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.

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

Mechanics of Old Faithful Geyser, Calistoga, CA

USGS Publications Warehouse

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

2012-01-01

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

Mechanics of Old Faithful Geyser, Calistoga, California

NASA Astrophysics Data System (ADS)

Rudolph, M. L.; Manga, M.; Hurwitz, S.; Johnston, M.; Karlstrom, L.; Wang, C.-Y.

2012-12-01

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

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

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.

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…

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.

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.

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

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.

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.

Geysers from the Tiger Stripes of Enceladus

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2015-10-01

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

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.

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.

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

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

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.

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

The Indonesian Lusi eruption has been spewing boiling water, gas, and sediments since the 29th of May 2006. Initially, numerous aligned eruptions sites appeared along the Watukosek fault system that was reactivated after the Yogyakarta earthquake occurring the 27th of May in the Java Island. Since its birth Lusi erupted with a pulsating behavior showing intermittent periods of stronger activity resulting in higher fluids and solid emissions intervals. Since 2010 two active vents are constantly active. We conducted detailed monitoring of such clastic geysering activity and this allowed us to distinguish four distinct phases that follow each other and that reoccur every 30 minutes: (1) regular bubbling activity (constant emission of water, mud breccia, and gas); (2) clastic geysering phase with intense bubbling (consisting in reduced vapor emission and more powerful diffused mud bursting); (3) clastic geysering with mud bursts and intense vapour discharge (typically dense plume that propagates up to 100 m in height); (4) quiescent phase marking the end of the geysering activity (basically no gas emissions or bursts observed). In order to better understand this pulsating behavior and to constrain the mechanisms controlling its activity, we designed a multidisciplinary monitoring of the eruption site combining the deployment of numerous instruments around the crater site. Processing of the collected data reveals the dynamic activity of Lusi's craters. Satellite images show that the location of these vents migrated along a NE-SW direction. This is subparallel to the direction of the Watukosek fault system that is the zone of (left) lateral deformation upon which Lusi developed in 2006. Coupling HR camera images with broadband and short period seismic stations allowed us to describe the seismic signal generated by clastic geysering and to constrain the depth of the source generating the signal. We measure a delay between the seismic (harmonic) record and the associated

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.

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

"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"

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.

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.

Phreatic eruptions and deformation of Ioto Island (Iwo-jima), Japan, triggered by deep magma injection

NASA Astrophysics Data System (ADS)

Ueda, Hideki; Nagai, Masashi; Tanada, Toshikazu

2018-03-01

On Ioto Island (Iwo-jima), 44 phreatic eruptions have been recorded since 1889, when people began to settle there. Four of these eruptions, after the beginning of continuous observation by seismometers in 1976, were accompanied by intense seismic activity and rapid crustal deformation beforehand. Other eruptions on Ioto were without obvious crustal activities. In this paper, we discuss the mechanisms of phreatic eruptions on Ioto. Regular geodetic surveys and continuous GNSS observations show that Ioto intermittently uplifts at an abnormally high rate. All of the four eruptions accompanied by the precursors took place during intermittent uplifts. The crustal deformation before and after one of these eruptions revealed that a sill-like deformation source in the shallow part of Motoyama rapidly inflated before and deflated after the beginning of the eruption. From the results of a seismic array and a borehole survey, it is estimated that there is a layer of lava at a depth of about 100-200 m, and there is a tuff layer about 200-500 m beneath it. The eruptions accompanied by the precursors probably occurred due to abrupt boiling of hot water in hydrothermal reservoirs in the tuff layer, sealed by the lava layer and triggered by intermittent uplift. For the eruptions without precursors, the hydrothermal systems are weakly sealed by clay or probably occurred on the same principle as a geyser because phreatic eruptions had occurred beforehand and hydrostatic pressure is applied to the hydrothermal reservoirs.

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.

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

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

view across all technical fields, as related to The Geysers steam-dominated geothermal system. The Geysers has seen many fundamental changes between 1990-2010 and yet the geothermal resource seems still to be robust to the extent that, long after its anticipated life span, we are seeing new geothermal projects being developed on the north and west peripheries of the field. It is hoped that this report provides a focused data source particularly for those just starting their geothermal careers, as well as those who have been involved in the interesting and challenging field of geothermal energy for many years. Despite many hurdles The Geysers has continued to generate electrical power for 50 years and its sustainability has exceeded many early researchers expectations. It also seems probable that, with the new projects described above, generation will continue for many years to come. The success of The Geysers is due to the technical skills and the financial acumen of many people, not only over the period covered by this report (1990-2010), but since the first kilowatt of power was generated in 1960. This Special Report celebrates those 50 years of geothermal development at The Geysers and attempts to document the activities that have brought success to the project so that a permanent record can be maintained. It is strongly hoped and believed that a publication similar to this one will be necessary in another 20 years to document further activities in the field.« less

Active Volcanic Eruptions on Io

NASA Technical Reports Server (NTRS)

1996-01-01

Six views of the volcanic plume named Prometheus, as seen against Io's disk and near the bright limb (edge) of the satellite by the SSI camera on the Galileo spacecraft during its second (G2) orbit of Jupiter. North is to the top of each frame. To the south-southeast of Prometheus is another bright spot that appears to be an active plume erupting from a feature named Culann Patera. Prometheus was active 17 years ago during both Voyager flybys, but no activity was detected by Voyager at Culann. Both of these plumes were seen to glow in the dark in an eclipse image acquired by the imaging camera during Galileo's first (G1) orbit, and hot spots at these locations were detected by Galileo's Near-Infrared Mapping Spectrometer.

The plumes are thought to be driven by heating sulfur dioxide in Io's subsurface into an expanding fluid or 'geyser'. The long-lived nature of these eruptions requires that a substantial supply of sulfur dioxide must be available in Io's subsurface, similar to groundwater. Sulfur dioxide gas condenses into small particles of 'snow' in the expanding plume, and the small particles scatter light and appear bright at short wavelengths. The images shown here were acquired through the shortest-wavelength filter (violet) of the Galileo camera. Prometheus is about 300 km wide and 75 km high and Culann is about 150 km wide and less than 50 km high. The images were acquired on September 4, 1996 at a range of 2,000,000 km (20 km/pixel resolution). Prometheus is named after the Greek fire god and Culann is named after the Celtic smith god.

The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the

Landslide Buries Valley of the Geysers

NASA Technical Reports Server (NTRS)

2007-01-01

Geysers are a rare natural phenomena found only in a few places, such as New Zealand, Iceland, the United States (Yellowstone National Park), and on Russia's far eastern Kamchatka Peninsula. On June 3, 2007, one of these rare geyser fields was severely damaged when a landslide rolled through Russia's Valley of the Geysers. The landslide--a mix of mud, melting snow, trees, and boulders--tore a scar on the land and buried a number of geysers, thermal pools, and waterfalls in the valley. It also blocked the Geyser River, causing a new thermal lake to pool upstream. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this infrared-enhanced image on June 11, 2007, a week after the slide. The image shows the valley, the landslide, and the new thermal lake. Even in mid-June, just days from the start of summer, the landscape is generally covered in snow, though the geologically heated valley is relatively snow free. The tree-covered hills are red (the color of vegetation in this false-color treatment), providing a strong contrast to the aquamarine water and the gray-brown slide. According to the Russian News and Information Agency (RIA) [English language], the slide left a path roughly a kilometer and a half (one mile) long and 200 meters (600 feet) wide. Within hours of the landslide, the water in the new lake inundated a number of additional geysers. The geysers directly buried under the landslide now lie under as much as 60 meters (180 feet) of material, according to RIA reports. It is unlikely that the geysers will be able to force a new opening through this thick layer, adds RIA. Among those directly buried is Pervenets (Firstborn), the first geyser found in the valley, in 1941. Other geysers, such as the Bolshoi (Greater) and Maly (Lesser) Geysers, were silenced when buried by water building up behind the new natural dam. According to Vladimir and Andrei Leonov of the Russian Federation Institute of

Clonal expansion of Epstein-Barr virus (EBV)-infected γδ T cells in patients with chronic active EBV disease and hydroa vacciniforme-like eruptions.

PubMed

Wada, Taizo; Toga, Akiko; Sakakibara, Yasuhisa; Toma, Tomoko; Hasegawa, Minoru; Takehara, Kazuhiko; Shigemura, Tomonari; Agematsu, Kazunaga; Yachie, Akihiro

2012-10-01

Chronic active Epstein-Barr virus (EBV) disease (CAEBV) is a systemic EBV-positive lymphoproliferative disorder characterized by fever, lymphadenopathy, and splenomegaly. Patients with CAEBV may present with cutaneous symptoms, including hypersensitivity to mosquito bites and hydroa vacciniforme (HV)-like eruptions. HV is a rare photodermatosis characterized by vesicles and crust formation after exposure to sunlight, with onset in childhood, and is associated with latent EBV infection. While γδ T cells have recently been demonstrated to be the major EBV-infected cell population in HV, the immunophenotypic features of EBV-infected γδ T cells in CAEBV with HV-like eruptions or HV remain largely undetermined. We describe three patients with CAEBV whose γδ T cells were found to be the major cellular target of EBV. HV-like eruptions were observed in two of these patients. A clonally expanded subpopulation of γδ T cells that were highly activated and T cell receptor Vγ9- and Vδ2-positive cells was demonstrated in all patients. We also show that the clonally expanded γδ T cells infiltrated into the HV-like eruptions in one patient from whom skin biopsy specimens were available. These results suggest the pathogenic roles of clonally expanded γδ T cells infected by EBV in patients with CAEBV and HV-like eruptions.

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.

Design Study for a Mars Geyser Hopper

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Microgravity Geyser and Flow Field Prediction

NASA Technical Reports Server (NTRS)

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

2006-01-01

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

Multi-wavelength and High-resolution Observations of Solar Eruptive Activities

NASA Astrophysics Data System (ADS)

Shen, Y. D.

2014-09-01

jet. The latter is associated with a simultaneous bubble-like and a jet-like CME. It is found that the jet-like CME is driven by the reconnection between the closed field and the ambient open field, while the bubble-like CME is associated with the mini-filament confined by the closed field. In Chapter 7, a quasi-periodic fast propagating (QFP) magnetosonic wave and the associated flare are studied. It is found that the wave and the flare have the same periods, suggesting their common origin. In addition, the leakage of photospheric p-mode oscillation to the corona is also an important source of QFP waves. Large-scale coronal waves are studied in Chapters 8 and 9. It is found that coronal waves can be observed in the low solar atmosphere like the top of the photosphere. Based on the analysis, we propose that large-scale coronal waves are fast magnetosonic or shock waves, which are driven by the expanding flanks of the associated CMEs. A short summary and unsolved problems are given in Chapter 10. Along with the fast development of many new solar telescopes, high quality observations will certainly help us to reveal the true physics behind various solar eruptive activities.

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

meteorological conditions. Soil temperature is measured near Vixen Geyser. The system will permit land managers, scientists and the public to keep track of changes to the hydrothermal system, including geyser eruptions, periodic basin-wide disturbances, or fluid-release events that may accompany or follow seismic activity.

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.

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.

Microgravity Propellant Tank Geyser Analysis and Prediction

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

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

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

The Plumbing System Feeding the Lusi Eruption Revealed by Ambient Noise Tomography

NASA Astrophysics Data System (ADS)

Fallahi, Mohammad Javad; Obermann, Anne; Lupi, Matteo; Karyono, Karyono; Mazzini, Adriano

2017-10-01

Lusi is a sediment-hosted hydrothermal system featuring clastic-dominated geyser-like eruption behavior in East Java, Indonesia. We use 10 months of ambient seismic noise cross correlations from 30 temporary seismic stations to obtain a 3-D model of shear wave velocity anomalies beneath Lusi, the neighboring Arjuno-Welirang volcanic complex, and the Watukosek fault system connecting the two. Our work reveals a hydrothermal plume, rooted at a minimum 6 km depth that reaches the surface at the Lusi site. Furthermore, the inversion shows that this vertical anomaly is connected to the adjacent volcanic complex through a narrow ( 3 km wide) low velocity corridor slicing the survey area at a depth of 4-6 km. The NE-SW direction of this elongated zone matches the strike of the Watukosek fault system. Distinct magmatic chambers are also inferred below the active volcanoes. The large-scale tomography features an exceptional example of a subsurface connection between a volcanic complex and a solitary erupting hydrothermal system hosted in a hydrocarbon-rich back-arc sedimentary basin. These results are consistent with a scenario where deep-seated fluids (e.g., magmas and released hydrothermal fluids) flow along a region of enhanced transmissivity (i.e., the Watukosek fault system damage zone) from the volcanic arc toward the back arc basin where Lusi resides. The triggered metamorphic reactions occurring at depth in the organic-rich sediments generated significant overpressure and fluid upwelling that is today released at the spectacular Lusi eruption site.

Analyses of Etna Eruptive Activity From 18th Century and Characterization of Flank Eruptions

NASA Astrophysics Data System (ADS)

del Carlo, P.; Branca, S.; Coltelli, M.

2003-12-01

Etna explosive activity has usually been considered subordinate with respect to the effusive eruptions. Nevertheless, in the last decade and overall after the 2001 and 2002 flank eruptions, explosive activity has drawn the attention of the scientific and politic communities owing to the damages that the long-lasting ash fall caused to Sicily's economy. We analyzed the eruptions from the 18th century to find some analogous behavior of Etna in the past. A study of the Etna historical record (Branca and Del Carlo, 2003) evidenced that after the 1727 eruption, there are no more errors in the attribution of the year of the eruption. Furthermore from this time on, the scientific quality of the chronicles allowed us to obtain volcanological information and to estimate the magnitude of the major explosive events. The main goal of this work was to characterize the different typologies of Etna eruptions in the last three centuries. Meanwhile, we have tried to find the possible relationship between the two kinds of activity (explosive and effusive) in order to understand the complexity of the eruptive phenomena and define the short-term behavior of Etna. On the base of the predominance of the eruptive typology (effusive or explosive) we have classified the flank eruptions in three classes: i) Type 1: almost purely effusive; ii) Type 2: the intensity of explosive activity comparable with the effusive; iii) Type 3: almost purely explosive with minor lava effusion (only the 1763 La Montagnola and 2002 eruptions belong to this class). Long-lasting explosive activity is produced by flank eruptions with continuous ash emission and prolonged fallout on the flanks (e.g. 1763, 1811, 1852-53, 1886, 1892, 2001 and 2002 eruptions). At summit craters continuous activity is weaker, whereas the strongest explosive eruptions are short-lived events. Furthermore, from the 18th to 20th century there were several years of intense and discontinuous summit explosive activity, from high strombolian

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.

Fluoride toothpaste: a cause of acne-like eruptions

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

Saunders, M.A. Jr.

1976-04-01

The author described closed comedonal or papular acne in about 65 adult females, aged 20 to 40, in a slightly fan-like distribution on the corner of the mouth and the chin and the proximal area of the cheeks. All patients had had extensive dermatological treatment including dietary control, tetracycline special washing agents, etc. The localization of the lesions suggested to the author that some kind of chemical carried in the saliva might be draining in the areas and in the follicles of the skin and induce this process. In view of the fact that erythematous eruptions resembling acne have beenmore » described following application of fluoridated steroids and after exposure to industrial halogram fumes the author suggested that his patients switch to a nonfluoridated toothpaste. In approximately one half of the patients, the lesions cleared within two to four weeks. When the remaining patients were asked to switch from their dentrifice containing brightening and other unknown chemicals, to baking soda and a commercially available mouthwash, nearly all those treated improved considerably; in most of them the acne-like eruptions cleared up completely. Several patients were concerned about their dental health and resumed the use of fluoride toothpaste; they promptly developed the same distribution of the acne-like eruption that had previously been present.« 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.

Io - Volcanic Eruption

NASA Technical Reports Server (NTRS)

1979-01-01

This photo of a volcanic eruption on Jupiter's satellite Io (dark fountain-like feature near the limb) was taken March 4, 1979, about 12 hours before Voyager 1's closest approach to Jupiter. This and the accompanying photo present the evidence for the first active volcanic eruption ever observed on another body in the solar system. This photo taken from a distance of 310,000 miles (499,000 kilometers), shows a plume-like structure rising more than 60 miles (100 kilometers) above the surface, a cloud of material being produced by an active eruption. At least four eruptions have been identified on Voyager 1 pictures and many more may yet be discovered on closer analysis. On a nearly airless body like Io, particulate material thrown out of a volcano follows a ballistic trajectory, accounting for the dome-like shape of the top of the cloud, formed as particles reach the top of their flight path and begin to fall back. Spherical expansion of outflowing gas forms an even larger cloud surrounding the dust. Several regions have been identified by the infrared instrument on Voyager 1 as being several hundred degrees Fahrenheit warmer than surrounding terrain, and correlated with the eruptions. The fact that several eruptions appear to be going on simultaneously makes Io the most active surface in the solar system and suggests to scientists that Io is undergoing continuous volcanism, revising downward the age of Io's surface once again. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

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

Temperature and Structure of Active Eruptions from a Handheld Camcorder

NASA Astrophysics Data System (ADS)

Radebaugh, Jani; Carling, Greg T.; Saito, Takeshi; Dangerfield, Anne; Tingey, David G.; Lorenz, Ralph D.; Lopes, Rosaly M.; Howell, Robert R.; Diniega, Serina; Turtle, Elizabeth P.

2014-11-01

A commercial handheld digital camcorder can operate as a high-resolution, short-wavelength, low-cost thermal imaging system for monitoring active volcanoes, when calibrated against a laboratory heated rock of similar composition to the given eruptive material. We utilize this system to find full pixel brightness temperatures on centimeter scales at close but safe proximity to active lava flows. With it, observed temperatures of a Kilauea tube flow exposed in a skylight reached 1200 C, compared with pyrometer measurements of the same flow of 1165 C, both similar to reported eruption temperatures at that volcano. The lava lake at Erta Ale, Ethiopia had crack and fountain temperatures of 1175 C compared with previous pyrometer measurements of 1165 C. Temperature calibration of the vigorously active Marum lava lake in Vanuatu is underway, challenges being excessive levels of gas and distance from the eruption (300 m). Other aspects of the fine-scale structure of the eruptions are visible in the high-resolution temperature maps, such as flow banding within tubes, the thermal gradient away from cracks in lake surfaces, heat pathways through pahoehoe crust and temperature zoning in spatter and fountains. High-resolution measurements such as these reveal details of temperature, structure, and change over time at the rapidly evolving settings of active lava flows. These measurement capabilities are desirable for future instruments exploring bodies with active eruptions like Io, Enceladus and possibly Venus.

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.

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.

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.

MINIFILAMENT ERUPTIONS THAT DRIVE CORONAL JETS IN A SOLAR ACTIVE REGION

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

Sterling, Alphonse C.; Moore, Ronald L.; Falconer, David A.

We present observations of eruptive events in an active region adjacent to an on-disk coronal hole on 2012 June 30, primarily using data from the Solar Dynamics Observatory ( SDO )/Atmospheric Imaging Assembly (AIA), SDO /Helioseismic and Magnetic Imager (HMI), and STEREO - B . One eruption is of a large-scale (∼100″) filament that is typical of other eruptions, showing slow-rise onset followed by a faster-rise motion starting as flare emissions begin. It also shows an “EUV crinkle” emission pattern, resulting from magnetic reconnections between the exploding filament-carrying field and surrounding field. Many EUV jets, some of which are surges,more » sprays and/or X-ray jets, also occur in localized areas of the active region. We examine in detail two relatively energetic ones, accompanied by GOES M1 and C1 flares, and a weaker one without a GOES signature. All three jets resulted from small-scale (∼20″) filament eruptions consistent with a slow rise followed by a fast rise occurring with flare-like jet-bright-point brightenings. The two more-energetic jets showed crinkle patters, but the third jet did not, perhaps due to its weakness. Thus all three jets were consistent with formation via erupting minifilaments, analogous to large-scale filament eruptions and to X-ray jets in polar coronal holes. Several other energetic jets occurred in a nearby portion of the active region; while their behavior was also consistent with their source being minifilament eruptions, we could not confirm this because their onsets were hidden from our view. Magnetic flux cancelation and emergence are candidates for having triggered the minifilament eruptions.« less

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

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.

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

regional k of the LGW fault in which CO2 flux coincides with the field spatial variation is estimated between 0.01.kh<0.1 md and 0.5.k v<1 md. The anticlinal trap serves as an essential fluid source and conducive environment for intensifying eruption at Crystal Geyser. Geyser-like discharge in the simulations sensitively responds to varying well permeability and radius, and CO2 recharge rate. Indeed, the cycling behavior of wellbore CO2 leakage turns into a constant discharge with time, indicating the potential switch of Crystal Geyser to a CO2-driven cold-water spring or even fumarole.

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.

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

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.

The Tarawera eruption, Lake Rotomahana, and the origin of the Pink and White Terraces

NASA Astrophysics Data System (ADS)

Keam, Ronald F.

2016-03-01

This chapter introduces the historical and geographical background for the scientific studies at Tarawera and Lake Rotomahana in the Taupo Volcanic Zone of New Zealand as detailed in this Special Issue of the Journal of Volcanology and Geothermal Research. It also presents the results of some original investigations. These are based partly on the large body of historical information that exists about the 1886 Tarawera eruption and the geothermal system at Rotomahana, and partly on the results of dedicated geological studies by other researchers within the Okataina Volcanic Centre where the historical events took place. Specifically, the new material here presented includes a detailed analysis of a previously almost neglected narrative by the only observer to witness the 1886 eruption from the southeast of the erupting craters and leave an account of his observations. The importance of a co-operative interplay between pre-existing tectonic deformation and its responses to strong seismic activity induced by magmatic intrusion is emphasised as being a major determinant in the course of the eruption, and as the main trigger of the eruption explosions that were audible throughout half of the land area of New Zealand. The chapter then concentrates on showing how the recent geological studies, in conjunction with ideas on the architecture of geysers, permit an explanation to be given as to how the unique Pink and White Terraces came to be formed.

Io - One of at Least Four Simultaneous Erupting Volcanic Eruptions

NASA Technical Reports Server (NTRS)

1979-01-01

This photo of an active volcanic eruption on Jupiter's satellite Io was taken 1 hour, 52 minutes after the accompanying picture, late in the evening of March 4, 1979, Pacific time. On the limb of the satellite can be seen one of at least four simultaneous volcanic eruptions -- the first such activity ever observed on another celestial body. Seen against the limb are plume-like structures rising more than 60 miles (100 kilometers) above the surface. Several eruptions have been identified with volcanic structures on the surface of Io, which have also been identified by Voyager 1's infrared instrument as being abnormally hot -- several hundred degrees warmer than surrounding terrain. The fact that several eruptions appear to be occurring at the same time suggests that Io has the most active surface in the solar system and that volcanism is going on there essentially continuously. Another characteristic of the observed volcanism is that it appears to be extremely explosive, with velocities more than 2,000 miles an hour (at least 1 kilometer per second). That is more violent than terrestrial volcanoes like Etna, Vesuvius or Krakatoa.

Solar Activity and Solar Eruptions

NASA Technical Reports Server (NTRS)

Sterling, Alphonse C.

2006-01-01

Our Sun is a dynamic, ever-changing star. In general, its atmosphere displays major variation on an 11-year cycle. Throughout the cycle, the atmosphere occasionally exhibits large, sudden outbursts of energy. These "solar eruptions" manifest themselves in the form of solar flares, filament eruptions, coronal mass ejections (CMEs), and energetic particle releases. They are of high interest to scientists both because they represent fundamental processes that occur in various astrophysical context, and because, if directed toward Earth, they can disrupt Earth-based systems and satellites. Research over the last few decades has shown that the source of the eruptions is localized regions of energy-storing magnetic field on the Sun that become destabilized, leading to a release of the stored energy. Solar scientists have (probably) unraveled the basic outline of what happens in these eruptions, but many details are still not understood. In recent years we have been studying what triggers these magnetic eruptions, using ground-based and satellite-based solar observations in combination with predictions from various theoretical models. We will present an overview of solar activity and solar eruptions, give results from some of our own research, and discuss questions that remain to be explored.

Active Eruptions in the NE Lau Basin

NASA Astrophysics Data System (ADS)

Resing, J. A.; Embley, R. W.

2009-12-01

NE Lau Response Team: K Rubin, E Baker, J Lupton, M Lilley, T Shank, S Merle, R Dziak, T Collasius (Jason 2 Expedition Leader), N Buck, T Baumberger, D Butterfield, D Clague, D Conlin, J Cowen, R Davis, L Evans, J Huber, M Keith, N Keller, P Michael, E Podowski, A-L Reysenbach, K Roe, H Thomas, S Walker. During a May 2009 cruise to W Mata volcano in the NE Lau Basin, we made the first observations of an active eruption on the deep-sea floor. The cruise was organized after volcanic activity was detected at two sites (W Mata volcano and NE Lau Spreading Center, NELSC) during a Nov. 2008 NOAA-PMEL expedition. At that time, both sites had elevated H2 concentrations and volcaniclastic shards in the hydrothermal plumes. Moored hydrophone data since Jan 2009 indicate that the activity at W Mata has been continuous between these expeditions. Results of our cruise and other work suggest that the NE Lau Basin hosts an unusually high level of magmatic activity, making it an ideal location to study the effects of magmatic processes on hydrothermal activity and associated ecosystems. W Mata was visited with 5 ROV Jason 2 dives and 2 dives with the MBARI autonomous mapping vehicle in May 2009. It was actively erupting at the 1200 m deep summit during each, so a hydrophone was deployed locally to collect acoustic data. Ship and shore-based analysis of HD video, molten lava, rocks, sediments, hot spring waters, and micro- and macro biological specimens collected by Jason 2 have provided a wealth of data. The eruption itself was characterized by extrusion of red, molten lava, extensive degassing, formation of large magma bubbles, explosive pyroclast ejection, and the active extrusion of pillow lavas. The erupting magmas are boninite, a relatively rare magma type found only at convergent margins. The hydrothermal fluids are generally acidic and all diffuse fluids collected were microbially active, even those at pH <3. W Mata was host to shrimp similar to those found at several other

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.

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

USGS Publications Warehouse

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

1998-01-01

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

SEMICIRCULAR-LIKE SECONDARY FLARE RIBBONS ASSOCIATED WITH A FAILED ERUPTION

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

Zheng, R.; Korsós, M. B.; Erdélyi, R., E-mail: r.zheng@sheffield.ac.uk, E-mail: robertus@sheffield.ac.uk

Flare ribbons (FRs) are one of the most apparent signatures of solar flares and have been treated as an indicator of magnetic reconnection. Drawing upon the observations from the Solar Dynamics Observatory, we present semicircular-like secondary FRs (SFRs) of a C2.3 flare on 2013 June 19. Before the flare eruption, two bipoles in this core region subsequently emerged. Due to the interaction between the two bipoles, a tether-cutting eruption took place in the core region. The SFRs, surrounding the core region nearly simultaneously with the flare onset, were much weaker than the two normal FRs. Two ends of the SFRsmore » experienced a separation and extension movement, but the middle part of the SFRs hardly expanded outward. We find SFRs are closely associated with the footpoint brightenings of some small loops around the core region. The eruption was confined by transequatorial loops (TLs), which resulted in the plasma material falling in the north end of the TLs and remote brightenings showing up in the south end of the TLs. The disappearance of the faint (filament) material during the emergence of the SFRs could indicate another eruption. We conclude that two or more magnetic reconnections are involved in this event and propose that SFRs consisting of a small part of true FRs resulted from the second magnetic reconnection and bright footpoints of loop clusters likely heated by the main flare.« less

Predicting eruptions from precursory activity using remote sensing data hybridization

NASA Astrophysics Data System (ADS)

Reath, K. A.; Ramsey, M. S.; Dehn, J.; Webley, P. W.

2016-07-01

Many volcanoes produce some level of precursory activity prior to an eruption. This activity may or may not be detected depending on the available monitoring technology. In certain cases, precursors such as thermal output can be interpreted to make forecasts about the time and magnitude of the impending eruption. Kamchatka (Russia) provides an ideal natural laboratory to study a wide variety of eruption styles and precursory activity prior to an eruption. At Bezymianny volcano for example, a clear increase in thermal activity commonly occurs before an eruption, which has allowed predictions to be made months ahead of time. Conversely, the eruption of Tolbachik volcano in 2012 produced no discernable thermal precursors before the large scale effusive eruption. However, most volcanoes fall between the extremes of consistently behaved and completely undetectable, which is the case with neighboring Kliuchevskoi volcano. This study tests the effectiveness of using thermal infrared (TIR) remote sensing to track volcanic thermal precursors using data from both the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Advanced Very High Resolution Radiometer (AVHRR) sensors. It focuses on three large eruptions that produced different levels and durations of effusive and explosive behavior at Kliuchevskoi. Before each of these eruptions, TIR spaceborne sensors detected thermal anomalies (i.e., pixels with brightness temperatures > 2 °C above the background temperature). High-temporal, low-spatial resolution (i.e., hours and 1 km) AVHRR data are ideal for detecting large thermal events occurring over shorter time scales, such as the hot material ejected following strombolian eruptions. In contrast, high-spatial, low-temporal resolution (i.e., days to weeks and 90 m) ASTER data enables the detection of much lower thermal activity; however, activity with a shorter duration will commonly be missed. ASTER and AVHRR data are combined to track low

Attaining high-resolution eruptive histories for active arc volcanoes with argon geochronology

NASA Astrophysics Data System (ADS)

Calvert, A. T.

2012-04-01

Geochronology of active arc volcanoes commonly illuminates eruptive behavior over tens to hundreds of thousands of years, lengthy periods of repose punctuated by short eruptive episodes, and spatial and compositional changes with time. Despite the >1 Gyr half-life of 40K, argon geochronology is an exceptional tool for characterizing Pleistocene to Holocene eruptive histories and for placing constraints on models of eruptive behavior. Reliable 40Ar/39Ar ages of calc-alkaline arc rocks with rigorously derived errors small enough (± 500 to 3,000 years) to constrain eruptive histories are attainable using careful procedures. Sample selection and analytical work in concert with geologic mapping and stratigraphic studies are essential for determining reliable eruptive histories. Preparation, irradiation and spectrometric techniques have all been optimized to produce reliable, high-precision results. Examples of Cascade and Alaska/Aleutian eruptive histories illustrating duration of activity from single centers, eruptive episodicity, and spatial and compositional changes with time will be presented: (1) Mt. Shasta, the largest Cascade stratovolcano, has a 700,000-year history (Calvert and Christiansen, 2011 Fall AGU). A similar sized and composition volcano (Rainbow Mountain) on the Cascade axis was active 1200-950 ka. The eruptive center then jumped west 15 km to the south flank of the present Mt. Shasta and produced a stratovolcano from 700-450 ka likely rivaling today's Mt. Shasta. The NW portion of that edifice failed in an enormous (>30 km3) debris avalanche. Vents near today's active summit erupted 300-135 ka, then 60-15 ka. A voluminous, but short-lived eruptive sequence occurred at 11 ka, including a summit explosion producing a subplinian plume, followed by >60 km3 andesite-dacite Shastina domes and flows, then by the flank dacite Black Butte dome. Holocene domes and flows subsequently rebuilt the summit and flowed to the north and east. (2) Mt. Veniaminof on

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.

Review of eruptive activity at Tianchi volcano, Changbaishan, northeast China: implications for possible future eruptions

NASA Astrophysics Data System (ADS)

Wei, Haiquan; Liu, Guoming; Gill, James

2013-04-01

One of the largest explosive eruptions in the past several thousand years occurred at Tianchi volcano, also known as Changbaishan, on the China-North Korea border. This historically active polygenetic central volcano consists of three parts: a lower basaltic shield, an upper trachytic composite cone, and young comendite ash flows. The Millennium Eruption occurred between 938 and 946 ad, and was preceded by two smaller and chemically different rhyolitic pumice deposits. There has been at least one additional, small eruption in the last three centuries. From 2002 to 2005, seismicity, deformation, and the helium and hydrogen gas contents of spring waters all increased markedly, causing regional concern. We attribute this event to magma recharge or volatile exhalation or both at depth, followed by two episodes of addition of magmatic fluids into the overlying aquifer without a phreatic eruption. The estimated present magma accumulation rate is too low by itself to account for the 2002-2005 unrest. The most serious volcanic hazards are ash eruption and flows, and lahars. The available geological information and volcano monitoring data provide a baseline for comprehensive assessment of future episodes of unrest and possible eruptive activity.

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

Volcanic eruptions on Io

NASA Technical Reports Server (NTRS)

Strom, R. G.; Schneider, N. M.; Terrile, R. J.; Hansen, C.; Cook, A. F.

1981-01-01

Nine eruption plumes which were observed during the Voyager 1 encounter with Io are discussed. During the Voyager 2 encounter, four months later, eight of the eruptions were still active although the largest became inactive sometime between the two encounters. Plumes range in height from 60 to over 300 km with corresponding ejection velocities of 0.5 to 1.0 km/s and plume sources are located on several plains and consist of fissures or calderas. The shape and brightness distribution together with the pattern of the surface deposition on a plume 3 is simulated by a ballistic model with a constant ejection velocity of 0.5 km/s and ejection angles which vary from 0-55 deg. The distribution of active and recent eruptions is concentrated in the equatorial regions and indicates that volcanic activity is more frequent and intense in the equatorial regions than in the polar regions. Due to the geologic setting of certain plume sources and large reservoirs of volatiles required for the active eruptions, it is concluded that sulfur volcanism rather than silicate volcanism is the most likely driving mechanism for the eruption plumes.

Persistent activity and violent strombolian eruptions at Vesuvius between 1631 and 1944

NASA Astrophysics Data System (ADS)

Scandone, Roberto; Giacomelli, Lisetta; Speranza, Francesca Fattori

2008-03-01

During the period 1631-1944, Vesuvius was in persistent activity with alternating mild strombolian explosions, quiet effusive eruptions, and violent strombolian eruptions. The major difference between the predominant style of activity and the violent strombolian stages is the effusion rate. The lava effusion rate during major eruptions was in the range 20-100 m 3/s, higher than during mild activity and quiet effusion (0.1-1 m 3/s). The products erupted during the mild activity and major paroxysms have different degree of crystallization. Highly porphyritic lava flows are slowly erupted during years-long period of mild activity. This activity is fed by a magma accumulating at shallow depth within the volcanic edifice. Conversely, during the major paroxysms, a fast lava flow precedes the eruption of a volatile-rich, crystal-poor magma. We show that the more energetic eruptions are fed by episodic, multiple arrival of discrete batches of magma rising faster and not degassing during the ascent. The rapidly ascending magma pushes up the liquid residing in the shallow reservoir and eventually reaches the surface with its full complement of volatiles, producing kilometer-high lava fountains. Rapid drainage of the shallow reservoir occasionally caused small caldera collapses. The major eruptions act to unplug the upper part of the feeding system, erupting the cooling and crystallizing magma. This pattern of activity lasted for 313 y, but with a progressive decrease in the number of more energetic eruptions. As a consequence, a cooling plug blocked the volcano until it eventually prevented the eruption of new magma. The yearly probability of having at least one violent strombolian eruption has decreased from 0.12 to 0.10 from 1944 to 2007, but episodic seismic crises since 1979 may be indicative of new episodic intrusions of magma batches.

A Cutaneous Lupus Erythematosus-Like Eruption Induced by Hydroxyurea.

PubMed

Yanes, Daniel A; Mosser-Goldfarb, Joy L

2017-01-01

Hydroxyurea is a medication with many well-described cutaneous side effects, notably the dermatomyositis-like eruption known as hydroxyurea dermopathy. Although systemic lupus erythematosus has been reported with hydroxyurea use, cutaneous lupus has not. We report a novel case of chronic cutaneous lupus induced by hydroxyurea and propose that this is a side effect that is distinct from hydroxyurea dermopathy. © 2016 Wiley Periodicals, Inc.

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.

Dueling Volcanoes: How Activity Levels At Kilauea Influence Eruptions At Mauna Loa

NASA Astrophysics Data System (ADS)

Trusdell, F.

2011-12-01

The eruption of Kilauea at Pu`u `O`o is approaching its 29th anniversary. During this time, Mauna Loa has slowly inflated following its most recent eruption in 1984. This is Mauna Loa's longest inter-eruptive interval observed in HVO's 100 years of operation. When will the next eruption of Mauna Loa take place? Is the next eruption of Mauna Loa tied to the current activity at Kilauea? Historically, eruptive periods at Kilauea and Mauna Loa volcanoes appear to be inversely correlated. In the past, when Mauna Loa was exceptionally active, Kilauea Volcano was in repose, recovery, or in sustained lava lake activity. Swanson and co-workers (this meeting) have noted that explosive activity on Kilauea, albeit sporadic, was interspersed between episodes of effusive activity. Specifically, Swanson and co-workers note as explosive the time periods between 300 B.C.E.-1000 C.E and 1500-1800 C.E. They also point to evidence for low magma supply to Kilauea during these periods and few flank eruptions. During the former explosive period, Mauna Loa was exceedingly active, covering approximately 37% of its surface or 1882 km2, an area larger than Kilauea. This period is also marked by summit activity at Mauna Loa sustained for 300 years. In the 1500-1800 C.E. period, Mauna Loa was conspicuously active with 29 eruptions covering an area of 446 km2. In the late 19th and early 20th century, Kilauea was dominated by nearly continuous lava-lake activity. Meanwhile Mauna Loa was frequently active from 1843 C.E. to 1919 C.E., with 24 eruptions for an average repose time of 3.5 years. I propose that eruptive activity at one volcano may affect eruptions at the other, due to factors that impact magma supply, volcanic plumbing, and flank motion. This hypothesis is predicated on the notion that when the rift zones of Kilauea, and in turn its mobile south flank, are active, Mauna Loa's tendency to erupt is diminished. Kilauea's rift zones help drive the south flank seaward, in turn, as Mauna

Eruptions that Drive Coronal Jets in a Solar Active Region

NASA Technical Reports Server (NTRS)

Sterling, Alphonse C.; Moore, Ronald L.; Falconer, David A.; Panesar, Navdeep K.; Akiyama, Sachiko; Yashiro, Seiji; Gopalswamy, Nat

2016-01-01

Solar coronal jets are common in both coronal holes and in active regions (e.g., Shibata et al. 1992, Shimojo et al. 1996, Cirtain et al. 2007. Savcheva et al. 2007). Recently, Sterling et al. (2015), using data from Hinode/XRT and SDO/AIA, found that coronal jets originating in polar coronal holes result from the eruption of small-scale filaments (minifilaments). The jet bright point (JBP) seen in X-rays and hotter EUV channels off to one side of the base of the jet's spire develops at the location where the minifilament erupts, consistent with the JBPs being miniature versions of typical solar flares that occur in the wake of large-scale filament eruptions. Here we consider whether active region coronal jets also result from the same minifilament-eruption mechanism, or whether they instead result from a different mechanism (e.g. Yokoyama & Shibata 1995). We present observations of an on-disk active region (NOAA AR 11513) that produced numerous jets on 2012 June 30, using data from SDO/AIA and HMI, and from GOES/SXI. We find that several of these active region jets also originate with eruptions of miniature filaments (size scale 20'') emanating from small-scale magnetic neutral lines of the region. This demonstrates that active region coronal jets are indeed frequently driven by minifilament eruptions. Other jets from the active region were also consistent with their drivers being minifilament eruptions, but we could not confirm this because the onsets of those jets were hidden from our view. This work was supported by funding from NASA/LWS, NASA/HGI, and Hinode. A full report of this study appears in Sterling et al. (2016).

A comparison study of a solar active-region eruptive filament and a neighboring non-eruptive filament

NASA Astrophysics Data System (ADS)

Jiang, Chao-Wei; Wu, Shi-Tsan; Feng, Xue-Shang; Hu, Qiang

2016-01-01

Solar active region (AR) 11283 is a very magnetically complex region and it has produced many eruptions. However, there exists a non-eruptive filament in the plage region just next to an eruptive one in the AR, which gives us an opportunity to perform a comparison analysis of these two filaments. The coronal magnetic field extrapolated using our CESE-MHD-NLFFF code reveals that two magnetic flux ropes (MFRs) exist in the same extrapolation box supporting these two filaments, respectively. Analysis of the magnetic field shows that the eruptive MFR contains a bald-patch separatrix surface (BPSS) cospatial very well with a pre-eruptive EUV sigmoid, which is consistent with the BPSS model for coronal sigmoids. The magnetic dips of the non-eruptive MFRs match Hα observation of the non-eruptive filament strikingly well, which strongly supports the MFR-dip model for filaments. Compared with the non-eruptive MFR/filament (with a length of about 200 Mm), the eruptive MFR/filament is much smaller (with a length of about 20 Mm), but it contains most of the magnetic free energy in the extrapolation box and holds a much higher free energy density than the non-eruptive one. Both the MFRs are weakly twisted and cannot trigger kink instability. The AR eruptive MFR is unstable because its axis reaches above a critical height for torus instability, at which the overlying closed arcades can no longer confine the MFR stably. On the contrary, the quiescent MFR is very firmly held by its overlying field, as its axis apex is far below the torus-instability threshold height. Overall, this comparison investigation supports that an MFR can exist prior to eruption and the ideal MHD instability can trigger an MFR eruption.

Kulanaokuaiki 3: Product of an Energetic, Diatreme-Like Eruption at Kilauea

NASA Astrophysics Data System (ADS)

Fiske, R. S.; Rose, T. R.; Swanson, D. A.

2006-12-01

initially exsolves from basaltic magma at ~10 km depth, was the likely propellant for the diatreme-like K-3 eruption. While reaming a conduit to the surface, the streaming CO2, knicked the upper part of a magma body (likely dike-shaped), initiating its disintegration. The first pulse of the eruption released scoria that, along with spalled conduit wall rocks, erupted to form the lower K-3 sub-unit. Following a brief pause, when the air partly cleared to form the mid-K-3 parting, a second pulse entrained scoria originating from progressively deeper and more olivine-rich parts of the magma body. As a result, scoria containing greater percentages of phenocrystic olivine was erupted, and these were showered over the south flank to produce the observed upside-down "magma-chamber grading" in the upper K-3 sub-unit. Multi-mach exit velocities are visualized, and entrained lithic clasts may have been carried to heights of 15-20 km. These clasts were carried to the southeast as they fell through high-level northwesterly winds.

Trends in intrusive and eruptive activity during Kilauea's long-lived east rift zone eruption

NASA Astrophysics Data System (ADS)

Orr, T. R.; Patrick, M. R.; Heliker, C.

2011-12-01

Kilauea Volcano's Pu`u `O`o eruption, continuing for nearly three decades, offers a unique opportunity to study trends in eruptive behavior. One such trend, that of uprift intrusion ± eruption, accompanied by crater floor collapse and eruptive hiatus, has been repeated several times at Pu`u `O`o. This includes the February 7, 1993, intrusion; the January 29, 1997, intrusion and eruption; the September 12, 1999, intrusion; and the June 17, 2007, intrusion and eruption. Activity resumed within Pu`u `O`o following each of these events, and crater refilling culminated eventually in the outbreak of lava from new vents on the flank of the Pu`u `O`o cone. The pattern was repeated again in 2011, when a brief fissure eruption uprift from Pu`u `O`o started on March 5. The Pu`u `O`o crater floor dropped about 115 m in response to the eruption, which ceased on March 9. After a short hiatus, lava reappeared in Pu`u `O`o on March 26, and the crater began to fill slowly thereafter by overflow from a central lava lake. Starting in late June 2011, however, the crater floor began to uplift in a wholesale fashion, suggesting an increase in the pressure beneath the Pu`u `O`o edifice. By late July, the lava within the crater had reached its highest level since early 2004, and lava had begun to overflow from the southwestern side of the crater. On August 3, the west side of the Pu`u `O`o cone was abruptly thrust upward as a sill was injected beneath that portion of the cone. Within minutes, lava began to erupt from a crack on the west flank of Pu`u `O`o, completing the pattern of intrusion, crater collapse, refilling, and breakout. During a long-lived eruption, maintaining a detailed observational and geophysical record is essential for recognizing patterns that may emerge. Recognizing such a pattern allowed Hawaiian Volcano Observatory scientists to prepare a response well in advance of the August 3, 2011 event, and provides guidance for responding to future eruption crises at Pu`u `O

A Study of a Compound Solar Eruption with Two Consecutive Erupting Magnetic Structures

NASA Astrophysics Data System (ADS)

Dhakal, Suman K.; Chintzoglou, Georgios; Zhang, Jie

2018-06-01

We report a study of a compound solar eruption that was associated with two consecutively erupting magnetic structures and correspondingly two distinct peaks, during impulsive phase, of an M-class flare (M8.5). Simultaneous multi-viewpoint observations from SDO, GOES and STEREO-A show that this compound eruption originated from two pre-existing sigmoidal magnetic structures lying along the same polarity inversion line. Observations of the associated pre-existing filaments further show that these magnetic structures are lying one on top of the other, separated by 12 Mm in height, in a so-called “double-decker” configuration. The high-lying magnetic structure became unstable and erupted first, appearing as an expanding hot channel seen at extreme ultraviolet wavelengths. About 12 minutes later, the low-lying structure also started to erupt and moved at an even faster speed compared to the high-lying one. As a result, the two erupting structures interacted and merged with each other, appearing as a single coronal mass ejection in the outer corona. We find that the double-decker configuration is likely caused by the persistent shearing motion and flux cancellation along the source active region’s strong-gradient polarity inversion line. The successive destabilization of these two separate but closely spaced magnetic structures, possibly in the form of magnetic flux ropes, led to a compound solar eruption. The study of the compound eruption provides a unique opportunity to reveal the formation process, initiation, and evolution of complex eruptive structures in solar active regions.

Volcan Baru: Eruptive History and Volcano-Hazards Assessment

USGS Publications Warehouse

Sherrod, David R.; Vallance, James W.; Tapia Espinosa, Arkin; McGeehin, John P.

2008-01-01

Volcan Baru is a potentially active volcano in western Panama, about 35 km east of the Costa Rican border. The volcano has had four eruptive episodes during the past 1,600 years, including its most recent eruption about 400?500 years ago. Several other eruptions occurred in the prior 10,000 years. Several seismic swarms in the 20th century and a recent swarm in 2006 serve as reminders of a restless tectonic terrane. Given this history, Volcan Baru likely will erupt again in the near or distant future, following some premonitory period of seismic activity and subtle ground deformation that may last for days or months. Future eruptions will likely be similar to past eruptions?explosive and dangerous to those living on the volcano?s flanks. Outlying towns and cities could endure several years of disruption in the wake of renewed volcanic activity. Described in this open-file report are reconnaissance mapping and stratigraphic studies, radiocarbon dating, lahar-inundation modeling, and hazard-analysis maps. Existing data have been compiled and included to make this report as comprehensive as possible. The report is prepared in coooperation with National Secretariat for Science, Technology and Innovation (SENACYT) of the Republic of Panama and the U.S. Agency for International Development (USAID).

Multiple coincident eruptive seismic tremor sources during the 2014-2015 eruption at Holuhraun, Iceland

NASA Astrophysics Data System (ADS)

Eibl, Eva P. S.; Bean, Christopher J.; Jónsdóttir, Ingibjörg; Höskuldsson, Armann; Thordarson, Thorvaldur; Coppola, Diego; Witt, Tanja; Walter, Thomas R.

2017-04-01

We analyze eruptive tremor during one of the largest effusive eruptions in historical times in Iceland (2014/2015 Holuhraun eruption). Seismic array recordings are compared with effusion rates deduced from Moderate Resolution Imaging Spectroradiometer recordings and ground video monitoring data and lead to the identification of three coexisting eruptive tremor sources. This contrasts other tremor studies that generally link eruptive tremor to only one source usually associated with the vent. The three sources are (i) a source that is stable in back azimuth and shows bursts with ramp-like decrease in amplitude at the beginning of the eruption: we link it to a process below the open vents where the bursts correlate with the opening of new vents and temporary increases in the lava fountaining height; (ii) a source moving by a few degrees per month while the tremor amplitude suddenly increases and decreases: back azimuth and slowness correlate with the growing margins of the lava flow field, whilst new contact with a river led to fast increases of the tremor amplitude; and (iii) a source moving by up to 25° southward in 4 days that cannot be related to any observed surface activity and might be linked to intrusions. We therefore suggest that eruptive tremor amplitudes/energies are used with caution when estimating eruptive volumes, effusion rates, or the eruption explosivity as multiple sources can coexist during the eruption phase. Our results suggest that arrays can monitor both the growth of a lava flow field and the activity in the vents.

Curtain eruptions from Enceladus' south-polar terrain.

PubMed

Spitale, Joseph N; Hurford, Terry A; Rhoden, Alyssa R; Berkson, Emily E; Platts, Symeon S

2015-05-07

Observations of the south pole of the Saturnian moon Enceladus revealed large rifts in the south-polar terrain, informally called 'tiger stripes', named Alexandria, Baghdad, Cairo and Damascus Sulci. These fractures have been shown to be the sources of the observed jets of water vapour and icy particles and to exhibit higher temperatures than the surrounding terrain. Subsequent observations have focused on obtaining close-up imaging of this region to better characterize these emissions. Recent work examined those newer data sets and used triangulation of discrete jets to produce maps of jetting activity at various times. Here we show that much of the eruptive activity can be explained by broad, curtain-like eruptions. Optical illusions in the curtain eruptions resulting from a combination of viewing direction and local fracture geometry produce image features that were probably misinterpreted previously as discrete jets. We present maps of the total emission along the fractures, rather than just the jet-like component, for five times during an approximately one-year period in 2009 and 2010. An accurate picture of the style, timing and spatial distribution of the south-polar eruptions is crucial to evaluating theories for the mechanism controlling the eruptions.

Curtain eruptions from Enceladus' south-polar terrain

NASA Astrophysics Data System (ADS)

Spitale, Joseph N.; Hurford, Terry A.; Rhoden, Alyssa R.; Berkson, Emily E.; Platts, Symeon S.

2015-05-01

Observations of the south pole of the Saturnian moon Enceladus revealed large rifts in the south-polar terrain, informally called `tiger stripes', named Alexandria, Baghdad, Cairo and Damascus Sulci. These fractures have been shown to be the sources of the observed jets of water vapour and icy particles and to exhibit higher temperatures than the surrounding terrain. Subsequent observations have focused on obtaining close-up imaging of this region to better characterize these emissions. Recent work examined those newer data sets and used triangulation of discrete jets to produce maps of jetting activity at various times. Here we show that much of the eruptive activity can be explained by broad, curtain-like eruptions. Optical illusions in the curtain eruptions resulting from a combination of viewing direction and local fracture geometry produce image features that were probably misinterpreted previously as discrete jets. We present maps of the total emission along the fractures, rather than just the jet-like component, for five times during an approximately one-year period in 2009 and 2010. An accurate picture of the style, timing and spatial distribution of the south-polar eruptions is crucial to evaluating theories for the mechanism controlling the eruptions.

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

Active submarine eruption of boninite in the northeastern Lau Basin

NASA Astrophysics Data System (ADS)

Resing, Joseph A.; Rubin, Kenneth H.; Embley, Robert W.; Lupton, John E.; Baker, Edward T.; Dziak, Robert P.; Baumberger, Tamara; Lilley, Marvin D.; Huber, Julie A.; Shank, Timothy M.; Butterfield, David A.; Clague, David A.; Keller, Nicole S.; Merle, Susan G.; Buck, Nathaniel J.; Michael, Peter J.; Soule, Adam; Caress, David W.; Walker, Sharon L.; Davis, Richard; Cowen, James P.; Reysenbach, Anna-Louise; Thomas, Hans

2011-11-01

Subduction of oceanic crust and the formation of volcanic arcs above the subduction zone are important components in Earth's geological and geochemical cycles. Subduction consumes and recycles material from the oceanic plates, releasing fluids and gases that enhance magmatic activity, feed hydrothermal systems, generate ore deposits and nurture chemosynthetic biological communities. Among the first lavas to erupt at the surface from a nascent subduction zone are a type classified as boninites. These lavas contain information about the early stages of subduction, yet because most subduction systems on Earth are old and well-established, boninite lavas have previously only been observed in the ancient geological record. Here we observe and sample an active boninite eruption occurring at 1,200m depth at the West Mata submarine volcano in the northeast Lau Basin, southwest Pacific Ocean. We find that large volumes of H2O, CO2 and sulphur are emitted, which we suggest are derived from the subducting slab. These volatiles drive explosive eruptions that fragment rocks and generate abundant incandescent magma-skinned bubbles and pillow lavas. The eruption has been ongoing for at least 2.5 years and we conclude that this boninite eruption is a multi-year, low-mass-transfer-rate eruption. Thus the Lau Basin may provide an important site for the long-term study of submarine volcanic eruptions related to the early stages of subduction.

Prediction of Solar Eruptions Using Filament Metadata

NASA Astrophysics Data System (ADS)

Aggarwal, Ashna; Schanche, Nicole; Reeves, Katharine K.; Kempton, Dustin; Angryk, Rafal

2018-05-01

We perform a statistical analysis of erupting and non-erupting solar filaments to determine the properties related to the eruption potential. In order to perform this study, we correlate filament eruptions documented in the Heliophysics Event Knowledgebase (HEK) with HEK filaments that have been grouped together using a spatiotemporal tracking algorithm. The HEK provides metadata about each filament instance, including values for length, area, tilt, and chirality. We add additional metadata properties such as the distance from the nearest active region and the magnetic field decay index. We compare trends in the metadata from erupting and non-erupting filament tracks to discover which properties present signs of an eruption. We find that a change in filament length over time is the most important factor in discriminating between erupting and non-erupting filament tracks, with erupting tracks being more likely to have decreasing length. We attempt to find an ensemble of predictive filament metadata using a Random Forest Classifier approach, but find the probability of correctly predicting an eruption with the current metadata is only slightly better than chance.

Historic hydrovolcanism at Deception Island (Antarctica): implications for eruption hazards

NASA Astrophysics Data System (ADS)

Pedrazzi, Dario; Németh, Károly; Geyer, Adelina; Álvarez-Valero, Antonio M.; Aguirre-Díaz, Gerardo; Bartolini, Stefania

2018-01-01

Deception Island (Antarctica) is the southernmost island of the South Shetland Archipelago in the South Atlantic. Volcanic activity since the eighteenth century, along with the latest volcanic unrest episodes in the twentieth and twenty-first centuries, demonstrates that the volcanic system is still active and that future eruptions are likely. Despite its remote location, the South Shetland Islands are an important touristic destination during the austral summer. In addition, they host several research stations and three summer field camps. Deception Island is characterised by a Quaternary caldera system with a post-caldera succession and is considered to be part of an active, dispersed (monogenetic), volcanic field. Historical post-caldera volcanism on Deception Island involves monogenetic small-volume (VEI 2-3) eruptions such forming cones and various types of hydrovolcanic edifices. The scientific stations on the island were destroyed, or severely damaged, during the eruptions in 1967, 1969, and 1970 mainly due to explosive activity triggered by the interaction of rising (or erupting) magma with surface water, shallow groundwater, and ice. We conducted a detailed revision (field petrology and geochemistry) of the historical hydrovolcanic post-caldera eruptions of Deception Island with the aim to understand the dynamics of magma-water interaction, as well as characterise the most likely eruptive scenarios from future eruptions. We specifically focused on the Crimson Hill (estimated age between 1825 and 1829), and Kroner Lake (estimated age between 1829 and 1912) eruptions and 1967, 1969, and 1970 events by describing the eruption mechanisms related to the island's hydrovolcanic activity. Data suggest that the main hazards posed by volcanism on the island are due to fallout, ballistic blocks and bombs, and subordinate, dilute PDCs. In addition, Deception Island can be divided into five areas of expected activity due to magma-water interaction, providing additional

Coronal Jets from Minifilament Eruptions in Active Regions

NASA Technical Reports Server (NTRS)

Martinez, Francisco; Sterling, Alphonse C.; Falconer, David A.; Moore, Ronald L.

2016-01-01

Solar coronal jets are transient (frequently of lifetime approx.10 min) features that shoot out from near the solar surface, become much longer than their width, and occur in all solar regions, including coronal holes, quiet Sun, and active regions (e.g., Shimojo et al. 1996, Cirtain et al. 2007). Sterling et al. (2015) and other studies found that in coronal holes and in quiet Sun the jets result when small-scale filaments, called "minifilaments" erupt onto nearby open or high-reaching field lines. Additional studies found that coronal-jet-onset locations (and hence presumably the minifilament-eruption-onset locations) coincided with locations of magnetic-flux cancelation. For active region (AR) jets however the situation is less clear. Sterling et al. (2016) studied jets in one active region over a 24-hour period; they found that some AR jets indeed resulted from minifilament eruptions, usually originating from locations of episodes of magnetic-flux cancelation. In some cases however they could not determine whether flux was emerging or canceling at the polarity inversion line from which the minifilament erupted, and for other jets of that region minifilaments were not conclusively apparent prior to jet occurrence. Here we further study AR jets, by observing them in a single AR over a one-week period, using X-ray images from Hinode/XRT and EUV/UV images from SDO/AIA, and line-of-sight magnetograms and white-light intensity-grams from SDO/HMI. We initially identified 13 prominent jets in the XRT data, and examined corresponding AIA and HMI data. For at least several of the jets, our findings are consistent with the jets resulting from minifilament eruptions, and originating from sites of magnetic-field cancelation.

Remote observations of eruptive clouds and surface thermal activity during the 2009 eruption of Redoubt volcano

NASA Astrophysics Data System (ADS)

Webley, P. W.; Lopez, T. M.; Ekstrand, A. L.; Dean, K. G.; Rinkleff, P.; Dehn, J.; Cahill, C. F.; Wessels, R. L.; Bailey, J. E.; Izbekov, P.; Worden, A.

2013-06-01

Volcanoes often erupt explosively and generate a variety of hazards including volcanic ash clouds and gaseous plumes. These clouds and plumes are a significant hazard to the aviation industry and the ground features can be a major hazard to local communities. Here, we provide a chronology of the 2009 Redoubt Volcano eruption using frequent, low spatial resolution thermal infrared (TIR), mid-infrared (MIR) and ultraviolet (UV) satellite remote sensing data. The first explosion of the 2009 eruption of Redoubt Volcano occurred on March 15, 2009 (UTC) and was followed by a series of magmatic explosive events starting on March 23 (UTC). From March 23-April 4 2009, satellites imaged at least 19 separate explosive events that sent ash clouds up to 18 km above sea level (ASL) that dispersed ash across the Cook Inlet region. In this manuscript, we provide an overview of the ash clouds and plumes from the 19 explosive events, detailing their cloud-top heights and discussing the variations in infrared absorption signals. We show that the timing of the TIR data relative to the event end time was critical for inferring the TIR derived height and true cloud top height. The ash clouds were high in water content, likely in the form of ice, which masked the negative TIR brightness temperature difference (BTD) signal typically used for volcanic ash detection. The analysis shown here illustrates the utility of remote sensing data during volcanic crises to measure critical real-time parameters, such as cloud-top heights, changes in ground-based thermal activity, and plume/cloud location.

Long-term eruptive activity at a submarine arc volcano.

PubMed

Embley, Robert W; Chadwick, William W; Baker, Edward T; Butterfield, David A; Resing, Joseph A; de Ronde, Cornel E J; Tunnicliffe, Verena; Lupton, John E; Juniper, S Kim; Rubin, Kenneth H; Stern, Robert J; Lebon, Geoffrey T; Nakamura, Ko-ichi; Merle, Susan G; Hein, James R; Wiens, Douglas A; Tamura, Yoshihiko

2006-05-25

Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes.

Long-term eruptive activity at a submarine arc volcano

USGS Publications Warehouse

Embley, R.W.; Chadwick, W.W.; Baker, E.T.; Butterfield, D.A.; Resing, J.A.; de Ronde, Cornel E. J.; Tunnicliffe, V.; Lupton, J.E.; Juniper, S.K.; Rubin, K.H.; Stern, R.J.; Lebon, G.T.; Nakamura, K.-I.; Merle, S.G.; Hein, J.R.; Wiens, D.A.; Tamura, Y.

2006-01-01

Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes. ?? 2006 Nature Publishing Group.

Products of Submarine Fountains and Bubble-burst Eruptive Activity at 1200 m on West Mata Volcano, Lau Basin

NASA Astrophysics Data System (ADS)

Clague, D. A.; Rubin, K. H.; Keller, N. S.

2009-12-01

An eruption was observed and sampled at West Mata Volcano using ROV JASON II for 5 days in May 2009 during the NSF-NOAA eruption response cruise to this region of suspected volcanic activity. Activity was focused near the summit at the Prometheus and Hades vents. Prometheus erupted almost exclusively as low-level fountains. Activity at Hades cycled between vigorous degassing, low fountains, and bubble-bursts, building up and partially collapsing a small spatter/scoria cone and feeding short sheet-like and pillow flows. Fire fountains at Prometheus produced mostly small primary pyroclasts that include Pele's hair and fluidal fragments of highly vesicular volcanic glass. These fragments have mostly shattered and broken surfaces, although smooth spatter-like surfaces also occur. As activity wanes, glow in the vent fades, and denser, sometimes altered volcanic clasts are incorporated into the eruption. The latter are likely from the conduit walls and/or vent-rim ejecta, drawn back into the vent by inrushing seawater that replaces water entrained in the rising volcanic plume. Repeated recycling of previously erupted materials eventually produces rounded clasts resembling beach cobbles and pitted surfaces on broken phenocrysts of pyroxene and olivine. We estimate that roughly 33% of near vent ejecta are recycled. Our best sample of this ejecta type was deposited in the drawer of the JASON II ROV during a particularly large explosion that occurred during plume sampling immediately above the vent. Elemental sulfur spherules up to 5 mm in diameter are common in ejecta from both vents and occur inside some of the lava fragments Hades activity included dramatic bubble-bursts unlike anything previously observed under water. The lava bubbles, sometimes occurring in rapid-fire sequence, collapsed in the water-column, producing fragments that are quenched in less than a second to form Pele's hair, limu o Pele, spatter-like lava blobs, and scoria. All are highly vesicular

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.

SYMPATHETIC FILAMENT ERUPTIONS CONNECTED BY CORONAL DIMMINGS

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

Jiang Yunchun; Yang Jiayan; Hong Junchao

2011-09-10

We present for the first time detailed observations of three successive, interdependent filament eruptions that occurred one by one within 5 hr from different locations beyond the range of a single active region. The first eruption was observed from an active region and was associated with a coronal mass ejection (CME), during which diffuse and complex coronal dimmings formed, largely extending to the two other filaments located in quiet-Sun regions. Then, both quiescent filaments consecutively underwent the second and third eruptions, while the nearby dimmings were persistent. Comparing the result of a derived coronal magnetic configuration, the magnetic connectivity betweenmore » the dimmings suggested that they were caused by the joint effect of simple expansion of overlying loop systems forced by the first eruption, as well as by its erupting field interacting or reconnecting with the surrounding magnetic structures. Note that the dimming process in the first eruption indicated a weakening and partial removal of an overlying magnetic field constraint on the two other filaments, and thus one can physically connect these eruptions as sympathetic. It appears that the peculiar magnetic field configuration in our event was largely favorable to the occurrence of sympathetic filament eruptions. Because coronal dimmings are frequent and common phenomena in solar eruptions, especially in CME events, it is very likely that they represent a universal agent that can link consecutive eruptions nearby with sympathetic eruptions.« less

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.

Homologous prominence non-radial eruptions: A case study

NASA Astrophysics Data System (ADS)

Duchlev, P.; Koleva, K.; Madjarska, M. S.; Dechev, M.

2016-10-01

The present study provides important details on homologous eruptions of a solar prominence that occurred in active region NOAA 10904 on 2006 August 22. We report on the pre-eruptive phase of the homologous feature as well as the kinematics and the morphology of a forth from a series of prominence eruptions that is critical in defining the nature of the previous consecutive eruptions. The evolution of the overlying coronal field during homologous eruptions is discussed and a new observational criterion for homologous eruptions is provided. We find a distinctive sequence of three activation periods each of them containing pre-eruptive precursors such as a brightening and enlarging of the prominence body followed by small surge-like ejections from its southern end observed in the radio 17 GHz. We analyse a fourth eruption that clearly indicates a full reformation of the prominence after the third eruption. The fourth eruption although occurring 11 h later has an identical morphology, the same angle of propagation with respect to the radial direction, as well as similar kinematic evolution as the previous three eruptions. We find an important feature of the homologous eruptive prominence sequence that is the maximum height increase of each consecutive eruption. The present analysis establishes that all four eruptions observed in Hα are of confined type with the third eruption undergoing a thermal disappearance during its eruptive phase. We suggest that the observation of the same direction of the magnetic flux rope (MFR) ejections can be consider as an additional observational criterion for MFR homology. This observational indication for homologous eruptions is important, especially in the case of events of typical or poorly distinguishable morphology of eruptive solar phenomena.

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.

Coronal Jets from Minifilament Eruptions in Active Regions

NASA Astrophysics Data System (ADS)

Sterling, A. C.; Martinez, F.; Falconer, D. A.; Moore, R. L.

2016-12-01

Solar coronal jets are transient (frequently of lifetime 10 min) features that shoot out from near the solar surface, become much longer than their width, and occur in all solar regions, including coronal holes, quiet Sun, and active regions (e.g., Shimojo et al. 1996, Certain et al. 2007). Sterling et al. (2015) and other studies found that in coronal holes and in quiet Sun the jets result when small-scale filaments, called ``minifilaments,'' erupt onto nearby open or high-reaching field lines. Additional studies found that coronal-jet-onset locations (and hence presumably the minifilament-eruption-onset locations) coincided with locations of magnetic-flux cancellation. For active region (AR) jets however the situation is less clear. Sterling et al. (2016) studied jets in one active region over a 24-hour period; they found that some AR jets indeed resulted from minifilament eruptions, usually originating from locations of episodes of magnetic-flux cancelation. In some cases however they could not determine whether flux was emerging or canceling at the polarity inversion line from which the minifilament erupted; and for other jets of that region minifilaments were not conclusively apparent prior to jet occurrence. Here we further study AR jets, by observing them in a single AR over a one-week period, using X-ray images from Hinode/XRT and EUV/UV images from SDO/AIA, and line-of-sight magnetograms and white-light intensity-grams from SDO/HMI. We initially identified 13 prominent jets in the XRT data, and examined corresponding AIA and HMI data. For at least several of the jets, our findings are consistent with the jets resulting from minifilament eruptions, and originating from sights of magnetic-field cancelation. Thus our findings support that, at least in many cases, AR coronal jets result from the same physical processes that produce coronal jets in quiet-Sun and coronal-hole regions. FM was supportedby the Research Experience for Undergraduates (REU) program at

High-resolution Observations of Sympathetic Filament Eruptions by NVST

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

Li, Shangwei; Su, Yingna; Zhou, Tuanhui

We investigate two sympathetic filament eruptions observed by the New Vacuum Solar Telescope on 2015 October 15. The full picture of the eruptions is obtained from the corresponding Solar Dynamics Observatory ( SDO )/Atmospheric Imaging Assembly (AIA) observations. The two filaments start from active region NOAA 12434 in the north and end in one large quiescent filament channel in the south. The left filament erupts first, followed by the right filament eruption about 10 minutes later. Clear twist structure and rotating motion are observed in both filaments during the eruption. Both eruptions failed, since the filaments first rise up, thenmore » flow toward the south and merge into the southern large quiescent filament. We also observe repeated activations of mini filaments below the right filament after its eruption. Using magnetic field models constructed based on SDO /HMI magnetograms via the flux rope insertion method, we find that the left filament eruption is likely to be triggered by kink instability, while the weakening of overlying magnetic fields due to magnetic reconnection at an X-point between the two filament systems might play an important role in the onset of the right filament eruption.« less

Monitoring Io's Volcanic Activity in the Visible and Infrared from JUICE - It's All About (Eruption) Style

NASA Astrophysics Data System (ADS)

Davies, A. G.; Matson, D.; McEwen, A. S.; Keszthelyi, L. P.

2012-12-01

The European Space Agency's Jupiter Icy Moons Explorer (JUICE) will provide many opportunities for long-range monitoring of Io's extraordinary silicate, high-temperature volcanic activity [1, 2]. A considerable amount of valuable work can be performed even with relatively low-spatial-resolution observations [2]. Techniques developed from the examination and analysis of Galileo Near Infrared Mapping Spectrometer (NIMS) data, as well as observations of terrestrial silicate volcanic activity, allows the identification of likely eruption style [2] at many locations where the entire eruption is sub-pixel. Good temporal coverage, especially for episodic eruptions (including high-energy "outburst" eruptions), is important for modelling purposes. With opportunities to observe Io on a regular basis (hours-days) during cruise/orbital reduction phases, a visible-to-near-infrared mapping spectrometer (covering ~0.4-5.5 μm) is the best instrument to chart the magnitude and variability of Io's volcanic activity, allowing comparison with an existing and constantly expanding set of Io observations [e.g. 1, 3]. The eruption temperature of Io's dominant silicate lava, a constraint on interior composition and conditions, is a major unanswered question in the wake of the Galileo mission [1]. A careful approach to instrument design is needed to ensure that observations by both imager and IR spectrometer on JUICE are capable of determining lava eruption temperature [e.g., 4] in low spatial resolution data. With an ideal thermal target (e.g., an outburst eruption, or the proposed lava lake at Pele) the imager should obtain multi-spectral data in a rapid sequence to allow stability of the thermal source to be quantified. Observations by imager and spectrometer have to be contemporaneous and unsaturated. References: [1] Davies, A. (2007) "Volcanism on Io", Cam. Univ. Press. [2] Davies, A. et al. (2010) JVGR, 194, 75-99. [3] Veeder, G. et al. (2012) Icarus, 219, 701-722. [4] Davies, A. et

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

Formation and Eruption Process of a Filament in Active Region NOAA 12241

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

Wang, Jincheng; Yan, Xiaoli; Qu, ZhongQuan

In order to better understand active-region filaments, we present an intensive study on the formation and eruption of a filament in active region NOAA 12241 during the period from 2014 December 18 to 19. Using observations from the Helioseismic and Magnetic Imager (HMI) vector magnetograms, we investigate the helicity injection rate, Lorentz force, and vertical electric current in the entire region associated with the filament. The helicity injection rate before eruption is found to be larger than that after eruption, while the vertical electric current undergoes an increase at first and then a gradual decrease, similar to what the magneticmore » flux undergoes. Meanwhile, we find that the right part of the filament is formed by magnetic reconnection between two bundles of magnetic field lines while the left part originated from shearing motion. The interaction of the two parts causes the eruption of this filament. The mean horizontal magnetic fields in the vicinity of the magnetic polarity inversion line (PIL) enhance rapidly during the eruption. Another striking phenomenon, where the vertical electric currents close to the magnetic PIL suddenly expand toward two sides during the eruption, is found. We propose that this fascinating feature is associated with the release of energy during the eruption.« less

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

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

Diverse Eruptive Activity Revealed by Acoustic and Electromagnetic Observations of the 14 July 2013 Intense Vulcanian Eruption of Tungurahua Volcano, Ecuador

NASA Astrophysics Data System (ADS)

Anderson, J. F.; Johnson, J. B.; Steele, A. L.; Ruiz, M. C.; Brand, B. D.

2018-04-01

During the powerful July 2013 eruption of Tungurahua volcano, Ecuador, we recorded exceptionally high amplitude, long-period infrasound (1,600-Pa peak-to-peak amplitude, 5.5-s period) on sensors within 2 km of the vent alongside electromagnetic signals from volcanic lightning serendipitously captured as interference. This explosion was one of Tungurahua's most powerful vulcanian eruptions since recent activity began in 1999, and its acoustic wave is among the most powerful volcanic infrasound ever recorded anywhere. We use these data to quantify erupted volume from the main explosion and to classify postexplosive degassing into distinct emission styles. Additionally, we demonstrate a highly effective method of recording lightning-related electromagnetic signals alongside infrasound. Detailed chronologies of powerful vulcanian eruptions are rare; this study demonstrates that diverse eruptive processes can occur in such eruptions and that near-vent infrasound and electromagnetic data can elucidate them.

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.

Eruption-induced modifications to volcanic seismicity at Ruapehu, New Zealand, and its implications for eruption forecasting

USGS Publications Warehouse

Bryan, C.J.; Sherburn, S.

2003-01-01

Broadband seismic data collected on Ruapehu volcano, New Zealand, in 1994 and 1998 show that the 1995-1996 eruptions of Ruapehu resulted in a significant change in the frequency content of tremor and volcanic earthquakes at the volcano. The pre-eruption volcanic seismicity was characterized by several independent dominant frequencies, with a 2 Hz spectral peak dominating the strongest tremor and volcanic earthquakes and higher frequencies forming the background signal. The post-eruption volcanic seismicity was dominated by a 0.8-1.4 Hz spectral peak not seen before the eruptions. The 2 Hz and higher frequency signals remained, but were subordinate to the 0.8-1.4 Hz energy. That the dominant frequencies of volcanic tremor and volcanic earthquakes were identical during the individual time periods prior to and following the 1995-1996 eruptions suggests that during each of these time periods the volcanic tremor and earthquakes were generated by the same source process. The overall change in the frequency content, which occurred during the 1995-1996 eruptions and remains as of the time of the writing of this paper, most likely resulted from changes in the volcanic plumbing system and has significant implications for forecasting and real-time assessment of future eruptive activity at Ruapehu.

Solar activity and erupting prominences [HD Video

NASA Image and Video Library

2017-12-08

Solar activity and erupting prominences. EIT 304A (Jan. 8-10, 2000) Credit: NASA/GSFC/SOHO/ESA To learn more go to the SOHO website: sohowww.nascom.nasa.gov/home.html To learn more about NASA's Sun Earth Day go here: sunearthday.nasa.gov/2010/index.php

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

, freshwater aquifer. A 2-D model of the AMT data indicates a resistive layer at about 200 m depth, which may correspond to the aquifer. High conductivity observed in the TEM and AMT data likely reflects saline fluids. Gravity data were collected at approximately 500 m station spacing along transects in Arroyo Alamo and Arroyo Seco 2 km to the south, and throughout the Chimayó Valley. The new data, combined with previously collected data, were used to create regional complete Bouguer anomaly and depth to basement maps. Two-dimensional forward models were constructed to provide a geohydrologic framework consistent with migration of CO2 rich brine up the Chimayó fault to mix with freshwater in the conglomeritic aquifer. The shallow, mixed groundwater emerges at the surface along the Roberts fault and drives the geyser at the Roberts well.

Can rain cause volcanic eruptions?

USGS Publications Warehouse

Mastin, Larry G.

1993-01-01

Volcanic eruptions are renowned for their violence and destructive power. This power comes ultimately from the heat and pressure of molten rock and its contained gases. Therefore we rarely consider the possibility that meteoric phenomena, like rainfall, could promote or inhibit their occurrence. Yet from time to time observers have suggested that weather may affect volcanic activity. In the late 1800's, for example, one of the first geologists to visit the island of Hawaii, J.D. Dana, speculated that rainfall influenced the occurrence of eruptions there. In the early 1900's, volcanologists suggested that some eruptions from Mount Lassen, Calif., were caused by the infiltration of snowmelt into the volcano's hot summit. Most such associations have not been provable because of lack of information; others have been dismissed after careful evaluation of the evidence.

Developing a NASA strategy for sampling a major Pinatubo-like volcanic eruption

NASA Astrophysics Data System (ADS)

Newman, P. A.; Jucks, K. W.; Maring, H. B.

2016-12-01

Based on history, it is reasonable to expect a major volcanic eruption in the foreseeable future. By "major volcanic eruption", we mean an eruption that injects a substantial amount of material, gases and particles, into the stratosphere as a result of one eruption event. Such a volcanic eruption can impact weather, climate, and atmospheric chemistry on regional, hemispheric and global scales over significant time periods. Further, such an eruption can be an unintended analog for a number of geo-engineering schemes for mitigating greenhouse warming of the Earth. In order to understand and project the consequences of a major eruption, it is necessary to make a number of observations from a variety of perspectives. Such an eruption will occur, in the immediate sense, unexpectedly. Therefore, it is wise to have a thoughtfully developed plan for executing a rapid response that makes useful observations. A workshop was held on 17-18 May 2016 at NASA GSFC to develop a NASA observation strategy that could be quickly implemented in response to a major volcanic eruption, and would characterize the changes to atmospheric (especially stratospheric) composition following a large volcanic eruption. In this presentation we will provide an overview of the elements of this strategy with respect to satellite, balloon, ground, and aircraft observations. In addition, models simulations and forecasts will play a key role in any response strategy. Results will also be shown from a spectrum of simulations of volcanic eruptions that support this NASA strategy.

Volcanomagnetic signals during the recent Popocatépetl (México) eruptions and their relation to eruptive activity

NASA Astrophysics Data System (ADS)

Martin-Del Pozzo, A. L.; Cifuentes-Nava, G.; Cabral-Cano, E.; Sánchez-Rubio, G.; Reyes, M.; Martínez-Bringas, Alicia; Garcia, E.; Arango-Galvan, C.

2002-03-01

An interdisciplinary approach correlating magnetic anomalies with composition of the ejecta in each eruption, as well as with seismicity, was used to study the effect of magmatic activity on the local magnetic record at Popocatépetl Volcano located 65 km southeast of México City. Eruptions began on December, 1994, and have continued with dome growth and ash emissions since then. The Tlamacas (TLA) geomagnetic total field monitoring station, located 5 km away from Popocatépetl's crater, was installed in December, 1997, in order to detect magnetic anomalies induced by this activity. Spatial correlation and weighted difference methods were applied to detect temporal geomagnetic anomalies using TLA's record and the Teoloyucan Magnetic Observatory as a reference station. Weighted differences were applied to cancel the effects of non-vulcanogenic external field variations. Magnetic anomalies over a 2-year time span were classified into four types correlating them with geochemical, seismic and visual monitoring of the volcanic activity. Magnetic anomalies are believed to be caused by magma injection and gas pressure build-up, which is sensitive to vent morphology and clearing during eruption, although some anomalies appear to be thermally related, changes in the stress field are very important. Most magnetic anomalies are short time signals that reverse to baseline level. Decreasing anomalies (-0.5 to -6.8 nT) precede eruptions by 1-8 days. The presence of a mafic magmatic component was determined by mineral examination and silica and magnesium analyses on the ejecta from the 1997-1999 eruptions. Whole rock analyses ranged from dacitic (65% SiO 2) to andesitic (57% SiO 2) with 2-6.6% MgO. The higher MgO, lower silica samples contain forsteritic olivine (Fo90). SiO 2 does not increase and MgO does not increase with time, suggesting ascent of small magma pulses which are consistent with the magnetic data.

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.

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

Snaking Filament Eruption

NASA Image and Video Library

2014-11-14

A filament (which at one point had an eerie similarity to a snake) broke away from the sun and out into space (Nov. 1, 2014). The video covers just over three hours of activity. This kind of eruptive event is called a Hyder flare. These are filaments (elongated clouds of gases above the sun's surface) that erupt and cause a brightening at the sun's surface, although no active regions are in that area. It did thrust out a cloud of particles but not towards Earth. The images were taken in the 304 Angstrom wavelength of extreme UV light. Credit: NASA/Solar Dynamics Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

SOLAR MULTIPLE ERUPTIONS FROM A CONFINED MAGNETIC STRUCTURE

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

Lee, Jeongwoo; Chae, Jongchul; Liu, Chang

2016-09-20

How eruption can recur from a confined magnetic structure is discussed based on the Solar Dynamics Observatory observations of the NOAA active region 11444, which produced three eruptions within 1.5 hr on 2012 March 27. The active region (AR) had the positive-polarity magnetic fields in the center surrounded by the negative-polarity fields around. Since such a distribution of magnetic polarity tends to form a dome-like magnetic fan structure confined over the AR, the multiple eruptions were puzzling. Our investigation reveals that this event exhibits several properties distinct from other eruptions associated with magnetic fan structures: (i) a long filament encirclingmore » the AR was present before the eruptions; (ii) expansion of the open–closed boundary (OCB) of the field lines after each eruption was suggestive of the growing fan-dome structure, and (iii) the ribbons inside the closed magnetic polarity inversion line evolved in response to the expanding OCB. It thus appears that in spite of multiple eruptions the fan-dome structure remained undamaged, and the closing back field lines after each eruption rather reinforced the fan-dome structure. We argue that the multiple eruptions could occur in this AR in spite of its confined magnetic structure because the filament encircling the AR was adequate for slipping through the magnetic separatrix to minimize the damage to its overlying fan-dome structure. The result of this study provides a new insight into the productivity of eruptions from a confined magnetic structure.« less

Eruptive history of the Dieng Mountains region, central Java, and potential hazards from future eruptions

USGS Publications Warehouse

Miller, C. Dan; Sushyar, R.; ,; Hamidi, S.

1983-01-01

The Dieng Mountains region consists of a complex of late Quaternary to recent volcanic stratocones, parasitic vents, and explosion craters. Six age groups of volcanic centers, eruptive products, and explosion craters are recognized in the region based on their morphology, degree of dissection, stratigraphic relationships, and degree of weathering. These features range in age from tens of thousands of years to events that have occurred this century. No magmatic eruptions have occurred in the Dieng Mountains region for at least several thousand years; volcanic activity during this time interval has consisted of phreatic eruptions and non-explosive hydrothermal activity. If future volcanic events are similar to those of the last few thousand years, they will consist of phreatic eruptions, associated small hot mudflows, emission of suffocating gases, and hydrothermal activity. Future phreatic eruptions may follow, or accompany, periods of increased earthquake activity; the epicenters for the seismicity may suggest where eruptive activity will occur. Under such circumstances, the populace within several kilometers of a potential eruption site should be warned of a possible eruption, given instructions about what to do in the event of an eruption, or temporarily evacuated to a safer location.

Eruption dynamics and explosive-effusive transitions during the 1400 cal BP eruption of Opala volcano, Kamchatka, Russia

NASA Astrophysics Data System (ADS)

Andrews, Benjamin J.; Dufek, Josef; Ponomareva, Vera

2018-05-01

Deposits and pumice from the 1400 cal BP eruption of Opala volcano record activity that occurred at the explosive-effusive transition, resulting in intermittent, or stop-start, behavior, where explosive activity resumed following a pause. The eruption deposited distinctive, biotite-bearing rhyolite tephra across much of Kamchatka, and its stratigraphy consists of a lithic-rich pumice fall, overlain by pumice falls and pyroclastic density deposits, with the proportion of the latter increasing with height. This sequence repeats such that the middle of the total deposit is marked by a lithic-rich fall with abundant obsidian clasts. Notably, the eruptive pumice are poorly vesiculated, with vesicle textures that record fragmentation of a partially collapsed magmatic foam. The eruption vent, Baranii Amphitheater is filled with obsidian lavas of the same composition as the rhyolite tephra. Based upon the stratigraphic and compositional relations, we divide the eruption into four phases. Phase I initiated with eruption of a lithic-rich pumice fall, followed by eruption of Plinian falls and pyroclastic density currents. During Phase II, the eruption paused for at least 5-6 h; in this time, microlites nucleated and began to grow in the magma. Phase III essentially repeated the Phase I sequence. Obsidian lavas were emplaced during Phase IV. The pumice textures suggest that the magma ascended very near the threshold decompression rate for the transition between explosive (fast) and effusive (slow) behavior. The pause during Phase II likely occurred as decompression slowed enough for the magma to develop sufficient permeability for gas to escape resulting in collapse of the magmatic foam, stopping the eruption and temporarily sealing the conduit. After about 5-6 h, eruption resumed with, once again, magma decompressing very near the explosive-effusive transition. Phase III ended when the decompression rate slowed and lava dome emplacement began. Distributions of pumice and

Analysis of the seismic activity associated with the 2010 eruption of Merapi Volcano, Java

NASA Astrophysics Data System (ADS)

Budi-Santoso, Agus; Lesage, Philippe; Dwiyono, Sapari; Sumarti, Sri; Subandriyo; Surono; Jousset, Philippe; Metaxian, Jean-Philippe

2013-07-01

The 2010 eruption of Merapi is the first large explosive eruption of the volcano that has been instrumentally observed. The main characteristics of the seismic activity during the pre-eruptive period and the crisis are presented and interpreted in this paper. The first seismic precursors were a series of four shallow swarms during the period between 12 and 4 months before the eruption. These swarms are interpreted as the result of perturbations of the hydrothermal system by increasing heat flow. Shorter-term and more continuous precursory seismic activity started about 6 weeks before the initial explosion on 26 October 2010. During this period, the rate of seismicity increased almost constantly yielding a cumulative seismic energy release for volcano-tectonic (VT) and multiphase events (MP) of 7.5 × 1010 J. This value is 3 times the maximum energy release preceding previous effusive eruptions of Merapi. The high level reached and the accelerated behavior of both the deformation of the summit and the seismic activity are distinct features of the 2010 eruption. The hypocenters of VT events in 2010 occur in two clusters at of 2.5 to 5 km and less than 1.5 km depths below the summit. An aseismic zone was detected at 1.5-2.5 km depth, consistent with studies of previous eruptions, and indicating that this is a robust feature of Merapi's subsurface structure. Our analysis suggests that the aseismic zone is a poorly consolidated layer of altered material within the volcano. Deep VT events occurred mainly before 17 October 2010; subsequent to that time shallow activity strongly increased. The deep seismic activity is interpreted as associated with the enlargement of a narrow conduit by an unusually large volume of rapidly ascending magma. The shallow seismicity is interpreted as recording the final magma ascent and the rupture of a summit-dome plug, which triggered the eruption on 26 October 2010. Hindsight forecasting of the occurrence time of the eruption is performed

Incorporating the eruptive history in a stochastic model for volcanic eruptions

NASA Astrophysics Data System (ADS)

Bebbington, Mark

2008-08-01

We show how a stochastic version of a general load-and-discharge model for volcanic eruptions can be implemented. The model tracks the history of the volcano through a quantity proportional to stored magma volume. Thus large eruptions can influence the activity rate for a considerable time following, rather than only the next repose as in the time-predictable model. The model can be fitted to data using point-process methods. Applied to flank eruptions of Mount Etna, it exhibits possible long-term quasi-cyclic behavior, and to Mauna Loa, a long-term decrease in activity. An extension to multiple interacting sources is outlined, which may be different eruption styles or locations, or different volcanoes. This can be used to identify an 'average interaction' between the sources. We find significant evidence that summit eruptions of Mount Etna are dependent on preceding flank eruptions, with both flank and summit eruptions being triggered by the other type. Fitted to Mauna Loa and Kilauea, the model had a marginally significant relationship between eruptions of Mauna Loa and Kilauea, consistent with the invasion of the latter's plumbing system by magma from the former.

Recent eruptive history of Mount Hood, Oregon, and potential hazards from future eruptions

USGS Publications Warehouse

Crandell, Dwight Raymond

1980-01-01

Each of three major eruptive periods at Mount Hood (12,000-15,000(?), 1,500-1,800, and 200-300 years ago) produced dacite domes, pyroclastic flows, and mudflows, but virtually no pumice. Most of the fine lithic ash that mantles the slopes of the volcano and the adjacent mountains fell from ash clouds that accompanied the pyroclastic flows. Widely scattered pumice lapilli that are present at the ground surface on the south, east, and north sides of Mount Hood may have been erupted during the mid-1800's, when the last known activity of the volcano occurred. The geologically recent history of Mount Hood suggests that the most likely eruptive event in the future will be the formation of another dome, probably within the present south-facing crater. The principal hazards that could accompany dome formation include pyroclastic flows and mudflows moving from the upper slopes of the volcano down the floors of valleys. Ash clouds which accompany pyroclastic flows may deposit as much as a meter of fine ash close to their source, and as much as 20 centimeters at a distance of 11 kilometers downwind from the pyroclastic flows. Other hazards that could result from such eruptions include laterally directed explosive blasts that could propel rock fragments outward from the sides of a dome at high speed, and toxic volcanic gases. The scarcity of pumiceous ash erupted during the last 15,000 years suggests that explosive pumice eruptions are not a major hazard at Mount Hood; thus, there seems to be little danger that such an eruption will significantly affect the Portland (Oregon) metropolitan area in the near future.

Yohimbine-induced cutaneous drug eruption, progressive renal failure, and lupus-like syndrome.

PubMed

Sandler, B; Aronson, P

1993-04-01

Yohimbine is an indole alkaloid obtained from the yohimbe tree, a common tree in West Africa. We describe a forty-two-year black man in whom a generalized erythrodermic skin eruption, progressive renal failure, and lupus-like syndrome developed following treatment with the drug, yohimbine. A literature review failed to reveal any reported association of these side effects. We review current information on yohimbine's use in male impotence, reported side effects, and its role as a drug allergen.

Volcanology and eruptive styles of Barren Island: an active mafic stratovolcano in the Andaman Sea, NE Indian Ocean

NASA Astrophysics Data System (ADS)

Sheth, Hetu C.; Ray, Jyotiranjan S.; Bhutani, Rajneesh; Kumar, Alok; Smitha, R. S.

2009-11-01

Barren Island (India) is a relatively little studied, little known active volcano in the Andaman Sea, and the northernmost active volcano of the great Indonesian arc. The volcano is built of prehistoric (possibly late Pleistocene) lava flows (dominantly basalt and basaltic andesite, with minor andesite) intercalated with volcaniclastic deposits (tuff breccias, and ash beds deposited by pyroclastic falls and surges), which are exposed along a roughly circular caldera wall. There are indications of a complete phreatomagmatic tephra ring around the exposed base of the volcano. A polygenetic cinder cone has existed at the centre of the caldera and produced basalt-basaltic andesite aa and blocky aa lava flows, as well as tephra, during historic eruptions (1787-1832) and three recent eruptions (1991, 1994-95, 2005-06). The recent aa flows include a toothpaste aa flow, with tilted and overturned crustal slabs carried atop an aa core, as well as locally developed tumuli-like elliptical uplifts having corrugated crusts. Based on various evidence we infer that it belongs to either the 1991 or the 1994-95 eruptions. The volcano has recently (2008) begun yet another eruption, so far only of tephra. We make significantly different interpretations of several features of the volcano than previous workers. This study of the volcanology and eruptive styles of the Barren Island volcano lays the ground for detailed geochemical-isotopic and petrogenetic work, and provides clues to what the volcano can be expected to do in the future.

Chronology of Postglacial Eruptive Activity and Calculation of Eruption Probabilities for Medicine Lake Volcano, Northern California

USGS Publications Warehouse

Nathenson, Manuel; Donnelly-Nolan, Julie M.; Champion, Duane E.; Lowenstern, Jacob B.

2007-01-01

Medicine Lake volcano has had 4 eruptive episodes in its postglacial history (since 13,000 years ago) comprising 16 eruptions. Time intervals between events within the episodes are relatively short, whereas time intervals between the episodes are much longer. An updated radiocarbon chronology for these eruptions is presented that uses paleomagnetic data to constrain the choice of calibrated ages. This chronology is used with exponential, Weibull, and mixed-exponential probability distributions to model the data for time intervals between eruptions. The mixed exponential distribution is the best match to the data and provides estimates for the conditional probability of a future eruption given the time since the last eruption. The probability of an eruption at Medicine Lake volcano in the next year from today is 0.00028.

Forecasting the duration of volcanic eruptions: an empirical probabilistic model

NASA Astrophysics Data System (ADS)

Gunn, L. S.; Blake, S.; Jones, M. C.; Rymer, H.

2014-01-01

The ability to forecast future volcanic eruption durations would greatly benefit emergency response planning prior to and during a volcanic crises. This paper introduces a probabilistic model to forecast the duration of future and on-going eruptions. The model fits theoretical distributions to observed duration data and relies on past eruptions being a good indicator of future activity. A dataset of historical Mt. Etna flank eruptions is presented and used to demonstrate the model. The data have been compiled through critical examination of existing literature along with careful consideration of uncertainties on reported eruption start and end dates between the years 1300 AD and 2010. Data following 1600 is considered to be reliable and free of reporting biases. The distribution of eruption duration between the years 1600 and 1669 is found to be statistically different from that following it and the forecasting model is run on two datasets of Mt. Etna flank eruption durations: 1600-2010 and 1670-2010. Each dataset is modelled using a log-logistic distribution with parameter values found by maximum likelihood estimation. Survivor function statistics are applied to the model distributions to forecast (a) the probability of an eruption exceeding a given duration, (b) the probability of an eruption that has already lasted a particular number of days exceeding a given total duration and (c) the duration with a given probability of being exceeded. Results show that excluding the 1600-1670 data has little effect on the forecasting model result, especially where short durations are involved. By assigning the terms `likely' and `unlikely' to probabilities of 66 % or more and 33 % or less, respectively, the forecasting model based on the 1600-2010 dataset indicates that a future flank eruption on Mt. Etna would be likely to exceed 20 days (± 7 days) but unlikely to exceed 86 days (± 29 days). This approach can easily be adapted for use on other highly active, well

Eruption History of Cone D: Implications for Current and Future Activity at Okmok Caldera

NASA Astrophysics Data System (ADS)

Beget, J.; Almberg, L.; Faust-Larsen, J.; Neal, C.

2008-12-01

Cone B at Okmok Caldera erupted in 1817, and since then activity has beeen centered in and around Cone A in the SW part of Okmok Caldera. However, prior to 1817 at least a half dozen other eruptive centers were active at various times within the caldera. Cone D was active between ca. 2000-1500 yr BP., and underwent at least two separate intervals characterized by violent hydromagmatic explosions and surge production followed by the construction of extensive lava deltas in a 150-m-deep intra-caldera lake. Reconstructions of cone morphology indicate the hydromagmatic explosions occurred when lake levels were shallow or when the eruptive cones had grown to reach the surface of the intra-caldera lake. The effusion rate over this interval averaged several million cubic meters of lava per year, implying even higher outputs during the actual eruptive episodes. At least two dozen tephra deposits on the volcano flanks date to this interval, and record frequent explosive eruptions. The pyroclastic flows and surges from Cone D and nearby cones extend as far as 14 kilometers from the caldera rim, where dozens of such deposits are preserved in a section as much as 6 m thick at a distance of 8 km beyond the rim. A hydromagmatic explosive eruption at ca. 1500 yr BP generated very large floods and resulted in the draining of the caldera lake. The 2008 hydromagmatic explosive eruptions in the Cone D area caused by interactions with lake water resulted in the generation of surges, floods and lahars that are smaller but quite similar in style to the prehistoric eruptions at Cone E ca. 2000-1500 yr BP. The style and magnitude of future eruptions at vents around Cone D will depend strongly on the evolution of the intra-caldera lake system.

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

A Comparative Study of the Eruptive and Non-eruptive Flares Produced by the Largest Active Region of Solar Cycle 24

NASA Astrophysics Data System (ADS)

Sarkar, Ranadeep; Srivastava, Nandita

2018-02-01

We investigate the morphological and magnetic characteristics of solar active region (AR) NOAA 12192. AR 12192 was the largest region of Solar Cycle 24; it underwent noticeable growth and produced 6 X-class flares, 22 M-class flares, and 53 C-class flares in the course of its disc passage. However, the most peculiar fact of this AR is that it was associated with only one CME in spite of producing several X-class flares. In this work, we carry out a comparative study between the eruptive and non-eruptive flares produced by AR 12192. We find that the magnitude of abrupt and permanent changes in the horizontal magnetic field and Lorentz force are significantly smaller in the case of the confined flares compared to the eruptive one. We present the areal evolution of AR 12192 during its disc passage. We find the flare-related morphological changes to be weaker during the confined flares, whereas the eruptive flare exhibits a rapid and permanent disappearance of penumbral area away from the magnetic neutral line after the flare. Furthermore, from the extrapolated non-linear force-free magnetic field, we examine the overlying coronal magnetic environment over the eruptive and non-eruptive zones of the AR. We find that the critical decay index for the onset of torus instability was achieved at a lower height over the eruptive flaring region, than for the non-eruptive core area. These results suggest that the decay rate of the gradient of overlying magnetic-field strength may play a decisive role to determine the CME productivity of the AR. In addition, the magnitude of changes in the flare-related magnetic characteristics are found to be well correlated with the nature of solar eruptions.

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

Introduction to the 2012-2013 Tolbachik eruption special issue

NASA Astrophysics Data System (ADS)

Edwards, Benjamin R.; Belousov, Alexander; Belousova, Marina; Volynets, Anna

2015-12-01

The Tolbachik volcanic complex in central Kamchatka holds a special place in global volcanological studies. It is one of 4 areas of extensive historic volcanic activity in the northern part of the Central Kamchatka Depression (the others being Klyuchevskoy, Bezymianny, Shiveluch), and is part of the Klyuchevskoy volcanic group, which is one of the most active areas of volcanism on Earth. Tolbachik is especially well-known due largely to the massive 1975-1976 eruption that became known as the Great Tolbachik Fissure eruption (GTFE; Fedotov, 1983; Fedotov et al., 1984). This was one of the first eruptions in Russia to be predicted based on precursory seismic activity, based on M5 earthquakes approximately one week before the eruption started, and was intensively studied during its course by a large number of Russian scientists. A summary of those studies was published, first in Russian and then in English, and it became widely read for many reasons. One in particular is that the eruption was somewhat unusual for a subduction zone setting; although many subduction zone stratovolcanoes have associated basaltic tephra cone-lava fields, this was the first such Hawaiian-style eruption to be widely observed. After the end of the eruption in 1976, the complex showed no signs of activity until 27 November 2012, when increased seismic activity was registered by the Kamchatka Branch of the Russian Geophysical Survey and a red glow from the eruption site was first noticed through the snowstorm haze. This prompted them, and then the Kamchatka Volcanic Emergency Response Team (KVERT) to issue an alert that activity was coming from the south flank of Plosky Tolbachik volcano, the younger of two volcanic edifices (the older is Ostry Tolbachik) that together make up the bulk of the complex along with tephra cone-lava fields that lie along a NE-SW fissure zone that transects Plosky Tolbachik. The new eruption lasted for more than 250 days and, like the 1975-1976 eruption, was

Seismicity and eruptive activity at Fuego Volcano, Guatemala: February 1975 -January 1977

USGS Publications Warehouse

Yuan, A.T.E.; McNutt, S.R.; Harlow, D.H.

1984-01-01

We examine seismic and eruptive activity at Fuego Volcano (14??29???N, 90?? 53???W), a 3800-m-high stratovolcano located in the active volcanic arc of Guatemala. Eruptions at Fuego are typically short-lived vulcanian eruptions producing ash falls and ash flows of high-alumina basalt. From February 1975 to December 1976, five weak ash eruptions occurred, accompanied by small earthquake swarms. Between 0 and 140 (average ??? 10) A-type or high-frequency seismic events per day with M > 0.5 were recorded during this period. Estimated thermal energies for each eruption are greater by a factor of 106 than cumulative seismic energies, a larger ratio than that reported for other volcanoes. Over 4000 A-type events were recorded January 3-7, 1977 (cumulative seismic energy ??? 109 joules), yet no eruption occurred. Five 2-hour-long pulses of intense seismicity separated by 6-hour intervals of quiescence accounted for the majority of events. Maximum likelihood estimates of b-values range from 0.7 ?? 0.2 to 2.1 ?? 0.4 with systematically lower values corresponding to the five intense pulses. The low values suggest higher stress conditions. During the 1977 swarm, a tiltmeter located 6 km southeast of Fuego recorded a 14 ?? 3 microradian tilt event (down to SW). This value is too large to represent a simple change in the elastic strain field due to the earthquake swarm. We speculate that the earthquake swarm and tilt are indicative of subsurface magma movement. ?? 1984.

Setting of the Father's Day Eruption at Kilauea

NASA Astrophysics Data System (ADS)

Swanson, D. A.

2007-12-01

the zone. The Koa`e fault system joins the east rift zone at the curve. The complex structural setting likely affects the frequency of magmatic activity in the segment. All of the eruptive and intrusive activity results in storage of isolated magma bodies. Not surprisingly, petrologists find evidence that summit magma mixes with stored, fractionated magma. The area near Makaopuhi Crater and Kane Nui o Hamo is a particular focus, inferred since the mid-1960s to harbor a shallow magma reservoir. All of the eruptions and intrusions are accompanied by sharp deflation and shallow seismicity at the summit and shallow seismicity and uplift along the intrusion or eruptive fissures. Most often, no seismicity occurs between the summit and the area of intrusion or eruption. Within that area, seismicity commonly migrates downrift but occasionally uprift. Similarly, crack opening generally progresses downrift, with a few exceptions. Cracks generally trend about 65 degrees and can be either left- or right-stepping. Cracks open along azimuths of 155-175, with local exceptions. There is no structural difference between eruptive cracks (fissures) and non- eruptive cracks. Single eruptive fissures rarely exceed 200 m in length, instead stepping within en echelon zones above a presumably linear dike. Since the late 1960s, widening has been measured across the active area during eruptions and intrusions, first by EDM and then by satellite-based systems. The opening is nearly symmetrical within the rift zone, but farther out the north flank barely responds whereas the south flank moves seaward. Available leveling data show uplift on either side of the dike and subsidence along the crest. Examples of deformation in the 1960s and 1970s will be presented, and bibliographic references to past activity will be available.

Volcanism in Iceland in historical time: Volcano types, eruption styles and eruptive history

NASA Astrophysics Data System (ADS)

Thordarson, T.; Larsen, G.

2007-01-01

The large-scale volcanic lineaments in Iceland are an axial zone, which is delineated by the Reykjanes, West and North Volcanic Zones (RVZ, WVZ, NVZ) and the East Volcanic Zone (EVZ), which is growing in length by propagation to the southwest through pre-existing crust. These zones are connected across central Iceland by the Mid-Iceland Belt (MIB). Other volcanically active areas are the two intraplate belts of Öræfajökull (ÖVB) and Snæfellsnes (SVB). The principal structure of the volcanic zones are the 30 volcanic systems, where 12 are comprised of a fissure swarm and a central volcano, 7 of a central volcano, 9 of a fissure swarm and a central domain, and 2 are typified by a central domain alone. Volcanism in Iceland is unusually diverse for an oceanic island because of special geological and climatological circumstances. It features nearly all volcano types and eruption styles known on Earth. The first order grouping of volcanoes is in accordance with recurrence of eruptions on the same vent system and is divided into central volcanoes (polygenetic) and basalt volcanoes (monogenetic). The basalt volcanoes are categorized further in accordance with vent geometry (circular or linear), type of vent accumulation, characteristic style of eruption and volcanic environment (i.e. subaerial, subglacial, submarine). Eruptions are broadly grouped into effusive eruptions where >95% of the erupted magma is lava, explosive eruptions if >95% of the erupted magma is tephra (volume calculated as dense rock equivalent, DRE), and mixed eruptions if the ratio of lava to tephra occupy the range in between these two end-members. Although basaltic volcanism dominates, the activity in historical time (i.e. last 11 centuries) features expulsion of basalt, andesite, dacite and rhyolite magmas that have produced effusive eruptions of Hawaiian and flood lava magnitudes, mixed eruptions featuring phases of Strombolian to Plinian intensities, and explosive phreatomagmatic and magmatic

Terbinafine induced pityriasis rosea-like eruption.

PubMed

George, Anisha; Bhatia, Anuradha; Kanish, Bimal; Williams, Abhilasha

2015-01-01

Terbinafine is an allylamine antifungal agent which is widely used for the treatment of fungal infections. Cutaneous side effects have been reported in 2% of the patients on terbinafine therapy with many morphological patterns. We report a case of terbinafine induced pityriasis rosea, a very rare side effect of terbinafine. This report emphasizes the importance of counseling the patient to report immediately in the event of a cutaneous eruption.

Terbinafine induced pityriasis rosea-like eruption

PubMed Central

George, Anisha; Bhatia, Anuradha; Kanish, Bimal; Williams, Abhilasha

2015-01-01

Terbinafine is an allylamine antifungal agent which is widely used for the treatment of fungal infections. Cutaneous side effects have been reported in 2% of the patients on terbinafine therapy with many morphological patterns. We report a case of terbinafine induced pityriasis rosea, a very rare side effect of terbinafine. This report emphasizes the importance of counseling the patient to report immediately in the event of a cutaneous eruption. PMID:26729964

WOVOdat as a worldwide resource to improve eruption forecasts

NASA Astrophysics Data System (ADS)

Widiwijayanti, Christina; Costa, Fidel; Zar Win Nang, Thin; Tan, Karine; Newhall, Chris; Ratdomopurbo, Antonius

2015-04-01

During periods of volcanic unrest, volcanologists need to interpret signs of unrest to be able to forecast whether an eruption is likely to occur. Some volcanic eruptions display signs of impending eruption such as seismic activity, surface deformation, or gas emissions; but not all will give signs and not all signs are necessarily followed by an eruption. Volcanoes behave differently. Precursory signs of an eruption are sometimes very short, less than an hour, but can be also weeks, months, or even years. Some volcanoes are regularly active and closely monitored, while other aren't. Often, the record of precursors to historical eruptions of a volcano isn't enough to allow a forecast of its future activity. Therefore, volcanologists must refer to monitoring data of unrest and eruptions at similar volcanoes. WOVOdat is the World Organization of Volcano Observatories' Database of volcanic unrest - an international effort to develop common standards for compiling and storing data on volcanic unrests in a centralized database and freely web-accessible for reference during volcanic crises, comparative studies, and basic research on pre-eruption processes. WOVOdat will be to volcanology as an epidemiological database is to medicine. We have up to now incorporated about 15% of worldwide unrest data into WOVOdat, covering more than 100 eruption episodes, which includes: volcanic background data, eruptive histories, monitoring data (seismic, deformation, gas, hydrology, thermal, fields, and meteorology), monitoring metadata, and supporting data such as reports, images, maps and videos. Nearly all data in WOVOdat are time-stamped and geo-referenced. Along with creating a database on volcanic unrest, WOVOdat also developing web-tools to help users to query, visualize, and compare data, which further can be used for probabilistic eruption forecasting. Reference to WOVOdat will be especially helpful at volcanoes that have not erupted in historical or 'instrumental' time and

Evolution of submarine eruptive activity during the 2011-2012 El Hierro event as documented by hydroacoustic images and remotely operated vehicle observations

NASA Astrophysics Data System (ADS)

Somoza, L.; González, F. J.; Barker, S. J.; Madureira, P.; Medialdea, T.; de Ignacio, C.; Lourenço, N.; León, R.; Vázquez, J. T.; Palomino, D.

2017-08-01

Submarine volcanic eruptions are frequent and important events, yet they are rarely observed. Here we relate bathymetric and hydroacoustic images from the 2011 to 2012 El Hierro eruption with surface observations and deposits imaged and sampled by ROV. As a result of the shallow submarine eruption, a new volcano named Tagoro grew from 375 to 89 m depth. The eruption consisted of two main phases of edifice construction intercalated with collapse events. Hydroacoustic images show that the eruptions ranged from explosive to effusive with variable plume types and resulting deposits, even over short time intervals. At the base of the edifice, ROV observations show large accumulations of lava balloons changing in size and type downslope, coinciding with the area where floating lava balloon fallout was observed. Peaks in eruption intensity during explosive phases generated vigorous bubbling at the surface, extensive ash, vesicular lapilli and formed high-density currents, which together with periods of edifice gravitational collapse, produced extensive deep volcaniclastic aprons. Secondary cones developed in the last stages and show evidence for effusive activity with lava ponds and lava flows that cover deposits of stacked lava balloons. Chaotic masses of heterometric boulders around the summit of the principal cone are related to progressive sealing of the vent with decreasing or variable magma supply. Hornitos represent the final eruptive activity with hydrothermal alteration and bacterial mats at the summit. Our study documents the distinct evolution of a submarine volcano and highlights the range of deposit types that may form and be rapidly destroyed in such eruptions.