86 results on '"*SUPERVOLCANOES"'
Search Results
2. HIDDEN INFERNO.
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Hall, Shannon
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SUPERVOLCANOES , *VOLCANIC eruptions , *LOW temperatures , *VOLCANOES - Abstract
The article reports that a supervolocano may be brewing underneath Chile, with a cold interior that is upending ideas about triggers of huge eruptions. Topics discussed include forces unleashed by historic supervolcanoes, how supervolcanoes erupt, concerns with the stone-cold temperature of Laguna del Maule and how frozen systems melt and mobilize so rapidly.
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- 2018
3. A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system, Colorado, USA.
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Morgan, Leah E., Johnstone, Samuel A., Gilmer, Amy K., Cosca, Michael A., and Thompson, Ren A.
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SUPERVOLCANOES , *VOLCANIC eruptions , *MAGMAS , *GEOCHRONOMETRY - Abstract
Establishing temporal constraints on major volcanic eruptions is limited by the precision of existing geochronometers. Prior work on the La Garita caldera (Colorado, USA), created by the eruption of the Fish Canyon Tuff, failed to resolve temporal differences between pre-, syn-, and post-collapse eruptive units. Here, we report 40Ar/39Ar geochronologic data supporting a ~100 ka eruptive history of the La Garita caldera, and resolving the timing of the pre-caldera Pagosa Peak Dacite, syn-caldera Fish Canyon Tuff, and post-caldera dacite of Nutras Creek. Minimizing uncertainty in neutron fluence by rotating samples during irradiation and employing Bayesian statistical interpretation of analytical data enables resolution of the ~60 ka pre-caldera eruptive history and a hiatus of 0-20 ka prior to the eruption of post-caldera lavas. The improved precision demonstrated using these methods provides previously unresolvable temporal constraints on physical processes in the La Garita magmatic system and underscores the potential of unraveling other closely spaced events in geologic time. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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4. Seismic evidence for significant melt beneath the Long Valley Caldera, California, USA.
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Flinders, Ashton F., Shelly, David R., Dawson, Philip B., Hill, David P., Tripoli, Barbara, and Yang Shen
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SUPERVOLCANOES , *VOLCANOES , *VOLCANIC ash, tuff, etc. , *MAGMAS , *RESERVOIRS - Abstract
A little more than 760 ka ago, a supervolcano on the eastern edge of California (United States) underwent one of North America's largest Quaternary explosive eruptions. Over this ~6-day-long eruption, pyroclastic flows blanketed the surrounding ~50 km with more than 1400 km³ of the now-iconic Bishop Tuff, with ashfall reaching as far east as Nebraska. Collapse of the volcano's magma reservoir created the restless Long Valley Caldera. Although no rhyolitic eruptions have occurred in 100 k.y., beginning in 1978, ongoing uplift suggests new magma may have intruded into the reservoir. Alternatively, the reservoir could be approaching final crystallization, with present-day uplift related to the expulsion of fluid from the last vestiges of melt. Despite 40 years of diverse investigations, the presence of large volumes of melt in Long Valley's magma reservoir remain unresolved. Here we show, through full waveform seismic tomography, a mid-crustal zone of low shear-wave velocity. We estimate the reservoir contains considerable quantities of melt, >1000 km³, at melt fractions as high as ~27%. While supervolcanoes like Long Valley are rare, understanding the volume and concentration of melt in their magma reservoirs is critical for determining their potential hazard. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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5. Exodus on the exploding Earth.
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Ravilious, Kate
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NATURAL disaster research , *EFFECT of volcanic eruptions on evolution (Biology) , *HUMAN evolution , *EFFECT of volcanic eruptions on Earth temperature , *VOLCANIC eruptions , *SUPERVOLCANOES ,ENVIRONMENTAL aspects - Abstract
The article discusses the impact of volcanic eruptions on early humans. The focus of the article is the supervolcano Toba on the Indonesian island of Sumatra that erupted 74,000 years ago. According to researchers, archaeological digs in India have provided clarification on the eruption and its effects, such as how it shaped human evolution and migration. Topics include the significance of the event which, according to scientists, happened during a crucial period of human evolution and criticism from some atmospheric scientists who argue that the climate changes that occurred after the volcanic eruption have been overestimated. An in-depth discussion regarding the adaptation by early hominins to the environmental changes caused by Toba's eruption is presented.
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- 2010
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6. Probing the Volcanic-Plutonic Connection and the Genesis of Crystal-rich Rhyolite in a Deeply Dissected Supervolcano in the Nevada Great Basin: Source of the Late Eocene Caetano Tuff.
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Watts, Kathryn E., John, David A., Colgan, Joseph P., Henry, Christopher D., Bindeman, Ilya N., and Schmitt, Axel K.
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VOLCANOLOGY , *IGNEOUS intrusions , *RHYOLITE , *SUPERVOLCANOES , *GEOCHEMISTRY - Abstract
Late Cenozoic faulting and large-magnitude extension in the Great Basin of the western USA has created locally deep windows into the upper crust, permitting direct study of volcanic and plutonic rocks within individual calderas. The Caetano caldera in north-central Nevada, formed during the mid-Tertiary ignimbrite flare-up, offers one of the best exposed and most complete records of caldera magmatism. Integrating whole-rock geochemistry, mineral chemistry, isotope geochemistry and geochronology with field studies and geologic mapping, we define the petrologic evolution of the magmatic system that sourced the >1100km³ Caetano Tuff. The intra-caldera Caetano Tuff is up to ~5km thick, composed of crystal-rich (30-45 vol. %), high-silica rhyolite, overlain by a smaller volume of comparably crystal-rich, low-silica rhyolite. It defies classification as either a monotonous intermediate or crystal-poor zoned rhyolite, as commonly ascribed to ignimbrite eruptions. Crystallization modeling based on the observed mineralogy and major and trace element geochemistry demonstrates that the compositional zonation can be explained by liquid-cumulate evolution in the Caetano Tuff magma chamber, with the more evolved lower Caetano Tuff consisting of extracted liquids that continued to crystallize and mix in the upper part of the chamber following segregation from a cumulate-rich, and more heterogeneous, source mush. The latter is represented in the caldera stratigraphy by the less evolved upper Caetano Tuff. Whole-rock major, trace and rare earth element geochemistry, modal mineralogy and mineral chemistry, O, Sr, Nd and Pb isotope geochemistry, sanidine Ar-Ar geochronology, and zircon U-Pb geochronology and trace element geochemistry provide robust evidence that the voluminous caldera intrusions (Carico Lake pluton and Redrock Canyon porphyry) are genetically equivalent to the least evolved Caetano Tuff and formed from magma that remained in the lower chamber after ignimbrite eruption and caldera collapse. Thus, the Caetano Tuff contradicts models for the mutually exclusive origins of voluminous volcanic and plutonic magmas in the upper crust. Crystal-scale O isotope data indicate that the Caetano Tuff is one of the most 18O-enriched rhyolites in the Great Basin (δ18Omagma = 10.2±0.2‰), supporting anatexis of local metasedimentary basement crust. Metapelite xenoliths in the Carico Lake pluton and ubiquitous xenocrystic zircons in the Caetano Tuff provide constraints for the anatexis process; these data point to shallow (<15 km) dehydration melting of a protolith similar to the Proterozoic McCoy Creek Group siliciclastic sediments in eastern Nevada, projected beneath Caetano in fault-stacked shelf sediments that were thickened during Mesozoic crustal shortening. Mean zircon U-Pb ages for different stratigraphic levels of the intra-caldera Caetano Tuff are 34.2-34.5 Ma, 0.2-0.5 Myr older than the caldera sanidine 40Ar/39Ar age of 34.00±0.03 Ma, documenting protracted duration of assembly and homogenization of isotopically diverse upper crustal melts, followed by crystallization and zonation to generate the Caetano Tuff magma chamber. Sanidine rims in the least evolved Caetano Tuff and in the Carico Lake pluton and Redrock Canyon porphyry have sharply zoned Ba domains that point to crystal growth during magmatic recharge events. The recharge magma is inferred to have been compositionally similar to the Caetano Tuff magma, with increased Ba resulting from remelting of Ba-rich sanidine cumulates. Mush reactivation to generate the Caetano Tuff eruption was sufficiently rapid to preserve compositional gradients in the intracaldera ignimbrite, calling into question models that predict homogeneity as a prerequisite for remobilizing crystal-rich ignimbrite magmas. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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7. Geodigest.
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GLACIERS , *GLACIOLOGISTS , *SUPERVOLCANOES , *GLOBAL warming ,GLACIERS & climate - Abstract
The article focuses on a new study by a team of French glaciologists, which reveals that glaciers of the Pyrenees may disappear by 2050. Topics discussed include impact of global warming, geophysical monitoring of the ground above active supervolcanoes, and the discovery of an iron dagger in the folds of the cloth of Tutankhamun's mummy.
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- 2016
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8. Age of the Laschamp excursion determined by U-Th dating of a speleothem geomagnetic record from North America.
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Lascu, Ioan, Feinberg, Joshua M., Dorale, Jeffrey A., Hai Cheng, and Edwards, R. Lawrence
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SUPERVOLCANOES , *LAST Glacial Maximum , *VOLCANIC eruptions , *SPELEOTHEMS , *GEOLOGICAL time scales , *GEOMAGNETISM , *ISOTOPE geology - Abstract
The Laschamp geomagnetic excursion was the first short-lived polarity event recognized and described in the paleomagnetic record, and to date remains the most studied geomagnetic event of its kind. In addition to its geophysical significance, the Laschamp is an important global geochronologic marker. The Laschamp excursion occurred around the time of the demise of Homo neanderthalensis, in conjunction with high-amplitude, rapid climatic oscillations leading into the Last Glacial Maximum, and coeval with a major supervolcano eruption in the Mediterranean. Thus, precise determination of the timing and duration of the Laschamp excursion would help in elucidating major scientific questions situated at the intersection of geology, paleoclimatology, and anthropology. Here we present a North American speleothem geomagnetic record of the Laschamp excursion that is directly dated using a combination of high-precision 230Th dates and annual layer counting using confocal microscopy. We have determined a maximum excursion duration that spans the interval 42.25-39.70 ka B.P., and an age of 41.10 ± 0.35 ka B.P. for the main phase of the excursion, during which the virtual geomagnetic pole was situated at the southernmost latitude in the record. Our chronology provides the first age bracketing of the Laschamp excursion using radioisotopic dating, and improves on previous age determinations based on 40Ar/39Ar dating of lava flows, and orbitally tuned sedimentary and ice-core records. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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9. Geodigest.
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GEOLOGY , *SUPERVOLCANOES , *SCIENTISTS , *DIAMONDS - Abstract
The article offers news briefs related to Geology as of January 1, 2016. Topics discussed include eruption of supervolanoes or massive magma chambers due to cracking or collapsing of the roof above them, discovery of first oceanic microplate in the Indian Ocean by scientist from the U.S. and Australia when the collision between India and Eurasia occurred leading to formation of the Himalayas, and discovery of second largest diamond by the Canadian mining firm Lucara Diamond Corp.
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- 2016
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10. Supervolcano's hidden secrets.
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Marshall, Michael
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SUPERVOLCANOES , *MAGMAS , *HISTORY of volcanic eruptions - Abstract
The article discusses the supervolcano the dormant Long Valley caldera, including its eruptions throughout prehistory and the magma of the supervolcano, referencing an article coauthored by scientist Ashton Flinders in the "Geology" journal.
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- 2018
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11. The Yellowstone magmatic system from the mantle plume to the upper crust.
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Hsin-Hua Huang, Fan-Chi Lin, Schmandt, Brandon, Farrell, Jamie, Smith, Robert B., and Tsai, Victor C.
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MAGMAS , *MANTLE plumes , *SUPERVOLCANOES , *VOLCANIC hazard analysis , *CRUST of the earth , *VOLCANIC gases , *VOLCANISM , *NATIONAL parks & reserves ,ENVIRONMENTAL conditions - Abstract
The article presents research on the magmatic system of the Yellowstone supervolcano which is located the Yellowstone National Park region of the U.S., and it mentions the supervolcano's mantle plume and magma reservoir in relation to the Earth's crust levels. Bimodal basaltic-rhyolitic volcanism is mentioned, along with volcanic hazard assessments and the discharge of carbon dioxide gas. The formation of America's Snake River Plain is also examined.
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- 2015
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12. Piggy-back Supervolcanoes--Long-Lived, Voluminous, Juvenile Rhyolite Volcanism in Mesoproterozoic Central Australia.
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Smithies, R. H., Howard, H. M., Kirkland, C. L., Korhonen, F. J., Medlin, C. C., Maier, W. D., de Gromard, R. Quentin, and Wingate, M. T. D.
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SUPERVOLCANOES , *RHYOLITE , *VOLCANISM , *PROTEROZOIC Era , *IGNIMBRITE - Abstract
The Talbot Sub-basin is one of several bimodal volcanic depositional centres of the Mesoproterozoic Bentley Basin in central Australia. It is dominated by rocks of rhyolitic composition and includes ignimbrites, some forming large to super-eruption size deposits. Ferroan, incompatible trace element enriched, A-type compositions, anhydrous mineralogy and clear evidence for local rheomorphism indicate high eruption temperatures, with apparent zircon-saturation temperatures suggesting crystallization at >900°C. Comagmatic basalt is of mantle origin with minor Proterozoic basement contamination. The rhyolites cover the same range of Nd isotope compositions (eNd(1070) +1·24 to -0·96) and La/Nb ratios (1·2-2·1) as the basalts (eNd(1070) +2·1 to -1·1: La/Nb 1·2-2·3) and are compositionally far removed from all older basement and country-rock components (average eNd(1070)=-4, La/Nb=10). The rhyolites and basalts are cogenetic through a process probably involving both fractional crystallization of mafic magmas and partial melting of recently crystallized mafic rock in a lower crustal intraplate, extraction of dacitic magmas to a voluminous upper crustal chamber system, and separation of rhyolite by processes involving rejuvenation and cannibalization of earlier chamber material. More than 230000km³ of parental basalt is required to form the >22000km³ of preserved juvenile rhyolite in the Talbot Sub-basin alone, which represents one of the most voluminous known felsic juvenile additions to intracontinental crust. Zircon U-Pb age components are complex and distinct from those of basement and country rock and contain antecrystic components reflecting dissolution-regrowth processes during periodic rejuvenation of earlier-emplaced chamber material without any significant interaction with country rock. The overall duration of magmatism was >30Myr but can be divided into between two and four separate intervals, each probably of a few hundred thousand years' duration and each probably reflecting one of the distinct lithostratigraphic groups defined in the sub-basin. Neither the composition nor style of felsic and mafic volcanism changes in any significant way from one volcanic event to the next and the range of zircon U-Pb ages indicates that each period utilized and cannibalized the same magma chamber. This volcanism forms a component of the 1090-1040Ma Giles Event in central Australia, associated with magma- dominated extension at the nexus of the cratonic elements of Proterozoic Australia. This event cannot be reasonably reconciled with any putative plume activity but rather reflects the >200Myr legacy of enhanced crustal geotherms that followed the final cratonic amalgamation of central Australia. [ABSTRACT FROM AUTHOR]
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- 2015
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13. Post-supereruption Magmatic Reconstruction of Taupo Volcano (New Zealand), as Reflected in Zircon Ages and Trace Elements.
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Barker, S. J., Wilson, C. J. N., Smith, E. G. C., Charlier, B. L. A., Wooden, J. L., Hiess, J., and Ireland, T. R.
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MAGMAS , *ZIRCON , *CRYSTALLIZATION , *VOLCANIC eruptions , *SUPERVOLCANOES ,TAUPO Volcanic Zone (N.Z.) - Abstract
New zircon U–Th model-age and trace element datasets are presented from Taupo volcano (New Zealand), which are used to investigate the timescales and broad-scale magmatic processes involving zircon crystallization after the caldera-forming 25·4 ka Oruanui supereruption. Detailed 14C-based chronologies and controls on vent locations allow the timing and location of post-caldera eruptions to be spatially and temporally constrained to an extent not possible for any other supervolcano. After ∼5 kyr of post-Oruanui quiescence, Taupo erupted three dacitic units, followed by another ∼5 kyr break, and then a sequence of rhyolitic units in three subgroups (SG1–SG3) from 12 ka onwards. Despite overlapping vent sites and crustal source domains between the Oruanui and post-Oruanui eruptions, U–Th zircon model ages in Taupo SG1 rhyolites (erupted from 12 to 10 ka) indicate only minor inheritance of crystals from the Oruanui magma source. Post-Oruanui model-age spectra are instead typically centred close to eruption ages with subordinate older pre-300 ka equiline grains in some units. U–Pb dating of these older grains shows that both 300–450 ka plutonic-derived and pre-100 Ma greywacke basement-derived zircons are present. The former largely coincide in age with zircons from the 350 ka Whakamaru eruption products, and are dominant over greywacke in young units that were vented within the outline of the Whakamaru caldera. Despite multiple ages and vent sites, trace element compositions are broadly similar in zircons, regardless of their ages. However, a small subset of zircons analysed from SG1 rhyolite (Units B and C) have notably high concentrations of U, Th, P, Y + (REE)3+ and Nb but with only minor variations in Hf and Ti. SG2 zircons typically have higher Sc contents, reflecting large-scale changes in melt chemistry and crystallizing mineral phases with time. The age spectra indicate that most Oruanui zircons were removed by thermally induced dissolution immediately following the supereruption. U–Th ages from single post-Oruanui eruptions show consistent inheritance of post-Oruanui grains with model ages that centre between the temporally separated but geographically overlapping eruption groups, generating model-age modes. Within the statistical limitations of the isotopic measurements, we interpret these repeated modes to be significant, resulting from incorporation of crystal populations from cyclic post-Oruanui periods of magmatic cooling and crystallization, acting within a crustal protolith chemically independent of that which was dominant in the Oruanui system. These periods of cooling and crystallization alternate with times of rejuvenation and eruption, sometimes demonstrably accompanying syn-eruptive regional rifting and mafic magma injection. Not only were the processes that developed the supersized Oruanui magma body rapid, but this huge magma system was effectively reset and rebuilt on a comparably short timescale. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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14. It All Starts With Heat.
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Wilkinson, Todd
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SUPERVOLCANOES , *SEISMOMETERS , *PARKS , *EARTHQUAKE intensity , *CALDERAS , *CRUST of the earth , *PLATE tectonics - Abstract
The article features the Yellowstone supervolcano located in Wyoming underneath the Yellowstone National Park. Topics mentioned include the record of seismometers on the number of earthquakes in a year indicating that the volcano is active, the caldera which is created by the ancient eruptions, and the illustration that the crust of the North American tectonic plate are moveable.
- Published
- 2016
15. Building zoned ignimbrites by recycling silicic cumulates: insight from the 1,000 km Carpenter Ridge Tuff, CO.
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Bachmann, Olivier, Deering, Chad, Lipman, Peter, and Plummer, Charles
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IGNIMBRITE , *VOLCANIC ash, tuff, etc. , *TITANIUM oxides , *TRACE elements , *BIOTITE , *SILICIC acid - Abstract
The ~1,000 km Carpenter Ridge Tuff (CRT), erupted at 27.55 Ma during the mid-tertiary ignimbrite flare-up in the western USA, is among the largest known strongly zoned ash-flow tuffs. It consists primarily of densely welded crystal-poor rhyolite with a pronounced, highly evolved chemical signature (high Rb/Sr, low Ba, Zr, Eu), but thickly ponded intracaldera CRT is capped by a more crystal-rich, less silicic facies. In the outflow ignimbrite, this upper zone is defined mainly by densely welded crystal-rich juvenile clasts of trachydacite composition, with higher Fe-Ti oxide temperatures, and is characterized by extremely high Ba (to 7,500 ppm), Zr, Sr, and positive Eu anomalies. Rare mafic clasts (51-53 wt% SiO) with Ba contents to 4,000-5,000 ppm and positive Eu anomalies are also present. Much of the major and trace-element variations in the CRT juvenile clasts can be reproduced via in situ differentiation by interstitial melt extraction from a crystal-rich, upper-crustal mush zone, with the trachydacite, crystal-rich clasts representing the remobilized crystal cumulate left behind by the melt extraction process. Late recharge events, represented by the rare mafic clasts and high-Al amphiboles in some samples, mixed in with parts of the crystal cumulate and generated additional scatter in the whole-rock data. Recharge was important in thermally remobilizing the silicic crystal cumulate by partially melting the near-solidus phases, as supported by: (1) ubiquitous wormy/sieve textures and reverse zoning patterns in feldspars and biotites, (2) absence of quartz in this very silicic unit stored at depths of >4-5 km, and (3) heterogeneous melt compositions in the trachydacite fiamme and mafic clasts, particularly in Ba, indicating local enrichment of this element due mostly to sanidine and biotite melting. The injection of hot, juvenile magma into the upper-crustal cumulate also imparted the observed thermal gradient to the deposits and the mixing overprint that partly masks the in situ differentiation process. The CRT provides a particularly clear perspective on processes of in situ crystal-liquid separation into a lower crystal-rich zone and an upper eruptible cap, which appears common in incrementally built upper-crustal magma reservoirs of high-flux magmatic provinces. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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16. Supervolcano eruptions driven by melt buoyancy in large silicic magma chambers.
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Malfait, Wim J., Seifert, Rita, Petitgirard, Sylvain, Perrillat, Jean-Philippe, Mezouar, Mohamed, Ota, Tsutomu, Nakamura, Eizo, Lerch, Philippe, and Sanchez-Valle, Carmen
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VOLCANIC eruptions , *SUPERVOLCANOES , *ENVIRONMENTAL impact analysis , *MAGMAS , *X-ray absorption - Abstract
Super-eruptions that dwarf all historical volcanic episodes in erupted volume and environmental impact are abundant in the geological record. Such eruptions of silica-rich magmas form large calderas. The mechanisms that trigger these super-eruptions are elusive because the processes occurring in conventional volcanic systems cannot simply be scaled up to the much larger magma chambers beneath supervolcanoes. Over-pressurization of the magma reservoir, caused by magma recharge, is a common trigger for smaller eruptions, but is insufficient to generate eruptions from large supervolcano magma chambers. Magma buoyancy can potentially create sufficient overpressure, but the efficiency of this trigger mechanism has not been tested. Here we use synchrotron measurements of X-ray absorption to determine the density of silica-rich magmas at pressures and temperatures of up to 3.6 GPa and 1,950 K, respectively. We combine our results with existing measurements of silica-rich magma density at ambient pressures to show that magma buoyancy can generate an overpressure on the roof of a large supervolcano magma chamber that exceeds the critical overpressure of 10-40 MPa required to induce dyke propagation, even when the magma is undersaturated in volatiles. We conclude that magma buoyancy alone is a viable mechanism to trigger a super-eruption, although magma recharge and mush rejuvenation, volatile saturation or tectonic stress may have been important during specific eruptions. [ABSTRACT FROM AUTHOR]
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- 2014
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17. Supervolcanoes within an ancient volcanic province in Arabia Terra, Mars.
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Michalski, Joseph R. and Bleacher, Jacob E.
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SUPERVOLCANOES , *ARABIA Terra (Mars) , *IGNEOUS provinces , *VOLCANISM , *SEDIMENTARY rocks , *MAGMATISM - Abstract
Several irregularly shaped craters located within Arabia Terra, Mars, represent a new type of highland volcanic construct and together constitute a previously unrecognized Martian igneous province. Similar to terrestrial supervolcanoes, these low-relief paterae possess a range of geomorphic features related to structural collapse, effusive volcanism and explosive eruptions. Extruded lavas contributed to the formation of enigmatic highland ridged plains in Arabia Terra. Outgassed sulphur and erupted fine-grained pyroclastics from these calderas probably fed the formation of altered, layered sedimentary rocks and fretted terrain found throughout the equatorial region. The discovery of a new type of volcanic construct in the Arabia volcanic province fundamentally changes the picture of ancient volcanism and climate evolution on Mars. Other eroded topographic basins in the ancient Martian highlands that have been dismissed as degraded impact craters should be reconsidered as possible volcanic constructs formed in an early phase of widespread, disseminated magmatism on Mars. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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18. 'Super-eruptions' and silicic volcanism from the Yellowstone volcanic field.
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Ellis, Ben S. and Mark, Darren F.
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SUPERVOLCANOES , *VOLCANISM , *FELSENMEER , *VOLCANIC eruptions , *GEOLOGICAL time scales - Abstract
Yellowstone is perhaps the world's most famous 'super-volcano' with an explosive history stretching back more than 2 million years and abundant contemporary evidence of a voluminous magmatic system. The first explosive eruption at Yellowstone was the largest, the Huckleberry Ridge Tuff with a volume estimated at 2500 km3 of deposit. However, recent work using high-precision geochronology has suggested that this 'poster-child' of super-eruptions is actually two distinct events separated by at least six thousand years. The geochronological data indicating differences between the constituent parts of the Huckleberry Ridge Tuff is supported by textural, geochemical and isotopic evidence from numerous studies. Advances in both technology and approaches in the sphere of geochronology are allowing for ever more closely spaced events to be temporally resolved; allowing re-investigation of deposits considered to represent 'super-eruptions' at much higher resolution. The appreciation that the Huckleberry Ridge Tuff represents two distinct events illustrates that these large, regionally catastrophic events from Yellowstone occurred more frequently than previously thought. Moreover, by being able to better constrain the intervals between super-eruptions we can investigate the timescales of magma generation during quiescent periods. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
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19. Introduction: The 36-18 Ma southern Great Basin, USA, ignimbrite province and flareup: Swarms of subduction-related supervolcanoes.
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Best, Myron G., Christiansen, Eric H., and Gromme, Sherman
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IGNIMBRITE , *MAGMAS , *VOLCANISM , *VOLCANIC eruptions , *SUPERVOLCANOES , *CENOZOIC Era - Abstract
During the middle Cenozoic, from 36 to 18 Ma, one of the greatest global expressions of long-lived, explosive silicic volcanism affected a large segment of southwestern North America, including central Nevada and southwestern Utah in the southern Great Basin. The southern Great Basin ignimbrite province, resulting from this flareup, harbors several tens of thousands of cubic kilometers of ash-flow deposits. They were created by more than two hundred explosive eruptions, at least thirty of which were super-eruptions of more than 1000 km3. Forty-two exposed calderas are as much as 60 km in diameter. As in other parts of southwestern North America affected by the ignimbrite flareup, rhyolite ash-flow tuffs are widespread throughout the southern Great Basin ignimbrite province. However, the province differs in two significant respects. First, extrusions of contemporaneous andesitic lavas were minimal. Their volume is only about 10% of the ignimbrite volume. Unlike other contemporaneous volcanic fields in southwestern North America, only a few major composite (strato-) volcanoes predated and developed during the flareup. Second, the central sector and especially the eastern sector of the province experienced super-eruptions of relatively uniform, crystal-rich dacite magmas; resulting deposits of these monotonous intermediates measure on the order of 16,000 km3. Following this 4 m.y. event, very large volumes of unusually hot and dry trachydacitic magmas were erupted. These two types of magmas and their erupted volumes are apparently without parallel in the middle Cenozoic of southwestern North America. A fundamental goal of this themed issue is to present basic stratigraphic, compositional, chronologic, and paleomagnetic data on the unusually plentiful and voluminous ignimbrites in the southern Great Basin ignimbrite province. These data permit rigorous correlations of the vast outflow sheets that span between mountain-range exposures across intervening valleys as well as correlation of the sheets with often-dissimilar accumulations of tuffwithin dismembered source calderas. Well-exposed collar zones of larger calderas reveal complex wall-collapse breccias. Calculated ignimbrite dimensions in concert with precise 40Ar/39Ar ages provide insights on the growth and longevity of the colossal crustal magma systems. Exactly how these subduction-related magma systems were sustained for millions of years to create multicyclic super-eruptions at a particular focus remains largely unanswered. What factors created eruptive episodes lasting millions of years separated by shorter intervals of inactivity? What might have been the role played by tears in the subducting plate focusing a high rate of mantle magma flux into the crust? What role might have been played by an unusually thick and still-warm crust inherited from earlier orogenies? Are the numerous super-eruptions, especially of the unusual monotonous intermediates and succeeding trachydacitic eruptions, during the Great Basin ignimbrite flareup simply a result of the coupling effect of high mantlemagma flux and a thick crust, or did other factors play a role? [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
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20. Implications of equilibrium and disequilibrium among crystal phases in the Bishop Tuff.
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EVANS, BERNARD W. and BACHMANN, OLIVIER
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SUPERVOLCANOES , *EQUILIBRIUM , *ORTHOPYROXENE , *SILICATES , *MAGNETITE - Abstract
Eruption of the Bishop Tuff magma preserved equilibrium of exchange components and element concentrations among magnetite, ilmenite, biotite, apatite, zircon, and liquid. Orthopyroxene and clinopyroxene were not in exchange equilibrium with the other MgFe-bearing phases, but they appear to have been in equilibrium among themselves. Internally consistent temperatures recorded by the FeTi-oxide, Ti-in-quartz, and Δ18O quartz-magnetite thermometers, coupled with evidence for magmatic corrosion of quartz and sanidine, indicate that an initially low-T (≈700 °C), near-H2O-saturated, high-SiO2 rhyolite magma was heated up to ≥800 °C and its crystal cargo partially melted by recharge of hotter melt from below. Oxygen fugacity and compositions of biotite, ilmenite, magnetite, and silicate liquid initially adjusted by internal rearrangement of components and conservation of oxygen. Partial melting of feldspars liberated Sr and Ba back into the melt. Mixing during recharge eventually re-introduced compatible elements (e.g., Mg, Ba, Sr) as well as foreign crystals of euhedral ortho- and clinopyroxene, which evidently never totally re-equilibrated with the rhyolite liquid. Introduction of CO2 and accompanying reduction in the aH2O during recharge raised crystallization temperatures of quartz and sanidine in the rhyolite sufficient to allow marginal regrowth of these phases with enhanced contents Ti, Ba, and Sr. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
21. Timing and characteristics of the Archean subaqueous Blake River Megacaldera Complex, Abitibi greenstone belt, Canada
- Author
-
Mueller, W.U., Friedman, R., Daigneault, R., Moore, L., and Mortensen, J.
- Subjects
- *
GEOLOGICAL time scales , *SUPERVOLCANOES , *COMPLEX compounds , *URANIUM-lead dating , *VOLCANOLOGY , *MOLECULAR structure , *ARCHAEAN , *STRUCTURAL geology - Abstract
Abstract: The Archean Blake River Group of the Abitibi greenstone belt represents a megacaldera complex which evolved over 8–11M.y. from approximately 2704 to 2696Ma. The early Misema Caldera developed from a series of amalgamated shield volcano complexes identified by the remnants of mafic dyke and sill systems. These remnants are found in the Jevis-Clericy, Montsabrais-Renault, Clifford-Tannahill and Colnet regions, where summit calderas are delineated by circular ring dyke structures. The secondary 330°-trending New Senator Caldera formed within the envelope of the Misema Caldera and exhibits a box-work graben-type structure. Finally, the felsic-dominated, 070°-striking Noranda Caldera, well known for its VMS endowment, represents the final collapse of the megacaldera complex. Deformation has overprinted the calderas, but structural patterns can be used in order to reconstruct the pre-existing volcanic architecture. Structures such as mafic ring dyke complexes and rhyolitic dome-flow complexes have nucleated fold geometries and synvolcanic fractures were reactivated within zones of ductile deformation. Precise U-Pb geochronological analyses were conducted in selected areas with specific emphasis on the Misema and New Senator calderas. Felsic volcanism progressed throughout the evolution of the megacaldera complex and intermediate to felsic units have been dated to limit this evolution. The Misema Caldera formed between 2704 and 2702Ma via the amalgamation of shield volcanoes that were probably active prior to 2704Ma. The New Senator Caldera was generated between 2702 and 2700Ma during paroxysmal felsic volcanism, followed by the collapse of the Noranda Caldera culminating between 2700–2696Ma. The Misema Caldera was generated by a gravitational stress field consistent with the formation of ring and radial dyke architecture, whereas the SE-trending New Senator Caldera is more compatible with a SW-trending principal compression direction related to oblique convergence in the Abitibi belt. The Noranda Caldera is interpreted as a NE rift structure that formed in the final stages of megacaldera evolution. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
22. Rheology of arc dacite lavas: experimental determination at low strain rates.
- Author
-
Avard, Geoffroy and Whittington, Alan
- Subjects
- *
VOLCANOES , *SUPERVOLCANOES , *VOLCANIC eruptions , *LAVA flows , *DOMES (Geology) - Abstract
Andesitic-dacitic volcanoes exhibit a large variety of eruption styles, including explosive eruptions, endogenous and exogenous dome growth, and kilometer-long lava flows. The rheology of these lavas can be investigated through field observations of flow and dome morphology, but this approach integrates the properties of lava over a wide range of temperatures. Another approach is through laboratory experiments; however, previous studies have used higher shear stresses and strain rates than are appropriate to lava flows. We measured the apparent viscosity of several lavas from Santiaguito and Bezymianny volcanoes by uniaxial compression, between 1,109 and 1,315 K, at low shear stress (0.085 to 0.42 MPa), low strain rate (between 1.1 × 10 and 1.9 × 10 s), and up to 43.7 % total deformation. The results show a strong variability of the apparent viscosity between different samples, which can be ascribed to differences in initial porosity and crystallinity. Deformation occurs primarily by compaction, with some cracking and/or vesicle coalescence. Our experiments yield apparent viscosities more than 1 order of magnitude lower than predicted by models based on experiments at higher strain rates. At lava flow conditions, no evidence of a yield strength is observed, and the apparent viscosity is best approached by a strain rate- and temperature-dependent power law equation. The best fit for Santiaguito lava, for temperatures between 1,164 and 1,226 K and strain rates lower than 1.8 × 10 s, is $$ \log {\eta_{\text{app}}} = - 0.738 + 9.24 \times {10^3}{/}T(K) - 0.654 \cdot \log \dot{\varepsilon } $$ where η is apparent viscosity and $$ \dot{\varepsilon } $$ is strain rate. This equation also reproduced 45 data for a sample from Bezymianny with a root mean square deviation of 0.19 log unit Pa s. Applying the rheological model to lava flow conditions at Santiaguito yields calculated apparent viscosities that are in reasonable agreement with field observations and suggests that internal shear heating may be significant ongoing heat source within these flows, enabling highly viscous lava to travel long distances. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
23. Zircon-scale insights into the history of a Supervolcano, Bishop Tuff, Long Valley, California, with implications for the Ti-in-zircon geothermometer.
- Author
-
Reid, Mary, Vazquez, Jorge, and Schmitt, Axel
- Subjects
- *
ZIRCON , *SUPERVOLCANOES , *TITANIUM , *TEMPERATURE measurements , *THERMOMETERS , *TRACE elements - Abstract
Zircon has the outstanding capacity to record chronological, thermal, and chemical information, including the storage history of zoned silicic magma reservoirs like the one responsible for the Bishop Tuff of eastern California, USA. Our novel ion microprobe approach reveals that Bishop zircon rims with diverse chemical characteristics surround intermediate domains with broadly similar compositions. The highest Y, REE, U, and Th concentrations tend to accompany the largest excesses in Y + REE:P beyond what can be explained by xenotime substitution in zircon. Apparent Ti-in-zircon temperatures of <720°C for zircon rims are distinctly lower than most of the range in eruption temperatures, as estimated from FeTi-oxide equilibria and zircon solubility at quench. While permissive of crystallization of zircon at near-solidus conditions, the low Ti-in-zircon temperatures are probably better explained by sources of inaccuracy in the temperature estimates. After apparently nucleating from different melts, zircons from across the Bishop Tuff compositional spectrum may have evolved to broadly similar chemical and thermal conditions and therefore it is possible that there was no significant thermal gradient in the magma reservoir at some stage in its evolution. There is also no compelling evidence for punctuated heat ± chemical influxes during the intermediate stages of zircon growth. Judging by the zircon record, the main volume of the erupted magma evolved normally by secular cooling but the latest erupted portion is characterized by a reversal in chemistry that appears to indicate perfusion of the magma reservoir by-or zircon entrainment in-a less evolved melt from the one in which the zircons had previously resided. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
24. The climatic impact of supervolcanic ash blankets.
- Author
-
Jones, Morgan, Sparks, R., and Valdes, Paul
- Subjects
- *
SUPERVOLCANOES , *VOLCANIC ash, tuff, etc. , *VOLCANIC eruptions , *CLIMATE change , *ALBEDO , *SURFACE of the earth - Abstract
Supervolcanoes are large caldera systems that can expel vast quantities of ash, volcanic gases in a single eruption, far larger than any recorded in recent history. These super-eruptions have been suggested as possible catalysts for long-term climate change and may be responsible for bottlenecks in human and animal populations. Here, we consider the previously neglected climatic effects of a continent-sized ash deposit with a high albedo and show that a decadal climate forcing is expected. We use a coupled atmosphere-ocean General Circulation Model (GCM) to simulate the effect of an ash blanket from Yellowstone volcano, USA, covering much of North America. Reflectivity measurements of dry volcanic ash show albedo values as high as snow, implying that the effects of an ash blanket would be severe. The modeling results indicate major disturbances to the climate, particularly to oscillatory patterns such as the El Niño Southern Oscillation (ENSO). Atmospheric disruptions would continue for decades after the eruption due to extended ash blanket longevity. The climatic response to an ash blanket is not significant enough to instigate a change to stadial periods at present day boundary conditions, though this is one of several impacts associated with a super-eruption which may induce long-term climatic change. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
25. A large magmatic sill complex beneath the Toba caldera.
- Author
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Jaxybulatov, K., Shapiro, N. M., Koulakov, I., Mordret, A., Landès, M., and Sens-Schönfelder, C.
- Subjects
- *
VOLCANIC eruptions , *SEISMIC anisotropy , *CALDERAS , *MAGMAS , *SUPERVOLCANOES , *SEISMIC tomography - Abstract
An understanding of the formation of large magmatic reservoirs is a key issue for the evaluation of possible strong volcanic eruptions in the future. We estimated the size and level of maturity of one of the largest volcanic reservoirs, based on radial seismic anisotropy. We used ambient-noise seismic tomography below the Toba caldera (in northern Sumatra) to observe the anisotropy that we interpret as the expression of a fine-scale layering caused by the presence of many partially molten sills in the crust below 7 kilometers. This result demonstrates that the magmatic reservoirs of present (non-eroded) supervolcanoes can be formed as large sill complexes and supports the concept of the long-term incremental evolution of magma bodies that lead to the largest volcanic eruptions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
26. When Yellowstone Explodes.
- Author
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Achenbach, Joel
- Subjects
- *
SUPERVOLCANOES , *CALDERAS , *VOLCANISM - Abstract
This article discusses the geology of Yellowstone National Park in Idaho, Wyoming, and Montana, which is located in a basin formed as the crater, or caldera, of a supervolcano. The geysers of Yellowstone such as Sawmill and Old Faithful are powered by hydrothermal activity that is a remnant of volcanic activity in the region. Research by geologists including Francis Boyd and Bob Christiansen into the possibility that this supervolcano is still active is considered.
- Published
- 2009
27. WHY WE'LL STILL BE HERE.
- Author
-
Brooks, Michael
- Subjects
- *
FORECASTING , *HUMAN beings , *BIOLOGICAL extinction , *FOSSIL mammals , *KNOWLEDGE transfer , *VIRUS diseases , *PANDEMICS , *SUPERVOLCANOES - Abstract
The article presents an overview of expert forecasting of the long-term survival of the human race. Topics include fossil evidence of the average survival time of mammal species, the ability of humans to share knowledge across a global network to solve problems, and the unlikelihood of a viral pandemic affecting the entire population. Possible threats are also discussed, such as supervolcano eruptions and cosmic phenomena involving solar flares, cosmic gamma ray bursts, or asteroids.
- Published
- 2012
- Full Text
- View/download PDF
28. North Korea and West align over supervolcano.
- Author
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Coghlan, Andy
- Subjects
- *
VOLCANIC activity prediction , *SUPERVOLCANOES - Abstract
The article reports on the collaboration of governments of North Korean and West countries on conducting volcanic activity predicition and monitoring for possible signs of volcanic eruption by Mount Paektu, a supervolcano located in North Korea.
- Published
- 2016
- Full Text
- View/download PDF
29. Geophysical Exploration Linking Deep Earth and Backyard Geology.
- Author
-
KERR, RICHARD A.
- Subjects
- *
GEOPHYSICS research , *SEISMIC arrays , *GEOPHYSICS methodology , *GEOPHYSICAL observatories , *SEISMOMETERS , *SUPERVOLCANOES , *SEISMIC wave studies , *EARTH'S mantle , *GEOLOGICAL formations - Abstract
The article discusses geophysical exploration of the Earth's mantle that links plate tectonics with the formation of some major geological formations in the U.S., such as the Yellowstone supervolcano in Wyoming and Idaho and the Colorado Plateau. An overview is presented of the EarthScope program investigating Earth's interior using a wave of seismometers stretched across the U.S. and its components, including the USArray, the Transportable Array (TA), the Plate Boundary Observatory (PBO), and the San Andreas Fault Observatory at Depth (SAFOD). Also discussed is what EarthScope is revealing about the role of deep features in shaping the geology at the surface.
- Published
- 2013
- Full Text
- View/download PDF
30. Giant magma chamber found under Yellowstone volcano.
- Subjects
- *
SUPERVOLCANOES , *VOLCANOES , *MAGMAS , *VOLCANOLOGICAL research , *VOLCANOLOGY - Abstract
The article discusses the discovery of a magma chamber underneath the Yellowstone supervolcano. Emphasis is given to topics such as the capacity of the chamber, failure to locate the chamber due to distortion of seismic waves used to visualize deep areas, and the discharge of carbon dioxide from the volcanic system.
- Published
- 2015
- Full Text
- View/download PDF
31. Dust Up.
- Subjects
- *
SUPERVOLCANOES , *VOLCANIC eruptions , *VOLCANIC ash, tuff, etc. , *VOLCANOES , *VOLCANIC activity prediction , *CHARTS, diagrams, etc. ,ENVIRONMENTAL aspects - Abstract
The article discusses research conducted by the U.S. Geological Survey regarding the possible effects from an eruption of the supervolcano in Yellowstone National Park in Wyoming. Diagrams are presented which display the distribution of ash, the amount of magma released, and the livestock and crops killed from a supervolcano eruption.
- Published
- 2015
- Full Text
- View/download PDF
32. Alaska may be hiding a supervolcano.
- Author
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GEIGER, BETH
- Subjects
- *
SUPERVOLCANOES , *VOLCANIC eruptions , *SULFUR dioxide - Abstract
The article reports that according to a study conducted by John Power, a geophysicist at the U.S. Geological Survey's Alaska Volcano Observatory in Anchorage, a wide crater, created when the supervolcano exploded, connects at least five existing volcanoes at Alaska's Aleutian Islands. It mentons that an analysis of volcanic gases such as sulfur dioxide, as well as patterns of microearthquakes in the area, further suggest the presence of a caldera.
- Published
- 2021
33. Bouncy magma sets off supervolcanoes.
- Author
-
Aron, Jacob
- Subjects
- *
SUPERVOLCANOES , *VOLCANIC eruptions , *MAGMAS , *BUOYANCY , *VOLCANIC activity prediction - Abstract
The article discusses studies published in "Nature Geoscience" which examined factors causing the eruption of a supervolcano. Topics highlighted include slow filling of supervolcano chambers with hot magma, effects of buoyancy on large magma chambers and monitoring of magma to allow scientists to estimate the risk of a blast from supervolcanoes.
- Published
- 2014
- Full Text
- View/download PDF
34. The Red Planet's supervolcanic past.
- Subjects
- *
MARTIAN volcanism , *SUPERVOLCANOES - Abstract
The article reports research by Jacob Bleacher of the U.S. National Aeronautics and Space Administration (NASA) and colleagues on supervolcanoes on Mars and their impact on the planet's condition.
- Published
- 2013
- Full Text
- View/download PDF
35. Alive! We survived a post Toba winter.
- Subjects
- *
DNA analysis , *SUPERVOLCANOES , *EFFECT of volcanic eruptions on Earth temperature - Abstract
The article discusses a genetic analysis of mammal DNA by Geoffrey Hayes of Northwestern University in Chicago, Illinois that found animals survived the eruption of the Toba supervolcano in Indonesia 74, 000 years ago, discrediting a theory that the eruption nearly wiped out human beings.
- Published
- 2013
- Full Text
- View/download PDF
36. Life after a supervolcano: it exists, but it's no fun.
- Author
-
Marshall, Michael
- Subjects
- *
CLIMATE change , *SUPERVOLCANOES , *HISTORY - Abstract
The article reports on research which Christine Lane of the University of Oxford in England conducted in 2013 to investigate the climatic effects of the Toba supervolcano which erupted 75,000 years ago on the island of Sumatra. Research which geophysicist Alan Robock of Rutgers University in New Brunswick, New Jersey and Hans-F. Graf of the University of Cambridge in England conducted and led to conclusions about supervolcanoes and climate change which differ from Lane's, is discussed.
- Published
- 2013
- Full Text
- View/download PDF
37. Handicapping the Other 20 Doomsdays.
- Subjects
- *
END of the world (Astronomy) , *IMPACT of asteroids with Earth , *SUPERVOLCANOES , *PANDEMICS , *GAMMA ray bursts , *SUPERMASSIVE black holes , *SOLAR flares - Abstract
The article provides a summary of the article "20 Ways the World Could End" in the October 2000 issue. Included among the most plausible are asteroid impacts, super volcanoes, and global epidemics. Included among the possible but very unlikely are gamma-ray bursts, black holes, and solar superflares. Scenarios of undetermined likelihood include alien invasions, robot takeover, and divine intervention.
- Published
- 2010
38. For the record.
- Subjects
- *
MAPS , *SUPERVOLCANOES , *ENDURANCE athletes - Abstract
Corrections to articles published within previous issues are presented including a map of the Channel Islands that was published in the April 24, 2010 issue, one on the Toba supervolcano that was published in the April 17, 2010 issue, and one on endurance world record holder Stephanie Mifsud that was published in the April 17, 2010 issue is presented.
- Published
- 2010
- Full Text
- View/download PDF
39. Yellowstone supervolcano is cool.
- Subjects
- *
VOLCANOES , *VOLCANIC eruptions , *SUPERVOLCANOES , *MANTLE plumes , *SEISMIC waves - Abstract
The article reports that Derek Schutt and Ken Dueker estimated the temperature of the plume of the supervolcano beneath Yellowstone National Park in Wyoming with the use of seismic waves. The supervolcano exploded 642,000 years ago, covering half of what is now the U.S. in ash. The source of its eruption is not certain, yet suspicion focuses on a large plume of hot mantle. The temperature of the plume is around 1450 degree Celsius which suggests an end to the sequence of mega-eruptions.
- Published
- 2008
- Full Text
- View/download PDF
40. Avoid earthquakes with lubrication.
- Subjects
- *
EARTHQUAKES , *VOLCANIC plumes , *SUPERVOLCANOES - Abstract
The article discusses how the Yellowstone plume may have lubricated oceanic crust, preventing earthquakes on the Pacific coast of North America. University of California professor Richard Allen and his team suggest that the Yellowstone plume lubricated the Juan de Fuca oceanic plate millions of years ago. The plume shifted to feed the Yellowstone supervolcano in Wyoming.
- Published
- 2007
41. UPDATES.
- Subjects
- *
SCIENCE , *SUPERVOLCANOES , *BIOMASS energy , *ETHANOL as fuel , *CATS , *HISTORY - Abstract
This article presents scientific updates. Researchers have found evidence that people who lived in Indonesia survived the largest volcanic blast in the past two million years. The biofuel called 2,5-dimethylfuran or DMF has 40 percent more energy than ethanol but research has to be conducted to evaluate the environmental impact. Genetic analysis believe that all 600 million house cats descend from five maternal lineages of a Near Eastern wild cat.
- Published
- 2007
- Full Text
- View/download PDF
42. Big Bang Theory.
- Author
-
Bartels, Meghan
- Subjects
- *
VOLCANIC eruptions , *SUPERVOLCANOES , *VOLCANIC ash, tuff, etc. , *FOOD shortages ,ENVIRONMENTAL aspects ,PINNACLE Point site (South Africa) - Abstract
The article presents information on the impact of the super-volcanic eruptions on the lives of people and the survival instincts of the people before and after the eruptions, highlighting the environmental changes brought in by the volcanic eruption. Topics include the importance of the survival point Pinnacle Point, after-effects of the eruption including food shortage.
- Published
- 2018
43. GSA, AGI, and New Mexico Bureau of Geology and Mineral Resources Bring Educational Opportunities to Students in New Mexico.
- Subjects
- *
SUPERVOLCANOES , *VOLCANIC eruptions , *EARTH sciences , *DOCUMENTARY films - Published
- 2018
44. Source of Present-Day Dust on Mars Found.
- Author
-
FREYDLIN, JULIE
- Subjects
- *
MARS (Planet) , *DUST , *SUPERVOLCANOES - Abstract
The article offers information on the Medusae Fossae Formation (MFF), discussing the fine dust found on Martian surface; the eruption of a supervolcano on the planet, which probably produced the dust; and the sulfur and chlorine found in the dust.
- Published
- 2018
45. Long-ago Supervolcano Created Mars Rock Formation.
- Author
-
FREYDLIN, JULIE
- Subjects
- *
ROCKS , *SUPERVOLCANOES , *MARS (Planet) - Abstract
The article discusses the study conducted by Lujendra Ojha and colleagues in which the investigated the porous rock or ice composition of the Medusae Fossae Formation (MFF), the largest rock deposits on Mars created by a supervolcano billion years ago.
- Published
- 2018
46. Recharging Volcano in Yellowstone.
- Subjects
- *
MAGMAS , *SUPERVOLCANOES - Abstract
The article informs that researchers at Washington State University (WSU), Pullman, have found a new way to estimate how fast magma is recharging beneath the supervolcano at Yellowstone National Park, and mentions views of Peter Larson, a professor in WSU's School of Environment, on same.
- Published
- 2018
47. Probing the underbelly of a supervolcano.
- Author
-
Shapiro, Nikolai M. and Koulakov, Ivan
- Subjects
- *
SUPERVOLCANOES , *VOLCANOES , *EXPLOSIVE volcanic eruptions , *MAGMAS , *CRUST of the earth , *SEISMIC tomography - Abstract
The article looks at the factors responsible for the behavior of different volcanoes. It discusses research by seismologist Hsin-Hua Huang and colleagues, reported in the current issue, on the use of seismic tomography to image the Yellowstone supervolcano in order to assess the volume of magma beneath it and thereby understand its high volume of escaping gases. Topics include the role of magma reservoirs in the Earth's crust in leading to volcanic supereruptions.
- Published
- 2015
- Full Text
- View/download PDF
48. On the road to a supervolcano.
- Author
-
Hartigan Shea, Rachel
- Subjects
- *
SUPERVOLCANOES - Abstract
The article talks about the hurdles faced by geologist Stephanie Grocke while investigating the Cerro Galán supervolcano in Cerro Galán caldera in northwestern Argentina and states that if the volcano's magma is close to the earth's surface it could erupt again.
- Published
- 2016
49. Lake sediments suggest mild volcanic winter after massive Toba eruption.
- Author
-
Oleson, Timothy
- Subjects
- *
LAKE sediments , *COOLING , *SUPERVOLCANOES - Abstract
The article reports that lake sediments in East Africa suggest that there was little or no cooling following the eruption of the Toba supervolcano on the island of Sumatra in Indonesia based on a study by Lily Jackson et al., published in the journal "Geology."
- Published
- 2016
50. SLEEPING GIANTS.
- Subjects
- *
SUPERVOLCANOES , *VOLCANIC eruptions , *MAGMAS , *EARTH pressure , *BUOYANCY , *PALEOSEISMOLOGY , *GEOLOGIC faults - Abstract
The article discusses the varying answers by studies on what factors has triggered the eruptions of supervolcano. Topics mentioned include the trigger of the pressure below the surface of build-up magma, the rare eruptions and happens for few weeks or days, and the suggest by 2014 study that effect of buoyancy caused their eruptions. It also mentioned the external factors including seismicity patterns, faults generation, and old faults reactivation.
- Published
- 2016
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