased calcite cement. Combined, these results demonstrate that CO2-related alteration generally weakens rock to fracturing (i.e. lowers fracture toughness), except in cases where calcite cementation is significantly increased. The natural system at Crystal Geyser demonstrates that water

Temporal static stress drop variations due to injection activity at The Geysers geothermal field, California

NASA Astrophysics Data System (ADS)

Staszek, M.; Orlecka-Sikora, B.; Leptokaropoulos, K.; Kwiatek, G.; Martínez-Garzón, P.

2017-07-01

We use a high-quality data set from the NW part of The Geysers geothermal field to determine statistical significance of temporal static stress drop variations and their relation to injection rate changes. We use a group of 322 seismic events which occurred in the proximity of Prati-9 and Prati-29 injection wells to examine the influence of parameters such as moment magnitude, focal mechanism, hypocentral depth, and normalized hypocentral distances from open-hole sections of injection wells on static stress drop changes. Our results indicate that (1) static stress drop variations in time are statistically significant, (2) statistically significant static stress drop changes are inversely related to injection rate fluctuations. Therefore, it is highly expected that static stress drop of seismic events is influenced by pore pressure in underground fluid injection conditions and depends on the effective normal stress and strength of the medium.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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;more » 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.« less

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rutqvist, Jonny; Dobson, Patrick F.; Garcia, Julio

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

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

DOE PAGES

Rutqvist, Jonny; Dobson, Patrick F.; Garcia, Julio; ...

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

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).

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.

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

NASA Astrophysics Data System (ADS)

Gomberg, Joan; Davis, Scott

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.

Temporal changes of static stress drop as a proxy for poroelastic effects at The Geysers geothermal field, California

NASA Astrophysics Data System (ADS)

Staszek, Monika; Orlecka-Sikora, Beata; Lasocki, Stanislaw; Kwiatek, Grzegorz; Leptokaropoulos, Konstantinos; Martinez-Garzon, Patricia

2017-04-01

One of the major environmental impacts of shale gas exploitation is triggered and induced seismicity. Due to the similarity of fluid injection process data from geothermal fields can be used as a proxy for shale gas exploitation associated seismicity. Therefore, in this paper we utilize 'The Geysers' dataset compiled within SHale gas Exploration and Exploitation induced Risks (SHEER) project. The dependence of earthquake static stress drops on pore pressure in the medium was previously suggested by Goertz-Allmann et al. (2011), who observed an increase of the static stress drop with the distance from injection well during reservoir stimulation at Deep Heat Mining project in Basel, Switzerland. Similar observation has been done by Kwiatek et al. (2014) in Berlín geothermal field, El Salvador. In this study, we use a high-quality data from The Geysers geothermal field to determine whether the static stress drops and the stress drop distributions change statistically significantly in time or not, and how such changes are correlated with the values of hypocenter depth, water injection rate, and distance from injection well. For the analyses we use a group of 354 earthquakes, which occurred in the proximity of Prati-9 and Prati-29 injection wells. Spectral parameters of these earthquakes were determined using mesh spectral ratio technique. Our results indicate that: (1) the static stress drop variation in time is statistically significant, (2) median static stress drop is inversely related to median injection rate. Therefore, it is highly expected that static stress drop is influenced by pore pressure in underground fluid injection conditions. References: Goertz-Allmann B., Goertz A., Wiemer S. (2011), Stress drop variations of induced earthquakes at the Basel geothermal site. Geophysical Research Letters, 38, L09308, doi:10.1029/2011GL047498. Kwiatek G., Bulut F., Bohnhoff M., Dresen G. (2014), High-resolution analysis of seismicity induced at Berlin geothermal field

Evolution of the Inca City region of Mars during southern spring.

NASA Astrophysics Data System (ADS)

Thomas, Nicolas; Hansen, Candice; Bridges, Nathan; McEwen, Alfred; Herkenhoff, Ken; Russell, Patrick

MOC and THEMIS observations of the southern seasonal polar cap of Mars have provided evidence of the existence of venting from the sub-surface during early southern spring. Kieffer [JGR, 112, E08005, 2007] has presented a general model of the venting process. He emphasized, however, that regional variability of jet/geyser formation remains poorly understood. In this work we choose to investigate one specific region, namely the "Inca City" region of the seasonal polar cap (295.8E, 81.4S), using a time series of observations acquired by the High Resolution Imaging Sciences Experiment (HiRISE) onboard Mars Reconnaissance Orbiter. The Inca City area shows a wide variety of different phenomena. For example, many dark fans appear on the surface within 5 weeks of the time when sunlight first reaches this southern latitude. Most fans appear to be consistent with the concept of geyser formation with subsequent airfall of dark material (as described by Kieffer). We can, however, identify some fan structures within this region which appear to suggest near-surface flow. We also find that the directions of many observed fans follow the local topography. We suggest mechanisms by which this might occur. We also investigate the surface structures in this specific region and study their evolution through southern spring. We find, for example, that so-called "spiders" can be aligned in rows (possibly in response to local topography). We also observe variability in the structure of spiders which may indicate changes in local topography or in the local substrate over short length scales. On relatively steep slopes, fans can be observed although there is no obvious spider formation. At the end of spring, sloped surfaces becomes homogeneous in colour and brightness as the fan material coats the entire downslope surface. In early spring we also observe rocks with dark rings surrounding them which might be thought to indicate activity/venting. However, most of these do not evolve over

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.

Full Moment Tensor Analysis Using First Motion Data at The Geysers Geothermal Field

NASA Astrophysics Data System (ADS)

Boyd, O.; Dreger, D. S.; Lai, V. H.; Gritto, R.

2012-12-01

Seismicity associated with geothermal energy production at The Geysers Geothermal Field in northern California has been increasing during the last forty years. We investigate source models of over fifty earthquakes with magnitudes ranging from Mw 3.5 up to Mw 4.5. We invert three-component, complete waveform data from broadband stations of the Berkeley Digital Seismic Network, the Northern California Seismic Network and the USA Array deployment (2005-2007) for the complete, six-element moment tensor. Some solutions are double-couple while others have substantial non-double-couple components. To assess the stability and significance of non-double-couple components, we use a suite of diagnostic tools including the F-test, Jackknife test, bootstrap and network sensitivity solution (NSS). The full moment tensor solutions of the studied events tend to plot in the upper half of the Hudson source type diagram where the fundamental source types include +CLVD, +LVD, tensile-crack, DC and explosion. Using the F-test to compare the goodness-of-fit values between the full and deviatoric moment tensor solutions, most of the full moment tensor solutions do not show a statistically significant improvement in fit over the deviatoric solutions. Because a small isotropic component may not significantly improve the fit, we include first motion polarity data to better constrain the full moment tensor solutions.

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

Unexplained neurological events during bathing in young people: Possible association with the use of gas geysers.

PubMed

Singh, Prabhjeet; Lamba, Anuraag; Bansal, Rajinder; Singh, Gagandeep

2008-04-01

Here, we report sudden, unexplained neurological collapse in 14 young people while bathing with hot water associated with the use of liquefied petroleum gas (LPG)-based water heaters (gas geysers) in ill-ventilated bathrooms. None of the patients reported any circumstantial evidence of seizures or prior epilepsy. One patient developed cortical blindness and demonstrated posterior leucoencephalopathy on imaging studies. The remaining patients made rapid and excellent recovery without any residual neurological sequelae. In these cases, the results of all routine investigations, i.e., serum chemistry, brain imaging (computed tomography in 2 and magnetic resonance imaging in 10) and electroencephalography were normal. The clinical clustering of these cases in winter months with similar presentations of reversible encephalopathy probably indicates an inhalational toxin exposure. Therefore, we postulate a hypothesis that harmful emissions consisting of carbon monoxide (CO), hydrocarbon gases (HC) and nitrogen oxides (NOx), produced by incomplete combustion of LPG might be responsible for the cellular injury and subsequent transient neurological deficits. Physicians should be aware of this entity in order to avoid misdiagnosis of this condition as seizures, and a public awareness should also be created regarding the proper use of these devices.

Analysis of In-Situ Stress During EGS Resource Development at The Geysers, CA

NASA Astrophysics Data System (ADS)

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

2016-12-01

Creating, identifying, and managing fractures and flow paths are essential tasks during Enhanced Geothermal Systems (EGS) resource development. Successful generation of a fracture network requires a priori knowledge of in-situ stress and natural fracture orientation and spacing. However, because the orientation and magnitude of in-situ stress may not be reliably available, and injecting fluids at high rates and volume may disturb the natural stress state, it is advantageous to monitor in-situ stress during the injection process. In this study we investigate M ≥ 1.3 seismicity in the vicinity of EGS development in the Northwest Geysers Prati 32 (P-32) injection well and Prati State 31 (PS-31) production well to determine moment magnitudes and focal mechanisms of events that occur before and during reservoir stimulation starting October 6, 2011. In general, event rate and magnitude increase as well as variability in focal mechanism during injection operations. We use our focal mechanism catalog of more than 150 events to estimate the stress tensor using the approach outlined in Hardebeck and Michaels (2006). Preliminary results of the stress inversion suggest temporal changes in the orientation of the principal stress axes during the first year of injection. It is found that the tension axis remains stable while the trend and plunge of the intermediate axis varies the most. The variations appear to be well resolved based on the 95% confidence intervals from the bootstrap analysis.

Stable-isotope studies of rocks and secondary minerals in a vapor-dominated hydrothermal system at The Geysers, Sonoma County, California

NASA Astrophysics Data System (ADS)

Lambert, Steven J.; Epstein, Samuel

1992-11-01

The Geysers, a vapor-dominated hydrothermal system, is developed in host rock of the Franciscan Formation, which contains veins of quartz and calcite whose δ 18O values record the temperatures and isotopic compositions of fluids prevailing during at least two different episodes of rock-fluid interaction. The first episode took place at about 200°C, during which marine silica and carbonate apparently interacted with ocean water entrapped in the sediments to form veins of quartz and calcite whose δ 18O values were around +19 and +16%, respectively. The calculated water/mineral ratios were less than unity. The water may have profoundly influenced the δ 18O values of spilitic basalts during their metamorphism to greenstones. Serpentinization and structural emplacement of ophiolite slabs were isotopically unrelated to this episode, which was essentially a low-grade (post-Cretaceous?) burial metamorphism. D/H ratios of actinolite, chlorite, and micas in host rocks were more profoundly altered during this episode than were 18O/ 16O ratios. A paleogeothermal gradient of about 53°C/km has been inferred for this episode, from δ 18O-depth distributions of vein minerals. The second episode, in part recorded by cogenetic vein quartz and calcite δ 18O values of +4 to +6% and +1 to +3%, respectively, began with large quantities of meteoric water circulating in fractures in the rock at temperatures of 160-180°C in response to the initiation of the Pliocene-Pleistocene Clear Lake magmatism. The temperature rose, and with the restricted circulation of fluids the ancestral hot-water system evolved into the presently active vapor-dominated system, which according to the cogenetic vein quartz and calcite δ 18O values involved temperatures as high as 320°C and fluid/mineral ratios near unity. The change in the oxygen-isotopic composition of the serpentinite within the host rock during this later activity was negligible. The δ 13C values of vein calcite at The Geysers reflect

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

Evolution of seismicity in relation to fluid injection in the North-Western part of The Geysers geothermal field

NASA Astrophysics Data System (ADS)

Leptokaropoulos, Konstantinos; Staszek, Monika; Lasocki, Stanisław; Martínez-Garzón, Patricia; Kwiatek, Grzegorz

2018-02-01

The Geysers geothermal field located in California, USA, is the largest geothermal site in the world, operating since the 1960s. We here investigate and quantify the correlation between temporal seismicity evolution and variation of the injection data by examination of time-series through specified statistical tools (binomial test to investigate significant rate changes, cross correlation between seismic and injection data, b-value variation analysis). To do so, we utilize seismicity and operational data associated with two injection wells (Prati-9 and Prati-29) which cover a time period of approximately 7 yr (from November 2007 to August 2014). The seismicity is found to be significantly positively correlated with the injection rate. The maximum correlation occurs with a seismic response delay of ˜2 weeks, following injection operations. Those results are very stable even after considering hypocentral uncertainties, by applying a vertical shift of the events foci up to 300 m. Our analysis indicates also time variations of b-value, which exhibits significant positive correlation with injection rates.

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.

27 CFR 9.94 - Howell Mountain.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell... Reservoir, CA.,” 1959 (photorevised 1980). (2) “Aetna Springs, CA.,” 1958 (photorevised 1981). (3) “Calistoga, CA.,” 1958 (photorevised 1980). (4) “St. Helena, CA.,” 1960 (photorevised 1980). (c) Boundaries...

27 CFR 9.94 - Howell Mountain.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell... Reservoir, CA.,” 1959 (photorevised 1980). (2) “Aetna Springs, CA.,” 1958 (photorevised 1981). (3) “Calistoga, CA.,” 1958 (photorevised 1980). (4) “St. Helena, CA.,” 1960 (photorevised 1980). (c) Boundaries...

27 CFR 9.94 - Howell Mountain.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell... Reservoir, CA.,” 1959 (photorevised 1980). (2) “Aetna Springs, CA.,” 1958 (photorevised 1981). (3) “Calistoga, CA.,” 1958 (photorevised 1980). (4) “St. Helena, CA.,” 1960 (photorevised 1980). (c) Boundaries...

27 CFR 9.94 - Howell Mountain.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell... Reservoir, CA.,” 1959 (photorevised 1980). (2) “Aetna Springs, CA.,” 1958 (photorevised 1981). (3) “Calistoga, CA.,” 1958 (photorevised 1980). (4) “St. Helena, CA.,” 1960 (photorevised 1980). (c) Boundaries...

27 CFR 9.94 - Howell Mountain.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Howell Mountain. (a) Name. The name of the viticultural area described in this section is “Howell... Reservoir, CA.,” 1959 (photorevised 1980). (2) “Aetna Springs, CA.,” 1958 (photorevised 1981). (3) “Calistoga, CA.,” 1958 (photorevised 1980). (4) “St. Helena, CA.,” 1960 (photorevised 1980). (c) Boundaries...

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

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.

Boiling Water at Hot Creek - The Dangerous and Dynamic Thermal Springs in California's Long Valley Caldera

USGS Publications Warehouse

Farrar, Christopher D.; Evans, William C.; Venezky, Dina Y.; Hurwitz, Shaul; Oliver, Lynn K.

2007-01-01

The beautiful blue pools and impressive boiling fountains along Hot Creek in east-central California have provided enjoyment to generations of visitors, but they have also been the cause of injury or death to some who disregarded warnings and fences. The springs and geysers in the stream bed and along its banks change location, temperature, and flow rates frequently and unpredictably. The hot springs and geysers of Hot Creek are visible signs of dynamic geologic processes in this volcanic region, where underground heat drives thermal spring activity.

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.

Accurate estimation of seismic source parameters of induced seismicity by a combined approach of generalized inversion and genetic algorithm: Application to The Geysers geothermal area, California

NASA Astrophysics Data System (ADS)

Picozzi, M.; Oth, A.; Parolai, S.; Bindi, D.; De Landro, G.; Amoroso, O.

2017-05-01

The accurate determination of stress drop, seismic efficiency, and how source parameters scale with earthquake size is an important issue for seismic hazard assessment of induced seismicity. We propose an improved nonparametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for attenuation and site contributions. Then, the retrieved source spectra are inverted by a nonlinear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (Mw 2-3.8) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations, more than 17.000 velocity records). We find a nonself-similar behavior, empirical source spectra that require an ωγ source model with γ > 2 to be well fit and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes and that the proportion of high-frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping faults in the fluid pressure diffusion.

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.

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.

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.

Multireaction equilibrium geothermometry: A sensitivity analysis using data from the Lower Geyser Basin, Yellowstone National Park, USA

USGS Publications Warehouse

King, Jonathan M.; Hurwitz, Shaul; Lowenstern, Jacob B.; Nordstrom, D. Kirk; McCleskey, R. Blaine

2016-01-01

A multireaction chemical equilibria geothermometry (MEG) model applicable to high-temperature geothermal systems has been developed over the past three decades. Given sufficient data, this model provides more constraint on calculated reservoir temperatures than classical chemical geothermometers that are based on either the concentration of silica (SiO2), or the ratios of cation concentrations. A set of 23 chemical analyses from Ojo Caliente Spring and 22 analyses from other thermal features in the Lower Geyser Basin of Yellowstone National Park are used to examine the sensitivity of calculated reservoir temperatures using the GeoT MEG code (Spycher et al. 2013, 2014) to quantify the effects of solute concentrations, degassing, and mineral assemblages on calculated reservoir temperatures. Results of our analysis demonstrate that the MEG model can resolve reservoir temperatures within approximately ±15°C, and that natural variation in fluid compositions represents a greater source of variance in calculated reservoir temperatures than variations caused by analytical uncertainty (assuming ~5% for major elements). The analysis also suggests that MEG calculations are particularly sensitive to variations in silica concentration, the concentrations of the redox species Fe(II) and H2S, and that the parameters defining steam separation and CO2 degassing from the liquid may be adequately determined by numerical optimization. Results from this study can provide guidance for future applications of MEG models, and thus provide more reliable information on geothermal energy resources during exploration.

Transferability of a Three-Dimensional Air Quality Model between Two Different Sites in Complex Terrain.

NASA Astrophysics Data System (ADS)

Lange, Rolf

1989-07-01

The three-dimensional, diagnostic, particle-in-cell transport and diffusion model MATHEW/ADPIC is used to test its transferability from one site in complex terrain to another with different characteristics, under stable nighttime drainage flow conditions. The two sites were subject to extensive drainage flow tracer experiments under the multilaboratory Atmospheric Studies in Complex Terrain (ASCOT) program: the first being a valley in the Geysers geothermal region of northern California, and the second a canyon in western Colorado. The domain in each case is approximately 10 × 10 km. The 1980 Geysers model evaluation is only quoted. The 1984 Brush Creek model evaluation is described in detail.Results from comparing computed with measured concentrations from a variety of tracer releases indicate that 52% of the 4531 samples from five experiments in Brush Creek and 50% of the 831 samples from four experiments in the Geysers agreed within a factor of 5. When an angular 10° uncertainty, consistent with anemometer reliability limits in complex terrain, was allowed to be applied to the model results, model performance improved such that 78% of samples compared within a factor of 5 for Brush Creek and 77% for the Geysers. Looking at the range of other factors of concentration ratios, results indicate that the model is satisfactorily transferable without tuning it to a specific site.

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.

The Northwest Geysers EGS Demonstration Project, California – Part 2: Modeling and interpretation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rutqvist, Jonny; Jeanne, Pierre; Dobson, Patrick F.

In this paper, we summarize the results of coupled thermal, hydraulic, and mechanical (THM) modeling in support of the Northwest Geysers EGS Demonstration Project, which aims at enhancing production from a known High Temperature Reservoir (HTR) (280–400 °C) located under the conventional (240 °C) geothermal steam reservoir. The THM modeling was conducted to investigate geomechanical effects of cold-water injection during the stimulation of the EGS, first to predict the extent of the stimulation zone for a given injection schedule, and then to conduct interpretive analyses of the actual stimulation. By using a calibrated THM model based on historic injection and microseismic datamore » at a nearby well, we could reasonably predict the extent of the stimulation zone around the injection well, at least for the first few months of injection. However, observed microseismic evolution and pressure responses over the one-year stimulation-injection revealed more heterogeneous behavior as a result of more complex geology, including a network of shear zones. Therefore, for an interpretive analysis of the one-year stimulation campaign, we included two sets of vertical shear zones within the model; a set of more permeable NW-striking shear zones and a set of less permeable NE-striking shear zones. Our modeling indicates that the microseismic events in this system are related to shear reactivation of pre-existing fractures, triggered by the combined effects of injection-induced cooling around the injection well and rapid (but small) changes in steam pressure as far as a kilometer from the injection well. Overall, the integrated monitoring and modeling of microseismicity, ground surface deformations, reservoir pressure, fluid chemical composition, and seismic tomography depict an EGS system hydraulically bounded by some of the NE-striking low permeability shear zones, with the more permeable NW-striking shear zone providing liquid flow paths for stimulation deep (several

The Northwest Geysers EGS Demonstration Project, California – Part 2: Modeling and interpretation

DOE PAGES

Rutqvist, Jonny; Jeanne, Pierre; Dobson, Patrick F.; ...

2015-09-02

In this paper, we summarize the results of coupled thermal, hydraulic, and mechanical (THM) modeling in support of the Northwest Geysers EGS Demonstration Project, which aims at enhancing production from a known High Temperature Reservoir (HTR) (280–400 °C) located under the conventional (240 °C) geothermal steam reservoir. The THM modeling was conducted to investigate geomechanical effects of cold-water injection during the stimulation of the EGS, first to predict the extent of the stimulation zone for a given injection schedule, and then to conduct interpretive analyses of the actual stimulation. By using a calibrated THM model based on historic injection and microseismic datamore » at a nearby well, we could reasonably predict the extent of the stimulation zone around the injection well, at least for the first few months of injection. However, observed microseismic evolution and pressure responses over the one-year stimulation-injection revealed more heterogeneous behavior as a result of more complex geology, including a network of shear zones. Therefore, for an interpretive analysis of the one-year stimulation campaign, we included two sets of vertical shear zones within the model; a set of more permeable NW-striking shear zones and a set of less permeable NE-striking shear zones. Our modeling indicates that the microseismic events in this system are related to shear reactivation of pre-existing fractures, triggered by the combined effects of injection-induced cooling around the injection well and rapid (but small) changes in steam pressure as far as a kilometer from the injection well. Overall, the integrated monitoring and modeling of microseismicity, ground surface deformations, reservoir pressure, fluid chemical composition, and seismic tomography depict an EGS system hydraulically bounded by some of the NE-striking low permeability shear zones, with the more permeable NW-striking shear zone providing liquid flow paths for stimulation deep (several

Reservoir Changes Derived from Seismic Observations at The Geysers Geothermal Field, CA, USA

NASA Astrophysics Data System (ADS)

Gritto, R.; Jarpre, S.

2012-04-01

Induced seismicity associated with the exploitation of geothermal fields is used as a tool to characterize and delineate changes associated with injection and production of fluids from the reservoir. At the same time public concern of felt seismicity has led to objections against the operation of geothermal reservoirs in close proximity to population centers. Production at the EGS sites in Basel (Switzerland) was stopped after renewed seismicity caused concern and objection from the public in the city. Operations in other geothermal reservoirs had to be scaled back or interrupted due to an unexpected increase in seismicity (Soultz-sous-forêt, France, Berlín, El Salvador). As a consequence of these concerns and in order to optimize the use of induced seismicity for reservoir engineering purposes, it becomes imperative to understand the relationship between seismic events and stress changes in the reservoir. We will address seismicity trends at The Geysers Geothermal Reservoir, CA USA, to understand the role of historical seismicity associated with past injection of water and/or production of steam. Our analysis makes use of a comprehensive database of earthquakes and associated phase arrivals from 2004 to 2011. A high-precision sub-set of the earthquake data was selected to analyze temporal changes in seismic velocities and Vp/Vs-ratio throughout the whole reservoir. We find relatively low Vp/Vs values in 2004 suggestive of a vapor dominated reservoir. With passing time, however, the observed temporal increase in Vp/Vs, coupled with a decrease in P- and S-wave velocities suggests the presence of fluid-filled fractured rock. Considering the start of a continuous water injection project in 2004, it can be concluded that the fluid saturation of the reservoir has successfully recovered. Preliminary results of 3-D velocity inversions of seismic data appear to corroborate earlier findings that the lowest Vp/Vs estimates are observed in the center of the reservoir

Use of high-resolution satellite images for characterization of geothermal reservoirs in the Tarapaca Region, Chile

NASA Astrophysics Data System (ADS)

Arellano-Baeza, A. A.; Montenegro A., C.

2010-12-01

The use of renewable and clean sources of energy is becoming crucial for sustainable development of all countries, including Chile. Chilean Government plays special attention to the exploration and exploitation of geothermal energy, total electrical power capacity of which could reach 16.000 MW. In Chile the main geothermal fields are located in the Central Andean Volcanic Chain in the North, between the Central valley and the border with Argentina in the center, and in the fault system Liquiñe-Ofqui in the South of the country. High resolution images from the Lansat satellite have been used to characterize the geothermal field in the region of the Puchuldiza geysers, Colchane, Region of Tarapaca, North of Chile, located at the altitude of 4000 m. Structure of lineaments associated to the geothermal field have been extracted from the images using the lineament detection technique developed by authors. These structures have been compared with the distribution of main geological structures obtained in the field. It was found that the lineament analysis is a power tool for the detection of faults and joint zones associated to the geothermal fields.

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

Hot Spot at Yellowstone

ERIC Educational Resources Information Center

Dress, Abby

2005-01-01

Within this huge national park (over two million acres spread across Wyoming, Montana, and Idaho) are steaming geysers, hot springs, bubbling mudpots, and fumaroles, or steam vents. Drives on the main roads of Yellowstone take tourists through the major hot attractions, which also include Norris Geyser Basin, Upper and Lower Geyser Basin, West…

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.

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.

Seismic and aseismic deformations and impact on reservoir permeability: The case of EGS stimulation at The Geysers, California, USA

DOE PAGES

Jeanne, Pierre; Rutqvist, Jonny; Rinaldi, Antonio Pio; ...

2015-10-27

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 showmore » that 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. 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.« less

Seismic and aseismic deformations and impact on reservoir permeability: The case of EGS stimulation at The Geysers, California, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeanne, Pierre; Rutqvist, Jonny; Rinaldi, Antonio Pio

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 showmore » that 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. 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.« less

An integrated methodology for sub-surface fracture characterization using microseismic data: A case study at the NW Geysers

NASA Astrophysics Data System (ADS)

Aminzadeh, Fred; Tafti, Tayeb A.; Maity, Debotyam

2013-04-01

Geothermal and unconventional hydrocarbon reservoirs are often characterized by low permeability and porosity. So, they are difficult to produce and require stimulation techniques, such as thermal shear deactivation and hydraulic fracturing. Fractures provide porosity for fluid storage and permeability for fluid movement and play an important role in production from this kind of reservoirs. Hence, characterization of fractures has become a vitally important consideration in every aspect of exploration, development and production so as to provide additional energy resources for the world. During the injection or production of fluid, induced seismicity (micro-seismic events) can be caused by reactivated shears created fractures or the natural fractures in shear zones and faults. Monitoring these events can help visualize fracture growth during injection stimulation. Although the locations of microseismic events can be a useful characterization tool and have been used by many authors, we go beyond these locations to characterize fractures more reliably. Tomographic inversion, fuzzy clustering, and shear wave splitting are three methods that can be applied to microseismic data to obtain reliable characteristics about fractured areas. In this article, we show how each method can help us in the characterization process. In addition, we demonstrate how they can be integrated with each other or with other data for a more holistic approach. The knowledge gained might be used to optimize drilling targets or stimulation jobs to reduce costs and maximize production. Some of the concepts discussed in this paper are general in nature, and may be more applicable to unconventional hydrocarbon reservoirs than the metamorphic and igneous reservoir rocks at The Geysers geothermal field.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, J.M.; Yadav, S.

Waters from geysers, hot springs, and pools of Yellowstone National Park have been analyzed. We report 422 complete major ion analyses from 330 different locations of geysers, hot springs, and pools, collected from 1974 to 1978. Many of the analyses from Upper, Midway, Lower, and Norris Geyser Basin are recollections of features previously reported.

Geothermal Monitoring in Yellowstone National Park

NASA Astrophysics Data System (ADS)

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

2007-12-01

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

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.

Fault-controlled advective, diffusive, and eruptive CO 2 leakage from natural reservoirs in the Colorado Plateau, East-Central Utah

NASA Astrophysics Data System (ADS)

Jung, Na-Hyun

This study investigated a natural analogue for CO2 leakage near Green River, Utah, aiming to understand the influence of various factors on CO2 leakage and to reliably predict underground CO2 behavior after injection for geologic CO2 sequestration. Advective, diffusive, and eruptive characteristics of CO2 leakage were assessed via a soil CO2 flux survey and numerical modeling. The field results show anomalous CO2 fluxes (> 10 g m-2 d-1 ) along the faults, particularly adjacent to CO2-driven cold springs and geysers (e.g., 36,259 g m-2 d-1 at Crystal Geyser), ancient travertines (e.g., 5,917 g m-2 d-1), joint zones in sandstone (e.g., 120 g m-2 d-1), and brine discharge zones (e.g., 5,515 g m-2 d-1). Combined with similar isotopic ratios of gas and progressive evolution of brine chemistry at springs and geysers, a gradual decrease of soil CO2 flux from the Little Grand Wash (LGW; ~36,259 g m -2 d-1) to Salt Wash (SW; ~1,428 g m-2 d-1) fault zones reveals the same CO2 origin and potential southward transport of CO2 over 10-20 km. The numerical simulations exhibit lateral transport of free CO2 and CO2-rich brine from the LGW to SW fault zones through the regional aquifers (e.g., Entrada, Navajo, Kayenta, Wingate, White Rim). CO2 travels predominantly as an aqueous phase (XCO2=~0.045) as previously suggested, giving rise to the convective instability that further accelerates CO2 dissolution. While the buoyant free CO2 always tends to ascend, a fraction of dense CO2-rich brine flows laterally into the aquifer and mixes with the formation fluids during upward migration along the fault. The fault always enhances advective CO2 transport regardless of its permeability (k). However, only low-k fault prevents unconditional upright migration of CO2 and induces fault-parallel movement, feeding the northern aquifers with more CO2. Low-k fault also impedes lateral southward fluid flow from the northern aquifers, developing anticlinal CO2 traps at shallow depths (<300 m). The

Source and fate of inorganic solutes in the Gibbon River, Yellowstone National Park, Wyoming, USA: I. Low-flow discharge and major solute chemistry

USGS Publications Warehouse

McCleskey, R. Blaine; Nordstrom, D. Kirk; Susong, David D.; Ball, James W.; Holloway, JoAnn M.

2010-01-01

The Gibbon River in Yellowstone National Park (YNP) is an important natural resource and habitat for fisheries and wildlife. However, the Gibbon River differs from most other mountain rivers because its chemistry is affected by several geothermal sources including Norris Geyser Basin, Chocolate Pots, Gibbon Geyser Basin, Beryl Spring, and Terrace Spring. Norris Geyser Basin is one of the most dynamic geothermal areas in YNP, and the water discharging from Norris is much more acidic (pH 3) than other geothermal basins in the upper-Madison drainage (Gibbon and Firehole Rivers). Water samples and discharge data were obtained from the Gibbon River and its major tributaries near Norris Geyser Basin under the low-flow conditions of September 2006. Surface inflows from Norris Geyser Basin were sampled to identify point sources and to quantify solute loading to the Gibbon River. The source and fate of the major solutes (Ca, Mg, Na, K, SiO2, Cl, F, HCO3, SO4, NO3, and NH4) in the Gibbon River were determined in this study and these results may provide an important link in understanding the health of the ecosystem and the behavior of many trace solutes. Norris Geyser Basin is the primary source of Na, K, Cl, SO4, and N loads (35–58%) in the Gibbon River. The largest source of HCO3 and F is in the lower Gibbon River reach. Most of the Ca and Mg originate in the Gibbon River upstream from Norris Geyser Basin. All the major solutes behave conservatively except for NH4, which decreased substantially downstream from Gibbon Geyser Basin, and SiO2, small amounts of which precipitated on mixing of thermal drainage with the river. As much as 9–14% of the river discharge at the gage is from thermal flows during this period.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 mixturemore » 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.« less

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.

Isolation and characterization of a CO2-tolerant Lactobacillus strain from Crystal Geyser, Utah, U.S.A.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santillan, Eugenio-Felipe U.; Shanahan, Timothy M.; Omelon, Christopher R.

2015-07-23

When CO 2 is sequestered into the deep subsurface, changes to the subsurface microbial community will occur. Capnophiles, microorganisms that grow in CO 2-rich environments, are some organisms that may be selected for under the new environmental conditions. To determine whether capnophiles comprise an important part of CO 2-rich environments, an isolate from Crystal Geyser, Utah, U.S.A., a CO 2- rich spring considered a carbon sequestration analog, was characterized. The isolate was cultured under varying CO 2, pH, salinity, and temperature, as well as different carbon substrates and terminal electron acceptors (TEAs) to elucidate growth conditions and metabolic activity. Designatedmore » CG-1, the isolate is related (99%) to Lactobacillus casei in 16S rRNA gene identity, growing at PCO 2 between 0 and 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 h. CG-1 grows in neutral pH, 0.25 M NaCl, and between 25° and 45°C and consumes glucose, lactose, sucrose, or crude oil, likely performing lactic acid fermentation. Fatty acid profiles between 0.1 and 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 CO 2 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 CO 2 for sequestration. Furthermore, our ability to culture an environmental isolate indicates that organisms found in CO 2 environments from previous genomic and metagenomics studies are viable, metabolizing, and potentially affecting the surrounding environment.« less

Liquid propellant reorientation in a low-gravity environment

NASA Technical Reports Server (NTRS)

Sumner, I. E.

1978-01-01

An existing empirical analysis relating to the reorientation of liquids in cylindrical tanks due to propulsive settling in a low gravity environment was extended to include the effects of geyser formation in the Weber number range from 4 to 10. Estimates of the minimum velocity increment required to be imposed on the propellant tank to achieve liquid reorientation were made. The resulting Bond numbers, based on tank radius, were found to be in the range from 3 to 5, depending upon the initial liquid fill level, with higher Bond number required for high initial fill levels. The resulting Weber numbers, based on tank radius and the velocity of the liquid leading edge, were calculated to be in the range from 6.5 to 8.5 for cylindrical tanks having a fineness ratio of 2.0, with Weber numbers of somewhat greater values for longer cylindrical tanks. It, therefore, appeared to be advantageous to allow small geysers to form and then dissipate into the surface of the collected liquid in order to achieve the minimum velocity increment. The Bond numbers which defined the separation between regions in which geyser formation did and did not occur due to propulsive settling in a spherical tank configuration ranged from 2 to 9 depending upon the liquid fill level.

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

The Lusi mud eruption dynamics: constraints from field data.

NASA Astrophysics Data System (ADS)

Mazzini, Adriano; Sciarra, Alessandra; Lupi, Matteo; Mauri, Guillaume; Karyono, Karyono; Husein, Alwi; Aquino, Ida; Ricco, Ciro; Obermann, Anne; Hadi, Soffian

2017-04-01

clastic geyser explosion of approximately 3 s. This, in agreement with previous studies, corresponds to a source located some tens of meters depth inside the conduits. We ascribe the harmonic seismic signal to rise of batches of H2O-CO2-CH4 fluids inside the conduit. Once they approach the water-vapour region the sudden pressure drop triggers flashing and the exsolution of the dissolved CO2 and CH4. In the last part of our study we verified whether the powerful clastic geysering (emitting jets up to 20 m high) may induce local deformation of the mud edifice. During the stronger geysering events we measure an increase and drop of gravity overtime that are related to change of mud density within the feeder conduit. We process continuous camera recordings with a video magnifying tool capable of enhancing small variations in the recorded images. Results highlight that major eruptive events are preceded by a deformation of the mud edifice surrounding the vents. Ongoing studies aim to verify if these events are also captured by the tiltmeter measurements. This study represents a step forward to better understand the activity that characterizes Lusi. Further studies will help to better constrain the reactions and dynamics ongoing inside the conduit.

Developing an ecosystem perspective from experimental monitoring programs: II. Ecophysiological responses of a rare geothermal grass to soil water.

PubMed

Pavlik, B M

2001-08-01

Measurements of xylem water potential, leaf conductance, and leaf pressure-volume characteristics on the geothermal endemic Dichanthelium lanuginosum var. thermale (DILA) were used to delineate operational ranges during wet and dry years and among several microsites at Little Geysers, Sonoma County, California, USA. Plants seldom experienced water potentials more negative that -1.5 MPa. Other nongeothermal, widespread species experienced the lower water potentials typical of chaparral and woodland plants. DILA was able to effectively utilize geothermal water while the widespread species could not and was able to keep stomata open during most of the year. There was evidence to suggest that DILA had some ability to acclimate with significant shifts in Pio and psio during the dry 1994 summer, especially in the upland microhabitat. Nevertheless, minimum leaf turgor values in the upland came very close to, or dropped below, the 0.2-0.3 MPa threshold thought necessary to maintain stomatal opening and photosynthesis. DILA thus depends upon the unique water status of fumarole soils in the vicinity of the Little Geysers to persist in an otherwise lethal regional mosaic of climate, soil, and vegetation. The physiological data were used to derive reference ranges for subsequent monitoring of DILA at Little Geysers. Such ranges are required to determine the future impact, if any, of geothermal development on the persistence of this rare grass and its complex ecosystem.

Crump Geyser Exploration and Drilling Project. High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fairbank, Brian D.; Smith, Nicole

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 2more » 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

Fault-controlled CO2 leakage from natural reservoirs in the Colorado Plateau, East-Central Utah

NASA Astrophysics Data System (ADS)

Jung, Na-Hyun; Han, Weon Shik; Watson, Z. T.; Graham, Jack P.; Kim, Kue-Young

2014-10-01

The study investigated a natural analogue for soil CO2 fluxes where CO2 has naturally leaked on the Colorado Plateau, East-Central Utah in order to identify various factors that control CO2 leakage and to understand regional-scale CO2 leakage processes in fault systems. The total 332 and 140 measurements of soil CO2 flux were made at 287 and 129 sites in the Little Grand Wash (LGW) and Salt Wash (SW) fault zones, respectively. Measurement sites for CO2 flux involved not only conspicuous CO2 degassing features (e.g., CO2-driven springs/geysers) but also linear features (e.g., joints/fractures and areas of diffusive leakage around a fault damage zone). CO2 flux anomalies were mostly observed along the fault traces. Specifically, CO2 flux anomalies were focused in the northern footwall of the both LGW and SW faults, supporting the existence of north-plunging anticlinal CO2 trap against south-dipping faults as well as higher probability of the north major fault traces as conduits. Anomalous CO2 fluxes also appeared in active travertines adjacent to CO2-driven cold springs and geysers (e.g., 36,259 g m-2 d-1 at Crystal Geyser), ancient travertines (e.g., 5,917 g m-2 d-1), joint zones in sandstone (e.g., 120 g m-2 d-1), and brine discharge zones (e.g., 5,515 g m-2 d-1). These observations indicate that CO2 has escaped through those pathways and that CO2 leakage from these fault zones does not correspond to point source leakage. The magnitude of CO2 flux is progressively reduced from north (i.e. the LGW fault zone, ∼36,259 g m-2 d-1) to south (i.e. the SW fault zone, ∼1,428 g m-2 d-1) despite new inputs of CO2 and CO2-saturated brine to the northerly SW fault from depth. This discrepancy in CO2 flux is most likely resulting from the differences in fault zone architecture and associated permeability structure. CO2-rich fluids from the LGW fault zone may become depleted with respect to CO2 during lateral transport, resulting in an additional decrease in CO2 fluxes

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

NASA Astrophysics Data System (ADS)

Kieffer, Susan Werner

1984-09-01

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 H 2O 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

Modeling of two-phase flow instabilities during startup transients utilizing RAMONA-4B methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paniagua, J.; Rohatgi, U.S.; Prasad, V.

1996-10-01

RAMONA-4B code is currently under development for simulating thermal hydraulic instabilities that can occur in Boiling Water Reactors (BWRs) and the Simplified Boiling Water Reactor (SBWR). As one of the missions of RAMONA-4B is to simulate SBWR startup transients, where geysering or condensation-induced instability may be encountered, the code needs to be assessed for this application. This paper outlines the results of the assessments of the current version of RAMONA-4B and the modifications necessary for simulating the geysering or condensation-induced instability. The test selected for assessment are the geysering tests performed by Prof Aritomi (1993).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walters, M.A.; Sternfeld, J.N.; Haizlip, J.R.

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 lithologicmore » 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.« less

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

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

Comparative Study of Earthquake Clustering in Relation to Hydraulic Activities at Geothermal Fields in California

NASA Astrophysics Data System (ADS)

Martínez-Garzón, P.; Zaliapin, I. V.; Ben-Zion, Y.; Kwiatek, G.; Bohnhoff, M.

2017-12-01

We investigate earthquake clustering properties from three geothermal reservoirs to clarify how earthquake patterns respond to hydraulic activities. We process ≈ 9 years from four datasets corresponding to the Geysers (both the entire field and a local subset), Coso and Salton Sea geothermal fields, California. For each, the completeness magnitude, b-value and fractal dimension are calculated and used to identify seismicity clusters using the nearest-neighbor approach of Zaliapin and Ben-Zion [2013a, 2013b]. Estimations of temporal evolution of different clustering properties in relation to hydraulic parameters point to different responses of earthquake dynamics to hydraulic operations in each case study. The clustering at the Geysers at local scale and Salton Sea are most and least affected by hydraulic activities, respectively. The response of the earthquake clustering from different datasets to the hydraulic activities may reflect the regional seismo-tectonic complexity as well as the dimension of the geothermal activities performed (e.g. number of active wells and superposition of injection + production activities).Two clustering properties significantly respond to hydraulic changes across all datasets: the background rates and the proportion of clusters consisting of a single event. Background rates are larger at the Geysers and Coso during high injection-production periods, while the opposite holds for the Salton Sea. This possibly reflects the different physical mechanisms controlling seismicity at each geothermal field. Additionally, a lower proportion of singles is found during time periods with higher injection-production rates. This may reflect decreasing effective stress in areas subjected to higher pore pressure and larger earthquake triggering by stress transfer.

Bridging Surface and Subsurface Observations of the Pulsating Behavior of Lusi: a New-born Sedimentary Hosted Hydrothermal System in East Java.

NASA Astrophysics Data System (ADS)

Mazzini, A.; Husein, A.; Karyono, K.; Lupi, M.; Obermann, A.; Hadi, S.

2015-12-01

The Lusi eruption started the 29th of May 2006 in Eastern Java, Indonesia. Since its birth Lusi presented a pulsating behaviour with geyser-like activity. To date Lusi is still active and never stopped erupting enormous amounts of mud, clasts, water and gas with peaks of activity reaching 180.000 km3/day. The erupting activity is characterized by[ML1] three main behaviours: 1) regular activity, which consists in the constant emission of mud breccia (i.e. viscous mud containing clay, silt, sand and clasts up to 10 cm in diameter) associated with the expulsion of water both in a liquid and vapour state as well as other gasses (i.e. mostly CO2 and CH4). Occasional powerful bursts of mud may reach up ten meters in height. 2) geysering activity consisting in more powerful eruptive events that do not seem to have a regular pattern. These typically lasts up to five minutes and comprise an initial phase marked by an elevated bubbling in the crater zone followed by an increasing amount of vapour released throughout the geysering phase. 3) quasi-absence of degassing from the main crater(s). This phase follows the geysering activity and is generally short-lived In order to investigate the mechanisms controlling Lusi pulsating behaviour, we deployed a network of five seismometers around the crater. The seismic records highlight that the seismic signal of Lusi is characterised by tremor and volcano-tectonic events. Tremor events occur in 1 Hz and 3 Hz frequency bands while volcano tectonic events are rich in high frequencies (i.e. 2-15 Hz). We also identify an emerging signal lasting from approximately one to ten minutes. This signal appears throughout the dataset and it is characterized by a frequency content between 5 Hz and 10 Hz. To verify whether such long-lasting signal could be associated to the geysering phase we coupled the seismic monitoring with a HD camera to record the crater activity. Results reveal that the onset of such signal precedes the visual evidence of

Processing of analogues of plume fallout in cold regions of Enceladus by energetic electrons

NASA Astrophysics Data System (ADS)

Bergantini, A.; Pilling, S.; Nair, B. G.; Mason, N. J.; Fraser, H. J.

2014-10-01

Context. Enceladus, a small icy moon of Saturn, is one of the most remarkable bodies in the solar system. This moon is a geologically active object, and despite the lower temperatures on most of its surface, the geothermally heated south polar region presents geysers that spouts a plume made of water (~90%), carbon dioxide, methane, ammonia, and methanol, among other molecules. Most of the upward-moving particles do not have the velocity to escape from the gravitational influence of the moon and fall back to the surface. The molecules in the ice are continuously exposed to ionizing radiation, such as UV and X-rays photons, cosmic rays, and electrons. Over time, the ionizing radiation promotes molecular bond rupture, destroying and also forming molecules, radicals, and fragments. Aims: We analyse the processing of an ice mixture analogue to the Enceladus fallout ice in cold resurfaced areas (north pole) by 1 keV electrons. The main goal is to search for complex species that have not yet been detected in this moon, and to determine relevant physico-chemical parameters, such as destruction and formation cross-sections and the half-life of the studied molecules in the ice. Methods: The experiment consisted of the electron irradiation of an Enceladus-like ice mixture (H2O:CO2:CH4:NH3:CH3OH) in an ultra-high vacuum chamber at 20 K. The analysis was made by infrared spectrometry in the mid-infrared region (4000-800 cm-1 or 2.5-12.5 μm). Results: The absolute dissociation cross-sections of the parent molecules, the formation cross-section of daughter species, and the half-life of the parental species in a simulated Enceladus irradiation scenario were determined. Among the produced species, CO (carbon monoxide), OCN- (cyanate anion), HCONH2 (formamide), and H2CO (formaldehyde) were tentatively detected.

Atlas of Yellowstone

USGS Publications Warehouse

Pierce, Kenneth L.; Marcus, A. W.; Meachan, J. E.; Rodman, A. W.; Steingisser, A. Y.; Allan, Stuart; West, Ross

2012-01-01

Established in 1872, Yellowstone National Park was the world’s first national park. In a fitting tribute to this diverse and beautiful region, the Atlas of Yellowstone is a compelling visual guide to this unique national park and its surrounding area. Ranging from art to wolves, from American Indians to the Yellowstone Volcano, and from geysers to population, each page explains something new about the dynamic forces shaping Yellowstone. Equal parts reference and travel guide, the Atlas of Yellowstone is an unsurpassed resource.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brauner, Edwin Jr.; Carlson, Daniel C.

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 anothermore » 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.« less

California's geothermal resource potential

NASA Technical Reports Server (NTRS)

Leibowitz, L. P.

1978-01-01

According to a U.S. Geological Survey estimate, recoverable hydrothermal energy in California may amount to 19,000 MW of electric power for a 30-year period. At present, a geothermal installation in the Geysers region of the state provides 502 MWe of capacity; an additional 1500 MWe of electric generating capacity is scheduled to be in operation in geothermal fields by 1985. In addition to hydrothermal energy sources, hot-igneous and conduction-dominated resources are under investigation for possible development. Land-use conflicts, environmental concerns and lack of risk capital may limit this development.

New stands of species of the Paramecium aurelia complex (Ciliophora, Protista) in Russia (Siberia, Kamchatka).

PubMed

Przyboś, Ewa; Rautian, Maria; Surmacz, Marta; Bieliavskaya, Alexandra

2013-01-01

New stands of P. primaurelia, P. biaurelia, and P. dodecaurelia were found in Russia. P. primaurelia was recorded in Tulun (Siberia, Irkutsk region) and in three stands situated on the Kamchatka peninsula: in Lake Chalaktyrskoye, in the Valley of Geysers, and Petropavlovsk Kamchatski. P. biaurelia was also found in Tulun and in two stands in the vicinity of Lake Baikal and the Buriatia region. P. dodecaurelia was recorded in Cheboksary in European Russia and in other stands situated in Asian Russia: Novosibirsk, the vicinity of Lake Baikal, Buriatia, Kamchatka (Petropavlovsk Kamchatski, Lake Chalaktyrskoye, and Nalychevo). These data extend the ranges of species of the P. aurelia complex in Russia, however, this large territory remains understudied.

Analysis of the potential geochemical reactions in the Enceladus' hydrothermal environment

NASA Astrophysics Data System (ADS)

Ramirez-Cabañas, A. K.; Flandes, A.

2017-12-01

Enceladus is the sixth largest moon of Saturn and differs from its other moons, because of its cryovolcanic geysers that emanate from its south pole. The instruments of the Cassini spacecraft reveal different compounds in the gases and the dust of the geysers, such as salts (sodium chloride, sodium bicarbonate and/or sodium carbonate), as well as silica traces (Postberg et al., 2008, 2009) that could be the result of a hydrothermal environment (Hsu et al., 2014, Sekine et al., 2014). By means of a thermodynamic analysis, we propose and evaluate potential geochemical reactions that could happen from the interaction between the nucleus surface and the inner ocean of Enceladus. These reactions may well lead to the origin of the compounds found in the geysers. From this analysis, we propose that, at least, two minerals must be present in the condritic nucleus of Enceladus: olivines (fayalite and fosterite) and feldspar (orthoclase and albite). Subsequently, taking as reference the hydrothermal processes that take place on Earth, we propose the different stages of a potential hydrothermal scenario for Enceladus.

Effect of Ice-Shell Thickness Variations on the Tidal Deformation of Enceladus

NASA Astrophysics Data System (ADS)

Choblet, G.; Cadek, O.; Behounkova, M.; Tobie, G.; Kozubek, T.

2015-12-01

Recent analysis of Enceladus's gravity and topography has suggested that the thickness of the ice shell significantly varies laterally - from 30-40 km in the south polar region to 60 km elsewhere. These variations may influence the activity of the geysers and increase the tidal heat production in regions where the ice shell is thinned. Using a model including a regional or global subsurface ocean and Maxwell viscoelasticity, we investigate the impact of these variations on the tidal deformation of the moon and its heat production. For that purpose, we use different numerical approaches - finite elements, local application of 1d spectral method, and a generalized spectral method. Results obtained with these three approaches for various models of ice-shell thickness variations are presented and compared. Implications of a reduced ice shell thickness for the south polar terrain activity are discussed.

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

Advective, Diffusive and Eruptive Leakage of CO2 and Brine within Fault Zone

NASA Astrophysics Data System (ADS)

Jung, N. H.; Han, W. S.

2014-12-01

This study investigated a natural analogue for CO2 leakage near the Green River, Utah, aiming to understand the influence of various factors on CO2 leakage and to reliably predict underground CO2 behavior after injection for geologic CO2 sequestration. Advective, diffusive, and eruptive characteristics of CO2 leakage were assessed via a soil CO2 flux survey and numerical modeling. The field results show anomalous CO2 fluxes (> 10 g m-2 d-1) along the faults, particularly adjacent to CO2-driven cold springs and geysers (e.g., 36,259 g m-2 d-1 at Crystal Geyser), ancient travertines (e.g., 5,917 g m-2 d-1), joint zones in sandstone (e.g., 120 g m-2 d-1), and brine discharge zones (e.g., 5,515 g m-2 d-1). Combined to similar isotopic ratios of gas and progressive evolution of brine chemistry at springs and geysers, a gradual decrease of soil CO2 flux from the Little Grand Wash (LGW; ~36,259 g m-2 d-1) to Salt Wash (SW; ~1,428 g m-2 d-1) fault zones reveals the same CO2 origin and potential southward transport of CO2 over 10-20 km. The numerical simulations overtly exhibit lateral transport of free CO2 and CO2-rich brine from the LGW to SW fault zones through the regional aquifers (e.g., Entrada, Navajo, Kayenta, Wingate, White Rim). CO2 travels predominantly as an aqueous phase (Xco2=~0.045) as previously suggested, giving rise to the convective instability that further accelerates CO2 dissolution. While the buoyant free CO2 always tends to ascend, a fraction of dense CO2-rich brine flows laterally into the aquifer and mixes with the formation fluids during upward migration along the fault. The fault always enhances advective CO2 transport regardless of its permeability (k). However, only the low-k fault scenario engenders development of CO2 anticlinal trap within the shallow aquifers (Entrada and Navajo), concentrating high CO­­­2 fluxes (~1,273 g m-2 d-1) within the northern footwall of the LGW fault similar to the field. Moreover, eruptive CO2 leakage at a well

Disparity of Chlorine to Fluorine Concentration Ratios Between Thermal Waters and Rocks of Yellowstone National Park, USA

NASA Astrophysics Data System (ADS)

McConville, E. G.; Szymanski, M. E.; Hurwitz, S.; Lowenstern, J. B.; Hayden, L. A.

2016-12-01

Low chlorine to fluorine concentration ratios (Cl/F) of 0.5 by weight are observed in Yellowstone rhyolites within glass inclusions and erupted rhyolitic glass. In contrast, Yellowstone thermal waters have Cl/F of >10 and Cl/F of waters at Norris Geyser Basin can exceed 100. Similar Cl/F have been observed in other volcanic hydrothermal systems (e.g., Lassen, Long Valley Caldera). The goal of this study is to identify fluorine-bearing minerals that could remove a substantial amount of F from the hydrothermal fluids within the Yellowstone caldera and in the Norris Geyser Basin near the northern margin of the caldera. We used a scanning electron microscope (SEM) to study thin sections from core samples obtained during research drilling by the USGS in the 1960s. The Y-2 well (Lower Geyser Basin) penetrated mostly Plateau Rhyolites ( 0.15 Ma) and Y-7 and Y-8 wells (Upper Geyser Basin) penetrated glacial sandstones and conglomerates, underlain by the Biscuit Basin flow ( 0.5 Ma). The thin sections from Y-12 in the Norris Geyser Basin are all from the Lava Creek Tuff. Fluorine-bearing minerals are found in all drill cores. Fluorite is present in Y-2 at a depth of 153 m, in Y-7 at 65m, and in Y-12 at 276 m. Fluoroapatite first appears in the Biscuit Basin flow at 60 m in Y-7 and 59 m in Y-8. Rare earth fluorocarbonates, such as bastnaesite (Ce,La,Y)CO3F and/or parisite Ca(Ce,La)2(CO3)3F2, are predominantly found in Y-12 at depths >276 m. Our estimated abundances of these fluorine-bearing minerals are at least 2 orders of magnitude less than required to substantially affect the Cl/F ratio in thermal waters. Fluorine-bearing minerals may be more abundant at greater depth. Another possible explanation is that the fluorite is too fine-grained to be identified by SEM. Finally, the high Cl/F in thermal waters could be explained by the ascent of Cl-rich fluid from a cooling magma body or from older crustal rocks that underlie the caldera.

Geophysical setting of the 2000 ML 5.2 Yountville, California, earthquake: Implications for seismic Hazard in Napa Valley, California

USGS Publications Warehouse

Langenheim, V.E.; Graymer, R.W.; Jachens, R.C.

2006-01-01

The epicenter of the 2000 ML 5.2 Yountville earthquake was located 5 km west of the surface trace of the West Napa fault, as defined by Helley and Herd (1977). On the basis of the re-examination of geologic data and the analysis of potential field data, the earthquake occurred on a strand of the West Napa fault, the main basin-bounding fault along the west side of Napa Valley. Linear aeromagnetic anomalies and a prominent gravity gradient extend the length of the fault to the latitude of Calistoga, suggesting that this fault may be capable of larger-magnitude earthquakes. Gravity data indicate an ???2-km-deep basin centered on the town of Napa, where damage was concentrated during the Yountville earthquake. It most likely played a minor role in enhancing shaking during this event but may lead to enhanced shaking caused by wave trapping during a larger-magnitude earthquake.

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

Reduction of operations and maintenance costs at geothermal power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruton, C.J.; Stevens, C.G.; Rard, J.A.

1997-12-31

To reduce chemical costs at geothermal power plants, we are investigating: (a) improved chemical processes associated with H{sub 2}S abatement techniques, and (b) the use of cross dispersive infrared spectrometry to monitor accurately, reliably, and continuously H{sub 2}S emissions from cooling towers. The latter is a new type of infrared optical technology developed by LLNL for non-proliferation verification. Initial work is focused at The Geysers in cooperation with Pacific Gas and Electric. Methods for deploying the spectrometer on-site at The Geysers are being developed. Chemical analysis of solutions involved in H{sub 2}S abatement technologies is continuing to isolate the chemicalmore » forms of sulfur produced.« less

Relationships between Boron concentrations and trout in the firehole river, Wyoming: Historical information and preliminary results of a field study

USGS Publications Warehouse

Meyer, J.S.; Boelter, A.M.; Woodward, D.F.; Goldstein, J.N.; Farag, A.M.; Hubert, W.A.

1998-01-01

The Firehole River (FHR) in Yellowstone National Park (YNP) is a world- renowned recreational fishery that predominantly includes rainbow trout (RBT, Oncorhynchus mykiss) and brown trout (BNT, Salmo trutta). The trout populations apparently are closed to immigration and have been self- sustaining since 1955. Inputs from hot springs and geysers increase the temperature and mineral content of the water, including elevating the boron (B) concentrations to a maximum of ~1 mg B/L. Both RBT and BNT reside in warm-water reaches, except when the water is extremely warm (???~25??C) during midsummer. They spawn in late fall and early winter, with documented spawning of BNT in the cold-water reach upstream from the Upper Geyser Basin and of RBT in the Lower Geyser Basin reach, where water temperatures presumably are the warmest; however, successful recruitment of RBT in waters containing ~1 mg B/L has not been demonstrated conclusively. Thus, we began investigating the relationships among temperature, B concentrations, other water-quality parameters, and the distribution and reproduction of trout in the FHR in spring 1997. However, atypical high water flows and concomitant lower than historical temperatures and B concentrations during summer 1997 preclude conclusions about avoidance of high B concentrations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walters, M.A.; Sternfeld, J.N.; Haizlip, J.R.

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 500/sup 0/F, rock temperatures apparently exceeding 600/sup 0/F, and steam enthalpies of about 1320 Btu/lb. The HTR in the northwest Geysers is probably a deep, evolving system in contrast to the shallower, leaky, and mature steam reservoir(s) in the central and southeastern portions of the field. Before natural venting and nearby production caused pressures to decline, the HTR was a liquid-dominated system with some connate water - the connate water being the source ofmore » the high gas contents, chloride, and unique isotopic composition relative to steam from a typical Geysers reservoir. Therefore, the present boundary between the typical reservoir and HTR is a transient, thermodynamic condition due to the recent evolution of a vapor-dominated zone from a liquid-dominated zone that has yet to cool down. It also demarks a previous liquid-to-vapor interface. Pressure in the two reservoirs is essentially the same because they are in communication with each other. In other words, the temperature change in the HTR is lagging (behind) the pressure change.« less

The Origin of High-angle Dip-slip Earthquakes at Geothermal Fields in California

NASA Astrophysics Data System (ADS)

Barbour, A. J.; Schoenball, M.; Martínez-Garzón, P.; Kwiatek, G.

2016-12-01

We examine the source mechanisms of earthquakes occurring in three California geothermal fields: The Geysers, Salton Sea, and Coso. We find source mechanisms ranging from strike slip faulting, consistent with the tectonic settings, to dip slip with unusually steep dip angles which are inconsistent with local structures. For example, we identify a fault zone in the Salton Sea Geothermal Field imaged using precisely-relocated hypocenters with a dip angle of 60° yet double-couple focal mechanisms indicate higher-angle dip-slip on ≥75° dipping planes. We observe considerable temporal variability in the distribution of source mechanisms. For example, at the Salton Sea we find that the number of high angle dip-slip events increased after 1989, when net-extraction rates were highest. There is a concurrent decline in strike-slip and strike-slip-normal faulting, the mechanisms expected from regional tectonics. These unusual focal mechanisms and their spatio-temporal patterns are enigmatic in terms of our understanding of faulting in geothermal regions. While near-vertical fault planes are expected to slip in a strike-slip sense, and dip slip is expected to occur on moderately dipping faults, we observe dip slip on near-vertical fault planes. However, for plausible stress states and accounting for geothermal production, the resolved fault planes should be stable. We systematically analyze the source mechanisms of these earthquakes using full moment tensor inversion to understand the constraints imposed by assuming a double-couple source. Applied to The Geysers field, we find a significant reduction in the number of high-angle dip-slip mechanisms using the full moment tensor. The remaining mechanisms displaying high-angle dip-slip could be consistent with faults accommodating subsidence and compaction associated with volumetric strain changes in the geothermal reservoir.

Detectability of geothermal areas using Skylab X-5 data

NASA Technical Reports Server (NTRS)

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

1975-01-01

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

Monitoring Geothermal Features in Yellowstone National Park with ATLAS Multispectral Imagery

NASA Technical Reports Server (NTRS)

Spruce, Joseph; Berglund, Judith

2000-01-01

The National Park Service (NPS) must produce an Environmental Impact Statement for each proposed development in the vicinity of known geothermal resource areas (KGRAs) in Yellowstone National Park. In addition, the NPS monitors indicator KGRAs for environmental quality and is still in the process of mapping many geothermal areas. The NPS currently maps geothermal features with field survey techniques. High resolution aerial multispectral remote sensing in the visible, NIR, SWIR, and thermal spectral regions could enable YNP geothermal features to be mapped more quickly and in greater detail In response, Yellowstone Ecosystems Studies, in partnership with NASA's Commercial Remote Sensing Program, is conducting a study on the use of Airborne Terrestrial Applications Sensor (ATLAS) multispectral data for monitoring geothermal features in the Upper Geyser Basin. ATLAS data were acquired at 2.5 meter resolution on August 17, 2000. These data were processed into land cover classifications and relative temperature maps. For sufficiently large features, the ATLAS data can map geothermal areas in terms of geyser pools and hot springs, plus multiple categories of geothermal runoff that are apparently indicative of temperature gradients and microbial matting communities. In addition, the ATLAS maps clearly identify geyserite areas. The thermal bands contributed to classification success and to the computation of relative temperature. With masking techniques, one can assess the influence of geothermal features on the Firehole River. Preliminary results appear to confirm ATLAS data utility for mapping and monitoring geothermal features. Future work will include classification refinement and additional validation.

Steam explosions, earthquakes, and volcanic eruptions -- what's in Yellowstone's future?

USGS Publications Warehouse

Lowenstern, Jacob B.; Christiansen, Robert L.; Smith, Robert B.; Morgan, Lisa A.; Heasler, Henry

2005-01-01

Yellowstone, one of the world?s largest active volcanic systems, has produced several giant volcanic eruptions in the past few million years, as well as many smaller eruptions and steam explosions. Although no eruptions of lava or volcanic ash have occurred for many thousands of years, future eruptions are likely. In the next few hundred years, hazards will most probably be limited to ongoing geyser and hot-spring activity, occasional steam explosions, and moderate to large earthquakes. To better understand Yellowstone?s volcano and earthquake hazards and to help protect the public, the U.S. Geological Survey, the University of Utah, and Yellowstone National Park formed the Yellowstone Volcano Observatory, which continuously monitors activity in the region.

Fountains of Enceladus

NASA Image and Video Library

2005-11-28

Recent Cassini images of Saturn's moon Enceladus backlit by the sun show the fountain-like sources of the fine spray of material that towers over the south polar region. This image was taken looking more or less broadside at the "tiger stripe" fractures observed in earlier Enceladus images. It shows discrete plumes of a variety of apparent sizes above the limb (edge) of the moon. This image was acquired on Nov. 27, 2005. Imaging scientists, as reported in the journal Science on March 10, 2006, believe that the jets are geysers erupting from pressurized subsurface reservoirs of liquid water above 273 degrees Kelvin (0 degrees Celsius). http://photojournal.jpl.nasa.gov/catalog/PIA07758

Parametric Investigation of Liquid Jets in Low Gravity

NASA Technical Reports Server (NTRS)

Chato, David J.

2005-01-01

An axisymmetric phase field model is developed and used to model surface tension forces on liquid jets in microgravity. The previous work in this area is reviewed and a baseline drop tower experiment selected for model comparison. This paper uses the model to parametrically investigate the influence of key parameters on the geysers formed by jets in microgravity. Investigation of the contact angle showed the expected trend of increasing contact angle increasing geyser height. Investigation of the tank radius showed some interesting effects and demonstrated the zone of free surface deformation is quite large. Variation of the surface tension with a laminar jet showed clearly the evolution of free surface shape with Weber number. It predicted a breakthrough Weber number of 1.

Imaging subsurface hydrothermal structure using a dense geophone array in Yellowstone

NASA Astrophysics Data System (ADS)

Wu, S. M.; Lin, F. C.; Farrell, J.; Smith, R. B.

2016-12-01

The recent development of ambient noise cross-correlation and the availability of large N seismic arrays allow for the study of detailed shallow crustal structure. In this study, we apply multi-component noise cross-correlation to explore shallow hydrothermal structure near Old Faithful geyser in Yellowstone National Park using a temporary geophone array. The array was composed of 133 three-component 5-Hz geophones and was deployed for two weeks during November 2015. The average station spacing is 50 meters and the full aperture of the array is around 1 km with good azimuthal and spatial coverage. The Upper Geyser Basin, where Old Faithful is located, has the largest concentration of geysers in the world. This unique active hydrothermal environment and hence the extremely inhomogeneous noise source distribution makes the construction of empirical Green's functions difficult based on the traditional noise cross-correlation method. In this presentation, we show examples of the constructed cross-correlation functions and demonstrate their spatial and temporal relationships with known hydrothermal activity. We also demonstrate how useful seismic signals can be extracted from these cross-correlation functions and used for subsurface imaging. In particular, we will discuss the existence of a recharge cavity beneath Old Faithful revealed by the noise cross-correlations. In addition, we also investigated the temporal structure variation based on time-lapse noise cross-correlations and these preliminary results will also be discussed.

Simulations of the Tendrils

NASA Image and Video Library

2015-04-14

This collage of NASA Cassini spacecraft images and computer simulations shows how long, sinuous features from Enceladus can be modeled by tracing the trajectories of tiny, icy grains ejected from the moon south polar geysers.

Fountains of Enceladus - Image #2

NASA Image and Video Library

2005-11-28

Recent Cassini images of Saturn's moon Enceladus backlit by the sun show the fountain-like sources of the fine spray of material that towers over the south polar region. The image was taken looking more or less broadside at the "tiger stripe" fractures observed in earlier Enceladus images. It shows discrete plumes of a variety of apparent sizes above the limb of the moon. The greatly enhanced and colorized image shows the enormous extent of the fainter, larger-scale component of the plume. Imaging scientists, as reported in the journal Science on March 10, 2006, believe that the jets are geysers erupting from pressurized subsurface reservoirs of liquid water above 273 degrees Kelvin (0 degrees Celsius). http://photojournal.jpl.nasa.gov/catalog/PIA07759

Fifteenth workshop on geothermal reservoir engineering: Proceedings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-01-01

The Fifteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23--25, 1990. Major topics included: DOE's geothermal research and development program, well testing, field studies, geosciences, geysers, reinjection, tracers, geochemistry, and modeling.

GEOTHERMAL ENVIRONMENTAL IMPACT ASSESSMENT: BASELINE DATA FOR FOUR GEOTHERMAL AREAS IN THE UNITED STATES

EPA Science Inventory

This report describes the existing data on climatology, hydrology, water chemistry, seismicity, and subsidence in the Rio Grande Rift Zone, New Mexico; The Geysers, California; the Klamath Falls, Oregon; and with special emphasis, The Imperial Valley, California.

Discriminating Characteristics of Tectonic and Human-Induced Seismicity

NASA Astrophysics Data System (ADS)

Zaliapin, I. V.; Ben-Zion, Y.

2015-12-01

We analyze statistical features of background and clustered subpopulations of earthquakes in different regions in an effort to distinguish between human-induced and natural seismicity. Analysis of "end-member" areas known to be dominated by human-induced earthquakes (the Geyser geothermal field in northern California and TauTona gold mine in South Africa) and regular tectonic activity (the San Jacinto fault zone in southern California and Coso region excluding the Coso geothermal field in eastern central California) reveals several distinguishing characteristics. Induced seismicity is shown to have (i) higher rate of background events (both absolute and relative to the total rate), (ii) faster temporal offspring decay, (iii) higher intensity of repeating events, (iv) larger proportion of small clusters, and (v) larger spatial separation between parent and offspring, compared to regular tectonic activity. These differences also successfully discriminate seismicity within the Coso and Salton Sea geothermal fields in California before and after the expansion of geothermal production during the 1980s.

ANALYSIS OF GEOTHERMAL WASTES FOR HAZARDOUS COMPONENTS

EPA Science Inventory

Regulations governing the disposal of hazardous wastes led to an assessment for geothermal solid wastes for potentially hazardous properties. Samples were collected from three active geothermal sites in the western United States: The Geysers, Imperial Valley, and northwestern Nev...

GEOTHERMAL ENVIRONMENTAL IMPACT ASSESSMENT: SUBSURFACE ENVIRONMENTAL ASSESSMENT FOR FOUR GEOTHERMAL SYSTEMS

EPA Science Inventory

This is the second in a series of reports concerning the environmental assessments of effluent extraction, energy conversion, and waste disposal in geothermal systems. This study involves the subsurface environmental impact of the Imperial Valley and The Geysers, California; Klam...

Encroaching Shadow

NASA Image and Video Library

2014-07-28

This image from NASA Cassini spacecraft, one of those acquired in the survey conducted by the Cassini imaging science team of the geyser basin at the south pole of Enceladus, was taken as Cassini was looking across the moon south pole.

78 FR 10206 - Notice of Final Supplementary Rules for Public Lands Managed by the Ukiah Field Office in Lake...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-13

... within the following areas: Lost Valley--40 acres (Cow Mountain Management Area, Mendocino County..., Sonoma County). d. The following rules apply to Cache Creek, Cow Mountain, Knoxville, Geysers, Indian... hour after sunset except for long-term parking for overnight backcountry visitors. Cow Mountain...

Delineating Spatial Patterns in the Yellowstone Hydrothermal System using Geothermometry

NASA Astrophysics Data System (ADS)

King, J.; Hurwitz, S.; Lowenstern, J. B.

2015-12-01

Yellowstone National Park is unmatched with regard to its quantity of active hydrothermal features. Origins of thermal waters in its geyser basins have been traced to mixing of a deep parent water with meteoric waters in shallow local reservoirs (Fournier, 1989). A mineral-solution equilibrium model was developed to calculate water-rock chemical re-equilibration temperatures in these shallow reservoirs. We use the GeoT program, which uses water composition data as input to calculate saturation indices of selected minerals; the "best-clustering" minerals are then statistically determined to infer reservoir temperatures (Spycher et al., 2013). We develop the method using water composition data from Heart Lake Geyser Basin (HLGB), for which both chemical and isotopic geothermometers predict a reservoir water temperature of 205°C ± 10°C (Lowenstern et al., 2012), and minerals found in drill cores in Yellowstone's geyser basins. We test the model for sensitivity to major element composition, pH, Total Inorganic Carbon (TIC) and selected minerals to optimize model parameters. Calculated temperatures are most accurate at pH values below 9.0, and closely match the equilibrium saturation indices of quartz, stilbite, microcline, and albite. The model is optimized with a TIC concentration that is consistent with the mass of diffuse CO2 flux in HLGB (Lowenstern et al., 2012). We then use water compositions from other thermal basins in Yellowstone in search of spatial variations in reservoir temperatures. We then compare the calculated temperatures with various SiO2 and cation geothermometers.

Proposed Perrier Ocean for Enceladus

NASA Image and Video Library

2010-10-04

A graphic laid atop an image of Enceladus jets taken by NASA Cassini imaging cameras shows bubbles in seawater traveling through a passage in the ice crust to feed a geyser. Seawater flows back down to the subsurface ocean through cracks in the ice.

76 FR 31979 - Notice of Interim Final Supplementary Rules for Public Lands Managed by the Ukiah Field Office in...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-02

... parts, soil, rocks, minerals, or cave resources within the following ACECs: Lost Valley--40 acres (Cow... Creek, Cow Mountain, Knoxville, Geysers, Indian Valley, Black Forest, the Cedars of Sonoma County and... hour after sunset except for long-term parking for overnight backcountry visitors. Cow Mountain...

The dark side of the mushroom spring microbial mat: Life in the shadow of chlorophototrophs. I. Microbial diversity based on 16S rRNA gene amplicons and metagenomics

USDA-ARS?s Scientific Manuscript database

Microbial-mat communities in the effluent channels of Octopus and Mushroom Springs within the Lower Geyser Basin at Yellowstone National Park have been studied for nearly 50 years. The emphasis has mostly focused on the chlorophototrophic bacterial organisms of the phyla Cyanobacteria and Chloroflex...

Monitoring gas and heat emissions at Norris Geyser Basin, Yellowstone National Park, USA based on a combined eddy covariance and Multi-GAS approach

NASA Astrophysics Data System (ADS)

Lewicki, J. L.; Kelly, P. J.; Bergfeld, D.; Vaughan, R. G.; Lowenstern, J. B.

2017-11-01

We quantified gas and heat emissions in an acid-sulfate, vapor-dominated area (0.04-km2) of Norris Geyser Basin, located just north of the 0.63 Ma Yellowstone Caldera and near an area of anomalous uplift. From 14 May to 3 October 2016, an eddy covariance system measured half-hourly CO2, H2O and sensible (H) and latent (LE) heat fluxes and a Multi-GAS instrument measured (1 Hz frequency) atmospheric H2O, CO2 and H2S volumetric mixing ratios. We also measured soil CO2 fluxes using the accumulation chamber method and temperature profiles on a grid and collected fumarole gas samples for geochemical analysis. Eddy covariance CO2 fluxes ranged from - 56 to 885 g m- 2 d- 1. Using wavelet analysis, average daily eddy covariance CO2 fluxes were locally correlated with average daily environmental parameters on several-day to monthly time scales. Estimates of CO2 emission rate from the study area ranged from 8.6 t d- 1 based on eddy covariance measurements to 9.8 t d- 1 based on accumulation chamber measurements. Eddy covariance water vapor fluxes ranged from 1178 to 24,600 g m- 2 d- 1. Nighttime H and LE were considered representative of hydrothermal heat fluxes and ranged from 4 to 183 and 38 to 504 W m- 2, respectively. The total hydrothermal heat emission rate (H + LE + radiant) estimated for the study area was 11.6 MW and LE contributed 69% of the output. The mean ± standard deviation of H2O, CO2 and H2S mixing ratios measured by the Multi-GAS system were 9.3 ± 3.1 parts per thousand, 467 ± 61 ppmv, and 0.5 ± 0.6 ppmv, respectively, and variations in the gas compositions were strongly correlated with diurnal variations in environmental parameters (wind speed and direction, atmospheric temperature). After removing ambient H2O and CO2, the observed variations in the Multi-GAS data could be explained by the mixing of relatively H2O-CO2-H2S-rich fumarole gases with CO2-rich and H2O-H2S-poor soil gases. The fumarole H2O/CO2 and CO2/H2S end member ratios (101.7 and 27

Monitoring gas and heat emissions at Norris Geyser Basin, Yellowstone National Park, USA based on a combined eddy covariance and Multi-GAS approach

USGS Publications Warehouse

Lewicki, Jennifer L.; Kelly, Peter; Bergfeld, Deborah; Vaughan, R. Greg; Lowenstern, Jacob B.

2017-01-01

We quantified gas and heat emissions in an acid-sulfate, vapor-dominated area (0.04-km2) of Norris Geyser Basin, located just north of the 0.63 Ma Yellowstone Caldera and near an area of anomalous uplift. From 14 May to 3 October 2016, an eddy covariance system measured half-hourly CO2, H2O and sensible (H) and latent (LE) heat fluxes and a Multi-GAS instrument measured (1 Hz frequency) atmospheric H2O, CO2 and H2S volumetric mixing ratios. We also measured soil CO2 fluxes using the accumulation chamber method and temperature profiles on a grid and collected fumarole gas samples for geochemical analysis. Eddy covariance CO2 fluxes ranged from − 56 to 885 g m− 2 d− 1. Using wavelet analysis, average daily eddy covariance CO2 fluxes were locally correlated with average daily environmental parameters on several-day to monthly time scales. Estimates of CO2emission rate from the study area ranged from 8.6 t d− 1 based on eddy covariance measurements to 9.8 t d− 1 based on accumulation chamber measurements. Eddy covariance water vapor fluxes ranged from 1178 to 24,600 g m− 2 d− 1. Nighttime H and LEwere considered representative of hydrothermal heat fluxes and ranged from 4 to 183 and 38 to 504 W m− 2, respectively. The total hydrothermal heat emission rate (H + LE + radiant) estimated for the study area was 11.6 MW and LE contributed 69% of the output. The mean ± standard deviation of H2O, CO2 and H2S mixing ratios measured by the Multi-GAS system were 9.3 ± 3.1 parts per thousand, 467 ± 61 ppmv, and 0.5 ± 0.6 ppmv, respectively, and variations in the gas compositions were strongly correlated with diurnal variations in environmental parameters (wind speed and direction, atmospheric temperature). After removing ambient H2O and CO2, the observed variations in the Multi-GAS data could be explained by the mixing of relatively H2O-CO2-H2S-rich fumarole gases with CO2-rich and H2O-H2S-poor soil gases. The

Geothermal Program Review XI: proceedings. Geothermal Energy - The Environmental Responsible Energy Technology for the Nineties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-10-01

These proceedings contain papers pertaining to current research and development of geothermal energy in the USA. The seven sections of the document are: Overview, The Geysers, Exploration and Reservoir Characterization, Drilling, Energy Conversion, Advanced Systems, and Potpourri. The Overview presents current DOE energy policy and industry perspectives. Reservoir studies, injection, and seismic monitoring are reported for the geysers geothermal field. Aspects of geology, geochemistry and models of geothermal exploration are described. The Drilling section contains information on lost circulation, memory logging tools, and slim-hole drilling. Topics considered in energy conversion are efforts at NREL, condensation on turbines and geothermal materials.more » Advanced Systems include hot dry rock studies and Fenton Hill flow testing. The Potpourri section concludes the proceedings with reports on low-temperature resources, market analysis, brines, waste treatment biotechnology, and Bonneville Power Administration activities. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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'',more » 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.« less

Identifying bubble collapse in a hydrothermal system using hidden Markov models

USGS Publications Warehouse

Dawson, P.B.; Benitez, M.C.; Lowenstern, J. B.; Chouet, B.A.

2012-01-01

Beginning in July 2003 and lasting through September 2003, the Norris Geyser Basin in Yellowstone National Park exhibited an unusual increase in ground temperature and hydrothermal activity. Using hidden Markov model theory, we identify over five million high-frequency (>15Hz) seismic events observed at a temporary seismic station deployed in the basin in response to the increase in hydrothermal activity. The source of these seismic events is constrained to within ???100 m of the station, and produced ???3500-5500 events per hour with mean durations of ???0.35-0.45s. The seismic event rate, air temperature, hydrologic temperatures, and surficial water flow of the geyser basin exhibited a marked diurnal pattern that was closely associated with solar thermal radiance. We interpret the source of the seismicity to be due to the collapse of small steam bubbles in the hydrothermal system, with the rate of collapse being controlled by surficial temperatures and daytime evaporation rates. copyright 2012 by the American Geophysical Union.

Identifying bubble collapse in a hydrothermal system using hiddden Markov models

USGS Publications Warehouse

Dawson, Phillip B.; Benitez, M.C.; Lowenstern, Jacob B.; Chouet, Bernard A.

2012-01-01

Beginning in July 2003 and lasting through September 2003, the Norris Geyser Basin in Yellowstone National Park exhibited an unusual increase in ground temperature and hydrothermal activity. Using hidden Markov model theory, we identify over five million high-frequency (>15 Hz) seismic events observed at a temporary seismic station deployed in the basin in response to the increase in hydrothermal activity. The source of these seismic events is constrained to within ~100 m of the station, and produced ~3500–5500 events per hour with mean durations of ~0.35–0.45 s. The seismic event rate, air temperature, hydrologic temperatures, and surficial water flow of the geyser basin exhibited a marked diurnal pattern that was closely associated with solar thermal radiance. We interpret the source of the seismicity to be due to the collapse of small steam bubbles in the hydrothermal system, with the rate of collapse being controlled by surficial temperatures and daytime evaporation rates.

Triton Hopper: Exploring Neptune's Captured Kuiper Belt Object

NASA Technical Reports Server (NTRS)

Oleson, Steve; Landis, Geoffrey

2018-01-01

Neptune's moon Triton is a fascinating object, a dynamic moon with an atmosphere, and geysers. Triton is unique in the outer solar system in that it is most likely a captured Kuiper belt object (KBO), a leftover building block of the solar system. When Voyager flew by it was the coldest body yet found in our solar system (33 degrees Kelvin) and had volcanic activity, geysers, and a thin atmosphere. It is covered in ices made from nitrogen, water, and carbon-dioxide, and shows surface deposits of tholins, organic compounds that may be precursor chemicals to the origin of life. Exploring Triton will be a challenge well beyond anything done in previous missions; but the unique environment of Triton also allows some new possibilities for mobility. We developed a conceptual design of a Triton Hopping probe that both analyzes the surface and collects it for use to propel its hops. The Hopper would land near the South Pole in 2040 where geysers have been detected. Depending the details of propulsion chosen the Hopper should be able to jump over 300 kilometers in 60 hops or less, exploring the surface and thin atmosphere on its way. This craft will autonomously carry out detailed scientific investigations on the surface, below the surface (drilling) and in the upper atmosphere to provide unprecedented knowledge of a KBO-turned moon and expanding NASA's existing capabilities in deep space planetary exploration to include Hoppers using different ices for propellant. Triton is roughly 2700 kilometers in diameter with a surface of mostly frozen nitrogen, mostly water ice crust and core of metal and rock. Its gravity is half that of Earth's Moon and its atmosphere is 170,000th of Earth's or 0.3 of Mars.The mission concept studied investigated the full surface and atmospheric phenomenon: chemical composition of surface and near subsurface materials, the thin atmosphere, volcanic and geyser activity. Measurements of all these aspects of Triton's unique environment can only be

The Northwest Geysers EGS Demonstration Project, California

DOE PAGES

Garcia, Julio; Hartline, Craig; Walters, Mark; ...

2015-09-04

Our project goal is to demonstrate the feasibility of stimulating a deep high-temperature reservoir (HTR) (up to 400 °C, 750 °F). There were two previously abandoned wells, Prati State 31 (PS-31) and Prati 32 (P-32), reopened and deepened to be used as an injection and production doublet to stimulate the HTR. The deepened portions of both wells have conductive temperature gradients of 10 °F/100 ft (182 °C/km), produce connate native fluids and magmatic gas, and the rocks were isotopically unexchanged by meteoric water. The ambient temperature meteoric water injected into these hot dry rocks has evidently created a permeability volume of several cubic kilometers asmore » determined by seismic monitoring. Preliminary isotopic analyses of the injected and produced water indicate that 50–75% of the steam from the created EGS reservoir is injection-derived.« less

HYDROGEOLOGY OF THE THERMAL LANDSLIDE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vantine, J.

1985-01-22

The large Thermal Landslide overlies the initial area of geothermal development at The Geysers. The landslide is waterbearing while the underlying Franciscan formation bedrock units are essentially non-waterbearing except where affected by hydrothermal alteration. Perched ground water moving through the landslide is heated prior to discharge as spring flow.

Io Plume Monitoring (frames 1-36)

NASA Image and Video Library

1997-11-04

A sequence of full disk Io images was taken prior to Galileo's second encounter with Ganymede. The purpose of these observations was to view all longitudes of Io and search for active volcanic plumes. The images were taken at intervals of approximately one hour corresponding to Io longitude increments of about ten degrees. Because both the spacecraft and Io were traveling around Jupiter the lighting conditions on Io (e.g. the phase of Io) changed dramatically during the sequence. These images were registered at a common scale and processed to produce a time-lapse "movie" of Io. This movie combines all of the plume monitoring frames obtained by the Solid State Imaging system aboard NASA's Galileo spacecraft. The most prominent volcanic plume seen in this movie is Prometheus (latitude 1.6 south, longitude 153 west). The plume becomes visible as it moves into daylight, crosses the center of the disk, and is seen in profile against the dark of space at the edge of Io. This plume was first seen by the Voyager 1 spacecraft in 1979 and is believed to be a geyser-like eruption of sulfur dioxide snow and gas. Although details of the region around Prometheus have changed in the seventeen years since Voyager's visit, the shape and height of the plume have not changed significantly. It is possible that this geyser has been erupting nearly continuously over this time. Galileo's primary 24 month mission includes eleven orbits around Jupiter and will provide observations of Jupiter, its moons and its magnetosphere. North is to the top of all frames. The smallest features which can be discerned range from 13 to 31 kilometers across. The images were obtained between the 2nd and the 6th of September, 1996. The animation can be viewed at http://photojournal.jpl.nasa.gov/catalog/PIA01073

Full moment tensor and source location inversion based on full waveform adjoint method

NASA Astrophysics Data System (ADS)

Morency, C.

2012-12-01

The development of high-performance computing and numerical techniques enabled global and regional tomography to reach high levels of precision, and seismic adjoint tomography has become a state-of-the-art tomographic technique. The method was successfully used for crustal tomography of Southern California (Tape et al., 2009) and Europe (Zhu et al., 2012). Here, I will focus on the determination of source parameters (full moment tensor and location) based on the same approach (Kim et al, 2011). The method relies on full wave simulations and takes advantage of the misfit between observed and synthetic seismograms. An adjoint wavefield is calculated by back-propagating the difference between observed and synthetics from the receivers to the source. The interaction between this adjoint wavefield and the regular forward wavefield helps define Frechet derivatives of the source parameters, that is, the sensitivity of the misfit with respect to the source parameters. Source parameters are then recovered by minimizing the misfit based on a conjugate gradient algorithm using the Frechet derivatives. First, I will demonstrate the method on synthetic cases before tackling events recorded at the Geysers. The velocity model used at the Geysers is based on the USGS 3D velocity model. Waveform datasets come from the Northern California Earthquake Data Center. Finally, I will discuss strategies to ultimately use this method to characterize smaller events for microseismic and induced seismicity monitoring. References: - Tape, C., Q. Liu, A. Maggi, and J. Tromp, 2009, Adjoint tomography of the Southern California crust: Science, 325, 988992. - Zhu, H., Bozdag, E., Peter, D., and Tromp, J., 2012, Structure of the European upper mantle revealed by adjoint method: Nature Geoscience, 5, 493-498. - Kim, Y., Q. Liu, and J. Tromp, 2011, Adjoint centroid-moment tensor inversions: Geophys. J. Int., 186, 264278. Prepared by LLNL under Contract DE-AC52-07NA27344.

Some inner satellites of giant planets are still outgassing: Triton, Enceladus, Io

NASA Astrophysics Data System (ADS)

Kochemasov, Gennady G.

2010-05-01

Process of atmospheric formation in the Solar system continues. There are three celestial bodies (except Earth) still emitting considerable amounts of volatiles though these bodies' masses do not allow keeping appreciable amounts of emitted volatiles in their vicinity and creating real atmospheres. It was earlier shown that the wave oscillations in form of stationary waves more or less rapidly changing their phases (plus to minus and inversely) sweep out volatiles from planetary depths [1]. These stationary waves, proportional in their amplitudes to the radii of tectonic granules (Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2) and inversely proportional to orbital frequencies, form the planetary surface relief range of which increases with the solar distance [2]. In the opposite direction increases the sweeping out force of these waves and, consequently, atmospheric masses increase [3]. In the satellite systems of the outer giant planets this regularity is preserved in that the inner satellites (even small as Enceladus) surprisingly continue to push out volatiles. To do so, really very thorough washing out of entire body should be executed by very fine oscillations. Very fast orbits (Triton - 5.9 days; Enceladus - 1.37 d.; Io - 1.769 d.) secure this. Titan with rather fast orbit (16 d.) has enough mass and gravity to create and keep an atmosphere. Triton has a tenuous nitrogen atmosphere with small amounts of methane. A part of its crust (the southern "continental" segment) is dotted with geysers believed to erupt nitrogen with some admixture of dust entrained from beneath the surface. The geyser plumes are up to 8 km high. There are many streaks of dark material laid down by the geyser activity. Enceladus spews out icy material from the south pole region called "Tiger stripes". Some of the tiny ice particles go into Saturn orbit, forming the doughnut-shaped E ring ("detached Enceladus' atmosphere"). Io has at the moment more than 150 active volcanoes making

NREL/PG&E Condensation System Increases Geothermal Power Plant Efficiency

Science.gov Websites

. Geothermal power plants like The Geysers produce energy by collecting steam from underground reservoirs and NREL/PG&E Condensation System Increases Geothermal Power Plant Efficiency For more information world's largest producer of geothermal power has improved its power production efficiency thanks to a new

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.

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…

Problems due to superheating of cryogenic liquids

NASA Astrophysics Data System (ADS)

Hands, B. A.

1988-12-01

Superheating can cause several problems in the storage of cryogenic liquids: stratification can cause unexpectedly high tank pressures or, in multicomponent liquids, rollover with its consequential high vaporization rate; geysering causes the rapid expulsion of static liquid from a vertical tube; chugging is a similar phenomenon observed when liquid flows through a reasonably well-insulated pipe.

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.

Hawaii Regional Sediment Management (RSM): Regional Sediment Budget for the West Maui Region

DTIC Science & Technology

2016-06-01

Increased sedimentation associated with loss of forest land, historical agriculture practices, stream channelization , and rapid development has...ER D C/ CH L TR -1 6- 5 Regional Sediment Management (RSM) Program Hawaii Regional Sediment Management (RSM): Regional Sediment Budget...acwc.sdp.sirsi.net/client/default. Regional Sediment Management (RSM) Program ERDC/CHL TR-16-5 June 2016 Hawaii Regional Sediment Management

Median Filtering Methods for Non-volcanic Tremor Detection

NASA Astrophysics Data System (ADS)

Damiao, L. G.; Nadeau, R. M.; Dreger, D. S.; Luna, B.; Zhang, H.

2016-12-01

Various properties of median filtering over time and space are used to address challenges posed by the Non-volcanic tremor detection problem. As part of a "Big-Data" effort to characterize the spatial and temporal distribution of ambient tremor throughout the Northern San Andreas Fault system, continuous seismic data from multiple seismic networks with contrasting operational characteristics and distributed over a variety of regions are being used. Automated median filtering methods that are flexible enough to work consistently with these data are required. Tremor is characterized by a low-amplitude, long-duration signal-train whose shape is coherent at multiple stations distributed over a large area. There are no consistent phase arrivals or mechanisms in a given tremor's signal and even the durations and shapes among different tremors vary considerably. A myriad of masquerading noise, anthropogenic and natural-event signals must also be discriminated in order to obtain accurate tremor detections. We present here results of the median methods applied to data from four regions of the San Andreas Fault system in northern California (Geysers Geothermal Field, Napa, Bitterwater and Parkfield) to illustrate the ability of the methods to detect tremor under diverse conditions.

The dynamics behind Titan's methane clouds.

PubMed

Mitchell, Jonathan L; Pierrehumbert, Raymond T; Frierson, Dargan M W; Caballero, Rodrigo

2006-12-05

We present results of an axisymmetric global circulation model of Titan with a simplified suite of atmospheric physics forced by seasonally varying insolation. The recent discovery of midlatitude tropospheric clouds on Titan has caused much excitement about the roles of surface sources of methane and the global circulation in forming clouds. Although localized surface sources, such as methane geysers or "cryovolcanoes," have been invoked to explain these clouds, we find in this work that clouds appear in regions of convergence by the mean meridional circulation and over the poles during solstices, where the solar forcing reaches its seasonal maximum. Other regions are inhibited from forming clouds because of dynamical transports of methane and strong subsidence. We find that for a variety of moist regimes, i.e., with the effect of methane thermodynamics included, the observed cloud features can be explained by the large-scale dynamics of the atmosphere. Clouds at the solsticial pole are found to be a robust feature of Titan's dynamics, whereas isolated midlatitude clouds are present exclusively in a variety of moist dynamical regimes. In all cases, even without including methane thermodynamics, our model ceases to produce polar clouds approximately 4-6 terrestrial years after solstices.

Thermophiles in the genomic era: Biodiversity, science, and applications.

PubMed

Urbieta, M Sofía; Donati, Edgardo R; Chan, Kok-Gan; Shahar, Saleha; Sin, Lee Li; Goh, Kian Mau

2015-11-01

Thermophiles and hyperthermophiles are present in various regions of the Earth, including volcanic environments, hot springs, mud pots, fumaroles, geysers, coastal thermal springs, and even deep-sea hydrothermal vents. They are also found in man-made environments, such as heated compost facilities, reactors, and spray dryers. Thermophiles, hyperthermophiles, and their bioproducts facilitate various industrial, agricultural, and medicinal applications and offer potential solutions to environmental damages and the demand for biofuels. Intensified efforts to sequence the entire genome of hyperthermophiles and thermophiles are increasing rapidly, as evidenced by the fact that over 120 complete genome sequences of the hyperthermophiles Aquificae, Thermotogae, Crenarchaeota, and Euryarchaeota are now available. In this review, we summarise the major current applications of thermophiles and thermozymes. In addition, emphasis is placed on recent progress in understanding the biodiversity, genomes, transcriptomes, metagenomes, and single-cell sequencing of thermophiles in the genomic era. Copyright © 2015 Elsevier Inc. All rights reserved.

Program Setup Time and Learning Curves associated with "ready to fly" Drone Mapping Hardware and Software.

NASA Astrophysics Data System (ADS)

Wilcox, T.

2016-12-01

How quickly can students (and educators) get started using a "ready to fly" UAS and popular publicly available photogrammetric mapping software for student research at the undergraduate level? This poster presentation focuses on the challenges of starting up your own drone-mapping program for undergraduate research in a compressed timescale of three months. Particular focus will be given to learning the operation of the platforms, hardware and software interface challenges, and using these electronic systems in real-world field settings that pose a range of physical challenges to both operators and equipment. We will be using a combination of the popular DJI Phantom UAS and Pix4D mapping software to investigate mass wasting processes and potential hazards present in public lands popular with recreational users. Projects are aimed at characterizing active geological hazards that operate on short timescales and may include gully headwall erosion in Flaming Geyser State Park and potential landslide instability within Capital State Forest, both in the Puget Sound region of Washington State.

Geologic nozzles

USGS Publications Warehouse

Werner, Kieffer S.

1989-01-01

The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the geyser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by the debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. -from Author

Thinking regionally: narrative, the medical humanities and region.

PubMed

Waddington, Keir

2015-06-01

Drawing on multiple literatures from history, geography, anthropology, sociology and literature, this essay asks questions about what we mean by region and why narratives of region should matter to the medical humanities. The essay surveys how region can be used as a lens of analysis, exploring the various academic approaches to region and their limitations. It argues that regions are dynamic but also unstable as a category of analysis and are often used uncritically by scholars. In encouraging scholars working in the medical humanities to be aware that regions are not simple objective or analytical boxes, the essay shows how an awareness of region helps challenge metropolitan whiggism and ideas of core and periphery to give a more prominent place to hinterlands, market towns and rural environments. Furthermore, the essay considers how incorporating region into our understanding of illness can offer new insights. It demonstrates the need for scholars to be attuned to the narratives constructed around regions, suggesting that regions can be viewed as discursive formations that provide a frame for understanding both collective and personal ideas of, and responses to, health and illness, disease and healing, to create what Megan Davies calls a more nuanced 'intellectual cartography'. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Areas of ground subsidence due to geofluid withdrawal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grimsrud, G.P.; Turner, B.L.; Frame, P.A.

1978-08-01

Detailed information is provided on four geothermal areas with histories of subsidence. These were selected on the basis of: physical relevance of subsidence areas to high priority US geothermal sites in terms of withdrawn geofluid type, reservoir depth, reservoir geology and rock characteristics, and overburden characteristics; and data completeness, quality, and availability. The four areas are: Chocolate Bayou, Raft River Valley, Wairakei, and the Geysers. (MHR)

Chemical indicators of subsurface temperature applied to hot spring waters of Yellowstone National Park, Wyoming, U.S.A.

USGS Publications Warehouse

Fournier, R.O.; Truesdell, A.H.

1970-01-01

Under favorable conditions the chemistry of hot springs may give reliable indications of subsurface temperatures and circulation patterns. These chemical indicators can be classified by the type of process involved: {A table is presented}. All these indicators have certain limitations. The silica geothermometer gives results independent of the local mineral suite and gas partial pressures, but may be affected by dilution. Alkali ratios are strongly affected by the local mineral suite and the formation of complex ions. Carbonate-chloride ratios are strongly affected by subsurface PCO2. The relative concentration of volatiles can be very misleading in high-pressure liquid systems. In Yellowstone National Park most thermal waters issue from hot, shallow aquifers with pressures in excess of hydrostatic by 2 to 6 bars and with large flows (the flow of hot spring water from the Park is greater than 4000 liters per second). These conditions should be ideal for the use of chemical indicators to estimate aquifer temperatures. In five drill holes aquifer temperatures were within 2??C of that predicted from the silica content of nearby hot springs; the temperature level off at a lower value than predicted in only one hole, and in four other holes drilling was terminated before the predicted aquifer temperature was reached. The temperature-Na/K ratio relationship does not follow any published experimental or empirical curve for water-feldspar or water-clay reactions. We suspect that ion exchange reactions involving zeolites in the Yellowstone rocks result in higher Na/K ratios at given temperatures than result from feldspar or clay reactions. Comparison of SiO2 and Cl/(HCO3 + CO3) suggest that because of higher subsurface PCO2 in Upper Geyser Basin a given Cl/(HCO3 + CO3) ratio there means a higher temperature than in Lower Geyser Basin. No correlation was found in Yellowstone Park between the subsurface regions of highest temperature and the relative concentration of volatile

A parametric study of Enceladus plumes based on DSMC calculations for retrieving the outgassing parameters as measured by Cassini instruments

NASA Astrophysics Data System (ADS)

Mahieux, Arnaud; Goldstein, David B.; Varghese, Philip; Trafton, Laurence M.

2017-10-01

The vapor and particulate plumes arising from the southern polar regions of Enceladus are a key signature of what lies below the surface. Multiple Cassini instruments (INMS, CDA, CAPS, MAG, UVIS, VIMS, ISS) measured the gas-particle plume over the warm Tiger Stripe region and there have been several close flybys. Numerous observations also exist of the near-vent regions in the visible and the IR. The most likely source for these extensive geysers is a subsurface liquid reservoir of somewhat saline water and other volatiles boiling off through crevasse-like conduits into the vacuum of space.In this work, we use a DSMC code to simulate the plume as it exits a vent, considering axisymmetric conditions, in a vertical domain extending up to 10 km. Above 10 km altitude, the flow is collisionless and well modeled in a separate free molecular code. We perform a DSMC parametric and sensitivity study of the following vent parameters: vent diameter, outgassed flow density, water gas/water ice mass flow ratio, gas and ice speed, and ice grain diameter. We build parametric expressions of the plume characteristics at the 10 km upper boundary (number density, temperature, velocity) that will be used in a Bayesian inversion algorithm in order to constrain source conditions from fits to plume observations by various instruments on board the Cassini spacecraft and assess the parametric sensitivity study.

regioneR: an R/Bioconductor package for the association analysis of genomic regions based on permutation tests.

PubMed

Gel, Bernat; Díez-Villanueva, Anna; Serra, Eduard; Buschbeck, Marcus; Peinado, Miguel A; Malinverni, Roberto

2016-01-15

Statistically assessing the relation between a set of genomic regions and other genomic features is a common challenging task in genomic and epigenomic analyses. Randomization based approaches implicitly take into account the complexity of the genome without the need of assuming an underlying statistical model. regioneR is an R package that implements a permutation test framework specifically designed to work with genomic regions. In addition to the predefined randomization and evaluation strategies, regioneR is fully customizable allowing the use of custom strategies to adapt it to specific questions. Finally, it also implements a novel function to evaluate the local specificity of the detected association. regioneR is an R package released under Artistic-2.0 License. The source code and documents are freely available through Bioconductor (http://www.bioconductor.org/packages/regioneR). rmalinverni@carrerasresearch.org. © The Author 2015. Published by Oxford University Press.

Propellant Management in Booster and Upper Stage Propulsion Systems

NASA Technical Reports Server (NTRS)

Fisher, Mark F.

1997-01-01

A summary review of some of the technical issues which surround the design of the propulsion systems for Booster and Upper Stage systems are presented. The work focuses on Propellant Geyser, Slosh, and Orientation. A brief description of the concern is given with graphics which help the reader to understand the physics of the situation. The most common solutions to these problems are given with there respective advantages and disadvantages.

Regional governance: strategies and disputes in health region management.

PubMed

Santos, Adriano Maia dos; Giovanella, Ligia

2014-08-01

To analyze the regional governance of the health systemin relation to management strategies and disputes. 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. 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. The characteristics identified a regionalized system with a conflictive pattern of governance and intermediate institutionalism. The regional interagency committee

Differential depth distribution of microbial function and putative symbionts through sediment-hosted aquifers in the deep terrestrial subsurface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Probst, Alexander J.; Ladd, Bethany; Jarett, Jessica K.

An enormous diversity of previously unknown bacteria and archaea has been discovered recently, yet their functional capacities and distributions in the terrestrial subsurface remain uncertain. Here, we continually sampled a CO 2-driven geyser (Colorado Plateau, Utah, USA) over its 5-day eruption cycle to test the hypothesis that stratified, sandstone-hosted aquifers sampled over three phases of the eruption cycle have microbial communities that differ both in membership and function. Genome-resolved metagenomics, single-cell genomics and geochemical analyses confirmed this hypothesis and linked microorganisms to groundwater compositions from different depths. Autotrophic Candidatus “Altiarchaeum sp.” and phylogenetically deep-branching nanoarchaea dominate the deepest groundwater. Amore » nanoarchaeon with limited metabolic capacity is inferred to be a potential symbiont of the Ca. “Altiarchaeum”. Candidate Phyla Radiation bacteria are also present in the deepest groundwater and they are relatively abundant in water from intermediate depths. During the recovery phase of the geyser, microaerophilic Fe- and S-oxidizers have high in situ genome replication rates. Autotrophic Sulfurimonas sustained by aerobic sulfide oxidation and with the capacity for N 2 fixation dominate the shallow aquifer. Overall, 104 different phylum-level lineages are present in water from these subsurface environments, with uncultivated archaea and bacteria partitioned to the deeper subsurface.« less

Differential depth distribution of microbial function and putative symbionts through sediment-hosted aquifers in the deep terrestrial subsurface

DOE PAGES

Probst, Alexander J.; Ladd, Bethany; Jarett, Jessica K.; ...

2018-01-29

An enormous diversity of previously unknown bacteria and archaea has been discovered recently, yet their functional capacities and distributions in the terrestrial subsurface remain uncertain. Here, we continually sampled a CO 2-driven geyser (Colorado Plateau, Utah, USA) over its 5-day eruption cycle to test the hypothesis that stratified, sandstone-hosted aquifers sampled over three phases of the eruption cycle have microbial communities that differ both in membership and function. Genome-resolved metagenomics, single-cell genomics and geochemical analyses confirmed this hypothesis and linked microorganisms to groundwater compositions from different depths. Autotrophic Candidatus “Altiarchaeum sp.” and phylogenetically deep-branching nanoarchaea dominate the deepest groundwater. Amore » nanoarchaeon with limited metabolic capacity is inferred to be a potential symbiont of the Ca. “Altiarchaeum”. Candidate Phyla Radiation bacteria are also present in the deepest groundwater and they are relatively abundant in water from intermediate depths. During the recovery phase of the geyser, microaerophilic Fe- and S-oxidizers have high in situ genome replication rates. Autotrophic Sulfurimonas sustained by aerobic sulfide oxidation and with the capacity for N 2 fixation dominate the shallow aquifer. Overall, 104 different phylum-level lineages are present in water from these subsurface environments, with uncultivated archaea and bacteria partitioned to the deeper subsurface.« less

Taphonomy of silicified filamentous microbes in modern geothermal sinters-Implications for identification

USGS Publications Warehouse

Jones, Brian; Renaut, Robin W.; Rosen, Michael R.

2001-01-01

Silicified microbes found on the discharge aprons around modern geysers and hot springs commonly appear to be preserved superbly. This can be attributed to their rapid silicification, which often begins while they are alive. In geological terms, therefore, they are silicified instantaneously. Thus, it might be expected that these microbes should be good replicas of the living organisms and, therefore, easy to identify in terms of extant taxa. Silicified microbes found on the discharge aprons around geysers and hot springs of North Island, New Zealand, are preserved through replacement and/or encrustation. Organic matter is typically absent, and examples of sheaths being partly replaced or coated by other minerals, such as iron oxide, have not yet been recognized. Accordingly, the cellular-level information needed for microbe identification must be gleaned from features preserved in the silica. Unfortunately, the silicification processes commonly destroy and/or disguise most of the taxonomic features that are necessary for reliable identification in terms of extant taxa. Silicification may, for example, obscure the presence of a sheath and/or significantly alter the size of the microbes. The loss and/or modification of such important taxonomic features means that the identification of silicified microbes is fraught with problems and must be approached with caution.

Continuous measurement of nontidal variations of gravity

NASA Technical Reports Server (NTRS)

Goodkind, John M.

1986-01-01

Records from seven superconducting gravimeters operated at five different locations in California and one in Boulder, CO, are examined after removal of tides and the gravitational attraction of the atmosphere. Fluctuations over periods between a few days and several months were observed at all sites with peak amplitudes of order 10 microgal. By contrast, a 640-day record obtained with one of the instruments in Germany showed peak fluctuations of only 2 microgal. In most of the records the causes of these aperiodic variations were not determined so that they serve to set limits on the vertical motion or displacement of mass at the respective locations. However, at The Geysers geothermal field, much of the gravity variation is correlated with seismic activity, reinjection rate, and rainfall. Measurements of this type were not possible prior to the development of the superconducting device. Consequently, these results provide the first evidence for the existence of gravity variations on the time scale and of the magnitude described here. Vertical crustal motion, motion related to seismic events, and hydrological phenomena can lead to variations on this scale. Unambiguous identification of causal relationships will require either special circumstances such as found at The Geysers or operation of the instruments in pairs.

Resilience and receptivity worked in tandem to sustain a geothermal mat community amidst erratic environmental conditions.

PubMed

Ghosh, Wriddhiman; Roy, Chayan; Roy, Rimi; Nilawe, Pravin; Mukherjee, Ambarish; Haldar, Prabir Kumar; Chauhan, Neeraj Kumar; Bhattacharya, Sabyasachi; Agarwal, Atima; George, Ashish; Pyne, Prosenjit; Mandal, Subhrangshu; Rameez, Moidu Jameela; Bala, Goutam

2015-07-17

To elucidate how geothermal irregularities affect the sustainability of high-temperature microbiomes we studied the synecological dynamics of a geothermal microbial mat community (GMMC) vis-à-vis fluctuations in its environment. Spatiotemporally-discrete editions of a photosynthetic GMMC colonizing the travertine mound of a circum-neutral hot spring cluster served as the model-system. In 2010 a strong geyser atop the mound discharged mineral-rich hot water, which nourished a GMMC continuum from the proximal channels (PC) upto the slope environment (SE) along the mound's western face. In 2011 that geyser extinguished and consequently the erstwhile mats disappeared. Nevertheless, two relatively-weaker vents erupted in the southern slope and their mineral-poor outflow supported a small GMMC patch in the SE. Comparative metagenomics showed that this mat was a relic of the 2010 community, conserved via population dispersal from erstwhile PC as well as SE niches. Subsequently in 2012, as hydrothermal activity augmented in the southern slope, ecological niches widened and the physiologically-heterogeneous components of the 2011 "seed-community" split into PC and SE meta-communities, thereby reclaiming either end of the thermal gradient. Resilience of incumbent populations, and the community's receptiveness towards immigrants, were the key qualities that ensured the GMMC's sustenance amidst habitat degradation and dispersal to discrete environments.

Regional alternative transportation evaluation report - Region 4

DOT National Transportation Integrated Search

2013-08-15

The U.S. Fish and Wildlife Service (FWS) and the U.S. Department of Transportation (DOT) Volpe Center (Volpe Center) conducted a regional alternative transportation evaluation (RATE) in Region 4, which is comprised of Alabama, Arkansas, Florida, Geor...

Regional alternative transportation evaluation report - region 5

DOT National Transportation Integrated Search

2011-11-14

The U.S. Fish and Wildlife Service (FWS) and the U.S. Department of Transportation (DOT) Volpe Center (Volpe Center) conducted a regional alternative transportation evaluation (RATE) in Region 3, which is comprised of Illinois, Indiana, Iowa, Michiga...

Regional alternative transportation evaluation report - region 2

DOT National Transportation Integrated Search

2012-03-01

The U.S. Fish and Wildlife Service (FWS) and the U.S. Department of Transportation (DOT) Volpe : Center (Volpe Center) conducted a regional alternative transportation evaluation (RATE) in Region 2, : which is comprised of Arizona, Oklahoma, New Mexic...

75 FR 28564 - Fisheries of the Northeast Region; Pacific Region

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... the Northeast Region; Pacific Region AGENCY: National Marine Fisheries Service (NMFS), National... Secretary of Commerce (Secretary), has determined that in the Northeast Region, Gulf of Maine/Georges Bank... to overfishing and are in an overfished condition. Also, in the Northeast Region, Southern New...

Regional alternative transportation evaluation report - region 1

DOT National Transportation Integrated Search

2011-01-21

The U.S. Fish and Wildlife Service (FWS) and the U.S. Department of Transportation (DOT) Volpe Center (Volpe Center) conducted a regional alternative transportation evaluation (RATE) in Region 1, which is comprised of Oregon, Idaho, Washington, and H...

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

Regional Security Arrangements in the East Asia Region.

DTIC Science & Technology

2000-03-16

ASEAN) and the ASEAN Regional Forum (ARF). Both are critical to effective multilateralism in the region but must overcome the dual handicaps of...encouragement and guidance of my research adviser, Dr John Garofano of the Strategic Studies Institute. I enjoyed his tutelage and learned much. I also...such as the Association of South East Asian Nations6 (ASEAN) and the Asia-Pacific Economic Cooperation (APEC) forum to address regional issues

Short papers of the Fourth International Conference, Geochronology, Cosmochronology, Isotope Geology, 1978

USGS Publications Warehouse

Zartman, Robert E.

1978-01-01

Tritium content of both hot and cold waters in Yellowstone National Park was used to infer something of the ground-water system feeding hot springs and geysers. Curves in three figures show: (1) Tritium content of water leaving piston flow and well mixed ground-water systems in Yellowstone Park; (2) tritium in precipitation, mixed reservoirs, and cold waters of Yellowstone Park, and (3) tritium in mixed reservoirs and hot waters of Yellowstone Park. (Woodard-USGS)

Contact Angle Influence on Geysering Jets in Microgravity Investigated

NASA Technical Reports Server (NTRS)

Chato, David J.

2004-01-01

Microgravity poses many challenges to the designer of spacecraft tanks. Chief among these are the lack of phase separation and the need to supply vapor-free liquid or liquid-free vapor to the spacecraft processes that require fluid. One of the principal problems of phase separation is the creation of liquid jets. A jet can be created by liquid filling, settling of the fluid to one end of the tank, or even closing a valve to stop the liquid flow. Anyone who has seen a fountain knows that jets occur in normal gravity also. However, in normal gravity, the gravity controls and restricts the jet flow. In microgravity, with gravity largely absent, surface tension forces must be used to contain jets. To model this phenomenon, a numerical method that tracks the fluid motion and the surface tension forces is required. Jacqmin has developed a phase model that converts the discrete surface tension force into a barrier function that peaks at the free surface and decays rapidly away. Previous attempts at this formulation were criticized for smearing the interface. This can be overcome by sharpening the phase function, double gridding the fluid function, and using a higher-order solution for the fluid function. The solution of this equation can be rewritten as two coupled Poisson equations that also include the velocity.

A Snowball in Space

NASA Image and Video Library

2013-12-23

Saturn's moon Enceladus, covered in snow and ice, resembles a perfectly packed snowball in this image from NASA's Cassini mission. Cassini has imaged Enceladus many times throughout its mission, discovering a fractured surface and the now-famous geysers that erupt icy particles and water vapor from fractures crossing the moons' 200-mile-wide (300-kilometer-wide) south polar terrain. The mountain ridge seen in the south in this image is part of the undulating mountain belt that circumscribes this region. This view looks toward the leading side of Enceladus (313 miles, 504 kilometers across). North on Enceladus is up and rotated 6 degrees to the left. The image was taken with the Cassini spacecraft narrow-angle camera on March 10, 2012, using filters sensitive to ultraviolet, visible and infrared light (spanning wavelengths from 338 to 750 nanometers). The view was acquired at a distance of approximately 106,000 miles (170,000 kilometers) from Enceladus. Image scale is 3,336 feet (1 kilometer) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA17182

Regional Solutions for Regional Problems: East Timor and Solomon Islands

DTIC Science & Technology

2012-03-21

concludes that the key factors underpinning effective regional solutions are: a regional state willing to take a leadership role and committed to achieving...a regional state willing to take a leadership role and committed to achieving a successful outcome; legitimacy through host nation request and/or an...effective international action often turns on the political will of coalitions of countries that comprise regional or international institutions

High-resolution aeromagnetic mapping of volcanic terrain, Yellowstone National Park

USGS Publications Warehouse

Finn, C.A.; Morgan, L.A.

2002-01-01

High-resolution aeromagnetic data acquired over Yellowstone National Park (YNP) show contrasting patterns reflecting differences in rock composition, types and degree of alteration, and crustal structures that mirror the variable geology of the Yellowstone Plateau. The older, Eocene, Absaroka Volcanic Supergroup, a series of mostly altered, andesitic volcanic and volcaniclastic rocks partially exposed in mountains on the eastern margin of YNP, produces high-amplitude, positive magnetic anomalies, strongly contrasting with the less magnetic, younger, latest Cenozoic, Yellowstone Plateau Group, primarily a series of fresh and variably altered rhyolitic rocks covering most of YNP. The Yellowstone caldera is the centerpiece of the Yellowstone Plateau; part of its boundary can be identified on the aeromagnetic map as a series of discontinuous, negative magnetic anomalies that reflect faults or zones along which extensive hydrothermal alteration is localized. The large-volume rhyolitic ignimbrite deposits of the 0.63-Ma Lava Creek Tuff and the 2.1-Ma Huckleberry Ridge Tuff, which are prominent lithologies peripheral to the Yellowstone caldera, produce insignificant magnetic signatures. A zone of moderate amplitude positive anomalies coincides with the mapped extent of several post-caldera rhyolitic lavas. Linear magnetic anomalies reflect the rectilinear fault systems characteristic of resurgent domes in the center of the caldera. Peripheral to the caldera, the high-resolution aeromagnetic map clearly delineates flow unit boundaries of pre- and post-caldera basalt flows, which occur stratigraphically below the post-caldera rhyolitic lavas and are not exposed extensively at the surface. All of the hot spring and geyser basins, such as Norris, Upper and Lower Geyser Basins, West Thumb, and Gibbon, are associated with negative magnetic anomalies, reflecting hydrothermal alteration that has destroyed the magnetic susceptibility of minerals in the volcanic rocks. Within

Regionalization: A Story Map Lesson on Regions

ERIC Educational Resources Information Center

Edmondson, Deborah

2018-01-01

This lesson introduces the concept of regionalization and types of regions. After a brief introductory activity, students explore a story map to learn the material. The teacher can project the story map on a screen for all students to follow or students may work individually on computers. Working individually will allow students to set their own…

Predicting human age using regional morphometry and inter-regional morphological similarity

NASA Astrophysics Data System (ADS)

Wang, Xun-Heng; Li, Lihua

2016-03-01

The goal of this study is predicting human age using neuro-metrics derived from structural MRI, as well as investigating the relationships between age and predictive neuro-metrics. To this end, a cohort of healthy subjects were recruited from 1000 Functional Connectomes Project. The ages of the participations were ranging from 7 to 83 (36.17+/-20.46). The structural MRI for each subject was preprocessed using FreeSurfer, resulting in regional cortical thickness, mean curvature, regional volume and regional surface area for 148 anatomical parcellations. The individual age was predicted from the combination of regional and inter-regional neuro-metrics. The prediction accuracy is r = 0.835, p < 0.00001, evaluated by Pearson correlation coefficient between predicted ages and actual ages. Moreover, the LASSO linear regression also found certain predictive features, most of which were inter-regional features. The turning-point of the developmental trajectories in human brain was around 40 years old based on regional cortical thickness. In conclusion, structural MRI could be potential biomarkers for the aging in human brain. The human age could be successfully predicted from the combination of regional morphometry and inter-regional morphological similarity. The inter-regional measures could be beneficial to investigating human brain connectome.

The zitterbewegung region

NASA Astrophysics Data System (ADS)

Sidharth, B. G.; Das, Abhishek

2017-07-01

This paper deals with a precise description of the region of zitterbewegung below the Compton scale and the stochastic nature associated with it. We endeavor to delineate this particular region by means of Ito’s calculus and instigate certain features that are in sharp contrast with conventional physics. Interestingly, our work substantiates that the zitterbewegung region represents a pre-space-time region and from therein emerges the notion of our conventional space-time. Interestingly, this unique region engenders the relativistic and quantum mechanical aspects of space-time.

The origin of external oxygen in Jupiter and Saturn's environments

NASA Astrophysics Data System (ADS)

Cavalié, T.; Lellouch, E.; Hartogh, P.; Moreno, R.; Billebaud, F.; Bockelée-Morvan, D.; Biver, N.; Cassidy, T.; Courtin, R.; Crovisier, J.; Dobrijevic, M.; Feuchtgruber, H.; González, A.; Greathouse, T.; Jarchow, C.; Kidger, M.; Lara, L. M.; Rengel, M.; Orton, G.; Sagawa, H.; de Val-Borro, M.

2014-12-01

This paper reviews the recent findings of the Herschel Solar System Observations Key Program (Hartogh et al. 2009), as well as ground-based supporting observations, regarding the origin of external oxygen in the environments of Jupiter and Saturn. Herschel-HIFI and PACS observations have been used to shown that the Shoemaker-Levy 9 comet is the source of Jupiter's stratospheric water, and that Enceladus (and its geysers) are most probably the source of water for Saturn and Titan.

[Chromosomal variation in Chironomus plumosus L. (Diptera, Chironomidae) from populations of Bryansk region, Saratov region (Russia), and Gomel region (Belarus)].

PubMed

Belyanina, S I

2015-02-01

Cytogenetic analysis was performed on samples of Chironomus plumosus L. (Diptera, Chironomidae) taken from waterbodies of various types in Bryansk region (Russia) and Gomel region (Belarus). Karyotypes of specimens taken from stream pools of the Volga were used as reference samples. The populations of Bryansk and Gomel regions (except for a population of Lake Strativa in Starodubskii district, Bryansk region) exhibit broad structural variation, including somatic mosaicism for morphotypes of the salivary gland chromosome set, decondensation of telomeric sites, and the presence of small structural changes, as opposed to populations of Saratov region. As compared with Saratov and Bryansk regions, the Balbiani ring in the B-arm of chromosome I is repressed in populations of Gomel region. It is concluded that the chromosome set of Ch. plumosus in a range of waterbodies of Bryansk and Gomel regions is unstable.

About Regional Energy Deployment System Model-ReEDS | Regional Energy

Science.gov Websites

Deployment System Model | Energy Analysis | NREL About Regional Energy Deployment System Model -ReEDS About Regional Energy Deployment System Model-ReEDS The Regional Energy Deployment System (ReEDS ) is a long-term, capacity-expansion model for the deployment of electric power generation technologies

Microglial brain region-dependent diversity and selective regional sensitivities to ageing

PubMed Central

Grabert, Kathleen; Michoel, Tom; Karavolos, Michail H; Clohisey, Sara; Baillie, J Kenneth; Stevens, Mark P; Freeman, Tom C; Summers, Kim M; McColl, Barry W

2015-01-01

Microglia play critical roles in neural development, homeostasis and neuroinflammation and are increasingly implicated in age-related neurological dysfunction. Neurodegeneration often occurs in disease-specific spatially-restricted patterns, the origins of which are unknown. We performed the first genome-wide analysis of microglia from discrete brain regions across the adult lifespan of the mouse and reveal that microglia have distinct region-dependent transcriptional identities and age in a regionally variable manner. In the young adult brain, differences in bioenergetic and immunoregulatory pathways were the major sources of heterogeneity and suggested that cerebellar and hippocampal microglia exist in a more immune vigilant state. Immune function correlated with regional transcriptional patterns. Augmentation of the distinct cerebellar immunophenotype and a contrasting loss in distinction of the hippocampal phenotype among forebrain regions were key features during ageing. Microglial diversity may enable regionally localised homeostatic functions but could also underlie region-specific sensitivities to microglial dysregulation and involvement in age-related neurodegeneration. PMID:26780511

Revisiting regional flood frequency analysis in Slovakia: the region-of-influence method vs. traditional regional approaches

NASA Astrophysics Data System (ADS)

Gaál, Ladislav; Kohnová, Silvia; Szolgay, Ján.

2010-05-01

During the last 10-15 years, the Slovak hydrologists and water resources managers have been devoting considerable efforts to develop statistical tools for modelling probabilities of flood occurrence in a regional context. Initially, these models followed concepts to regional flood frequency analysis that were based on fixed regions, later the Hosking and Wallis's (HW; 1997) theory was adopted and modified. Nevertheless, it turned out to be that delineating homogeneous regions using these approaches is not a straightforward task, mostly due to the complex orography of the country. In this poster we aim at revisiting flood frequency analyses so far accomplished for Slovakia by adopting one of the pooling approaches, i.e. the region-of-influence (ROI) approach (Burn, 1990). In the ROI approach, unique pooling groups of similar sites are defined for each site under study. The similarity of sites is defined through Euclidean distance in the space of site attributes that had also proved applicability in former cluster analyses: catchment area, afforested area, hydrogeological catchment index and the mean annual precipitation. The homogeneity of the proposed pooling groups is evaluated by the built-in homogeneity test by Lu and Stedinger (1992). Two alternatives of the ROI approach are examined: in the first one the target size of the pooling groups is adjusted to the target return period T of the estimated flood quantiles, while in the other one, the target size is fixed, regardless of the target T. The statistical models of the ROI approach are inter-compared by the conventional regionalization approach based on the HW methodology where the parameters of flood frequency distributions were derived by means of L-moment statistics and a regional formula for the estimation of the index flood was derived by multiple regression methods using physiographic and climatic catchment characteristics. The inter-comparison of different frequency models is evaluated by means of the

Making the operation of a geothermal power plant cost competitive

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooley, D.

1997-12-31

In the late 1980s and the 1990s several forces combined to motivate geothermal generators at The Geysers into becoming more efficient. One is the declining steam resource, another is the {open_quotes}cliff{close_quote} of the Standard Offer 4 (ISO4) contract payments, and a third is the electric restructuring movement in California. Geothermal projects in California and Nevada have reported feeling these or other influences which have caused them to review their operations, the way that they have done things in the past and are doing things today, and the way that they want or need to do things in the future. Whilemore » there is no single or simple recipe for making a power plant cost competitive all of the generators at The Geysers have taken steps and implemented strategies to lower the cost of production at their power plant(s). This paper reviews some of these approaches and identifies several instances when the same or similar problems were addressed differently. Approaches differ because of internal economics, the degree to which a generator is willing or allowed to take risk, and the different opinions of what the future holds, especially as to what the market clearing price for energy will be in the deregulated electricity market of the future.« less

Ring and plasma - The enigmae of Enceladus

NASA Technical Reports Server (NTRS)

Haff, P. K.; Siscoe, G. L.; Eviatar, A.

1983-01-01

The E ring associated with the Kronian moon Enceladus has a lifetime of only a few thousand years against sputtering by slow corotating O ions. The existence of the ring implies the necessity for a continuous supply of matter. Possible particle source mechanisms on Enceladus include meteoroidal impact ejection and geysering. Estimates of ejection rates of particulate debris following small meteoroid impact are on the order of 3 x 10 to the -18th g/(sq cm sec), more than an order of magnitude too small to sustain the ring. A geyser source would need to generate a droplet supply at a rate of approximately 10 to the -16th g/(sq cm sec) in order to account for a stable ring. Enceladus and the ring particles also directly supply both plasma and vapor to space via sputtering. The absence of a 60 eV plasma at the Voyager 2 Enceladus L-shell crossing, such as might have been expected from sputtering, cannot be explained by absorption and moderation of plasma ions by ring particles, because the ring is too diffuse. Evidently, the effective sputtering yield in the vicinity of Enceladus is on the order of, or smaller than, 0.4, about an order of magnitude less than te calculated value. Small scale surface roughness may account for some of this discrepancy.

Resilience and receptivity worked in tandem to sustain a geothermal mat community amidst erratic environmental conditions

PubMed Central

Ghosh, Wriddhiman; Roy, Chayan; Roy, Rimi; Nilawe, Pravin; Mukherjee, Ambarish; Haldar, Prabir Kumar; Chauhan, Neeraj Kumar; Bhattacharya, Sabyasachi; Agarwal, Atima; George, Ashish; Pyne, Prosenjit; Mandal, Subhrangshu; Rameez, Moidu Jameela; Bala, Goutam

2015-01-01

To elucidate how geothermal irregularities affect the sustainability of high-temperature microbiomes we studied the synecological dynamics of a geothermal microbial mat community (GMMC) vis-à-vis fluctuations in its environment. Spatiotemporally-discrete editions of a photosynthetic GMMC colonizing the travertine mound of a circum-neutral hot spring cluster served as the model-system. In 2010 a strong geyser atop the mound discharged mineral-rich hot water, which nourished a GMMC continuum from the proximal channels (PC) upto the slope environment (SE) along the mound’s western face. In 2011 that geyser extinguished and consequently the erstwhile mats disappeared. Nevertheless, two relatively-weaker vents erupted in the southern slope and their mineral-poor outflow supported a small GMMC patch in the SE. Comparative metagenomics showed that this mat was a relic of the 2010 community, conserved via population dispersal from erstwhile PC as well as SE niches. Subsequently in 2012, as hydrothermal activity augmented in the southern slope, ecological niches widened and the physiologically-heterogeneous components of the 2011 “seed-community” split into PC and SE meta-communities, thereby reclaiming either end of the thermal gradient. Resilience of incumbent populations, and the community’s receptiveness towards immigrants, were the key qualities that ensured the GMMC’s sustenance amidst habitat degradation and dispersal to discrete environments. PMID:26184838

Redefining Region: Social Construction in a Regional Watershed Education Partnership.

ERIC Educational Resources Information Center

Alibrandi, Marsha

What constitutes a region? In what ways do people define or construct the regions in which they live and work? This paper presents findings of a case study of a regional watershed partnership that examined the social ecological processes of social construction-in-action. The study sought to examine how a major watershed's educators collaborated to…

Three Short Videos by the Yellowstone Volcano Observatory

USGS Publications Warehouse

Wessells, Stephen; Lowenstern, Jake; Venezky, Dina

2009-01-01

This is a collection of videos of unscripted interviews with Jake Lowenstern, who is the Scientist in Charge of the Yellowstone Volcano Observatory (YVO). YVO was created as a partnership among the U.S. Geological Survey (USGS), Yellowstone National Park, and University of Utah to strengthen the long-term monitoring of volcanic and earthquake unrest in the Yellowstone National Park region. Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety. These video presentations give insights about many topics of interest about this area. Title: Yes! Yellowstone is a Volcano An unscripted interview, January 2009, 7:00 Minutes Description: USGS Scientist-in-Charge of Yellowstone Volcano Observatory, Jake Lowenstern, answers the following questions to explain volcanic features at Yellowstone: 'How do we know Yellowstone is a volcano?', 'What is a Supervolcano?', 'What is a Caldera?','Why are there geysers at Yellowstone?', and 'What are the other geologic hazards in Yellowstone?' Title: Yellowstone Volcano Observatory An unscripted interview, January 2009, 7:15 Minutes Description: USGS Scientist-in-Charge of Yellowstone Volcano Observatory, Jake Lowenstern, answers the following questions about the Yellowstone Volcano Observatory: 'What is YVO?', 'How do you monitor volcanic activity at Yellowstone?', 'How are satellites used to study deformation?', 'Do you monitor geysers or any other aspect of the Park?', 'Are earthquakes and ground deformation common at Yellowstone?', 'Why is YVO a relatively small group?', and 'Where can I get more information?' Title: Yellowstone Eruptions An unscripted interview, January 2009, 6.45 Minutes Description: USGS Scientist-in-Charge of Yellowstone Volcano Observatory, Jake Lowenstern, answers the following questions to explain volcanic

Io Plume Monitoring (frames 1-36)

NASA Technical Reports Server (NTRS)

1997-01-01

A sequence of full disk Io images was taken prior to Galileo's second encounter with Ganymede. The purpose of these observations was to view all longitudes of Io and search for active volcanic plumes. The images were taken at intervals of approximately one hour corresponding to Io longitude increments of about ten degrees. Because both the spacecraft and Io were traveling around Jupiter the lighting conditions on Io (e.g. the phase of Io) changed dramatically during the sequence. These images were registered at a common scale and processed to produce a time-lapse 'movie' of Io. This movie combines all of the plume monitoring frames obtained by the Solid State Imaging system aboard NASA's Galileo spacecraft.

The most prominent volcanic plume seen in this movie is Prometheus (latitude 1.6 south, longitude 153 west). The plume becomes visible as it moves into daylight, crosses the center of the disk, and is seen in profile against the dark of space at the edge of Io. This plume was first seen by the Voyager 1 spacecraft in 1979 and is believed to be a geyser-like eruption of sulfur dioxide snow and gas. Although details of the region around Prometheus have changed in the seventeen years since Voyager's visit, the shape and height of the plume have not changed significantly. It is possible that this geyser has been erupting nearly continuously over this time. Galileo's primary 24 month mission includes eleven orbits around Jupiter and will provide observations of Jupiter, its moons and its magnetosphere.

North is to the top of all frames. The smallest features which can be discerned range from 13 to 31 kilometers across. The images were obtained between the 2nd and the 6th of September, 1996.

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

Best Merge Region Growing Segmentation with Integrated Non-Adjacent Region Object Aggregation

NASA Technical Reports Server (NTRS)

Tilton, James C.; Tarabalka, Yuliya; Montesano, Paul M.; Gofman, Emanuel

2012-01-01

Best merge region growing normally produces segmentations with closed connected region objects. Recognizing that spectrally similar objects often appear in spatially separate locations, we present an approach for tightly integrating best merge region growing with non-adjacent region object aggregation, which we call Hierarchical Segmentation or HSeg. However, the original implementation of non-adjacent region object aggregation in HSeg required excessive computing time even for moderately sized images because of the required intercomparison of each region with all other regions. This problem was previously addressed by a recursive approximation of HSeg, called RHSeg. In this paper we introduce a refined implementation of non-adjacent region object aggregation in HSeg that reduces the computational requirements of HSeg without resorting to the recursive approximation. In this refinement, HSeg s region inter-comparisons among non-adjacent regions are limited to regions of a dynamically determined minimum size. We show that this refined version of HSeg can process moderately sized images in about the same amount of time as RHSeg incorporating the original HSeg. Nonetheless, RHSeg is still required for processing very large images due to its lower computer memory requirements and amenability to parallel processing. We then note a limitation of RHSeg with the original HSeg for high spatial resolution images, and show how incorporating the refined HSeg into RHSeg overcomes this limitation. The quality of the image segmentations produced by the refined HSeg is then compared with other available best merge segmentation approaches. Finally, we comment on the unique nature of the hierarchical segmentations produced by HSeg.

Body region dissatisfaction predicts attention to body regions on other women.

PubMed

Lykins, Amy D; Ferris, Tamara; Graham, Cynthia A

2014-09-01

The proliferation of "idealized" (i.e., very thin and attractive) women in the media has contributed to increasing rates of body dissatisfaction among women. However, it remains relatively unknown how women attend to these images: does dissatisfaction predict greater or lesser attention to these body regions on others? Fifty healthy women (mean age=21.8 years) viewed images of idealized and plus-size models; an eye-tracker recorded visual attention. Participants also completed measures of satisfaction for specific body regions, which were then used as predictors of visual attention to these regions on models. Consistent with an avoidance-type process, lower levels of satisfaction with the two regions of greatest reported concern (mid, lower torso) predicted less attention to these regions; greater satisfaction predicted more attention to these regions. While this visual attention bias may aid in preserving self-esteem when viewing idealized others, it may preclude the opportunity for comparisons that could improve self-esteem. Copyright © 2014 Elsevier Ltd. All rights reserved.

Marine Corps Installations National Capital RegionRegional Contracting Office Generally Implemented Recommendations

DTIC Science & Technology

2016-07-29

Corps Installations National Capital Region–Regional Contracting Office Generally Implemented Recommendations J U LY 2 9 , 2 0 1 6 Report No...Installations National Capital Region–Regional Contracting Office Generally Implemented Recommendations Objective We determined whether the Marine...Corps Regional Contracting Office–National Capital Region implemented the recommendations in Report No. DODIG-2015-095, “Small Business Contracting

[Regional ecological planning and ecological network construction: a case study of "Ji Triangle" Region].

PubMed

Li, Bo; Han, Zeng-Lin; Tong, Lian-Jun

2009-05-01

By the methods of in situ investigation and regional ecological planning, the present ecological environment, ecosystem vulnerability, and ecological environment sensitivity in "Ji Triangle" Region were analyzed, and the ecological network of the study area was constructed. According to the ecological resources abundance degree, ecological recovery, farmland windbreak system, environmental carrying capacity, forestry foundation, and ecosystem integrity, the study area was classified into three regional ecological function ecosystems, i. e., east low hill ecosystem, middle plain ecosystem, and west plain wetland ecosystem. On the basis of marking regional ecological nodes, the regional ecological corridor (Haerbin-Dalian regional axis, Changchun-Jilin, Changchun-Songyuan, Jilin-Songyuan, Jilin-Siping, and Songyuan-Siping transportation corridor) and regional ecological network (one ring, three links, and three belts) were constructed. Taking the requests of regional ecological security into consideration, the ecological environment security system of "Ji Triangle" Region, including regional ecological conservation district, regional ecological restored district, and regional ecological management district, was built.

75 FR 44223 - Fisheries of the Northeast Region; South Atlantic Region

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-28

... the Northeast Region; South Atlantic Region AGENCY: National Marine Fisheries Service (NMFS), National... Secretary of Commerce (Secretary), has determined that in the Northeast Region, wolffish is in an overfished... accordance with 16 U.S.C. 1853(a)(15) and 50 CFR 600.310(j)(2)(i). In January 2009, the Northeast Data Poor...

Comparison of DMSP and SECS region-1 and region-2 ionospheric current boundary

NASA Astrophysics Data System (ADS)

Weygand, J. M.; Wing, S.

2016-06-01

The region-1 and region-2 boundary has traditionally been identified using data from a single spacecraft crossing the auroral region and measuring the large scale changes in the cross track magnetic field. With data from the AUTUMN, CANMOS, CARISMA, GIMA, DTU MGS, MACCS, McMAC, STEP, THEMIS, and USGS ground magnetometer arrays we applied a state-of-art technique based on spherical elementary current system (SECS) method developed by Amm and Viljanen (1999) in order to calculate maps of region-1 and region-2 current system over the North American and Greenland auroral region. Spherical elementary current (SEC) amplitude (proxy for vertical currents) maps can be inferred at 10 s temporal resolution, ~1.5° geographic latitude (Glat), and 3.5° geographic longitude (Glon) spatial resolution. We compare the location of the region-1 and region-2 boundary obtained by the DMSP spacecraft with the region-1 and region-2 boundary observed in the SEC current amplitudes. We find that the boundaries typically agree within 0.2°±1.3°. These results indicate that the location of the region-1 and region-2 boundary can reasonably be determined from ground magnetometer data. The SECS maps represent a value-added product from the magnetometer database and can be used for contextual interpretation in conjunction with other missions as well as help with our understanding of magnetosphere-ionosphere coupling mechanisms using the ground arrays and the magnetospheric spacecraft data.

Comparison of DMSP and SECS region-1 and region-2 ionospheric current boundary✩

PubMed Central

Weygand, J.M.; Wing, S.

2017-01-01

The region-1 and region-2 boundary has traditionally been identified using data from a single spacecraft crossing the auroral region and measuring the large scale changes in the cross track magnetic field. With data from the AUTUMN, CANMOS, CARISMA, GIMA, DTU MGS, MACCS, McMAC, STEP, THEMIS, and USGS ground magnetometer arrays we applied a state-of-art technique based on spherical elementary current system (SECS) method developed by Amm and Viljanen (1999) in order to calculate maps of region-1 and region-2 current system over the North American and Greenland auroral region. Spherical elementary current (SEC) amplitude (proxy for vertical currents) maps can be inferred at 10 s temporal resolution, ~1.5° geographic latitude (Glat), and 3.5° geographic longitude (Glon) spatial resolution. We compare the location of the region-1 and region-2 boundary obtained by the DMSP spacecraft with the region-1 and region-2 boundary observed in the SEC current amplitudes. We find that the boundaries typically agree within 0.2° ± 1.3°. These results indicate that the location of the region-1 and region-2 boundary can reasonably be determined from ground magnetometer data. The SECS maps represent a value-added product from the magnetometer database and can be used for contextual interpretation in conjunction with other missions as well as help with our understanding of magnetosphere-ionosphere coupling mechanisms using the ground arrays and the magnetospheric spacecraft data. PMID:29056861

Comparison of DMSP and SECS region-1 and region-2 ionospheric current boundary.

PubMed

Weygand, J M; Wing, S

2016-06-01

The region-1 and region-2 boundary has traditionally been identified using data from a single spacecraft crossing the auroral region and measuring the large scale changes in the cross track magnetic field. With data from the AUTUMN, CANMOS, CARISMA, GIMA, DTU MGS, MACCS, McMAC, STEP, THEMIS, and USGS ground magnetometer arrays we applied a state-of-art technique based on spherical elementary current system (SECS) method developed by Amm and Viljanen (1999) in order to calculate maps of region-1 and region-2 current system over the North American and Greenland auroral region. Spherical elementary current (SEC) amplitude (proxy for vertical currents) maps can be inferred at 10 s temporal resolution, ~1.5° geographic latitude (Glat), and 3.5° geographic longitude (Glon) spatial resolution. We compare the location of the region-1 and region-2 boundary obtained by the DMSP spacecraft with the region-1 and region-2 boundary observed in the SEC current amplitudes. We find that the boundaries typically agree within 0.2° ± 1.3°. These results indicate that the location of the region-1 and region-2 boundary can reasonably be determined from ground magnetometer data. The SECS maps represent a value-added product from the magnetometer database and can be used for contextual interpretation in conjunction with other missions as well as help with our understanding of magnetosphere-ionosphere coupling mechanisms using the ground arrays and the magnetospheric spacecraft data.

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.

Regional economy : review and outlook for the New York-New Jersey Metropolitan Region

DOT National Transportation Integrated Search

1999-08-01

This report contains a summary of the 1998 economic gains of the New York-New Jersey metropolitan region. The table of contents lists following chapter headings: Outlook; The NY-NJ Region Up Close : 1998; Regional Employment - Regional Patterns of Gr...

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.

Medium-frequency impulsive-thrust-activated liquid hydrogen reorientation with Geyser

NASA Technical Reports Server (NTRS)

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

1992-01-01

Efficient technique are studied for accomplishing propellant resettling through the minimization of propellant usage through impulsive thrust. A comparison between the use of constant-thrust and impulsive-thrust accelerations for the activation of propellant resettlement shows that impulsive thrust is superior to constant thrust for liquid reorientation in a reduced-gravity environment. This study shows that when impulsive thrust with 0.1-1.0-, and 10-Hz frequencies for liquid-fill levels in the range between 30-80 percent is considered, the selection of 1.0-Hz-frequency impulsive thrust over the other frequency ranges of impulsive thrust is the optimum. Characteristics of the slosh waves excited during the course of 1.0-Hz-frequency impulsive-thrust liquid reorientation were also analyzed.

Gas geyser--a cause of fatal domestic carbon monoxide poisoning.

PubMed

Mohankumar, T S; Kanchan, Tanuj; Pinakini, K S; Menezes, Ritesh G; Singh, Manisha; Sirohi, Parmendra; Anwar, Naureen

2012-11-01

Carbon monoxide is responsible for a large number of accidental domestic poisoning and deaths throughout the world. Domestic carbon monoxide poisoning is rarely reported in India and remains an under recognized problem. The diagnosis of carbon monoxide poisoning is usually based on autopsy findings, circumstantial evidence and estimation of carboxy-haemoglobin in blood. We report a case of fatal accidental carbon monoxide poisoning in a bathroom where an LPG gas water heater was installed recently. Cherry pink discolouration of the body and organs on autopsy suggested carbon monoxide poisoning. Laboratory analysis of blood by UV visible spectrophotometry revealed presence of dangerous levels of carboxy-haemoglobin. Effective preventive measures can help in bringing down the mortality and morbidity associated with carbon monoxide poisoning. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Active Regions Blossoming

NASA Image and Video Library

2015-10-28

As a pair of active regions began to rotate into view, their towering magnetic field lines above them bloomed into a dazzling display of twisting arches (Oct. 27-28, 2015). Some of the lines reached over and connected with the neighboring active region. Active regions are usually the source of solar storms. The images were taken in a wavelength of extreme ultraviolet light. http://photojournal.jpl.nasa.gov/catalog/PIA20048

Numerical simulation of water injection into vapor-dominated reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pruess, K.

1995-01-01

Water injection into vapor-dominated reservoirs is a means of condensate disposal, as well as a reservoir management tool for enhancing energy recovery and reservoir life. We review different approaches to modeling the complex fluid and heat flow processes during injection into vapor-dominated systems. Vapor pressure lowering, grid orientation effects, and physical dispersion of injection plumes from reservoir heterogeneity are important considerations for a realistic modeling of injection effects. An example of detailed three-dimensional modeling of injection experiments at The Geysers is given.

Regional Air Pollutions in Three Different Regions of Asia From a Transcontinental Transport Perspective

NASA Astrophysics Data System (ADS)

Pochanart, P.; Kanaya, Y.; Komazaki, Y.; Liu, Y.; Akimoto, H.

2007-12-01

Asia is known as one of the regions with the fastest rate of growing in industrialization and urbanization. As a result, the rapid increases of large-scale air pollution in Asia emerge as a serious concern at both domestic and international levels. Apart from the problems of air quality degradation, emission control, environmental risk, and health effect in a domestic level, evidences from scientific studies indicate that by the long-range transport, Asian air pollution is becoming a global problem. Observations and model studies confirm that air pollution from Asia could be transported to North America or farther. In this work, we investigate the Asian air pollutions, in particular ozone and some other atmospheric components such as carbon monoxide and black carbon, from the ground- based observations in the three different regions, namely 1) background region of Siberia and central Asia, 2) highly anthropogenic region in eastern China, and 3) the rim region of the Asia-Pacific. In a transcontinental transport perspective, these regions are regarded as the inflow region, source region, and outflow region of Asia, respectively. From the results, it is found that the influences from large-scale emission in East Asia are observed clearly in the source region, and to the significant extent in the outflow region. For the inflow region of Asia, our data in Siberia and Kyrgyzstan indicate that air masses in this region are mostly intact from large-scale anthropogenic emission, and remain much of the global background atmospheric pollution characteristic. When the air masses are transported to source region, the air pollutants level increased sharply and frequent episodes of extremely high pollutions have been observed. Our results show good correlation between the residence time of air masses over the source region in eastern China and the observed levels of air pollutants verifying the strong enhancements by anthropogenic emissions from industrialization and

Internal motions of HII regions and giant HII regions

NASA Technical Reports Server (NTRS)

Chu, You-Hua; Kennicutt, Robert C., Jr.

1994-01-01

We report new echelle observations of the kinematics of 30 HII regions in the Large Magellanic Clouds (LMC), including the 30 Doradus giant HII region. All of the HII regions possess supersonic velocity dispersions, which can be attributed to a combination of turbulent motions and discrete velocity splitting produced by stellar winds and/or embedded supernova remnants (SNRs). The core of 30 Dor is unique, with a complex velocity structure that parallels its chaotic optical morphology. We use our calibrated echelle data to measure the physical properties and energetic requirements of these velocity structures. The most spectacular structures in 30 Dor are several fast expanding shells, which appear to be produced at least partially by SNRs.

Regional planning handbook

DOT National Transportation Integrated Search

2002-02-01

Regional Transportation Planning is long-range (20+ years), area-wide, and involves federal, state, regional, and local agencies; Native American Tribal Governments, public entities, private and community based organizations, and individuals working ...

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...

Influence of Turbulence on the Restraint of Liquid Jets by Surface Tension in Microgravity Investigated

NASA Technical Reports Server (NTRS)

Chato, David J.

2002-01-01

Microgravity poses many challenges to the designer of spacecraft tanks. Chief among these are the lack of phase separation and the need to supply vapor-free liquid or liquidfree vapor to the spacecraft processes that require fluid. One of the principal problems of phase separation is the creation of liquid jets. A jet can be created by liquid filling, settling of the fluid to one end of the tank, or even closing a valve to stop the liquid flow. Anyone who has seen a fountain knows that jets occur in normal gravity also. However, in normal gravity, the gravity controls and restricts the jet flow. In microgravity, with gravity largely absent, surface tension forces must contain jets. To model this phenomenon, a numerical method that tracks the fluid motion and the surface tension forces is required. Jacqmin has developed a phase model that converts the discrete surface tension force into a barrier function that peaks at the free surface and decays rapidly away. Previous attempts at this formulation were criticized for smearing the interface. This can be overcome by sharpening the phase function, double gridding the fluid function, and using a higher order solution for the fluid function. The solution of this equation can be rewritten as two coupled Poisson equations that also include the velocity. After the code was implemented in axisymmetric form and verified by several test cases at the NASA Glenn Research Center, the drop tower runs of Aydelott were modeled. Work last year with a laminar model was found to overpredict Aydelott's results, except at the lowest Reynolds number conditions of 400. This year, a simple turbulence model was implemented by adding a turbulent viscosity based on the mixing-length hypothesis and empirical measurements of previous works. Predictions made after this change was implemented have been much closer to experimentally observed flow patterns and geyser heights. Two model runs is shown. The first, without any turbulence correction

An Assessment of the Appalachian Regional Commission's Regional Education Service Agencies Program.

ERIC Educational Resources Information Center

Waller, John D.; And Others

This report presents the results of a study of Regional Education Service Agencies (RESAs) in Appalachia, with particular attention to the Appalachian Regional Commission's (ARC) RESA program and the 22 RESAs that have received ARC assistance. RESAs are organizations established to provide a range of educational services on a regional basis by…

CO2 Jets and Wind Patterns on Mars

NASA Astrophysics Data System (ADS)

Hatcher, Chase; Aye, K.-Michael; Portyankina, Ganna

2017-10-01

In Martian winters, the poles get covered by a layer of transparent CO2 ice. In spring, sunlight causes substrate under the ice to heat up which sublimates CO2 under the ice. The accumulating gas eventually causes the ice above it to rupture and the CO2 and substrate mixture spews out like a geyser and settles back down on the surface. The shape, size, and alignment of the deposits on the surface as viewed by the HiRISE camera are related to physical processes like sublimation, weather, and wind on Mars. The jet deposits are identified by citizen scientists on a website called Planet Four. Users are shown sections of HiRISE images and asked to mark different surface features with different tools. The markings are averaged, filtered, and sorted to ensure that the data accurately represents the images. By analyzing trends in the change of different characteristics of these surface features over time, we conclude that different regions on Mars have different sublimation processes and different wind patterns. We also conclude that wind and weather patterns generally repeat from year to year, and that sediment deposits affect local weather as well.

Extremophile Diatoms: Implications to the Drake Equation

NASA Technical Reports Server (NTRS)

Sterrenburg, Frithjof A. S.; Hoover, Richard B.

2011-01-01

Diatoms are unicellular Eukaryotes that (as a group and phylogenetically) are not strictly regarded as extremophiles , since the vast majority of diatoms are mesophilic photoautotrophs. However, among the terrestrial Eukaryotes, diatoms are by far the single group of organisms with the ability to inhabit the greatest range of hostile environments on Earth. They are the dominant eukaryotes in the polar regions; in fumaroles, hot springs and geysers; and in hypersaline and hyperalkaline lakes and pools. Cryophilic species such as Fragilaria sublinearis and Chaetoceras fragilis are able to carry out respiration at extremely low rates at low temperatures in darkness. The Drake Equation refers to the likelihood of there being intelligent life at the technological level of electromagnetic communication. However, consideration of the range of conditions suitable for the habitability of eukaryotic diatoms and prokaryotic extremophiles, the likelihood that life exists elsewhere in the cosmos becomes many orders of magnitude greater than that predicted by the classical Drake Equation. In this paper we review the characteristics of diatoms as eukaryotic extremophiles and consider the implications to adjustments needed to the Drake Equation to assess the possibility that life exists elsewhere in the Universe.

Source and fate of inorganic solutes in the Gibbon River, Yellowstone National Park, Wyoming, USA. II. Trace element chemistry

USGS Publications Warehouse

McCleskey, R. Blaine; Nordstrom, D. Kirk; Susong, David D.; Ball, James W.; Taylor, Howard E.

2010-01-01

The Gibbon River in Yellowstone National Park receives inflows from several geothermal areas, and consequently the concentrations of many trace elements are elevated compared to rivers in non-geothermal watersheds. Water samples and discharge measurements were obtained from the Gibbon River and its major tributaries near Norris Geyser Basin under the low-flow conditions of September 2006 allowing for the identification of solute sources and their downstream fate. Norris Geyser Basin, and in particular Tantalus Creek, is the largest source of many trace elements (Al, As, B, Ba, Br, Cs, Hg, Li, Sb, Tl, W, and REEs) to the Gibbon River. The Chocolate Pots area is a major source of Fe and Mn, and the lower Gibbon River near Terrace Spring is the major source of Be and Mo. Some of the elevated trace elements are aquatic health concerns (As, Sb, and Hg) and knowing their fate is important. Most solutes in the Gibbon River, including As and Sb, behave conservatively or are minimally attenuated over 29 km of fluvial transport. Some small attenuation of Al, Fe, Hg, and REEs occurs but primarily there is a transformation from the dissolved state to suspended particles, with most of these elements still being transported to the Madison River. Dissolved Hg and REEs loads decrease where the particulate Fe increases, suggesting sorption onto suspended particulate material. Attenuation from the water column is substantial for Mn, with little formation of Mn as suspended particulates.

Remotely triggered seismicity on the United States west coast following the Mw 7.9 Denali fault earthquake

USGS Publications Warehouse

Prejean, S.G.; Hill, D.P.; Brodsky, E.E.; Hough, S.E.; Johnston, M.J.S.; Malone, S.D.; Oppenheimer, D.H.; Pitt, A.M.; Richards-Dinger, K. B.

2004-01-01

The Mw 7.9 Denali fault earthquake in central Alaska of 3 November 2002 triggered earthquakes across western North America at epicentral distances of up to at least 3660 km. We describe the spatial and temporal development of triggered activity in California and the Pacific Northwest, focusing on Mount Rainier, the Geysers geothermal field, the Long Valley caldera, and the Coso geothermal field.The onset of triggered seismicity at each of these areas began during the Love and Raleigh waves of the Mw 7.9 wave train, which had dominant periods of 15 to 40 sec, indicating that earthquakes were triggered locally by dynamic stress changes due to low-frequency surface wave arrivals. Swarms during the wave train continued for ∼4 min (Mount Rainier) to ∼40 min (the Geysers) after the surface wave arrivals and were characterized by spasmodic bursts of small (M ≤ 2.5) earthquakes. Dynamic stresses within the surface wave train at the time of the first triggered earthquakes ranged from 0.01 MPa (Coso) to 0.09 MPa (Mount Rainier). In addition to the swarms that began during the surface wave arrivals, Long Valley caldera and Mount Rainier experienced unusually large seismic swarms hours to days after the Denali fault earthquake. These swarms seem to represent a delayed response to the Denali fault earthquake. The occurrence of spatially and temporally distinct swarms of triggered seismicity at the same site suggests that earthquakes may be triggered by more than one physical process.

Genome-reconstruction for eukaryotes from complex natural microbial communities.

PubMed

West, Patrick T; Probst, Alexander J; Grigoriev, Igor V; Thomas, Brian C; Banfield, Jillian F

2018-04-01

Microbial eukaryotes are integral components of natural microbial communities, and their inclusion is critical for many ecosystem studies, yet the majority of published metagenome analyses ignore eukaryotes. In order to include eukaryotes in environmental studies, we propose a method to recover eukaryotic genomes from complex metagenomic samples. A key step for genome recovery is separation of eukaryotic and prokaryotic fragments. We developed a k -mer-based strategy, EukRep, for eukaryotic sequence identification and applied it to environmental samples to show that it enables genome recovery, genome completeness evaluation, and prediction of metabolic potential. We used this approach to test the effect of addition of organic carbon on a geyser-associated microbial community and detected a substantial change of the community metabolism, with selection against almost all candidate phyla bacteria and archaea and for eukaryotes. Near complete genomes were reconstructed for three fungi placed within the Eurotiomycetes and an arthropod. While carbon fixation and sulfur oxidation were important functions in the geyser community prior to carbon addition, the organic carbon-impacted community showed enrichment for secreted proteases, secreted lipases, cellulose targeting CAZymes, and methanol oxidation. We demonstrate the broader utility of EukRep by reconstructing and evaluating relatively high-quality fungal, protist, and rotifer genomes from complex environmental samples. This approach opens the way for cultivation-independent analyses of whole microbial communities. © 2018 West et al.; Published by Cold Spring Harbor Laboratory Press.

Dynamics of the Yellowstone hydrothermal system

USGS Publications Warehouse

Hurwitz, Shaul; Lowenstern, Jacob B.

2014-01-01

The Yellowstone Plateau Volcanic Field is characterized by extensive seismicity, episodes of uplift and subsidence, and a hydrothermal system that comprises more than 10,000 thermal features, including geysers, fumaroles, mud pots, thermal springs, and hydrothermal explosion craters. The diverse chemical and isotopic compositions of waters and gases derive from mantle, crustal, and meteoric sources and extensive water-gas-rock interaction at variable pressures and temperatures. The thermal features are host to all domains of life that utilize diverse inorganic sources of energy for metabolism. The unique and exceptional features of the hydrothermal system have attracted numerous researchers to Yellowstone beginning with the Washburn and Hayden expeditions in the 1870s. Since a seminal review published a quarter of a century ago, research in many fields has greatly advanced our understanding of the many coupled processes operating in and on the hydrothermal system. Specific advances include more refined geophysical images of the magmatic system, better constraints on the time scale of magmatic processes, characterization of fluid sources and water-rock interactions, quantitative estimates of heat and magmatic volatile fluxes, discovering and quantifying the role of thermophile microorganisms in the geochemical cycle, defining the chronology of hydrothermal explosions and their relation to glacial cycles, defining possible links between hydrothermal activity, deformation, and seismicity; quantifying geyser dynamics; and the discovery of extensive hydrothermal activity in Yellowstone Lake. Discussion of these many advances forms the basis of this review.

Regional Alternative Transportation Evaluation: Region 8

DOT National Transportation Integrated Search

2016-02-28

The U.S. Fish and Wildlife Service (FWS), Federal Lands Highway (FLH), and the U.S. Department of Transportation (DOT) Volpe Center (Volpe Center) have conducted regional alternative transportation evaluations (RATEs) in almost each of FWSs eight ...

Innovative Technological Development of Russian Mining Regions (on Example of Kemerovo Region)

NASA Astrophysics Data System (ADS)

Shavina, Evgeniya; Kalenov, Oleg

2017-11-01

A characteristic trend of many countries modern development is the transition to an innovative economy. At present, this is the only opportunity to secure and maintain a high standard of living for the population. Moreover, innovative development of Russian can be achieved during technological progress in its regions. In this regard, it is necessary to assess the innovative potential of the region and identify the most actual problems that impede the transition to the trajectory of innovative development. The authors outline several main indicators that help to determine the level of innovation and technological development of one of the largest industrial areas of Russia - Kemerovo region. The special economic role of Kemerovo region as a large territorial old-industrial complex of Western Siberia requires a large-scale work to solve the most acute problems of regional development. It is necessary to find the answer for existing problems through the implementation of a system of state regulation aimed at making the innovation component a leading factor of the regional economy competitiveness.

ERLN Regional Support

EPA Pesticide Factsheets

Regional labs play important roles in the Environmental Response Laboratory Network. They can serve as point of contact; coordinate sample flow, special analytical service requests, or training exercises; and partner with regional emergency/disaster staff.

Delaware Valley Regional Planning Commission Philadelphia Metropolitan Region : planning for congestion

DOT National Transportation Integrated Search

2009-04-01

The Delaware Valley Regional Planning Commission uses a systematic process for managing traffic congestion and monitoring transportation system performance in the Philadelphia metropolitan region. Guided by an advisory team of stakeholders, the agenc...

The effect of regional politics on regional life expectancy in Italy (1980-2010).

PubMed

Jonker, Marcel F; D'Ippolito, Edoardo; Eikemo, Terje A; Congdon, Peter D; Nante, Nicola; Mackenbach, Johan P; Kamphuis, Carlijn B M

2017-03-01

The evidence on the association between politics and health is scarce considering the importance of this topic for population health. Studies that investigated the effect of different political regimes on health outcomes show inconsistent results. Bayesian time-series cross-section analyses are used to examine the overall impact of regional politics on variations in Italian regional life expectancy (LE) at birth during the period 1980-2010. Our analyses control for trends in and unobserved determinants of regional LE, correct for temporal as well as spatial autocorrelation, and employ a flexible specification for the timing of the political effects. In the period from 1980 to 1995, we find no evidence that the communist, left-oriented coalitions and Christian Democratic, centre-oriented coalitions have had an effect on regional LE. In the period from 1995 onwards, after a major reconfiguration of Italy's political regimes and a major healthcare reform, we again find no evidence that the Centre-Left and Centre-Right coalitions have had a significant impact on regional LE. The presented results provide no support for the notion that different regional political regimes in Italy have had a differential effect on regional LE, even though Italian regions have had considerable and increasing autonomy over healthcare and health-related policies and expenditures.

Regional travel survey

DOT National Transportation Integrated Search

1992-04-01

Mid-America Regional Council, the designated Metropolitan Planning Organization for the Kansas City Metropolitan Area, performed a Small Sample Travel Survey for the Kansas City region to collect data to update the MARC travel demand models. The resu...

Energized Active Regions

NASA Image and Video Library

2017-06-02

A pair of relatively small (but frenetic) active regions rotated into view, spouting off numerous small flares and sweeping loops of plasma (May 31-June 2, 2017). At first, only the one active region was observed, but mid-way though the video clip a second one behind the first can be picked out. The dynamic regions were easily the most remarkable areas on the sun during this 42-hour period. The images were taken in a wavelength of extreme ultraviolet light. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA21756

The Main Sequence of Explosive Solar Active Regions: Comparison of Emerging and Mature Active Regions

NASA Technical Reports Server (NTRS)

Falconer, David; Moore, Ron

2011-01-01

For mature active regions, an active region s magnetic flux content determines the maximum free energy the active region can have. Most Large flares and CMEs occur in active regions that are near their free-energy limit. Active-region flare power radiated in the GOES 1-8 band increases steeply as the free-energy limit is approached. We infer that the free-energy limit is set by the rate of release of an active region s free magnetic energy by flares, CMEs and coronal heating balancing the maximum rate the Sun can put free energy into the active region s magnetic field. This balance of maximum power results in explosive active regions residing in a "mainsequence" in active-region (flux content, free energy content) phase space, which sequence is analogous to the main sequence of hydrogen-burning stars in (mass, luminosity) phase space.

Environmental management on the basis of Complex Regional Indicators Concept: case of the Murmansk region

NASA Astrophysics Data System (ADS)

Kozlov, A.; Gutman, S.; Zaychenko, I.; Rytova, E.; Nijinskaya, P.

2015-09-01

The article presents an approach to sustainable environmental development of the Murmansk region of the Russian Federation based on the complex regional indicators as a transformation of a balance scorecard method. The peculiarities of Murmansk region connected with sustainable environmental development are described. The complex regional indicators approach allows to elaborate the general concept of complex regional development taking into consideration economic and non-economic factors with the focus on environmental aspects, accumulated environmental damage in particular. General strategic chart of sustainable environmental development of the Murmansk region worked out on the basis of complex regional indicators concept is composed. The key target indicators of sustainable ecological development of the Murmansk region are presented for the following strategic chart components: regional finance; society and market; industry and entrepreneurship; training, development and innovations. These charts are to be integrated with international environmental monitoring systems.

HRM: HII Region Models

NASA Astrophysics Data System (ADS)

Wenger, Trey V.; Kepley, Amanda K.; Balser, Dana S.

2017-07-01

HII Region Models fits HII region models to observed radio recombination line and radio continuum data. The algorithm includes the calculations of departure coefficients to correct for non-LTE effects. HII Region Models has been used to model star formation in the nucleus of IC 342.

Triton: A hot potato

NASA Technical Reports Server (NTRS)

Kirk, R. L.; Brown, R. H.

1991-01-01

The effect of sunlight on the surface of Triton was studied. Widely disparate models of the active geysers observed during Voyager 2 flyby were proposed, with a solar energy source almost their only feature. Yet Triton derives more of its heat from internal sources (energy released by the radioactive decay) than any other icy satellite. The effect of this relatively large internal heat on the observable behavior of volatiles on Triton's surface is investigated. The following subject areas are covered: the Global Energy Budget; insulation polar caps; effect on frost stability; mantle convection; and cryovolcanism.

NCG turbocompressor development program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichols, K.E.

1997-12-31

Barber-Nichols, Pacific Gas and Electric and UNOCAL as an industry group applied for a DOE grant under the GTO to develop a new type of compressor that could be used to extract non-condensable gas (NCG) from the condensers of geothermal power plants. This grant (DE-FG07-951A13391) was awarded on September 20, 1995. The installation and startup of the turbocompressor at the PG&E Geysers Unit 11 is covered by this paper. The turbocompressor has operated several days at 17000rpm while the plant was producing 50 to 70 MW.

Health region development from the perspective of system theory - an empirical cross-regional case study.

PubMed

Volgger, Michael; Mainil, Tomas; Pechlaner, Harald; Mitas, Ondrej

2015-01-01

Governments are increasingly establishing health regions to deal with current challenges of public health service. These regions are seen as instruments to balance public and private stakeholders, and offer health care to regional citizens as well as to medical/health tourists. However, it is still unclear how the development of such health regions as well as their governance may be conceptualized. We apply Luhmann's system theory approach in the context of a cross-regional case study that compares health region developments in the Autonomous Province of Bolzano-South Tyrol (Italy) with particular regard to the Eastern Dolomites and in the province of Zeeland (the Netherlands). We suggest that Luhmann's system theory provides a useful set of criteria to evaluate and judge health region development. Fully developed health regions can be understood as auto-poietic systems. By emphasizing programs, personnel, and communication channels, these case studies illustrate the suitability of the system theory toolset to analyze the governance and spatial embeddedness of health regions. Additionally, the study contributes to literature by indicating that health regions are closely related to identity issues and to decision making in regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Regional Scale/Regional Climate Model Development and Its Applications at Goddard

NASA Technical Reports Server (NTRS)

Tao, W.-K.; Lau, W.; Qian, J.; Jia, Y.; Wetzel, P.; Chou, M.-D.; Wang, Y.; Lynn, B.

2000-01-01

A Regional Land-Atmosphere Climate Simulation System (RELACS) is being developed and implemented at NASA Goddard Space Flight Center. One of the major goals of RELACS is to use a regional scale model (Penn State/NCAR MM5) with improved physical processes and in particular land-related processes, to understand the role of the land surface and its interaction with convection and radiation as well as the water/energy cycles in the Indo-China/South China Sea (SCS)/China, N. America and S. America region.

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...

METHOD OF CONDUCTING A PERSON BETWEEN A SAFE REGION AND A DANGEROUS REGION

DOEpatents

Moulthrop, H.A.

1957-11-12

This invention relates to a method for conducting a person between a safe region and a dangerous or con taminated region so that he may work in the dangerous region without risk to himself or the hinderance of an attached tube, and without danger of contaminating the safe region. A safely suit in which a person is to work is connected by a thermoplastic tube, turned partially inside out, to a hole in the wall separating the dangerous region. The tube is sealed by pressure and separated into two parts at the seal, whereupon the person in the suit may move around freely in the dangerous area. When the person desires to exit the dangerous region, the parts of the tube are resealed, removing a portion of the tube at the seal, and the person leaves the hole whcre he entered, seals the tube to close the hole, and cuts his suit free from the tube. Bands of masking tape inside and outside of the tube at predetermined points simplify the pressure sealing of the tube at the desired points. This patent provides a simple, safe and economical method of freely working in a dangerous region.

Regional aerosol emissions and temperature response: Local and remote climate impacts of regional aerosol forcing

NASA Astrophysics Data System (ADS)

Lewinschal, Anna; Ekman, Annica; Hansson, Hans-Christen

2017-04-01

Emissions of anthropogenic aerosols vary substantially over the globe and the short atmospheric residence time of aerosols leads to a highly uneven radiative forcing distribution, both spatially and temporally. Regional aerosol radiative forcing can, nevertheless, exert a large influence on the temperature field away from the forcing region through changes in heat transport or the atmospheric or ocean circulation. Moreover, the global temperature response distribution to aerosol forcing may vary depending on the geographical location of the forcing. In other words, the climate sensitivity in one region can vary depending on the location of the forcing. The surface temperature distribution response to changes in sulphate aerosol forcing caused by sulphur dioxide (SO2) emission perturbations in four different regions is investigated using the Norwegian Earth System Model (NorESM). The four regions, Europe, North America, East and South Asia, are all regions with historically high aerosol emissions and are relevant from both an air-quality and climate policy perspective. All emission perturbations are defined relative to the year 2000 emissions provided for the Coupled Model Intercomparison Project phase 5. The global mean temperature change per unit SO2 emission change is similar for all four regions for similar magnitudes of emissions changes. However, the global temperature change per unit SO2 emission in simulations where regional SO2 emission were removed is substantially higher than that obtained in simulations where regional SO2 emissions were increased. Thus, the climate sensitivity to regional SO2 emissions perturbations depends on the magnitude of the emission perturbation in NorESM. On regional scale, on the other hand, the emission perturbations in different geographical locations lead to different regional temperature responses, both locally and in remote regions. The results from the model simulations are used to construct regional temperature potential

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…

USEPA REGION 10 REGIONAL ENVIRONMENTAL MONITORING AND ASSESSMENT PROGRAM: PROGRAM OVERVIEW

EPA Science Inventory

The USEPA designed and implemented the Environmental Assessment Program (EMAP) to determine the current status, extent, changes, and trends in indicators of the condition of the Nations ecological resources on regional and national scales with known confidence. USEPA Region 10s ...

Brainstem Encoding of Aided Speech in Hearing Aid Users with Cochlear Dead Region(s).

PubMed

Hassaan, Mohammad Ramadan; Ibraheem, Ola Abdallah; Galhom, Dalia Helal

2016-07-01

Neural encoding of speech begins with the analysis of the signal as a whole broken down into its sinusoidal components in the cochlea, which has to be conserved up to the higher auditory centers. Some of these components target the dead regions of the cochlea causing little or no excitation. Measuring aided speech-evoked auditory brainstem response elicited by speech stimuli with different spectral maxima can give insight into the brainstem encoding of aided speech with spectral maxima at these dead regions. This research aims to study the impact of dead regions of the cochlea on speech processing at the brainstem level after a long period of hearing aid use. This study comprised 30 ears without dead regions and 46 ears with dead regions at low, mid, or high frequencies. For all ears, we measured the aided speech-evoked auditory brainstem response using speech stimuli of low, mid, and high spectral maxima. Aided speech-evoked auditory brainstem response was producible in all subjects. Responses evoked by stimuli with spectral maxima at dead regions had longer latencies and smaller amplitudes when compared with the control group or the responses of other stimuli. The presence of cochlear dead regions affects brainstem encoding of speech with spectral maxima perpendicular to these regions. Brainstem neuroplasticity and the extrinsic redundancy of speech can minimize the impact of dead regions in chronic hearing aid users.

Self-organizing map network-based precipitation regionalization for the Tibetan Plateau and regional precipitation variability

NASA Astrophysics Data System (ADS)

Wang, Nini; Yin, Jianchuan

2017-12-01

A precipitation-based regionalization for the Tibetan Plateau (TP) was investigated for regional precipitation trend analysis and frequency analysis using data from 1113 grid points covering the period 1900-2014. The results utilizing self-organizing map (SOM) network suggest that four clusters of precipitation coherent zones can be identified, including the southwestern edge, the southern edge, the southeastern region, and the north central region. Regionalization results of the SOM network satisfactorily represent the influences of the atmospheric circulation systems such as the East Asian summer monsoon, the south Asian summer monsoon, and the mid-latitude westerlies. Regionalization results also well display the direct impacts of physical geographical features of the TP such as orography, topography, and land-sea distribution. Regional-scale annual precipitation trend as well as regional differences of annual and seasonal total precipitation were investigated by precipitation index such as precipitation concentration index (PCI) and Standardized Anomaly Index (SAI). Results demonstrate significant negative long-term linear trends in southeastern TP and the north central part of the TP, indicating arid and semi-arid regions in the TP are getting drier. The empirical mode decomposition (EMD) method shows an evolution of the main cycle with 4 and 12 months for all the representative grids of four sub-regions. The cross-wavelet analysis suggests that predominant and effective period of Indian Ocean Dipole (IOD) on monthly precipitation is around ˜12 months, except for the representative grid of the northwestern region.

Brainstem Encoding of Aided Speech in Hearing Aid Users with Cochlear Dead Region(s)

PubMed Central

Hassaan, Mohammad Ramadan; Ibraheem, Ola Abdallah; Galhom, Dalia Helal

2016-01-01

Introduction  Neural encoding of speech begins with the analysis of the signal as a whole broken down into its sinusoidal components in the cochlea, which has to be conserved up to the higher auditory centers. Some of these components target the dead regions of the cochlea causing little or no excitation. Measuring aided speech-evoked auditory brainstem response elicited by speech stimuli with different spectral maxima can give insight into the brainstem encoding of aided speech with spectral maxima at these dead regions. Objective  This research aims to study the impact of dead regions of the cochlea on speech processing at the brainstem level after a long period of hearing aid use. Methods  This study comprised 30 ears without dead regions and 46 ears with dead regions at low, mid, or high frequencies. For all ears, we measured the aided speech-evoked auditory brainstem response using speech stimuli of low, mid, and high spectral maxima. Results  Aided speech-evoked auditory brainstem response was producible in all subjects. Responses evoked by stimuli with spectral maxima at dead regions had longer latencies and smaller amplitudes when compared with the control group or the responses of other stimuli. Conclusion  The presence of cochlear dead regions affects brainstem encoding of speech with spectral maxima perpendicular to these regions. Brainstem neuroplasticity and the extrinsic redundancy of speech can minimize the impact of dead regions in chronic hearing aid users. PMID:27413404

Regional Hospital Input Price Indexes

PubMed Central

Freeland, Mark S.; Schendler, Carol Ellen; Anderson, Gerard

1981-01-01

This paper describes the development of regional hospital input price indexes that is consistent with the general methodology used for the National Hospital Input Price Index. The feasibility of developing regional indexes was investigated because individuals inquired whether different regions experienced different rates of increase in hospital input prices. The regional indexes incorporate variations in cost-share weights (the amount an expense category contributes to total spending) associated with hospital type and location, and variations in the rate of input price increases for various regions. We found that between 1972 and 1979 none of the regional price indexes increased at average annual rates significantly different from the national rate. For the more recent period 1977 through 1979, the increase in one Census Region was significantly below the national rate. Further analyses indicated that variations in cost-share weights for various types of hospitals produced no substantial variations in the regional price indexes relative to the national index. We consider these findings preliminary because of limitations in the availability of current, relevant, and reliable data, especially for local area wage rate increases. PMID:10309557

Securing non-volatile memory regions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faraboschi, Paolo; Ranganathan, Parthasarathy; Muralimanohar, Naveen

Methods, apparatus and articles of manufacture to secure non-volatile memory regions are disclosed. An example method disclosed herein comprises associating a first key pair and a second key pair different than the first key pair with a process, using the first key pair to secure a first region of a non-volatile memory for the process, and using the second key pair to secure a second region of the non-volatile memory for the same process, the second region being different than the first region.

Regional geology and tectonics

USGS Publications Warehouse

Nokleberg, Warren J.; Bundtzen, Thomas K.; Nokleberg, Warren J.; Price, Raymond A.; Scholl, David W.; Stone, David B.

2017-01-01

This chapter describes the regional geology and tectonic origins of the major geologic units for the Northern Cordillera. The goals of the chapter are to: (1) provide a summary and regional overview of this vast region that contains a complicated geologic history; and (2) describe the major geologic units and tectonic events that cover a broad geologic time span from the Proterozoic to the Holocene (Recent).

Final Report: Pilot Region-Based Optimization Program for Fund-Lead Sites, EPA Region III

EPA Pesticide Factsheets

This report describes a pilot study for a Region-based optimization program, implemented by a Regional Optimization Evaluation Team (ROET) that was conducted in U.S. EPA Region III at Fund-lead sites with pump-and-treat (P&T) systems.

Active Regions' Magnetic Connection

NASA Image and Video Library

2017-05-22

Several bright bands of plasma connect from one active region to another, even though they are tens of thousands of miles away from each other (May 17-18, 2017). Active regions are, by their nature, strong magnetic areas with north and south poles. The plasma consists of charged particles that stream along the magnetic field lines between these two regions. These connecting lines are clearly visible in this wavelength of extreme ultraviolet light. Other loops and strands of bright plasma can be seen rising up and out of smaller active regions as well. The video covers about one day's worth of activity. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA21638

U.S. Fish and Wildlife Service regional alternative transportation evaluation : region 6

DOT National Transportation Integrated Search

2014-04-01

The U.S. Fish and Wildlife Service (FWS) and the U.S. Department of Transportation (DOT) Volpe Center (Volpe Center) conducted a regional alternative transportation evaluation (RATE) in Region 6, which is comprised of Colorado, Kansas, Montana, Nebra...

Global Inventory of Regional and National Qualifications Frameworks. Volume II: National and Regional Cases

ERIC Educational Resources Information Center

UNESCO Institute for Lifelong Learning, 2015

2015-01-01

This second volume of the "Global Inventory of Regional and National Qualifications Frameworks" focuses on national and regional cases of national qualifications frameworks for eighty- six countries from Afghanistan to Uzbekistan and seven regional qualifications frameworks. Each country profile provides a thorough review of the main…

Tidal-Induced Internal Ocean Waves as an Explanation for Enceladus' Tiger Stripe Pattern and Hotspot Activity

NASA Astrophysics Data System (ADS)

Vermeersen, B. L. A.; Maas, L. R.; van Oers, S.; Rabitti, A.; Jara-Orue, H.

2014-12-01

One of the most peculiar features on Saturn moon Enceladus is its so-called tiger stripe pattern at the geologically active South Polar Terrain (SPT), as first observed in detail by the Cassini spacecraft early 2005. It is generally assumed that the four almost parallel surface lines that constitute this pattern are faults in the icy surface overlying a confined salty water reservoir. Indeed, later Cassini observations have shown that salty water jets originate from the tiger stripes [e.g., Hansen et al., Science, 311, 1422-1425, 2006; Postberg et al., Nature, 474, 620-622, 2011]. More recently, Porco et al. [Astron. J., 148:45, Sep. 2014] and Nimmo et al. [Astron. J., 148:46, Sep. 2014] have reported strong evidence that the geysers are not caused by frictional heating at the surface, but that geysers must originate deeper in Enceladus' interior. Tidal flexing models, like those of Hurford et al., Nature, 447, 292-294, 2007, give a good match for the brightness variations Cassini observes, but they seem to fail to reproduce the exact timing of plume brightening. Although jet activity is thus strongly connected to tidal forcing, another mechanism must be involved as well. Last year, we formulated the original idea [Vermeersen et al., AGU Fall Meeting 2013, abstract #P53B-1848] that the tiger stripe pattern is formed and maintained by induced, tidally and rotationally driven, wave-attractor motions in the ocean underneath the icy surface of the tiger-stripe region. Such wave-attractor motions are observed in water tank experiments in laboratories on Earth and in numerical experiments [Maas et al., Nature, 338, 557-561, 1997; Drijfhout and Maas, J. Phys. Oceanogr., 37, 2740-2763, 2007; Hazewinkel et al., Phys. Fluids, 22, 107102, 2010]. The latest observations by Porco et al. and Nimmo et al. seem to be in agreement with this tidal-induced wave attractor phenomenon, both with respect to tiger stripe pattern and with respect to timing of hotspot activity. However, in

Etiology of Childhood Infectious Diarrhea in a Developed Region of China: Compared to Childhood Diarrhea in a Developing Region and Adult Diarrhea in a Developed Region.

PubMed

Wang, Xin; Wang, Jing; Sun, Hao; Xia, Shengli; Duan, Ran; Liang, Junrong; Xiao, Yuchun; Qiu, Haiyan; Shan, Guangliang; Jing, Huaiqi

2015-01-01

In China, great differences in economy, social characteristics and hygiene exist between developing and developed regions. A comparative study of infectious diarrhea between two regions was needed. Three groups of diarrheal patients were collected: children ≤5 year-olds from Beijing (developed region) and Henan Province (developing region), and adults over 18 year-olds from Beijing. A questionnaire was used to survey and feces samples were examined for 16 enteropathogens. We enrolled 1422 children and 1047 adults from developed region and 755 children from developing region. Virus positive rates were 32.98% for children and 23.67% for adults in developed region. The most prevalent pathogen for children was rotavirus whereas for adults was norovirus. Bacterial isolation rates were 13.92% for children from developed region, while 29.14% for children from the developing regions. For the greatest difference, Shigella accounted for 50.79% and was the dominant pathogen in the developing region, whereas in the developed region it was only 1.45%. There was no significant relationship between the local levels of development with diarrheogenic Escherichia coli (DEC) categories. But it was seen the notable differences between the population with different age: enteropathogenic E.coli (EPEC) and enteroaggregative E.coli (EAggEC) were the primary classes of DEC in children from both regions, whereas it was enterotoxigenic E.coli (ETEC) in adults. The symptoms of Shigella and Salmonella infection, such as bloody stools, white blood cells (WBC) and red blood cells (RBC) positivity and fever were similar in children, which may lead to the misidentification. Yersinia enterocolitica and shiga toxin-producing E.coli (STEC) infections were firstly reported in Beijing. There was a large difference in etiology of bacterial diarrhea between children in developing and developed regions of China.

49 CFR Appendix C to Part 241 - Geographical Boundaries of FRA's Regions and Addresses of FRA's Regional Headquarters

Code of Federal Regulations, 2012 CFR

2012-10-01

...) address of the Regional Administrator for Region 1 is: [email protected]gov. (2) Region 2 consists of....dot.gov. (3) Region 3 consists of Kentucky, Tennessee, North Carolina, South Carolina, Georgia... E-mail address of the Regional Administrator for Region 3 is: [email protected]gov. (4) Region 4...

49 CFR Appendix C to Part 241 - Geographical Boundaries of FRA's Regions and Addresses of FRA's Regional Headquarters

Code of Federal Regulations, 2011 CFR

2011-10-01

...) address of the Regional Administrator for Region 1 is: [email protected]gov. (2) Region 2 consists of....dot.gov. (3) Region 3 consists of Kentucky, Tennessee, North Carolina, South Carolina, Georgia... E-mail address of the Regional Administrator for Region 3 is: [email protected]gov. (4) Region 4...

Ultrasound in regional anaesthesia.

PubMed

Griffin, J; Nicholls, B

2010-04-01

Ultrasound guidance is rapidly becoming the gold standard for regional anaesthesia. There is an ever growing weight of evidence, matched with improving technology, to show that the use of ultrasound has significant benefits over conventional techniques, such as nerve stimulation and loss of resistance. The improved safety and efficacy that ultrasound brings to regional anaesthesia will help promote its use and realise the benefits that regional anaesthesia has over general anaesthesia, such as decreased morbidity and mortality, superior postoperative analgesia, cost-effectiveness, decreased postoperative complications and an improved postoperative course. In this review we consider the evidence behind the improved safety and efficacy of ultrasound-guided regional anaesthesia, before discussing its use in pain medicine, paediatrics and in the facilitation of neuraxial blockade. The Achilles' heel of ultrasound-guided regional anaesthesia is that anaesthetists are far more familiar with providing general anaesthesia, which in most cases requires skills that are achieved faster and more reliably. To this ends we go on to provide practical advice on ultrasound-guided techniques and the introduction of ultrasound into a department.

50 CFR 100.22 - Subsistence resource regions.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Bristol Bay Region; (5) Yukon-Kuskokwim Delta Region; (6) Western Interior Region; (7) Seward Peninsula Region; (8) Northwest Arctic Region; (9) Eastern Interior Region; (10) North Slope Region. (b) You may...

REGIONAL RESEARCH, METHODS, AND SUPPORT

EPA Science Inventory

The Human Exposure and Atmospheric Sciences Division (HEASD) has several collaborations with regional partners through the Regional Science Program (RSP) managed by ORD's Office of Science Policy (OSP). These projects resulted from common interests outlined in the Regional Appli...

Regional hydrothermal commercialization plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-07-14

This plan for the Rocky Mountain Basin and Range Region articulates the complete range of initiatives (federal, state, local, and industrial) required for the early commercialization of the regions geothermal resources. (MHR)

Region 9 RTOC Charter

EPA Pesticide Factsheets

U.S. EPA Pacific Southwest (Region 9) Regional Tribal Operations Committee (RTOC) Charter as amended 11/13/2014: Mission, Goals, Scope, Structure & Membership, Meetings, Administration, Charter Amendment/Review, and Current Working Draft.

CO2 Uptake and Fixation by a Thermoacidophilic Microbial Community Attached to Precipitated Sulfur in a Geothermal Spring▿ †

PubMed Central

Boyd, Eric S.; Leavitt, William D.; Geesey, Gill G.

2009-01-01

Carbon fixation at temperatures above 73°C, the upper limit for photosynthesis, is carried out by chemosynthetic thermophiles. Yellowstone National Park (YNP), Wyoming possesses many thermal features that, while too hot for photosynthesis, presumably support chemosynthetic-based carbon fixation. To our knowledge, in situ rates of chemosynthetic reactions at these high temperatures in YNP or other high-temperature terrestrial geothermal springs have not yet been reported. A microbial community attached to precipitated elemental sulfur (So floc) at the source of Dragon Spring (73°C, pH 3.1) in Norris Geyser Basin, YNP, exhibited a maximum rate of CO2 uptake of 21.3 ± 11.9 μg of C 107 cells−1 h−1. When extrapolated over the estimated total quantity of So floc at the spring's source, the So floc-associated microbial community accounted for the uptake of 121 mg of C h−1 at this site. On a per-cell basis, the rate was higher than that calculated for a photosynthetic mat microbial community dominated by Synechococcus spp. in alkaline springs at comparable temperatures. A portion of the carbon taken up as CO2 by the So floc-associated biomass was recovered in the cellular nucleic acid pool, demonstrating that uptake was coupled to fixation. The most abundant sequences in a 16S rRNA clone library of the So floc-associated community were related to chemolithoautotrophic Hydrogenobaculum strains previously isolated from springs in the Norris Geyser Basin. These microorganisms likely contributed to the uptake and fixation of CO2 in this geothermal habitat. PMID:19429558

32 CFR 1605.7 - Region Manager.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Region Manager. 1605.7 Section 1605.7 National... ORGANIZATION Region Administration § 1605.7 Region Manager. (a) Subject to the direction and control of the Director of Selective Service, the Region Manager of Selective Service for each region shall be in...

About Region 8’s Central Regional Laboratory

EPA Pesticide Factsheets

The Region 8 laboratory plays a critical role in protecting people's health and the environment through the analysis of air, water, soil, and biota samples (plant, fish, and occasionally, mammalian tissue).

Regional Test Centers | Photovoltaic Research | NREL

Science.gov Websites

Regional Test Centers Regional Test Centers Five Regional Test Centers (RTCs), established by the the bankability of new photovoltaic (PV) technologies. Photo of the Regional Test Centers The DOE Regional Test Centers help to validate PV technologies in a range of different climates. Pictured here is

Regional Smart Growth Alliances

EPA Pesticide Factsheets

This page describes the Urban Land Institute regional smart growth alliances that received funding from EPA to help support economic development, accommodate growth, enhance quality of, and protect the environment in regions across the country.

Selection of USSR foreign similarity regions

NASA Technical Reports Server (NTRS)

Disler, J. M. (Principal Investigator)

1982-01-01

The similarity regions in the United States and Canada were selected to parallel the conditions that affect labeling and classification accuracies in the U.S.S.R. indicator regions. In addition to climate, a significant condition that affects labeling and classification accuracies in the U.S.S.R. is the proportion of barley and wheat grown in a given region (based on sown areas). The following regions in the United States and Canada were determined to be similar to the U.S.S.R. indicator regions: (1) Montana agrophysical unit (APU) 104 corresponds to the Belorussia high barley region; (2) North Dakota and Minnesota APU 20 and secondary region southern Manitoba and Saskatchewan correspond to the Ural RSFSR barley and spring wheat region; (3) Montana APU 23 corresponds to he North Caucasus barley and winter wheat region. Selection criteria included climates, crop type, crop distribution, growth cycles, field sizes, and field shapes.

REGIONAL SCALE COMPARATIVE RISK ASSESSMENT

EPA Science Inventory

Regional Vulnerability Assessment (ReVA) is an approach to regional-scale ecological risk assessment that is currently under development by EPA's Office of Research and Development. The pilot assessment will be done for the mid-Atlantic region and builds on data collected for th...

Numerical Simulation of Regional Circulation in the Monterey Bay Region

NASA Technical Reports Server (NTRS)

Tseng, Y. H.; Dietrich, D. E.; Ferziger, J. H.

2003-01-01

The objective of this study is to produce a high-resolution numerical model of Mon- terey Bay area in which the dynamics are determined by the complex geometry of the coastline, steep bathymetry, and the in uence of the water masses that constitute the CCS. Our goal is to simulate the regional-scale ocean response with realistic dynamics (annual cycle), forcing, and domain. In particular, we focus on non-hydrostatic e ects (by comparing the results of hydrostatic and non-hydrostatic models) and the role of complex geometry, i.e. the bay and submarine canyon, on the nearshore circulation. To the best of our knowledge, the current study is the rst to simulate the regional circulation in the vicinity of Monterey Bay using a non-hydrostatic model. Section 2 introduces the high resolution Monterey Bay area regional model (MBARM). Section 3 provides the results and veri cation with mooring and satellite data. Section 4 compares the results of hydrostatic and non-hydrostatic models.

REGIONAL VULNERABILITY ASSESSMENT OF THE MID-ATLANTIC REGION: EVALUATION OF INTEGRATION METHODS AND ASSESSMENTS RESULTS

EPA Science Inventory

This report describes methods for quantitative regional assessment developed by the Regional Vulnerability Assessment (ReVA) program. The goal of ReVA is to develop regional-scale assessments of the magnitude, extent, distribution, and uncertainty of current and anticipated envir...

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.

Eighteen Years of the Great Lakes Regional Counseling Psychology Conference: Revisiting the Need for Regional Conferences

ERIC Educational Resources Information Center

Delgado-Romero, Edward A.; Bowman, Sharon L.; Gerstein, Lawrence H.

2006-01-01

The Great Lakes Regional Conference on Counseling Psychology is the only conference to continuously fulfill the 1987 mandate issued by Division 17 for regional counseling conferences. The rationale for regional conferences is reviewed, and the 18-year history of the Great Lakes Regional Conference is examined. The authors conclude by noting the…

Region 9 Tribal Program

EPA Pesticide Factsheets

EPA Region 9 helps tribes strengthen management of environmental programs in Indian country, and ensure that tribes have a voice in decisions. The region serves 148 federally recognized tribes with the states of Arizona, California, and Nevada.

36 CFR 242.22 - Subsistence resource regions.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Kuskokwim Delta Region; (6) Western Interior Region; (7) Seward Peninsula Region; (8) Northwest Arctic Region; (9) Eastern Interior Region; (10) North Slope Region. (b) You may obtain maps delineating the...

Solar Water Heater

NASA Technical Reports Server (NTRS)

1993-01-01

As a Jet Propulsion Laboratory (JPL) scientist Dr. Eldon Haines studied the solar energy source and solar water heating. He concluded he could build a superior solar water heating system using the geyser pumping principle. He resigned from JPL to develop his system and later form Sage Advance Corporation to market the technology. Haines' Copper Cricket residential system has no moving parts, is immune to freeze damage, needs no roof-mounted tanks, and features low maintenance. It provides 50-90 percent of average hot water requirements. A larger system, the Copper Dragon, has been developed for commercial installations.

Orion’s protective backshell installed on This Week @NASA - August 25, 2014

NASA Image and Video Library

2014-08-25

Engineers at Kennedy Space Center have finished installing the Orion spacecraft’s backshell – the black protective tiles on the cone-shaped sides of NASA’s new deep space capsule. The backshell tiles are the same type that protected the underside of space shuttles -- and will not only provide protection from debris while in space but from extreme temperatures in that area of the spacecraft as it returns from space – which could exceed 31-hundred degrees Fahrenheit. Also, SLS anti-geyser testing, Webb’s replica backplane, Arctic Sea ice loss, Ancient Earth, Alien Earths and more!

The eastern front of the Sierra Nevada; prone to earthquakes and volcanic eruption

USGS Publications Warehouse

Rinehart, C.D.; Smith, W.C.

1981-01-01

On Sunday morning, May 25, 1980, the weather at Mammoth Lakes, Calif., was sunny and brisk. Suddenly, just before 9:33 a.m, the world became a jarring, lurching, unstable place. Along the front of the Sierra Nevada, the muffled thunder of rockfalls and avalanches prolonged the confusion of sound and motion and added the spectacle of large, rising dust clouds. Three geysers, one 30 ft high, suddenly roared into the air at Hot Creek, although none survived more than a few hours. Some new boiling pools appeared, while many existing hot springs and pools became hotter and more active. 

Slosh wave excitation due to cryogenic liquid reorientation in space-based propulsion system

NASA Technical Reports Server (NTRS)

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

1991-01-01

The objective of the cryogenic fluid management of the spacecraft propulsion system is to develop the technology necessary for acquistion or positioning of liquid and vapor within a tank in reduced gravity to enable liquid outflow or vapor venting. In this study slosh wave excitation induced by the resettling flow field activated by 1.0 Hz medium frequency impulsive reverse gravity acceleration during the course of liquid fluid reorientation with the initiation of geyser for liquid filled levels of 30, 50, and 80 percent have been studied. Characteristics of slosh waves with various frequencies excited are discussed.

Materials for geothermal production

NASA Astrophysics Data System (ADS)

Kukacka, L. E.

Advances in the development of new materials continue to be made in the geothermal materials project. Many successes have already been accrued and the results used commercially. In FY-91, work was focused on reducing well drilling, fluid transport and energy conversion costs. Specific activities performed included lightweight CO2 resistant well cements, thermally conductive and scale resistant protective liner systems, chemical systems for lost circulation control, corrosion mitigation in process components at The Geysers, and elastomer-metal bonding systems. Efforts to transfer the technologies developed in these efforts to other energy-related sectors of the economy continued, and considerable success was achieved.

Cryogenic propellant management: Integration of design, performance and operational requirements

NASA Technical Reports Server (NTRS)

Worlund, A. L.; Jamieson, J. R., Jr.; Cole, T. W.; Lak, T. I.

1985-01-01

The integration of the design features of the Shuttle elements into a cryogenic propellant management system is described. The implementation and verification of the design/operational changes resulting from design deficiencies and/or element incompatibilities encountered subsequent to the critical design reviews are emphasized. Major topics include: subsystem designs to provide liquid oxygen (LO2) tank pressure stabilization, LO2 facility vent for ice prevention, liquid hydrogen (LH2) feedline high point bleed, pogo suppression on the Space Shuttle Main Engine (SSME), LO2 low level cutoff, Orbiter/engine propellant dump, and LO2 main feedline helium injection for geyser prevention.

Teaching Regional Perspectives in Canada.

ERIC Educational Resources Information Center

McCreath, Peter

1978-01-01

Defines Canadian regionalism in terms of geographical features and their political, social, and economic implications, rather than in terms of political and provincial boundaries. The significance of regionalism is mentioned as an important topic for Canadian studies. Increasing awareness and acceptance of regional perspectives is presented as an…

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.

"Mature Regionalism" and the Genesis of "Functional Projects": "Educational Regionalism" in Small (and Micro-States)

ERIC Educational Resources Information Center

Jules, Tavis D.

2017-01-01

This article advances that the movement towards "deeper" Caribbean integration has generated a shift from "immature" regionalism to a "mature" form of regionalism. Thus, mature regionalism, a new governance mechanism, in regulating the institutional and legal framework of Caribbean Single Market and Economy is…

Spatial analysis on China's regional air pollutants and CO2 emissions: emission pattern and regional disparity

NASA Astrophysics Data System (ADS)

Dong, Liang; Liang, Hanwei

2014-08-01

China has suffered from serious air pollution and CO2 emission. Challenges of emission reduction policy not only come from technology advancement, but also generate from the fact that, China has pronounced disparity between regions, in geographical and socioeconomic. How to deal with regional disparity is important to achieve the reduction target effectively and efficiently. This research conducts a spatial analysis on the emission patterns of three air pollutants named SO2, NOx and PM2.5, and CO2, in China's 30 provinces, applied with spatial auto-correlation and multi regression modeling. We further analyze the regional disparity and inequity issues with the approach of Lorenz curve and Gini coefficient. Results highlight that: there is evident cluster effect for the regional air pollutants and CO2 emissions. While emission amount increases from western regions to eastern regions, the emission per GDP is in inverse trend. The Lorenz curve shows an even larger unequal distribution of GDP/emissions than GDP/capita in 30 regions. Certain middle and western regions suffers from a higher emission with lower GDP, which reveal the critical issue of emission leakage. Future policy making to address such regional disparity is critical so as to promote the emission control policy under the “equity and efficiency” principle.

Central Atlantic regional ecological test site: A prototype regional environmental information system

NASA Technical Reports Server (NTRS)

Alexander, R. H. (Principal Investigator)

1973-01-01

The author has identified the following significant results. A comparison of photomorphic regions from an uncontrolled ERTS-1 mosaic of CARETS to land use areas on a map published in the National Atlas revealed close correlations in non-urban regions. Such regional scale analysis of ERTS-1 data has the potential for providing an economical sampling strategy for selecting sites for more detailed field measurements if other environmental variables can be correlated with patterns on ERTS-1 imagery. ERTS-1 imagery has also revealed for the first time the appearance of CARETS during the winter months. Investigators have identified extensive areas of conifers, which have previously been indistinguishable from deciduous vegetation. Imagery has also shown very clearly the extent of snow cover at a particular time over the region. The evaluation of ERTS-1 imagery used for the land use mapping of the shore zone of CARETS, has shown that the presence or absence of elements of an hierarchal system of shoreline landforms can help identify areas of potential rapid change. Changes in land use class distributions on the Barrier Islands signify the environmental response to natural and man-caused processes. Both environmental vulnerability and sensitivity can be estimated from the repetitive ERTS-1 coverage of long reaches of the CARETS coast. Results indicate potential applications to land use planning, management, and regional environmental quality analysis.

Water masers in NGC7538 region

NASA Astrophysics Data System (ADS)

Kameya, Osamu

We observed H2O masers towards NGC7538 molecular-cloud core using VERA (VLBI Experiment of Radio Astrometry). This region is in the Perseus arm at a distance of about 2.7 kpc and is famous for its multiple, massive star formation. There are three areas there, N(IRS1-3), E(IRS9), and S(IRS11), each having a strong IR source(s), ultra-compact HII region(s), bipolar outflow, high-density core, and OH/H2O/CH3OH masers. We made differential VLBI observations towards the NGC7538 H2O maser sources at N and S and a reference source, Cepheus A H2O maser, simultaneously. The Cepheus A region is separated by 2 degrees from the NGC7538 region. The positions of H2O masers in N and S regions, distributed around the ultra-compact HII regions, are basically consistent with those found by means of interferometric observations of past 29 years. The masers may come from interface regions between the ultra-compact HII regions and the environments of dense molecular gas.

76 FR 9630 - Federal Regulatory Enforcement Fairness Hearing; National Ombudsman and Region VI Regional Small...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

... Administration (SBA). ACTION: Notice of open hearing of the Regional (Region VI) Small Business Regulatory... location, date and time of the Regional Small Business Regulatory Fairness hearing. This hearing is open to... Chasse Room, New Orleans, LA 70140. SUPPLEMENTARY INFORMATION: Pursuant to the Small Business Regulatory...

EPA'S REGIONAL VULNERABILITY ASSESSMENT PROGRAM: TOOLS TO FACILITATE REGIONAL TO LOCAL DECISION-MAKING

EPA Science Inventory

EPA's Regional Vulnerability Assessment (ReVA) program is developing and testing approaches to conducting comparative environmental risk assessments at the regional scale, considering impacts to ecological human, and fiscal health endpoints. It seeks an objective and quantifiable...

Verbal working memory performance correlates with regional white matter structures in the frontoparietal regions.

PubMed

Takeuchi, Hikaru; Taki, Yasuyuki; Sassa, Yuko; Hashizume, Hiroshi; Sekiguchi, Atsushi; Fukushima, Ai; Kawashima, Ryuta

2011-10-01

Working memory is the limited capacity storage system involved in the maintenance and manipulation of information over short periods of time. Previous imaging studies have suggested that the frontoparietal regions are activated during working memory tasks; a putative association between the structure of the frontoparietal regions and working memory performance has been suggested based on the analysis of individuals with varying pathologies. This study aimed to identify correlations between white matter and individual differences in verbal working memory performance in normal young subjects. We performed voxel-based morphometry (VBM) analyses using T1-weighted structural images as well as voxel-based analyses of fractional anisotropy (FA) using diffusion tensor imaging. Using the letter span task, we measured verbal working memory performance in normal young adult men and women (mean age, 21.7 years, SD=1.44; 42 men and 13 women). We observed positive correlations between working memory performance and regional white matter volume (rWMV) in the frontoparietal regions. In addition, FA was found to be positively correlated with verbal working memory performance in a white matter region adjacent to the right precuneus. These regions are consistently recruited by working memory. Our findings suggest that, among normal young subjects, verbal working memory performance is associated with various regions that are recruited during working memory tasks, and this association is not limited to specific parts of the working memory network. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hydrological regions in monsoon Asia

NASA Astrophysics Data System (ADS)

Kondoh, Akihiko; Budi Harto, Agung; Eleonora, Runtunuwu; Kojiri, Toshiharu

2004-11-01

Monsoon Asia is characterized by its diversity of natural and social environments. These environments range from humid tropics to arid regions and there exist associated various hydrological phenomena. This paper attempts to characterize the hydrological regions of monsoon Asia based on the water budget calculated using grid-based global datasets. A map of hydrological regions is created by ranking the value of water surplus and deficit. A humid zone with large water surplus extending from Southeast Asia to the Japanese archipelago, rapid transition from humid to arid environments in eastern China, and an arid region surrounded by a humid region in continental Southeast Asia are the most remarkable features in monsoon Asia. The map reveals that an essential characteristic of monsoon Asia is the proximity of the arid and humid environments. Many water problems and water management practices in a region can be easily understood by plotting them on a map. The boundaries of several large river basins are superimposed on the map, and examined for the water budget and flow regimes. The results are found to explain the regional characteristics of the seasonal runoff regimes satisfactorily. The importance of using a spatial framework for the comparative hydrological study in Monsoon Asia is highlighted.

Regional Variations in Diagnostic Practices

PubMed Central

Song, Yunjie; Skinner, Jonathan; Bynum, Julie; Sutherland, Jason; Wennberg, John E.; Fisher, Elliott S.

2010-01-01

BACKGROUND Current methods of risk adjustment rely on diagnoses recorded in clinical and administrative records. Differences among providers in diagnostic practices could lead to bias. METHODS We used Medicare claims data from 1999 through 2006 to measure trends in diagnostic practices for Medicare beneficiaries. Regions were grouped into five quintiles according to the intensity of hospital and physician services that beneficiaries in the region received. We compared trends with respect to diagnoses, laboratory testing, imaging, and the assignment of Hierarchical Condition Categories (HCCs) among beneficiaries who moved to regions with a higher or lower intensity of practice. RESULTS Beneficiaries within each quintile who moved during the study period to regions with a higher or lower intensity of practice had similar numbers of diagnoses and similar HCC risk scores (as derived from HCC coding algorithms) before their move. The number of diagnoses and the HCC measures increased as the cohort aged, but they increased to a greater extent among beneficiaries who moved to regions with a higher intensity of practice than among those who moved to regions with the same or lower intensity of practice. For example, among beneficiaries who lived initially in regions in the lowest quintile, there was a greater increase in the average number of diagnoses among those who moved to regions in a higher quintile than among those who moved to regions within the lowest quintile (increase of 100.8%; 95% confidence interval [CI], 89.6 to 112.1; vs. increase of 61.7%; 95% CI, 55.8 to 67.4). Moving to each higher quintile of intensity was associated with an additional 5.9% increase (95% CI, 5.2 to 6.7) in HCC scores, and results were similar with respect to laboratory testing and imaging. CONCLUSIONS Substantial differences in diagnostic practices that are unlikely to be related to patient characteristics are observed across U.S. regions. The use of clinical or claims-based diagnoses in

Flood regionalization: A hybrid geographic and predictor-variable region-of-influence regression method

USGS Publications Warehouse

Eng, K.; Milly, P.C.D.; Tasker, Gary D.

2007-01-01

To facilitate estimation of streamflow characteristics at an ungauged site, hydrologists often define a region of influence containing gauged sites hydrologically similar to the estimation site. This region can be defined either in geographic space or in the space of the variables that are used to predict streamflow (predictor variables). These approaches are complementary, and a combination of the two may be superior to either. Here we propose a hybrid region-of-influence (HRoI) regression method that combines the two approaches. The new method was applied with streamflow records from 1,091 gauges in the southeastern United States to estimate the 50-year peak flow (Q50). The HRoI approach yielded lower root-mean-square estimation errors and produced fewer extreme errors than either the predictor-variable or geographic region-of-influence approaches. It is concluded, for Q50 in the study region, that similarity with respect to the basin characteristics considered (area, slope, and annual precipitation) is important, but incomplete, and that the consideration of geographic proximity of stations provides a useful surrogate for characteristics that are not included in the analysis. ?? 2007 ASCE.

Complex Regional Pain Syndrome

MedlinePlus

... Other major and minor traumas — such as surgery, heart attacks, infections and even sprained ankles — can also lead to complex regional pain syndrome. It's not well-understood why these injuries can trigger complex regional pain syndrome. Not everyone who has ...

Identification of USSR Indicator Regions

NASA Technical Reports Server (NTRS)

Disler, J.; Breigh, H. (Principal Investigator)

1980-01-01

Potential indicator regions were determined by comparing the statistics for barley and wheat at the lowest administrative levels for which published statistics were available. Fourteen were selected for review based on their relative abundances of wheat and barely. These potential indicator regions were grouped according to three conditions that could affect labeling and classification accuracies: (1) high-barley content; (2) presence of barley and spring wheat; and (3) presence of barley and winter wheat. Each region was further evaluated based on the availability of crop calendars, LANDSAT acquisitions, and ancillary data. Based on the relative abundance of wheat and barley and the availability of data, three indicator regions were recommended. Within each region, individual oblasts and/or krays were selected according to segment availability and segment acquisition histories for potential barley separation.

32 CFR 1605.7 - Region Manager.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM SELECTIVE SERVICE SYSTEM... immediate charge of the Region Headquarters and shall be responsible for carrying out the region functions of the Selective Service System in the various States assigned to the region. (b) The Region Manager...

32 CFR 1605.7 - Region Manager.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM SELECTIVE SERVICE SYSTEM... immediate charge of the Region Headquarters and shall be responsible for carrying out the region functions of the Selective Service System in the various States assigned to the region. (b) The Region Manager...

32 CFR 1605.7 - Region Manager.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM SELECTIVE SERVICE SYSTEM... immediate charge of the Region Headquarters and shall be responsible for carrying out the region functions of the Selective Service System in the various States assigned to the region. (b) The Region Manager...

32 CFR 1605.7 - Region Manager.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM SELECTIVE SERVICE SYSTEM... immediate charge of the Region Headquarters and shall be responsible for carrying out the region functions of the Selective Service System in the various States assigned to the region. (b) The Region Manager...

Finding Distant Galactic HII Regions

NASA Astrophysics Data System (ADS)

Anderson, L. D.; Armentrout, W. P.; Johnstone, B. M.; Bania, T. M.; Balser, Dana S.; Wenger, Trey V.; Cunningham, V.

2015-12-01

The WISE Catalog of Galactic H ii Regions contains ˜2000 H ii region candidates lacking ionized gas spectroscopic observations. All candidates have the characteristic H ii region mid-infrared morphology of WISE 12 μ {{m}} emission surrounding 22 μ {{m}} emission, and additionally have detected radio continuum emission. We here report Green Bank Telescope hydrogen radio recombination line and radio continuum detections in the X-band (9 GHz; 3 cm) of 302 WISE H ii region candidates (out of 324 targets observed) in the zone 225^\\circ ≥slant {\\ell }≥slant -20^\\circ , | {\\text{}}b| ≤slant 6^\\circ . Here we extend the sky coverage of our H ii region Discovery Survey, which now contains nearly 800 H ii regions distributed across the entire northern sky. We provide LSR velocities for the 302 detections and kinematic distances for 131 of these. Of the 302 new detections, 5 have ({\\ell },{\\text{}}b,v) coordinates consistent with the Outer Scutum-Centaurus Arm (OSC), the most distant molecular spiral arm of the Milky Way. Due to the Galactic warp, these nebulae are found at Galactic latitudes >1° in the first Galactic quadrant, and therefore were missed in previous surveys of the Galactic plane. One additional region has a longitude and velocity consistent with the OSC but lies at a negative Galactic latitude (G039.183-01.422 -54.9 {km} {{{s}}}-1). With Heliocentric distances >22 kpc and Galactocentric distances >16 kpc, the OSC H ii regions are the most distant known in the Galaxy. We detect an additional three H ii regions near {\\ell }≃ 150^\\circ whose LSR velocities place them at Galactocentric radii >19 kpc. If their distances are correct, these nebulae may represent the limit to Galactic massive star formation.

Gyrating Active Region

NASA Image and Video Library

2017-01-26

On Jan. 20, 2017, NASA Solar Dynamics Observatory captured a small area of the sun highlighted three active region. Over half a day this active region sent dark swirls of plasma and bright magnetic arches twisting and turning above it. All the activity in the three areas was driven by competing magnetic forces. The dynamic action was observed in a wavelength of extreme ultraviolet light. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA11703

The regional climate model RegCM3 performances over several regions and climate regimes

NASA Astrophysics Data System (ADS)

Coppola, E.; Rauscher, S.; Gao, X.; Giorgi, F.; Im, E. S.; Mariotti, L.; Seth, A.; Sylla, M. B.

2009-04-01

Regional Climate models are more and more needed to provide high resolution regional climate information in climate impact studies. Water availability in a future scenario is the main request of policy makers for adaptation and mitigation purposes. However precipitation changes are unlikely to be as spatially coherent as temperature changes and they are closely related to the regional model itself. In addition model skill varies regionally. An example of several ICTP regional climate model (RegCM3) simulations is reported over China, Korea, Africa, Central and Southern America, Europe and Australia. Over China, Australia, and Korea the regional model improves the simulation compared to the driving GCM when compared with CRU observations. In China, for example, the higher resolution of the regional model inhibits the penetration of the monsoon precipitation front from the southern slope of the Himalaya onto the Tibetan Plateau. In Korea the nested domain simulation (20 km) shows an encouraging performance with regard to capturing extreme precipitation episodes and the finer spatial distribution reflects the detailed geography of the Korean Peninsula. Over South America, RegCM captures the annual cycle of precipitation over Northeast Brazil and the South American Monsoon region, although the monsoon onset occurs too early in the model. Precipitation over the Amazon is not well captured, with too little precipitation associated with weak easterlies and reduced moisture transport into the interior of the continent. RegCM simulates the annual cycle of precipitation over Central America and the Caribbean fairly well; in particular, the complex spatial distribution of the Mid-Summer Drought, a decrease in precipitation that occurs during the middle of the rainy season in July and August, is better captured by RegCM than by the GCM. In addition, RegCM simulates the strength and position of the Caribbean low level jet, a mesoscale feature related to precipitation anomalies

Iapetus' Equatorial Region

NASA Image and Video Library

2007-10-09

Cassini made a close flyby of Saturn's moon Iapetus on Sept. 10, 2007, and the visual and infrared mapping spectrometer obtained these images during that event. These two images show a higher resolution version of the equatorial region shown in PIA10010. The equatorial region includes the equatorial bulge which shows no differences in these compositions compared to surrounding regions. The color image on the right shows the results of mapping for three components of Iapetus' surface: carbon dioxide that is trapped or adsorbed in the surface (red), water in the form of ice (green), and a newly-discovered effect due to trace amount of dark particles in the ice creating what scientists call Rayleigh scattering (blue). The Rayleigh scattering effect is the main reason why the Earth's sky appears blue. There is a complex transition zone from the dark region, on the right, which is high in carbon dioxide, to the more ice-rich region on the left. Some crater floors are filled with carbon dioxide-rich dark material. As the ice becomes cleaner to the left, the small dark particles become more scattered and increase the Rayleigh scattering effect, again indicative of less than 2 percent dark sub-0.5-micron particles. The visual and infrared mapping spectrometer is like a digital camera, but instead of using three colors, it makes images in 352 colors, or wavelengths, from the ultraviolet to the near-infrared. The many wavelengths produce a continuous spectrum in each pixel, and these spectra measure how light is absorbed by different materials. By analyzing the absorptions expressed in each pixel, a map of the composition at each location on the moon can be constructed. http://photojournal.jpl.nasa.gov/catalog/PIA10011

Upper Extremity Regional Anesthesia

PubMed Central

Neal, Joseph M.; Gerancher, J.C.; Hebl, James R.; Ilfeld, Brian M.; McCartney, Colin J.L.; Franco, Carlo D.; Hogan, Quinn H.

2009-01-01

Brachial plexus blockade is the cornerstone of the peripheral nerve regional anesthesia practice of most anesthesiologists. As part of the American Society of Regional Anesthesia and Pain Medicine’s commitment to providing intensive evidence-based education related to regional anesthesia and analgesia, this article is a complete update of our 2002 comprehensive review of upper extremity anesthesia. The text of the review focuses on (1) pertinent anatomy, (2) approaches to the brachial plexus and techniques that optimize block quality, (4) local anesthetic and adjuvant pharmacology, (5) complications, (6) perioperative issues, and (6) challenges for future research. PMID:19282714

Identification of homogeneous regions for regionalization of watersheds by two-level self-organizing feature maps

NASA Astrophysics Data System (ADS)

Farsadnia, F.; Rostami Kamrood, M.; Moghaddam Nia, A.; Modarres, R.; Bray, M. T.; Han, D.; Sadatinejad, J.

2014-02-01

One of the several methods in estimating flood quantiles in ungauged or data-scarce watersheds is regional frequency analysis. Amongst the approaches to regional frequency analysis, different clustering techniques have been proposed to determine hydrologically homogeneous regions in the literature. Recently, Self-Organization feature Map (SOM), a modern hydroinformatic tool, has been applied in several studies for clustering watersheds. However, further studies are still needed with SOM on the interpretation of SOM output map for identifying hydrologically homogeneous regions. In this study, two-level SOM and three clustering methods (fuzzy c-mean, K-mean, and Ward's Agglomerative hierarchical clustering) are applied in an effort to identify hydrologically homogeneous regions in Mazandaran province watersheds in the north of Iran, and their results are compared with each other. Firstly the SOM is used to form a two-dimensional feature map. Next, the output nodes of the SOM are clustered by using unified distance matrix algorithm and three clustering methods to form regions for flood frequency analysis. The heterogeneity test indicates the four regions achieved by the two-level SOM and Ward approach after adjustments are sufficiently homogeneous. The results suggest that the combination of SOM and Ward is much better than the combination of either SOM and FCM or SOM and K-mean.

Future Earth, Global Science and Regional Programs: Building regional integrated science capacities in a global science organization

NASA Astrophysics Data System (ADS)

Tewksbury, J.

2016-12-01

Future Earth has emerged from the more than 30-year history of Global Change Research Programs, including IGBP, DIVERSITAS and IHDP. These programs supported interdisciplinary science in service of societies around the world. Now, their focus on building a greater understanding of changing Earth systems and their couplings with society has passed to Future Earth - with an important addition: Future Earth was also established to focus global change efforts around key societal challenges. The implications for the structure of Future Earth are large. Many challenges within topics, such as the water, energy, food nexus or the future of cities, are manifested within local, national, and regional contexts. How should we organize globally to most effectively confront these multi-scale challenges? The solution proposed in the framing of Future Earth was the formation of regional as well as national committees, as well as the formation of regional centers and offices. Regional Committees serve to both advocate for Future Earth in their regions and to advocate for regional interests in the global Future Earth platform, while regional Centers and offices are built into the Future Earth secretariat to perform a parallel regional implementation function. Implementation has not been easy, and the process has placed regionally-focused projects in an awkward place. Programs such as the Monsoon Asia Integrated Regional Study (MAIRS), the Northern Eurasia Earth Science Partnership Initiative (NEESPI), and the South/Southeast Asia Research Initiative (SARI) represent some of the best global change communities in the world, but by design, their focus is regional. The effective integration of these communities into the Future Earth architecture will be critical, and this integration will require the formation of strong regional committees and regional centers.

AnnotateGenomicRegions: a web application.

PubMed

Zammataro, Luca; DeMolfetta, Rita; Bucci, Gabriele; Ceol, Arnaud; Muller, Heiko

2014-01-01

Modern genomic technologies produce large amounts of data that can be mapped to specific regions in the genome. Among the first steps in interpreting the results is annotation of genomic regions with known features such as genes, promoters, CpG islands etc. Several tools have been published to perform this task. However, using these tools often requires a significant amount of bioinformatics skills and/or downloading and installing dedicated software. Here we present AnnotateGenomicRegions, a web application that accepts genomic regions as input and outputs a selection of overlapping and/or neighboring genome annotations. Supported organisms include human (hg18, hg19), mouse (mm8, mm9, mm10), zebrafish (danRer7), and Saccharomyces cerevisiae (sacCer2, sacCer3). AnnotateGenomicRegions is accessible online on a public server or can be installed locally. Some frequently used annotations and genomes are embedded in the application while custom annotations may be added by the user. The increasing spread of genomic technologies generates the need for a simple-to-use annotation tool for genomic regions that can be used by biologists and bioinformaticians alike. AnnotateGenomicRegions meets this demand. AnnotateGenomicRegions is an open-source web application that can be installed on any personal computer or institute server. AnnotateGenomicRegions is available at: http://cru.genomics.iit.it/AnnotateGenomicRegions.

Regionalism, Devolution and Education

ERIC Educational Resources Information Center

Bogdanor, Vernon

1977-01-01

Described are effects of political decentralization in the United Kingdom on political and social institutions, particularly education. The author concludes that regionalism could yield advantages of power decentralization, diversity of decision making, and educational systems which are more closely connected to regional and local traditions.…

[Regional health and autonomy conferences (CRSAs): the implications for medical democracy at a regional level].

PubMed

Devictor, Bernadette

2010-01-01

The HPST law seeks to reorganize the governance of healthcare at a regional level and to maintain the existence of regional health conferences, now known as regional health and autonomy conferences (CRSAs). The purpose of this article is to examine the new duties attributed to the CRSAs and to consider the various issues raised by their practice. The article also provides an analysis of the preconditions required for the successful implementation of medical democracy at a regional level, ie.: the involvement of the CRSAs in the assessment of regional healthcare policies, the mobilization of funds, the composition of the CRSAs (including the full range of healthcare areas), the importance of providing adequate support for territorial conferences, and the elaboration of a communicative space for fostering exchanges between CRSAs.

A regional approach to the environmental risk assessment in the Campania region

NASA Astrophysics Data System (ADS)

Minolfi, Giulia; Albanese, Stefano; Lima, Annamaria; De Vivo, Benedetto

2016-04-01

Environmental risk assessment and analysis has a crucial role for guaranteeing the safety of the population, especially in intensive urbanized and industrialized areas, such as the Campania region (Italy). In Italy, since 2006, the human health risk assessment has become mandatory for contaminated soil and waters at contaminated sites. While traditional risk assessment procedures are usually run at site specific level (brownfields), with this work we would like to introduce a freshly developed method to assess risks at regional level by means of GIS, considering the hazard due to the presence in the environment of a contaminated media, the land use variability and the actual distribution of the population. 3535 top soils were collected across the whole Campania region (Italy) with a sampling density of 1 sample/4 km2. Samples were analyzed at ACME Analytical Lab. Ltd (Vancouver, Canada), to determine the concentration of 52 elements, with a combined methods of ICP-MS and ICP-ES following an aqua regia digestion. After a detailed statistical data analysis and geochemical mapping, we reclassified the interpolated maps of some potentially toxic elements (Sb, As, Be, Cd, Co, Cr, Hg, Ni, Pb, Se, Sn, Tl, V, Zn), in accordance with the Italian environmental law (D.Lgs 152/2006), on the base of the trigger and action limits (CSC) for human safety established by this latter. The obtained maps were summed up in the GIS environment in order to get a cumulative map of the potential hazard for the topsoils of Campania region. Considering that environmental risk for the population is strongly influenced by the exposure pathways followed by contaminants to reach the human target, in the case of Campania region we evaluated as relevant pathways both the soil/dust and food ingestion. Furthermore to consider the influence of the land use in the onset of the risk, each land use type was associated with a specific value of a Land Use Risk Coefficient (LURC) which is also dependent on

Appalachian Regional Commission: 1987 Annual Report.

ERIC Educational Resources Information Center

Russell, Jack, Ed.; And Others

The Appalachian Regional Commission (ARC) used its $105 million appropriation for fiscal year 1987 to support three major program areas in the 13 state region: (1) creating and retaining regional jobs; (2) assisting in construction of basic facilities, particularly water and sewer systems, in the region's 90 poorest counties; and (3) working…

Database for the Quaternary and Pliocene Yellowstone Plateau volcanic field of Wyoming, Idaho, and Montana (Database for Professional Paper 729-G)

USGS Publications Warehouse

Koch, Richard D.; Ramsey, David W.; Christiansen, Robert L.

2011-01-01

The superlative hot springs, geysers, and fumarole fields of Yellowstone National Park are vivid reminders of a recent volcanic past. Volcanism on an immense scale largely shaped the unique landscape of central and western Yellowstone Park, and intimately related tectonism and seismicity continue even now. Furthermore, the volcanism that gave rise to Yellowstone's hydrothermal displays was only part of a long history of late Cenozoic eruptions in southern and eastern Idaho, northwestern Wyoming, and southwestern Montana. The late Cenozoic volcanism of Yellowstone National Park, although long believed to have occurred in late Tertiary time, is now known to have been of latest Pliocene and Pleistocene age. The eruptions formed a complex plateau of voluminous rhyolitic ash-flow tuffs and lavas, but basaltic lavas too have erupted intermittently around the margins of the rhyolite plateau. Volcanism almost certainly will recur in the Yellowstone National Park region. This digital release contains all the information used to produce the geologic maps published as plates in U.S. Geological Survey Professional Paper 729-G (Christiansen, 2001). The main component of this digital release is a geologic map database prepared using geographic information systems (GIS) applications. This release also contains files to view or print the geologic maps and main report text from Professional Paper 729-G.

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.

Cool transition region loops observed by the Interface Region Imaging Spectrograph

NASA Astrophysics Data System (ADS)

Huang, Z.; Xia, L.; Li, B.; Madjarska, M. S.

2015-12-01

An important class of loops in the solar atmosphere, cool transition region loops, have received little attention mainly due to instrumental limitations. We analyze a cluster of these loops in the on-disk active region NOAA 11934 recorded in a Si IV 1402.8 Å spectral raster and 1400Å slit-jaw (SJ) images taken by the Interface Region Imaging Spectrograph. We divide these loops into three groups and study their dynamics, evolution and interaction.The first group comprises geometrically relatively stable loops, which are finely scaled with 382~626 km cross-sections. Siphon flows in these loops are suggested by the Doppler velocities gradually changing from -10 km/s (blue-shifts) in one end to 20 km/s (red-shifts) in the other. Nonthermal velocities from 15 to 25 km/s were determined. The obtained physical properties suggest that these loops are impulsively heated by magnetic reconnection occurring at the blue-shifted footpoints where magnetic cancellation with a rate of 1015 Mx/s is found. The released magnetic energy is redistributed by the siphon flows. The second group corresponds to two active footpoints rooted in mixed-magnetic-polarity regions. Magnetic reconnection in both footpoints is suggested by explosive-event line profiles with enhanced wings up to 200 km/s and magnetic cancellation with a rate of ~1015 Mx/s. In the third group, an interaction between two cool loop systems is observed. Mixed-magnetic polarities are seen in their conjunction area where explosive-event line profiles and magnetic cancellation with a rate of 3×1015 Mx/s are found. This is a clear indication that magnetic reconnection occurs between these two loop systems. Our observations suggest that the cool transition region loops are heated impulsively most likely by sequences of magnetic reconnection events.

Cool Transition Region Loops Observed by the Interface Region Imaging Spectrograph

NASA Astrophysics Data System (ADS)

Huang, Zhenghua; Xia, Lidong; Li, Bo; Madjarska, Maria S.

2015-09-01

We report on the first Interface Region Imaging Spectrograph (IRIS) study of cool transition region loops, a class of loops that has received little attention in the literature. A cluster of such loops was observed on the solar disk in active region NOAA11934, in the Si iv 1402.8 Å spectral raster and 1400 Å slit-jaw images. We divide the loops into three groups and study their dynamics. The first group comprises relatively stable loops, with 382-626 km cross-sections. Observed Doppler velocities are suggestive of siphon flows, gradually changing from -10 km s-1 at one end to 20 km s-1 at the other end of the loops. Nonthermal velocities of 15 ˜ 25 km s-1 were determined. Magnetic cancellation with a rate of 1015 Mx s-1 is found at the blueshifted footpoints. These physical properties suggest that these loops are impulsively heated by magnetic reconnection, and the siphon flows play an important role in the energy redistribution. The second group corresponds to two footpoints rooted in mixed-magnetic-polarity regions, where magnetic cancellation with a rate of 1015 Mx s-1 and explosive-event line profiles with enhanced wings of up to 200 km s-1 were observed. In the third group, interaction between two cool loop systems is observed. Evidence for magnetic reconnection between the two loop systems is reflected in the explosive-event line profiles and magnetic cancellation with a rate of 3× {10}15 Mx s-1 observed in the corresponding area. The IRIS has provided opportunity for in-depth investigations of cool transition region loops. Further numerical experiments are crucial for understanding their physics and their roles in the coronal heating processes.

The Southern HII Region Discovery Survey

NASA Astrophysics Data System (ADS)

Wenger, Trey; Miller Dickey, John; Jordan, Christopher; Bania, Thomas M.; Balser, Dana S.; Dawson, Joanne; Anderson, Loren D.; Armentrout, William P.; McClure-Griffiths, Naomi

2016-01-01

HII regions are zones of ionized gas surrounding recently formed high-mass (OB-type) stars. They are among the brightest objects in the sky at radio wavelengths. HII regions provide a useful tool in constraining the Galactic morphological structure, chemical structure, and star formation rate. We describe the Southern HII Region Discovery Survey (SHRDS), an Australia Telescope Compact Array (ATCA) survey that discovered ~80 new HII regions (so far) in the Galactic longitude range 230 degrees to 360 degrees. This project is an extension of the Green Bank Telescope HII Region Discovery Survey (GBT HRDS), Arecibo HRDS, and GBT Widefield Infrared Survey Explorer (WISE) HRDS, which together discovered ~800 new HII regions in the Galactic longitude range -20 degrees to 270 degrees. Similar to those surveys, candidate HII regions were chosen from 20 micron emission (from WISE) coincident with 10 micron (WISE) and 20 cm (SGPS) emission. By using the ATCA to detect radio continuum and radio recombination line emission from a subset of these candidates, we have added to the population of known Galactic HII regions.

Regional Development Planning in the Slovak Republic

NASA Astrophysics Data System (ADS)

Rentková, Katarína

2017-10-01

Regional development is very closely related to a region and its competitive advantages which affect the competitiveness of the region. The regional development is influenced by many factors that act differently depending on the region. To ensure the effective and harmonized regional development, the systematic approach is needed. Every region is unique and differs from the other by the level of economic development, living standards of its inhabitants, unemployment rate and by employment possibilities. Regional policy is a strategic investment policy which focuses on all regions and cities in the European Union. The aim is to boost economic growth and to improve the quality of people’s lives. Solidarity is the main feature of the policy, because policy focuses on support for less developed regions. A fundamental aspect of regional development is to reduce disparities between the regions and cities. The paper focuses on the analysis of regional development of Slovakia. The intention is to follow the logical continuity of the article’s parts, the correctness and the adequacy of information and data. First part is focused on the definition of the regional policy and regional development. Important task is to identify the differences between European policies - regional, structural and cohesion policy. This section is prepared by using the analytical methods - the analysis, the casual and historical analysis. This part is based on literature review. The empirical part is based on statistics and secondary analysis which were aimed to analyse the regional development and effectiveness of its planning in the Slovak Republic. The question of this article is whether it is possible to plan the regional development by application of the plan for economic and social development, called the Municipal Development Plan.

The regional approach and regional studies method in the process of geography teaching

NASA Astrophysics Data System (ADS)

Dermendzhieva, Stela; Doikov, Martin

2017-03-01

We define the regional approach as a manner of relations among the global trends of development of the "Society-man-nature" system and the local differentiating level of knowledge. Conditionally, interactions interlace under the influence of the character of Geography as a science, education, approaches, goals and teaching methods. Global, national and local development differentiates in three concentric circles at the level of knowledge. It is determined as a conception of modern, complex and effective mechanism for young people, through which knowledge develops in regional historical and cultural perspective; self-consciousness for socio-economic and cultural integration is formed as a part of the. historical-geographical image of the native land. This way an attitude to the. native land is formed as a connecting construct between patriotism to the motherland and the same in global aspect. The possibility for integration and cooperation of the educative geographical content with all the local historical-geographical, regional, profession orientating, artistic, municipal and district institutions, is outlined. Contemporary geographical education appears to be a powerful and indispensable mechanism for organization of human sciences, while the regional approach and the application of the regional studies method stimulate and motivate the development and realization of optimal capacities for direct connection with the local structures and environments.

47 CFR 90.1211 - Regional plan.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Regional plan. 90.1211 Section 90.1211... § 90.1211 Regional plan. (a) To facilitate the shared use of the 4.9 GHz band, each region may submit a plan on guidelines to be used for sharing the spectrum within the region. Any such plan must be...

AnnotateGenomicRegions: a web application

PubMed Central

2014-01-01

Background Modern genomic technologies produce large amounts of data that can be mapped to specific regions in the genome. Among the first steps in interpreting the results is annotation of genomic regions with known features such as genes, promoters, CpG islands etc. Several tools have been published to perform this task. However, using these tools often requires a significant amount of bioinformatics skills and/or downloading and installing dedicated software. Results Here we present AnnotateGenomicRegions, a web application that accepts genomic regions as input and outputs a selection of overlapping and/or neighboring genome annotations. Supported organisms include human (hg18, hg19), mouse (mm8, mm9, mm10), zebrafish (danRer7), and Saccharomyces cerevisiae (sacCer2, sacCer3). AnnotateGenomicRegions is accessible online on a public server or can be installed locally. Some frequently used annotations and genomes are embedded in the application while custom annotations may be added by the user. Conclusions The increasing spread of genomic technologies generates the need for a simple-to-use annotation tool for genomic regions that can be used by biologists and bioinformaticians alike. AnnotateGenomicRegions meets this demand. AnnotateGenomicRegions is an open-source web application that can be installed on any personal computer or institute server. AnnotateGenomicRegions is available at: http://cru.genomics.iit.it/AnnotateGenomicRegions. PMID:24564446

Regional Ocean Data Assimilation

NASA Astrophysics Data System (ADS)

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.

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.

Agitated Active Region

NASA Image and Video Library

2016-10-11

An active region just rotating into view gave us a perfect view of the tussle of magnetic field lines above it (Oct. 10-11, 2016). The particles spiraling along the magnetic field lines become visible in extreme ultraviolet light, helping us to see the struggle going on. There were no eruptions during this period, although active regions are usually the source for solar storms. The video clip covers just one day's worth of activity. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA21109

Regional frequency analysis of extreme rainfall for the Baltimore Metropolitan region based on stochastic storm transposition

NASA Astrophysics Data System (ADS)

Zhou, Z.; Smith, J. A.; Yang, L.; Baeck, M. L.; Wright, D.; Liu, S.

2017-12-01

Regional frequency analyses of extreme rainfall are critical for development of engineering hydrometeorology procedures. In conventional approaches, the assumptions that `design storms' have specified time profiles and are uniform in space are commonly applied but often not appropriate, especially over regions with heterogeneous environments (due to topography, water-land boundaries and land surface properties). In this study, we present regional frequency analyses of extreme rainfall for Baltimore study region combining storm catalogs of rainfall fields derived from weather radar and stochastic storm transposition (SST, developed by Wright et al., 2013). The study region is Dead Run, a small (14.3 km2) urban watershed, in the Baltimore Metropolitan region. Our analyses build on previous empirical and modeling studies showing pronounced spatial heterogeneities in rainfall due to the complex terrain, including the Chesapeake Bay to the east, mountainous terrain to the west and urbanization in this region. We expand the original SST approach by applying a multiplier field that accounts for spatial heterogeneities in extreme rainfall. We also characterize the spatial heterogeneities of extreme rainfall distribution through analyses of rainfall fields in the storm catalogs. We examine the characteristics of regional extreme rainfall and derive intensity-duration-frequency (IDF) curves using the SST approach for heterogeneous regions. Our results highlight the significant heterogeneity of extreme rainfall in this region. Estimates of IDF show the advantages of SST in capturing the space-time structure of extreme rainfall. We also illustrate application of SST analyses for flood frequency analyses using a distributed hydrological model. Reference: Wright, D. B., J. A. Smith, G. Villarini, and M. L. Baeck (2013), Estimating the frequency of extreme rainfall using weather radar and stochastic storm transposition, J. Hydrol., 488, 150-165.

Regional collaboration among Urban Area Security Initiative regions: results of the Johns Hopkins urban area survey.

PubMed

Errett, Nicole A; Bowman, Calvin; Barnett, Daniel J; Resnick, Beth A; Frattaroli, Shannon; Rutkow, Lainie

2014-01-01

Regional collaboration has been identified as a potential facilitator of public health preparedness efforts. The Urban Area Security Initiative (UASI) grant program, administered by the Federal Emergency Management Agency (FEMA) since 2003, has provided 64 high-risk metropolitan areas funding to enhance their regional preparedness capabilities. This study describes informal and formal regional collaboration infrastructure, as well as regional collaboration-related activities and assessment methods, in FFY2010 UASI regions. A cross-sectional online survey was administered via Survey Monkey from September through December 2013. Points of contact from FFY2010 funded UASI metropolitan areas completed the survey, with a response rate of 77.8% (n=49). Summary statistics were calculated to describe the current informal and formal regional collaboration infrastructure. Additionally, the cross-sectional survey collected rates of agreement with 8 collaborative preparedness statements at 3 time points. The survey found that UASI regions are engaging in collaborative activities and investments to build capabilities, with most collaboration occurring in the prevention, protection, and response mission areas. Collaborative relationships in preparedness among emergency managers and municipal chief executive officers improved during the FFY2010 UASI performance period compared to the pre-UASI award period, with lasting effects. The majority of UASI regions reported conducting independent assessments of capabilities and their measurement at the UASI region level. Urban areas that received a FFY2010 UASI grant award are engaging in collaborative activities and have established interjurisdictional relationships in preparedness. The use of grant funds to encourage collaboration in preparedness has the potential to leverage limited resources and promote informed investments.

Regional Collaboration Among Urban Area Security Initiative Regions: Results of the Johns Hopkins Urban Area Survey

PubMed Central

Bowman, Calvin; Barnett, Daniel J.; Resnick, Beth A.; Frattaroli, Shannon; Rutkow, Lainie

2014-01-01

Regional collaboration has been identified as a potential facilitator of public health preparedness efforts. The Urban Area Security Initiative (UASI) grant program, administered by the Federal Emergency Management Agency (FEMA) since 2003, has provided 64 high-risk metropolitan areas funding to enhance their regional preparedness capabilities. This study describes informal and formal regional collaboration infrastructure, as well as regional collaboration–related activities and assessment methods, in FFY2010 UASI regions. A cross-sectional online survey was administered via Survey Monkey from September through December 2013. Points of contact from FFY2010 funded UASI metropolitan areas completed the survey, with a response rate of 77.8% (n=49). Summary statistics were calculated to describe the current informal and formal regional collaboration infrastructure. Additionally, the cross-sectional survey collected rates of agreement with 8 collaborative preparedness statements at 3 time points. The survey found that UASI regions are engaging in collaborative activities and investments to build capabilities, with most collaboration occurring in the prevention, protection, and response mission areas. Collaborative relationships in preparedness among emergency managers and municipal chief executive officers improved during the FFY2010 UASI performance period compared to the pre-UASI award period, with lasting effects. The majority of UASI regions reported conducting independent assessments of capabilities and their measurement at the UASI region level. Urban areas that received a FFY2010 UASI grant award are engaging in collaborative activities and have established interjurisdictional relationships in preparedness. The use of grant funds to encourage collaboration in preparedness has the potential to leverage limited resources and promote informed investments. PMID:25398073

Politics, Planning and Regionalism.

ERIC Educational Resources Information Center

Zukosky, Jerome

The concept of regionalism identifies the issues in public affairs pertaining to a region and develops structures through which citizens can participate in the decisionmaking process. This speech describes educational decisions in the State of New York as affected by local decentralization and by concentration of power at the State level. Relevant…

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…

Forest regions of Montana

Treesearch

Stephen F. Arno

1979-01-01

In this paper, Montana is divided into eight geographic subdivisions called "forest regions," based on distributions of tree and undergrowth species and the relationship of these patterns to climate and topography. The regions serve as a geographic reference for describing patterns of forest vegetation across the State. Data on the distributions of plant...

A preliminary regional assessment of earthquake-induced landslide susceptibility for Vrancea Seismic Region

NASA Astrophysics Data System (ADS)

Micu, Mihai; Balteanu, Dan; Ionescu, Constantin; Havenith, Hans; Radulian, Mircea; van Westen, Cees; Damen, Michiel; Jurchescu, Marta

2015-04-01

In seismically-active regions, earthquakes may trigger landslides enhancing the short-to-long term slope denudation and sediment delivery and conditioning the general landscape evolution. Co-seismic slope failures present in general a low frequency - high magnitude pattern which should be addressed accordingly by landslide hazard assessment, with respect to the generally more frequent precipitation-triggered landslides. The Vrancea Seismic Region, corresponding to the curvature sector of the Eastern Romanian Carpathians, represents the most active sub-crustal (focal depth > 50 km) earthquake province of Europe. It represents the main seismic energy source throughout Romania with significant transboundary effects recorded as far as Ukraine and Bulgaria. During the last 300 years, the region featured 14 earthquakes with M>7, among which seven events with magnitude above 7.5 and three between 7.7 and 7.9. Apart from the direct damages, the Vrancea earthquakes are also responsible for causing numerous other geohazards, such as ground fracturing, groundwater level disturbances and possible deep-seated landslide occurrences (rock slumps, rock-block slides, rock falls, rock avalanches). The older deep-seated landslides (assumed to have been) triggered by earthquakes usually affect the entire slope profile. They often formed landslide dams strongly influencing the river morphology and representing potential threats (through flash-floods) in case of lake outburst. Despite the large potential of this research issue, the correlation between the region's seismotectonic context and landslide predisposing factors has not yet been entirely understood. Presently, there is a lack of information provided by the geohazards databases of Vrancea that does not allow us to outline the seismic influence on the triggering of slope failures in this region. We only know that the morphology of numerous large, deep-seated and dormant landslides (which can possibly be reactivated in future

Obesity and Regional Immigrant Density.

PubMed

Emerson, Scott D; Carbert, Nicole S

2017-11-24

Canada has an increasingly large immigrant population. Areas of higher immigrant density, may relate to immigrants' health through reduced acculturation to Western foods, greater access to cultural foods, and/or promotion of salubrious values/practices. It is unclear, however, whether an association exists between Canada-wide regional immigrant density and obesity among immigrants. Thus, we examined whether regional immigrant density was related to obesity, among immigrants. Adult immigrant respondents (n = 15,595) to a national population-level health survey were merged with region-level immigrant density data. Multi-level logistic regression was used to model the odds of obesity associated with increased immigrant density. The prevalence of obesity among the analytic sample was 16%. Increasing regional immigrant density was associated with lower odds of obesity among minority immigrants and long-term white immigrants. Immigrant density at the region-level in Canada may be an important contextual factor to consider when examining obesity among immigrants.

Jumpy Active Region

NASA Image and Video Library

2017-01-03

A close-up view of one day in the life of a rather small active region shows the agitation and dynamism of its magnetic field (Dec. 21, 2016). This wavelength of extreme ultraviolet light reveals particles as they spin along the cascading arches of magnetic field lines above the active region. Some darker plasma rises up and spins around at the edge of the sun near the end of the video clip also being pulled by unseen magnetic forces. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA15032

Regional aquifer systems

NASA Astrophysics Data System (ADS)

The fifth in the American Water Resources Association (AWRA) Monograph series “Regional Aquifer Systems of the United States” has just been published as Monograph Series No. 13, “Aquifers of the Midwestern Area,” edited by L. A. Swain and A. Ivan Johnson. The 238-page publication is available for $18 to AWRA members and $21 for nonmembers.Each AWRA Annual Conference since 1985 has sponsored special seminars describing hydrologic, geochemical, and geologic characteristics of the Regional Aquifer System Analysis (RASA) studies carried out by the U.S. Geological Survey

Far Outer Galaxy H II Regions

NASA Technical Reports Server (NTRS)

Rudolph, A. L.; deGues, E. J.; Brand, J.; Wouterloot, J. G. A.; Gross, Anthony R. (Technical Monitor)

1994-01-01

We have made a multifrequency (6, 3.6, and 2 cm), high-resolution (3"-6"), radio continuum survey of IRAS selected sources from the catalogue of Wouterloot & Brand (1989) to search for and study H II regions in the far outer Galaxy. We identified 31 sources in this catalog with well determined galactocentric distances, and with R approx.. greater than 15 kpc and L(sub FIR) approx.greater than 10(exp 4) solar luminosity, indicating the presence of high-mass star-formation. We have observed 11 of these sources with the Very Large Array (VLA). We observed the sources at 6 and 2 cm using "scaled arrays", making possible a direct and reliable comparison of the data at these two wavelengths for the determination of spectral indices. We detected a total of 12 radio sources, of which 10 have spectral indices consistent with optically-thin free-free emission from H II regions. Combined with previous VLA observations by other investigators, we have data on a total of 15 H II regions at galactocentric distances of 15 to 18.2kpc, among the most remote H II regions found in our Galaxy. The sizes of the H II regions range from approx. less than 0.10 to 2.3 pc. Using the measured fluxes and sizes, we determine the electron densities, emission measures, and excitation parameters of the H II regions, as well as the fluxes of Lyman continuum photons needed to keep the nebulae ionized. The sizes and electron densities are consistent with most of the sources detected in this survey being compact or ultracompact H II regions. Seven of the fifteen H II regions have sizes approx. less than 0.20 pc. Assuming simple pressure-driven expansion of the H II regions, these sizes indicate ages approx. less than 5 x 10(exp 4) yr, or only 1% of the lifetime of an O star, which implies an unlikely overabundance of O stars in the outer Galaxy. Thus, the large number of compact H II regions suggests that the time these regions spend in a compact phase must be much longer than their dynamical

About EPA's Offices of Regional Counsel

EPA Pesticide Factsheets

Information about the U.S. EPA Offices of Regional Counsel (ORCs), which are located within each EPA Regional office and provide day-to-day support to each Region and Headquarters for all general legal matters.

The Evolution of Active Regions

NASA Astrophysics Data System (ADS)

Green, Lucie

2016-10-01

The solar corona is a highly dynamic environment which exhibits the largest releases of energy in the Solar System in the form of solar flares and coronal mass ejections. This activity predominantly originates from active regions, which store and release free magnetic energy and dominate the magnetic face of the Sun. Active regions can be long-lived features, being affected by the Sun's convective flows, differential rotation and meridional flows. The Sun's global coronal field can be seen as the superposed growth and subsequent diffusion of all previously formed active regions. This talk will look at active regions as an observable product of the solar dynamo and will discuss the physical processes that are at play which lead to the storage and release of free magnetic energy. What happens to flux that emerges into the corona so that it goes down an evolutionary path that leads to dynamic activity? And how does this activity vary with active region age? When an active region reaches the end of its lifetime, his much of the magnetic flux is recycled back into subsequent solar cycles? The current status of observations and modelling will be reviewed with a look to the future and fundamental questions that are still be be answered.

23 CFR 940.9 - Regional ITS architecture.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Architecture shall be used as a resource in the development of the regional ITS architecture. The regional ITS... 23 Highways 1 2010-04-01 2010-04-01 false Regional ITS architecture. 940.9 Section 940.9 Highways... INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS § 940.9 Regional ITS architecture. (a) A regional...

ON THE ACTIVE REGION BRIGHT GRAINS OBSERVED IN THE TRANSITION REGION IMAGING CHANNELS OF IRIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skogsrud, H.; Voort, L. Rouppe van der; Pontieu, B. De

The Interface Region Imaging Spectrograph (IRIS) provides spectroscopy and narrow band slit-jaw (SJI) imaging of the solar chromosphere and transition region at unprecedented spatial and temporal resolutions. Combined with high-resolution context spectral imaging of the photosphere and chromosphere as provided by the Swedish 1 m Solar Telescope (SST), we can now effectively trace dynamic phenomena through large parts of the solar atmosphere in both space and time. IRIS SJI 1400 images from active regions, which primarily sample the transition region with the Si iv 1394 and 1403 Å lines, reveal ubiquitous bright “grains” which are short-lived (two to five minute)more » bright roundish small patches of sizes 0.″5–1.″7 that generally move limbward with velocities up to about 30 km s{sup −1}. In this paper, we show that many bright grains are the result of chromospheric shocks impacting the transition region. These shocks are associated with dynamic fibrils (DFs), most commonly observed in Hα. We find that the grains show the strongest emission in the ascending phase of the DF, that the emission is strongest toward the top of the DF, and that the grains correspond to a blueshift and broadening of the Si iv lines. We note that the SJI 1400 grains can also be observed in the SJI 1330 channel which is dominated by C ii lines. Our observations show that a significant part of the active region transition region dynamics is driven from the chromosphere below rather than from coronal activity above. We conclude that the shocks that drive DFs also play an important role in the heating of the upper chromosphere and lower transition region.« less

Evaluation of regional climate simulations over the Great Lakes region driven by three global data sets

Treesearch

Shiyuan Zhong; Xiuping Li; Xindi Bian; Warren E. Heilman; L. Ruby Leung; William I. Jr. Gustafson

2012-01-01

The performance of regional climate simulations is evaluated for the Great Lakes region. Three 10-year (1990-1999) current-climate simulations are performed using the MM5 regional climate model (RCM) with 36-km horizontal resolution. The simulations employed identical configuration and physical parameterizations, but different lateral boundary conditions and sea-...

Geophysical Evidence for the Locations, Shapes and Sizes, and Internal Structures of Magma Chambers beneath Regions of Quaternary Volcanism

NASA Astrophysics Data System (ADS)

Iyer, H. M.

1984-04-01

delineating magma chambers with minimum horizontal and vertical dimensions of about 6 km. This technique has been used successfully to detect low-velocity anomalies, interpreted as magma bodies in the volume range 103-106 km3, in several volcanic centres in the U.S.A. and in Mt Etna, Sicily. Velocity models developed using teleseismic residuals of the Cascades volcanoes of Oregon and California, and Kilauea volcano, Hawaii, do not show appreciable storage of magma in the crust. However, regional models imply that large volumes of parental magma may be present in the upper mantle of these regions. In some volcanic centres, teleseismic delays are accompanied by P-wave attenuation, and linear inversion of spectral data have enabled computation of three-dimensional Q-models for these areas. The use of gravity data for magma chamber studies is illustrated by a study in the Geysers-Clear Lake volcanic field in California, where a strong gravity low has been modelled as a low-density body in the upper crust. This body is approximately in the same location as the low-velocity body delineated with teleseismic delays, and is interpreted as a magma body. In Yellowstone National Park, magnetic field data have been used to map the depth to the Curie isotherm, and the results show that high temperatures may be present at shallow depths beneath the Yellowstone caldera. The main application of electrical techniques in magma-related studies has been to understand the deep structure of continental rifts. Electromagnetic studies in several rift zones of the world provide constraints on the thermal structure and magma storage beneath these regions. Geophysical tools commonly used in resource exploration and earth-structure studies are also suited for the detection of magma chambers. Active seismic techniques, with controlled sources, and passive seismic techniques, with local and regional earthquakes and teleseisms, can be used to detect the drastic changes in velocity and attenuation that occur

Regional Diversity and Diversification in Mammals.

PubMed

Machac, Antonin; Graham, Catherine H

2017-01-01

The effects of regional diversity on diversification remain controversial. The classic hypothesis that diversification decelerates as regional diversity increases has been recently revived. Yet, there is little geographic evidence for slower diversification across regions of high diversity, and diversity is often thought to promote diversification through its effects on ecological divergence and speciation. Here, we use the newest phylogeny for mammals (4,990 species) and two different methods to test the effects of regional diversity on diversification. We find that regions of high diversity are dominated by expanding clades that are far from their estimated carrying capacities. Regions of low diversity host clades that are small and mostly saturated. These results were supported across mammals and their six largest orders. They were corroborated by the two methods when controlling for clade relatedness, clade nestedness, and clade size. Together, these results reject the hypothesis that high geographic concentration of mammals effectively suppresses their further diversification. Instead, highly diverse regions (especially the tropics) seem to act as the engine of mammalian richness.

Petroleum exploration plays and resource estimates, 1989, onshore United States; Region 1, Alaska; Region 2, Pacific Coast

USGS Publications Warehouse

Powers, Richard B.

1993-01-01

This study provides brief discussions of the petroleum geology, play descriptions, and resource estimates of 220 individually assessed exploration plays in all 80 onshore geologic provinces within nine assessment regions of the continental United States in 1989; these 80 onshore provinces were assessed in connection with the determination of the Nation's estimated undiscovered resources of oil and gas. The present report covers the 25 provinces that make up Region 1, Alaska, and Region 2, Pacific Coast. It is our intention to issue Region 3, Colorado Plateau and Basin and Range, and Region 4, Rocky Mountains and Northern Great Plains, in book form as well. Regions 5 through 9 (West Texas and Eastern New Mexico, Gulf Coast, Midcontinent, Eastern Interior and Atlantic Coast) will be released individually, as Open-File Reports.

Region Evolution eXplorer - A tool for discovering evolution trends in ontology regions.

PubMed

Christen, Victor; Hartung, Michael; Groß, Anika

2015-01-01

A large number of life science ontologies has been developed to support different application scenarios such as gene annotation or functional analysis. The continuous accumulation of new insights and knowledge affects specific portions in ontologies and thus leads to their adaptation. Therefore, it is valuable to study which ontology parts have been extensively modified or remained unchanged. Users can monitor the evolution of an ontology to improve its further development or apply the knowledge in their applications. Here we present REX (Region Evolution eXplorer) a web-based system for exploring the evolution of ontology parts (regions). REX provides an analysis platform for currently about 1,000 versions of 16 well-known life science ontologies. Interactive workflows allow an explorative analysis of changing ontology regions and can be used to study evolution trends for long-term periods. REX is a web application providing an interactive and user-friendly interface to identify (un)stable regions in large life science ontologies. It is available at http://www.izbi.de/rex.

Acoustic holograms of active regions

NASA Astrophysics Data System (ADS)

Chou, Dean-Yi

2008-10-01

We propose a method to study solar magnetic regions in the solar interior with the principle of optical holography. A magnetic region in the solar interior scatters the solar background acoustic waves. The scattered waves and background waves could form an interference pattern on the solar surface. We investigate the feasibility of detecting this interference pattern on the solar surface, and using it to construct the three-dimensional scattered wave from the magnetic region with the principle of optical holography. In solar acoustic holography, the background acoustic waves play the role of reference wave; the magnetic region plays the role of the target object; the interference pattern, acoustic power map, on the solar surface plays the role of the hologram.

Regional Reliability of Quantitative Signal Targeting with Alternating Radiofrequency (STAR) Labeling of Arterial Regions (QUASAR)

PubMed Central

Tatewaki, Yasuko; Higano, Shuichi; Taki, Yasuyuki; Thyreau, Benjamin; Murata, Takaki; Mugikura, Shunji; Ito, Daisuke; Takase, Kei; Takahashi, Shoki

2014-01-01

BACKGROUND AND PURPOSE Quantitative signal targeting with alternating radiofrequency labeling of arterial regions (QUASAR) is a recent spin labeling technique that could improve the reliability of brain perfusion measurements. Although it is considered reliable for measuring gray matter as a whole, it has never been evaluated regionally. Here we assessed this regional reliability. METHODS Using a 3-Tesla Philips Achieva whole-body system, we scanned four times 10 healthy volunteers, in two sessions 2 weeks apart, to obtain QUASAR images. We computed perfusion images and ran a voxel-based analysis within all brain structures. We also calculated mean regional cerebral blood flow (rCBF) within regions of interest configured for each arterial territory distribution. RESULTS The mean CBF over whole gray matter was 37.74 with intraclass correlation coefficient (ICC) of .70. In white matter, it was 13.94 with an ICC of .30. Voxel-wise ICC and coefficient-of-variation maps showed relatively lower reliability in watershed areas and white matter especially in deeper white matter. The absolute mean rCBF values were consistent with the ones reported from PET, as was the relatively low variability in different feeding arteries. CONCLUSIONS Thus, QUASAR reliability for regional perfusion is high within gray matter, but uncertain within white matter. PMID:25370338

Assistance Focus: Asia/Pacific Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

The Clean Energy Solutions Center, an initiative of the Clean Energy Ministerial, helps countries throughout the world create policies and programs that advance the deployment of clean energy technologies. Through the Solutions Center's no-cost 'Ask an Expert' service, a team of international experts has delivered assistance to countries in all regions of the world, including nearly 30 countries in the Asia/Pacific region. This document highlights a few examples of the Solutions Center's work in the region.

Veneto Region, Italy. Health system review.

PubMed

Toniolo, Franco; Mantoan, Domenico; Maresso, Anna

2012-01-01

The Health Systems in Transition (HiT) profiles are country-based reports that provide a detailed description of a health system and of policy initiatives in progress or under development. This HiT is one of the first to be written on a subnational level of government and focuses on the Veneto Region of northern Italy. HiTs examine different approaches to the organization, financing and delivery of health services and the role of the main actors in health systems; describe the institutional framework, process, content and implementation of health and health care policies; and highlight challenges and areas that require more in-depth analysis. The Veneto Region is one of Italy's richest regions and the health of its resident population compares favourably with other regions in Italy. Life expectancy for both men and women, now at 79.1 and 85.2 years, respectively, is slightly higher than the national average, while mortality rates are comparable to national ones. The major causes of death are tumours and cardiovascular diseases. Under Italy's National Health Service, the organization and provision of health care is a regional responsibility and regions must provide a nationally defined (with regional input) basic health benefit package to all of their citizens; extra services may be provided if budgets allow. Health care is mainly financed by earmarked central and regional taxes, with regions receiving their allocated share of resources from the National Health Fund. Historically, health budget deficits have been a major problem in most Italian regions, but since the early 2000s the introduction of efficiency measures and tighter procedures on financial management have contributed to a significant decrease in the Veneto Regions health budget deficit.The health system is governed by the Veneto Region government (Giunta) via the Departments of Health and Social Services, which receive technical support from a single General Management Secretariat. Health care is

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.

Introduction - regional monitoring programs

Treesearch

Richard L. Hutto; C. John Ralph

2005-01-01

There is increasing interest in the initiation of regional or statewide monitoring programs that are less extensive than national efforts such as the Breeding Bird Survey. A number of regional programs have been in existence for a decade or more, so the papers in this section represented an effort to bring together the collective experience of the people who had...

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

NASA Astrophysics Data System (ADS)

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

2015-12-01

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

Evaluation of the evolving stress field of the Yellowstone volcanic plateau, 1988 to 2010, from earthquake first-motion inversions

NASA Astrophysics Data System (ADS)

Russo, E.; Waite, G. P.; Tibaldi, A.

2017-03-01

Although the last rhyolite eruption occurred around 70 ka ago, the silicic Yellowstone volcanic field is still considered active due to high hydrothermal and seismic activity and possible recent magma intrusions. Geodetic measurements document complex deformation patterns in crustal strain and seismic activity likewise reveal spatial and temporal variations in the stress field. We use earthquake data recorded between 1988 and 2010 to investigate these variations and their possible causes in more detail. Earthquake relocations and a set of 369 well-constrained, double-couple, focal mechanism solutions were computed. Events were grouped according to location and time to investigate trends in faulting. The majority of the events have normal-faulting solutions, subordinate strike-slip kinematics, and very rarely, reverse motions. The dominant direction of extension throughout the 0.64 Ma Yellowstone caldera is nearly ENE, consistent with the perpendicular direction of alignments of volcanic vents within the caldera, but our study also reveals spatial and temporal variations. Stress-field solutions for different areas and time periods were calculated from earthquake focal mechanism inversion. A well-resolved rotation of σ3 was found, from NNE-SSW near the Hebgen Lake fault zone, to ENE-WSW near Norris Junction. In particular, the σ3 direction changed throughout the years around Norris Geyser Basin, from being ENE-WSW, as calculated in the study by Waite and Smith (2004), to NNE-SSW, while the other σ3 directions are mostly unchanged over time. The presence of ;chocolate tablet; structures, with two sets of nearly perpendicular normal faults, was identified in many stages of the deformation history both in the Norris Geyser Basin area and inside the caldera.

[Nitrogen flow in Huizhou region].

PubMed

Ma, Xiaobo; Wang, Zhaoyin; Koenig, Albert; Deng, Jiaquan

2006-06-01

Eutrophication is a serious problem of water body pollution. By the method of material flow accounting, this paper studied the human activities- related nitrogen flow in the system of environment and anthroposphere in Huizhou region. The non-point source pollution was quantified by export coefficient method, and the domestic discharge was estimated by demand-supply method. The statistic and dynamic analyses based on the investigation data of 1998 showed that the major nitrogen flows in this region were river loads, fertilizer and feedstuff imports, atmospheric deposition, animal excretes' degradation and volatilization, and the processes relating to burning and other emissions. In 1998, about 40% of nitrogen was detained in the system, which could be accumulated and yield potential environmental problems. The nitrogen export in this region was mainly by rivers, accounted for about 57%. A comparison of Huizhou region with the Danube and Changjiang basins showed that the unit area nitrogen exports in these three regions were of the same magnitude, and the per capita nitrogen exports were comparable.

2011 Bayou Regional

NASA Image and Video Library

2011-03-19

Students from 38 high school teams in seven states competed for top honors during the 2011 FIRST (For Inspiration and Recognition of Science and Technology) Robotics Bayou Regional competition held March 17-19 in the New Orleans area. In this photo, members of the robotics team from Gulfport High School guide their robot during the annual tournament. The robotics competition is designed to help encourage students to pursue studies and careers in the areas of science, technology, engineering and mathematics. John C. Stennis Space Center is a supporter of FIRST activities and the Bayou Regional tournament.

Mainshock-aftershock clustering in volcanic regions

USGS Publications Warehouse

Giron, Ricardo Garza; Brodsky, Emily E.; Prejean, Stephanie

2018-01-01

swarms and mainshock-aftershock sequences. The former is commonly thought to dominate in volcanic and geothermal regions, but aftershock production, including within swarms, is not well studied in volcanic regions. Here we compare mainshock-aftershock clustering in active volcanic regions in Japan to nearby nonvolcanic regions. We find that aftershock production is similar in both areas by two separate metrics: (1) Both volcanic and nonvolcanic regions have similar proportions of areas that cluster into mainshock-aftershock sequences. (2) Volcanic areas with mainshock-aftershock sequences have aftershock productivity at least as high as nonvolcanic regions. We also find that volcano-tectonic events that are precursors to an eruption are more common at volcanoes without mainshock-aftershock clusters than at volcanoes with well-defined mainshock-aftershock clusters. This last finding hints at a strategy to identify volcanic systems where cataloged earthquakes are good predictors of behavior.

Open magnetic fields in active regions

NASA Technical Reports Server (NTRS)

Svestka, Z.; Solodyna, C. V.; Howard, R.; Levine, R. H.

1977-01-01

Soft X-ray images and magnetograms of several active regions and coronal holes are examined which support the interpretation that some of the dark X-ray gaps seen between interconnecting loops and inner cores of active regions are foot points of open field lines inside the active regions. Characteristics of the investigated dark gaps are summarized. All the active regions with dark X-ray gaps at the proper place and with the correct polarity predicted by global potential extrapolation of photospheric magnetic fields are shown to be old active regions, indicating that field opening is accomplished only in a late phase of active-region development. It is noted that some of the observed dark gaps probably have nothing in common with open fields, but are either due to the decreased temperature in low-lying portions of interconnecting loops or are the roots of higher and less dense or cooler loops.

Diamagnetic region(s): structure of the unmagnetized plasma around Comet 67P/CG

NASA Astrophysics Data System (ADS)

Henri, P.; Vallières, X.; Hajra, R.; Goetz, C.; Richter, I.; Glassmeier, K.-H.; Galand, M.; Rubin, M.; Eriksson, A. I.; Nemeth, Z.; Vigren, E.; Beth, A.; Burch, J. L.; Carr, C.; Nilsson, H.; Tsurutani, B.; Wattieaux, G.

2017-07-01

The ESA's comet chaser Rosetta has monitored the evolution of the ionized atmosphere of comet 67P/Churyumov-Gerasimenko (67P/CG) and its interaction with the solar wind, during more than 2 yr. Around perihelion, while the cometary outgassing rate was highest, Rosetta crossed hundreds of unmagnetized regions, but did not seem to have crossed a large-scale diamagnetic cavity as anticipated. Using in situ Rosetta observations, we characterize the structure of the unmagnetized plasma found around comet 67P/CG. Plasma density measurements from RPC-MIP are analysed in the unmagnetized regions identified with RPC-MAG. The plasma observations are discussed in the context of the cometary escaping neutral atmosphere, observed by ROSINA/COPS. The plasma density in the different diamagnetic regions crossed by Rosetta ranges from ˜100 to ˜1500 cm-3. They exhibit a remarkably systematic behaviour that essentially depends on the comet activity and the cometary ionosphere expansion. An effective total ionization frequency is obtained from in situ observations during the high outgassing activity phase of comet 67P/CG. Although several diamagnetic regions have been crossed over a large range of distances to the comet nucleus (from 50 to 400 km) and to the Sun (1.25-2.4 au), in situ observations give strong evidence for a single diamagnetic region, located close to the electron exobase. Moreover, the observations are consistent with an unstable contact surface that can locally extend up to about 10 times the electron exobase.

Revisiting Health Regionalization in Canada.

PubMed

Barker, Paul; Church, John

2017-04-01

Twenty years ago, many of Canada's provinces began to introduce regional health authorities to address problems with their health care systems. With this action, the provinces sought to achieve advances in community decision-making, the integration of health services, and the provision of care in the home and community. The authorities were also to help restrict health care costs. An assessment of the authorities indicates, however, that over the past two decades they have been unable to meet their objectives. Community representatives continue to play little role in determining the appropriate health services for their regions. Gains have been made towards integrating health services, but the plan for a near seamless set of health services has not been realized. Funding for health services remains focused on hospital and physician care, and health care expenditures have until very recently been little affected by regional authorities. This disappointing performance has caused some provinces to abandon their regional authorities, but this article argues that the provision of greater autonomy and a better public appreciation of their role and potential may lead to more successful regional authorities. Accordingly, the objective of this article is to reveal the shortcomings of regional health authorities in Canada while at the same time arguing that changes can be made to increase the chances of more workable authorities.

Photospheric electric current and transition region brightness within an active region

NASA Technical Reports Server (NTRS)

Deloach, A. C.; Hagyard, M. J.; Rabin, D.; Moore, R. L.; Smith, B. J., Jr.; West, E. A.; Tandberg-Hanssen, E.

1984-01-01

Distributions of vertical electrical current density J(z) calculated from vector measurements of the photospheric magnetic field are compared with ultraviolet spectroheliograms to investigate whether resistive heating is an important source of enhanced emission in the transition region. The photospheric magnetic fields in Active Region 2372 were measured on April 6 and 7, 1980 with the Marshall Space Flight Center vector magnetograph; ultraviolet wavelength spectroheliograms (L-alpha and N V 1239 A) were obtained with the UV Spectrometer and Polarimeter experiment aboard the Solar Maximum Mission satellite. Spatial registration of the J(z) (5 arcsec resolution) and UV (3 arcsec resolution) maps indicates that the maximum current density is cospatial with a minor but persistent UV enhancement, but there is little detected current associated with other nearby bright areas. It is concluded that, although resistive heating may be important in the transition region, the currents responsible for the heating are largely unresolved in the present measurements and have no simple correlation with the residual current measured on 5-arcsec scales.

Regional Climate Modeling over the Marmara Region, Turkey, with Improved Land Cover Data

NASA Astrophysics Data System (ADS)

Sertel, E.; Robock, A.

2007-12-01

Land surface controls the partitioning of available energy at the surface between sensible and latent heat,and controls partitioning of available water between evaporation and runoff. Current land cover data available within the regional climate models such as Regional Atmospheric Modeling System (RAMS), the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) and Weather Research and Forecasting (WRF) was obtained from 1- km Advanced Very High Resolution Radiometer satellite images spanning April 1992 through March 1993 with an unsupervised classification technique. These data are not up-to-date and are not accurate for all regions and some land cover types such as urban areas. Here we introduce new, up-to-date and accurate land cover data for the Marmara Region, Turkey derived from Landsat Enhanced Thematic Mapper images into the WRF regional climate model. We used several image processing techniques to create accurate land cover data from Landsat images obtained between 2001 and 2005. First, all images were atmospherically and radiometrically corrected to minimize contamination effects of atmospheric particles and systematic errors. Then, geometric correction was performed for each image to eliminate geometric distortions and define images in a common coordinate system. Finally, unsupervised and supervised classification techniques were utilized to form the most accurate land cover data yet for the study area. Accuracy assessments of the classifications were performed using error matrix and kappa statistics to find the best classification results. Maximum likelihood classification method gave the most accurate results over the study area. We compared the new land cover data with the default WRF land cover data. WRF land cover data cannot represent urban areas in the cities of Istanbul, Izmit, and Bursa. As an example, both original satellite images and new land cover data showed the expansion of urban areas into the Istanbul metropolitan area, but in the WRF

23 CFR 940.9 - Regional ITS architecture.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION INTELLIGENT TRANSPORTATION SYSTEMS INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS § 940.9 Regional ITS architecture. (a) A regional... ITS project for that region advancing to final design. (d) The regional ITS architecture shall include...

23 CFR 940.9 - Regional ITS architecture.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION INTELLIGENT TRANSPORTATION SYSTEMS INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS § 940.9 Regional ITS architecture. (a) A regional... ITS project for that region advancing to final design. (d) The regional ITS architecture shall include...

23 CFR 940.9 - Regional ITS architecture.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION INTELLIGENT TRANSPORTATION SYSTEMS INTELLIGENT TRANSPORTATION SYSTEM ARCHITECTURE AND STANDARDS § 940.9 Regional ITS architecture. (a) A regional... ITS project for that region advancing to final design. (d) The regional ITS architecture shall include...

Region 6 Targeted Brownfields Assessment

EPA Pesticide Factsheets

A Target Brownfields Assessment (TBA) is a free service the EPA Region 6 Brownfields Team provides to communities to support their eligible brownfields projects. Region 6 consists of Arkansas, Louisiana, new Mexico, Oklahoma, and Texas.

Region 7 Air Program Reviews

EPA Pesticide Factsheets

Region 7 Air Program Reviews To ensure that our oversight responsibilities are met, Region 7 conducts at least one program review each year at a state or local agency in Iowa, Kansas, Missouri or Nebraska.

Mainshock-Aftershock Clustering in Volcanic Regions

NASA Astrophysics Data System (ADS)

Garza-Giron, Ricardo; Brodsky, Emily E.; Prejean, Stephanie G.

2018-02-01

Earthquakes break their general Poissonean behavior through two types of seismic bursts: swarms and mainshock-aftershock sequences. The former is commonly thought to dominate in volcanic and geothermal regions, but aftershock production, including within swarms, is not well studied in volcanic regions. Here we compare mainshock-aftershock clustering in active volcanic regions in Japan to nearby nonvolcanic regions. We find that aftershock production is similar in both areas by two separate metrics: (1) Both volcanic and nonvolcanic regions have similar proportions of areas that cluster into mainshock-aftershock sequences. (2) Volcanic areas with mainshock-aftershock sequences have aftershock productivity at least as high as nonvolcanic regions. We also find that volcano-tectonic events that are precursors to an eruption are more common at volcanoes without mainshock-aftershock clusters than at volcanoes with well-defined mainshock-aftershock clusters. This last finding hints at a strategy to identify volcanic systems where cataloged earthquakes are good predictors of behavior.

The Regional Structure of Technical Innovation

NASA Astrophysics Data System (ADS)

O'Neale, Dion

2014-03-01

There is strong evidence that the productivity per capita of cities and regions increases with population. One likely explanation for this phenomenon is that densely populated regions bring together otherwise unlikely combinations of individuals and organisations with diverse, specialised capabilities, leading to increased innovation and productivity. We have used the REGPAT patent database to construct a bipartite network of geographic regions and the patent classes for which those regions display a revealed comparative advantage. By analysing this network, we can infer relationships between different types of patent classes - and hence the structure of (patentable) technology. The network also provides a novel perspective for studying the combinations of technical capabilities in different geographic regions. We investigate measures such as the diversity and ubiquity of innovations within regions and find that diversity (resp. ubiquity) is positively (resp. negatively) correlated with population. We also find evidence of a nested structure for technical innovation. That is, specialised innovations tend to occur only when other more general innovations are already present.

Comets, Asteroids, and the Origin of the Biosphere

NASA Technical Reports Server (NTRS)

Hoover, Richard B.

2006-01-01

During the past few decades, the role of comets in the delivery of water, organics, and prebiotic chemicals to the Biosphere of Earth during the Hadean (4.5-3.8 Ga) period of heavy bombardment has become more widely accepted. However comets are still largely regarded as frigid, pristine bodies of protosolar nebula material that are entirely devoid of liquid water and consequently unsuitable for life in any form. Complex organic compounds have been observed comets and on the water rich asteroid 1998 KY26, which has color and radar reflectivity similar to the carbonaceous meteorites. Near infrared observations have indicated the presence of crystalline water ice and ammonia hydrate on the large Kuiper Belt object (50000) Quaoar with resurfacing that may indicate cryovolcanic outgassing and the Cassini spacecraft has detected water-ice geysers on Saturn s moon Enceladus. Spacecraft observations of the chemical compositions and characteristics of the nuclei of several comets (Halley, Borrelly, Wild 2, and Tempel 1) have now firmly established that comets contain a suite of complex organic chemicals; water is the predominant volatile; and that extremely high temperatures (approx.350-400 K) can be reached on the surface of the very black (albedo-0.03) nuclei when the comets are with 1.5 AU from the Sun. Impact craters and pinnacles observed on comet Wild 2 suggest a thick crust and episodic outbursts and jets observed on the nuclei of several comets are interpreted as indications that localized regimes of liquid water and water vapor can periodically exist beneath the crust of some comets. The Deep Impact observations indicate that the temperature on the nucleus of of comet Tempel 1 at 1.5 AU varied from 330K on the sunlit side to a minimum of 280+/-8 K. It is interesting that even the coldest region of the comet surface was slightly above the ice/liquid water phase transition temperature. These results suggest that pools and films of liquid water can exist in a wide

Regional reliability of quantitative signal targeting with alternating radiofrequency (STAR) labeling of arterial regions (QUASAR).

PubMed

Tatewaki, Yasuko; Higano, Shuichi; Taki, Yasuyuki; Thyreau, Benjamin; Murata, Takaki; Mugikura, Shunji; Ito, Daisuke; Takase, Kei; Takahashi, Shoki

2014-01-01

Quantitative signal targeting with alternating radiofrequency labeling of arterial regions (QUASAR) is a recent spin labeling technique that could improve the reliability of brain perfusion measurements. Although it is considered reliable for measuring gray matter as a whole, it has never been evaluated regionally. Here we assessed this regional reliability. Using a 3-Tesla Philips Achieva whole-body system, we scanned four times 10 healthy volunteers, in two sessions 2 weeks apart, to obtain QUASAR images. We computed perfusion images and ran a voxel-based analysis within all brain structures. We also calculated mean regional cerebral blood flow (rCBF) within regions of interest configured for each arterial territory distribution. The mean CBF over whole gray matter was 37.74 with intraclass correlation coefficient (ICC) of .70. In white matter, it was 13.94 with an ICC of .30. Voxel-wise ICC and coefficient-of-variation maps showed relatively lower reliability in watershed areas and white matter especially in deeper white matter. The absolute mean rCBF values were consistent with the ones reported from PET, as was the relatively low variability in different feeding arteries. Thus, QUASAR reliability for regional perfusion is high within gray matter, but uncertain within white matter. © 2014 The Authors. Journal of Neuroimaging published by the American Society of Neuroimaging.

U.S. Regional Deterrence Strategies

DTIC Science & Technology

1995-01-01

MOTIVATIONS OF REGIONAL ADVERSARIES ............................. 27 Regime Types ................................. 27 Domestic Political Instability...32 Historical Cases Illustrating the influence of Domestic Politics .................................. 36 China, 1950... Political Constraints ............................. 86 Military Constraints ............. II................89 Deterrence in U.S. Regional Strategy

MOVES regional level sensitivity analysis

DOT National Transportation Integrated Search

2012-01-01

The MOVES Regional Level Sensitivity Analysis was conducted to increase understanding of the operations of the MOVES Model in regional emissions analysis and to highlight the following: : the relative sensitivity of selected MOVES Model input paramet...

NV PFA Regional Data

DOE Data Explorer

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.

Doug Benevento, Regional Administrator for EPA's Mountains & Plains (Region 8)

EPA Pesticide Factsheets

The Region 8 administrator oversees the implementation and enforcement of the federal environmental rules and regulations in the states of Colorado, Montana, North Dakota, South Dakota, Utah and Wyoming.

The transition from hydrostatic to greater than hydrostatic fluid pressure in presently active continental hydrothermal systems in crystalline rock

USGS Publications Warehouse

Fournier, R.O.

1991-01-01

Pore-fluid pressure (Pf) > Ph has been encountered at the bottom of 3 geothermal exploration wells that attained temperatures > 370??C (at Larderello, Italy, at Nesjavellir, Iceland, and at The Geysers, California). Chemical sealing by deposition of minerals in veins appears to have allowed the development of the high Pf encountered in the above wells. The upper limit for the magnitude of Pf that can be attained is controlled by either the onset of shear fracturing (where differential stress is relatively high) that reopens clogged veins, or the hydraulic opening of new or old fractures (at relatively low values of differential stress). -from Author

Press abstracts of the 21st Lunar and Planetary Science Conference

NASA Technical Reports Server (NTRS)

1990-01-01

The Program Committee for the Twenty-fisrt Lunar and Planetary Science Conference has chosen these contributions as having the greatest potential interest for the general public. The papers in this collection were written for general presentation, avoiding jargon and unnecessarily complex terms. More technical abstracts will be found in Lunar and Planetary Science XXI. Representative titles are: Ancient Ocean-Land-Atmosphere Interactions on Mars: Global Model and Geological Evidence; Oxygen Isotopic Compositions of Ordinary Chondrites and Their Chondrules; Exposure Ages and Collisional History of L-Chondrite Parent Bodies; Models of Solar-Powered Geysers on Triton; and Search for Life: A Science Rationale for a Permanent Base on Mars.

HYDROTHERMAL MINERALOGY OF RESEARCH DRILL HOLE Y-3, YELLOWSTONE NATIONAL PARK, WYOMING.

USGS Publications Warehouse

Bargar, Keith E.; Beeson, Melvin H.

1984-01-01

The approximate paragenetic sequence of hydrothermal minerals in the Y-3 U. S. Geological Survey research diamond-drill hole in Lower Geyser Basin, Yellowstone National Park, Wyoming, is: hydrothermal chalcedony, hematite, pyrite, quartz, clay minerals (smectite and mixed-layer illite-smectite), calcite, chlorite, fluorite, pyrite, quartz, zeolite minerals (analcime, dachiardite, laumontite, stilbite, and yugawaralite), and clay minerals (smectite and mixed-layer illite-smectite). A few hydrothermal minerals that were identified in drill core Y-3 (lepidolite, aegirine, pectolite, and truscottite) are rarely found in modern geothermal areas. The alteration minerals occur primarily as vug and fracture fillings that were deposited from cooling thermal water. Refs.

Triton's streaks as windblown dust

NASA Technical Reports Server (NTRS)

Sagan, Carl; Chyba, Christopher

1990-01-01

Explanations for the surface streaks observed by Voyager 2 on Triton's southern hemisphere are discussed. It is shown that, despite Triton's tenuous atmosphere, low-cohesion dust trains with diameters of about 5 micron or less may be carried into suspension by aeolian surface shear stress, given expected geostrophic wind speeds of about 10 m/s. For geyser-like erupting dust plumes, it is shown that dust-settling time scales and expected wind velocities can produce streaks with length scales in good agreement with those of the streaks. Thus, both geyserlike eruptions or direct lifting by surface winds appear to be viable mechanisms for the origin of the streaks.

Central Atlantic regional ecological test site

NASA Technical Reports Server (NTRS)

Alexander, R. H.

1972-01-01

The work of the Central Atlantic Regional Ecological Test Site (CARETS) project is discussed. The primary aim of CARETS is to test the hypothesis that data from ERTS-A can be made an integral part of a regional land resources information system, encompassing both inventory of the resource base and monitoring of changes, along with their effects on the quality of the environment. Another objective of the project is to determine scaling factors for developing land use information and regional analysis for regions of any given size.

Modeling the Impacts of Global Climate and Regional Land Use Change on Regional Climate, Air Quality and Public Health in the New York Metropolitan Region

NASA Astrophysics Data System (ADS)

Rosenthal, J. E.; Knowlton, K. M.; Kinney, P. L.

2002-12-01

There is an imminent need to downscale the global climate models used by international consortiums like the IPCC (Intergovernmental Panel on Climate Change) to predict the future regional impacts of climate change. To meet this need, a "place-based" climate model that makes specific regional projections about future environmental conditions local inhabitants could face is being created by the Mailman School of Public Health at Columbia University, in collaboration with other researchers and universities, for New York City and the 31 surrounding counties. This presentation describes the design and initial results of this modeling study, aimed at simulating the effects of global climate change and regional land use change on climate and air quality over the northeastern United States in order to project the associated public health impacts in the region. Heat waves and elevated concentrations of ozone and fine particles are significant current public health stressors in the New York metropolitan area. The New York Climate and Health Project is linking human dimension and natural sciences models to assess the potential for future public health impacts from heat stress and air quality, and yield improved tools for assessing climate change impacts. The model will be applied to the NY metropolitan east coast region. The following questions will be addressed: 1. What changes in the frequency and severity of extreme heat events are likely to occur over the next 80 years due to a range of possible scenarios of land use and land cover (LU/LC) and climate change in the region? 2. How might the frequency and severity of episodic concentrations of ozone (O3) and airborne particulate matter smaller than 2.5 æm in diameter (PM2.5) change over the next 80 years due to a range of possible scenarios of land use and climate change in the metropolitan region? 3. What is the range of possible human health impacts of these changes in the region? 4. How might projected future human

Experiences from regional public funding agencies

PubMed Central

Alonso-Trujillo, Federico

2009-01-01

Introduction There is an increasing demand of social and health services by persons with long-term care (LTC) needs. On the other hand the devolution process has shifted governance and funding to regional agencies in many EU countries. Regional agencies are getting an increasing role in funding LTC. Knowledge transfer (KT) plays a key role in the development of regional funding agencies, as they should cooperate with both local and national agencies as well as several European organisations and companies operating in their regions. The communication barriers between social and health services play a particular role at regional level. Description of care or policy practice In Spain the 17 regions have full government autonomy in health and social care. These regions have developed different approaches to coordination of care and KT. Andalusia is the larger region in Spain. In order to coordinate provision and planning, the regional government has developed a network of cross-sectional agencies in specific areas such as Mental Health (FAISEM), Social Services in Ageing, Disabilities, Poverty and TICs (FASS), Emergency care (EPES), care related to gender (Instituto Andaluz de la Mujer), Health Care for the Elderly in the community (Living Lab and IAVANTE Foundation) or innovation in new technologies applied to social care (I2BC); among several others. A number of these public organisations are privately run. Discussion Coordination and links across these organisations as well as funding issues are discussed here. The relationship or coordination agencies with citizens and other stakeholders deserve special attention as well. Andalusia provides an interesting case of cross-sectorial coordination within the European context.

Regional Climate Simulation with a Variable Resolution Stretched Grid GCM: The Regional Down-Scaling Effects

NASA Technical Reports Server (NTRS)

Fox-Rabinovitz, Michael S.; Takacs, Lawrence L.; Suarez, Max; Sawyer, William; Govindaraju, Ravi C.

1999-01-01

The results obtained with the variable resolution stretched grid (SG) GEOS GCM (Goddard Earth Observing System General Circulation Models) are discussed, with the emphasis on the regional down-scaling effects and their dependence on the stretched grid design and parameters. A variable resolution SG-GCM and SG-DAS using a global stretched grid with fine resolution over an area of interest, is a viable new approach to REGIONAL and subregional CLIMATE studies and applications. The stretched grid approach is an ideal tool for representing regional to global scale interactions. It is an alternative to the widely used nested grid approach introduced a decade ago as a pioneering step in regional climate modeling. The GEOS SG-GCM is used for simulations of the anomalous U.S. climate events of 1988 drought and 1993 flood, with enhanced regional resolution. The height low level jet, precipitation and other diagnostic patterns are successfully simulated and show the efficient down-scaling over the area of interest the U.S. An imitation of the nested grid approach is performed using the developed SG-DAS (Data Assimilation System) that incorporates the SG-GCM. The SG-DAS is run with withholding data over the area of interest. The design immitates the nested grid framework with boundary conditions provided from analyses. No boundary condition buffer is needed for the case due to the global domain of integration used for the SG-GCM and SG-DAS. The experiments based on the newly developed versions of the GEOS SG-GCM and SG-DAS, with finer 0.5 degree (and higher) regional resolution, are briefly discussed. The major aspects of parallelization of the SG-GCM code are outlined. The KEY OBJECTIVES of the study are: 1) obtaining an efficient DOWN-SCALING over the area of interest with fine and very fine resolution; 2) providing CONSISTENT interactions between regional and global scales including the consistent representation of regional ENERGY and WATER BALANCES; 3) providing a high

Verbal Working Memory Performance Correlates with Regional White Matter Structures in the Frontoparietal Regions

ERIC Educational Resources Information Center

Takeuchi, Hikaru; Taki, Yasuyuki; Sassa, Yuko; Hashizume, Hiroshi; Sekiguchi, Atsushi; Fukushima, Ai; Kawashima, Ryuta

2011-01-01

Working memory is the limited capacity storage system involved in the maintenance and manipulation of information over short periods of time. Previous imaging studies have suggested that the frontoparietal regions are activated during working memory tasks; a putative association between the structure of the frontoparietal regions and working…

28 CFR 44.305 - Regional offices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Regional offices. 44.305 Section 44.305... Enforcement Procedures § 44.305 Regional offices. The Special Counsel, in consultation with the Attorney General, shall establish such regional offices as may be necessary to carry out his or her duties. ...

10 CFR 1.47 - NRC Regional Offices.

Code of Federal Regulations, 2010 CFR

2010-01-01

... NRC Regional Offices. Each Regional Administrator executes established NRC policies and assigned... 10 Energy 1 2010-01-01 2010-01-01 false NRC Regional Offices. 1.47 Section 1.47 Energy NUCLEAR... response within Regional boundaries set out in § 1.5(b) of this part. ...

10 CFR 1.47 - NRC Regional Offices.

Code of Federal Regulations, 2011 CFR

2011-01-01

... NRC Regional Offices. Each Regional Administrator executes established NRC policies and assigned... 10 Energy 1 2011-01-01 2011-01-01 false NRC Regional Offices. 1.47 Section 1.47 Energy NUCLEAR... response within Regional boundaries set out in § 1.5(b) of this part. ...

7 CFR 3570.93 - Regional Commission grants.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Appalachian Regional Commission (ARC) is authorized under the Appalachian Regional Development Act of 1965 to... 7 Agriculture 15 2010-01-01 2010-01-01 false Regional Commission grants. 3570.93 Section 3570.93... AGRICULTURE COMMUNITY PROGRAMS Community Facilities Grant Program § 3570.93 Regional Commission grants. (a...

Identifying robust regional precipitation responses to regional aerosol emissions perturbations in three coupled chemistry-climate models

NASA Astrophysics Data System (ADS)

Westervelt, D. M.; Fiore, A. M.; Lamarque, J. F.; Previdi, M. J.; Conley, A. J.; Shindell, D. T.; Mascioli, N. R.; Correa, G. J. P.; Faluvegi, G.; Horowitz, L. W.

2017-12-01

Regional emissions of anthropogenic aerosols and their precursors will likely decrease for the remainder of the 21st century, due to emission reduction policies enacted to protect human health. Although there is some evidence that regional climate effects of aerosols can be significant, we currently lack a robust understanding of the magnitude, spatio-temporal pattern, statistical significance, and physical processes responsible for these influences, especially for precipitation. Here, we aim to quantify systematically the precipitation response to regional changes in aerosols and investigate underlying mechanisms using three fully coupled chemistry-climate models: NOAA Geophysical Fluid Dynamics Laboratory Coupled Model 3 (GFDL-CM3), NCAR Community Earth System Model (CESM), and NASA Goddard Institute for Space Studies ModelE2 (GISS-E2). The central approach we use is to contrast a long control experiment (400 years, run with perpetual year 2000 emissions) with 14 individual aerosol emissions perturbation experiments ( 200 years each). We perturb emissions of sulfur dioxide (SO2) and carbonaceous aerosol (BC and OM) within several world regions and assess which responses are significant relative to internal variability determined by the control run and robust across the three models. Initial results show significant changes in precipitation in several vulnerable regions including the Western Sahel and the Indian subcontinent. SO2 emissions reductions from Europe and the United States have the largest impact on precipitation among most of the selected response regions. The precipitation response to emissions changes from these regions projects onto known modes of variability, such as the North Atlantic Oscillation (NAO) and the El Niño Southern Oscillation (ENSO). Across all perturbation experiments, we find a strong linear relationship between the responses of Sahel precipitation and the interhemispheric temperature difference, suggesting a common mechanism of an

Appalachian Regional Commission. Annual Report 1969.

ERIC Educational Resources Information Center

Appalachian Regional Commission, Washington, DC.

After 4 years of operation, the Appalachian Regional Commission (ARC) presents this 1969 annual report and evaluation of its activities as required by the Appalachian Regional Development Act of 1965. A brief overview is given of the history of the program, the Federal-state relationship, and strategies for regional development. Appalachia is then…

Intern Perceptions of Dialect and Regionalism

ERIC Educational Resources Information Center

O'Hara, Hunter

2005-01-01

Interns at The University of Tampa investigate how perceptions of dialect and regionalism may impact the learning environment and more precisely, the learner. Regionalism is defined as a belief that one's region of origin is a primary determinant of the quality of one's standards of living, social forms, customary beliefs, levels of…

Regional Profiles of Higher Education. Guide.

ERIC Educational Resources Information Center

Higher Education Funding Council for England, Bristol.

The Higher Education Funding Council for England (HEFCE) presents its second edition of its regional profiles of higher education. The document presents a range of information about higher education in England's nine government regions. The aim of the report is to assist stakeholders in debating the regional role of higher education, and to…

CPC - Monitoring & Data: Regional Climate Maps

Science.gov Websites

Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Site Map News Information CPC Web Team HOME > Monitoring and Data > Global Climate Data & Maps > Global Regional Climate Maps Regional Climate Maps Banner The Monthly regional analyses products are usually

17 CFR 200.27 - The Regional Directors.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false The Regional Directors. 200.27... § 200.27 The Regional Directors. Each Regional Director is responsible for executing the Commission's... matters, by the Deputy Director of the Division of Enforcement who is responsible for Regional Office...

78 FR 35149 - Addresses of Regional Offices

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-12

..., and Texas), 500 Gold Avenue SW., Room 9018 (P.O. Box 1306), Albuquerque, New Mexico 87102. (c) Midwest... 01035. (f) Mountain-Prairie Regional Office (Region 6--comprising the States of Colorado, Kansas...), Lakewood, Colorado 80228. (g) Alaska Regional Office (Region 7--comprising the State of Alaska), 1011 E...

Regional Climate Change Hotspots over Africa

NASA Astrophysics Data System (ADS)

Anber, U.

2009-04-01

Regional Climate Change Index (RCCI), is developed based on regional mean precipitation change, mean surface air temperature change, and change in precipitation and temperature interannual variability. The RCCI is a comparative index designed to identify the most responsive regions to climate change, or Hot- Spots. The RCCI is calculated for Seven land regions over North Africa and Arabian region from the latest set of climate change projections by 14 global climates for the A1B, A2 and B1 IPCC emission scenarios. The concept of climate change can be approaches from the viewpoint of vulnerability or from that of climate response. In the former case a Hot-Spot can be defined as a region for which potential climate change impacts on the environment or different activity sectors can be particularly pronounced. In the other case, a Hot-Spot can be defined as a region whose climate is especially responsive to global change. In particular, the characterization of climate change response-based Hot-Spot can provide key information to identify and investigate climate change Hot-Spots based on results from multi-model ensemble of climate change simulations performed by modeling groups from around the world as contributions to the Assessment Report of Intergovernmental Panel on Climate Change (IPCC). A Regional Climate Change Index (RCCI) is defined based on four variables: change in regional mean surface air temperature relative to the global average temperature change ( or Regional Warming Amplification Factor, RWAF ), change in mean regional precipitation ( , of present day value ), change in regional surface air temperature interannual variability ( ,of present day value), change in regional precipitation interannual variability ( , of present day value ). In the definition of the RCCI it is important to include quantities other than mean change because often mean changes are not the only important factors for specific impacts. We thus also include inter annual

Searching regional rainfall homogeneity using atmospheric fields

NASA Astrophysics Data System (ADS)

Gabriele, Salvatore; Chiaravalloti, Francesco

2013-03-01

The correct identification of homogeneous areas in regional rainfall frequency analysis is fundamental to ensure the best selection of the probability distribution and the regional model which produce low bias and low root mean square error of quantiles estimation. In an attempt at rainfall spatial homogeneity, the paper explores a new approach that is based on meteo-climatic information. The results are verified ex-post using standard homogeneity tests applied to the annual maximum daily rainfall series. The first step of the proposed procedure selects two different types of homogeneous large regions: convective macro-regions, which contain high values of the Convective Available Potential Energy index, normally associated with convective rainfall events, and stratiform macro-regions, which are characterized by low values of the Q vector Divergence index, associated with dynamic instability and stratiform precipitation. These macro-regions are identified using Hot Spot Analysis to emphasize clusters of extreme values of the indexes. In the second step, inside each identified macro-region, homogeneous sub-regions are found using kriging interpolation on the mean direction of the Vertically Integrated Moisture Flux. To check the proposed procedure, two detailed examples of homogeneous sub-regions are examined.

7 CFR 1780.48 - Regional commission grants.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 12 2010-01-01 2010-01-01 false Regional commission grants. 1780.48 Section 1780.48... Regional commission grants. Grants are sometimes made by regional commissions for projects eligible for RUS...) When RUS has funds in the project, no charge will be made for administering regional commission funds...

Appalachian Regional Commission: 1985 Annual Report.

ERIC Educational Resources Information Center

Appalachian Regional Commission, Washington, DC.

In the third year of its finish-up program, the Appalachian Regional Commission (ARC) used its area development appropriation of $44 million to target three broad areas: (1) creating and retaining jobs in the region; (2) providing basic public facilities in the worst-off Appalachian counties; and (3) improving health care throughout the region.…

Melt segregation from partially molten source regions - The importance of melt density and source region size

NASA Technical Reports Server (NTRS)

Stolper, E.; Hager, B. H.; Walker, D.; Hays, J. F.

1981-01-01

An investigation is conducted regarding the changes expected in the density contrast between basic melts and peridotites with increasing pressure using the limited data available on the compressibilities of silicate melts and data on the densities of mantle minerals. It is concluded that since compressibilities of silicate melts are about an order of magnitude greater than those of mantle minerals, the density contrast between basic melts and mantle minerals must diminish significantly with increasing pressure. An earlier analysis regarding the migration of liquid in partially molten source regions conducted by Walker et al. (1978) is extended, giving particular attention to the influence of the diminished density contrast between melt and residual crystals with increasing source region depth and to the influence of source region size. This analysis leads to several generalizations concerning the factors influencing the depths at which magmas will segregate from their source regions and the degrees of partial melting that can be achieved in these source regions before melt segregation occurs.

MISR Regional SAMUM 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 version used in support of the SAMUM Campaign. More information about the Level 1 and Level 2 products subsetted for the SAMUM ...

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 version used in support of the VBBE Campaign. More information about the Level 1 and Level 2 products subsetted for the VBBE ...

Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Midwest Region

DTIC Science & Technology

2008-09-01

supplement is applicable to the Midwest Region, which consists of all or portions of 14 states: Illinois, Indiana , Iowa, Kansas, Kentucky, Michigan...southern ends of present-day Lakes Michigan ERDC/EL TR-08-27 13 and Erie along the northern fringe of the Midwest Region in Illinois, Indiana , and...season. Multi-year droughts can also change the composition of plant communities over longer periods (Barkley 1986). Woody shrubs and trees in

East and central farming and forest region and Atlantic basin diversified farming region: LRRs N and S

Treesearch

Brad D. Lee; John M. Kabrick

2017-01-01

The central, unglaciated US east of the Great Plains to the Atlantic coast corresponds to the area covered by LRR N (East and Central Farming and Forest Region) and S (Atlantic Basin Diversified Farming Region). These regions roughly correspond to the Interior Highlands, Interior Plains, Appalachian Highlands, and the Northern Coastal Plains.