22 results match your criteria Bulletin Of Volcanology[Journal]

  • Page 1 of 1

In situ observation of the percolation threshold in multiphase magma analogues.

Bull Volcanol 2020 4;82(4):32. Epub 2020 Mar 4.

1Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Theresienstr. 41, 80333 Munich, Germany.

Magmas vesiculate during ascent, producing complex interconnected pore networks, which can act as outgassing pathways and then deflate or compact to volcanic plugs. Similarly, in-conduit fragmentation events during dome-forming eruptions create open systems transiently, before welding causes pore sealing. The percolation threshold is the first-order transition between closed- and open-system degassing dynamics. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-020-1370-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7056709PMC

Textural and geochemical constraints on andesitic plug emplacement prior to the 2004-2010 vulcanian explosions at Galeras volcano, Colombia.

Bull Volcanol 2019 7;81(1). Epub 2018 Dec 7.

4The Lyell Centre, British Geological Survey, Edinburgh, UK.

Hazardous sequences of vulcanian explosions are thought to result from the repeated emplacement and destruction of degassed, highly crystalline magma plugs in the shallow conduit of arc volcanoes. The processes governing the timing and magnitude of these explosions are thought to be related to magma ascent rate and efficiency of degassing and crystallisation. We study a rare suite of time-constrained ballistic bombs from the 2004-2010 period of activity of Galeras volcano to reconstruct magma plug architecture prior to six individual vulcanian explosions. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-018-1260-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6383983PMC
December 2018

Aggregation in particle rich environments: a textural study of examples from volcanic eruptions, meteorite impacts, and fluidized bed processing.

Bull Volcanol 2018 2;80(4):32. Epub 2018 Mar 2.

1Ludwig-Maximilians-Universität München LMU, Munich, Germany.

Aggregation is a common process occurring in many diverse particulate gas mixtures (e.g. those derived from explosive volcanic eruptions, meteorite impact events, and fluid bed processing). Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-018-1207-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5834565PMC
March 2018
5 Reads

Volcano alert level systems: managing the challenges of effective volcanic crisis communication.

Bull Volcanol 2018 13;80(5):46. Epub 2018 Apr 13.

2Disaster Risk and Resilience Group, Department of Geological Sciences, University of Canterbury, Private Bag, Christchurch, 48000 New Zealand.

Over the last four decades, volcano observatories have adopted a number of different communication strategies for the dissemination of information on changes in volcanic behaviour and potential hazards to a wide range of user groups. These commonly include a standardised volcano alert level system (VALS), used in conjunction with other uni-valent communication techniques (such as information statements, reports and maps) and multi-directional techniques (such as meetings and telephone calls). This research, based on interviews and observation conducted 2007-2009 at the five US Geological Survey (USGS) volcano observatories, and including some of the key users of the VALS, argues for the importance of understanding how communicating volcanic hazard information takes place as an everyday social practice, focusing on the challenges of working across the boundaries between the scientific and decision-making communities. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-018-1219-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560653PMC
April 2018
1 Read

Gravitational sliding of the Mt. Etna massif along a sloping basement.

Bull Volcanol 2018 23;80(4):40. Epub 2018 Mar 23.

1School of Environment, Earth and Ecosystem Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA UK.

Geological field evidence and laboratory modelling indicate that volcanoes constructed on slopes slide downhill. If this happens on an active volcano, then the movement will distort deformation data and thus potentially compromise interpretation. Our recent GPS measurements demonstrate that the entire edifice of Mt. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-018-1209-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560784PMC
March 2018
2 Reads

Rootless tephra stratigraphy and emplacement processes.

Bull Volcanol 2017 10;79(1):11. Epub 2017 Jan 10.

4Faculty and Institute of Earth Sciences, University of Iceland, Reykjavík, Iceland.

Volcanic rootless cones are the products of thermohydraulic explosions involving rapid heat transfer from active lava (fuel) to external sources of water (coolant). Rootless eruptions are attributed to molten fuel-coolant interactions (MFCIs), but previous studies have not performed systematic investigations of rootless tephrostratigraphy and grain-size distributions to establish a baseline for evaluating relationships between environmental factors, MFCI efficiency, fragmentation, and patterns of tephra dispersal. This study examines a 13. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-016-1086-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7115078PMC
January 2017

Magmatic gas percolation through the old lava dome of El Misti volcano.

Bull Volcanol 2017 24;79(6):46. Epub 2017 May 24.

1Department of Geography, University of Cambridge, Downing Place, Cambridge, CB2 3EN UK.

The proximity of the major city of Arequipa to El Misti has focused attention on the hazards posed by the active volcano. Since its last major eruption in the fifteenth century, El Misti has experienced a series of modest phreatic eruptions and fluctuating fumarolic activity. Here, we present the first measurements of the compositions of gas emitted from the lava dome in the summit crater. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-017-1129-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6979612PMC

Validation of a novel Multi-Gas sensor for volcanic HCl alongside HS and SO at Mt. Etna.

Bull Volcanol 2017 17;79(5):36. Epub 2017 Apr 17.

ISTO, CNRS/Université d'Orléans/BRGM, UMR 7327, 1a rue de la Férollerie, 45071 Orléans, France.

Volcanic gas emission measurements inform predictions of hazard and atmospheric impacts. For these measurements, Multi-Gas sensors provide low-cost in situ monitoring of gas composition but to date have lacked the ability to detect halogens. Here, two Multi-Gas instruments characterized passive outgassing emissions from Mt. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-017-1114-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6979509PMC

Conduit margin heating and deformation during the AD 1886 basaltic Plinian eruption at Tarawera volcano, New Zealand.

Bull Volcanol 2016;78:12. Epub 2016 Feb 13.

Department of Earth and Environmental Science, Ludwig-Maximilians-Universität (LMU), Theresienstr. 41, 80333 Munich, Germany.

During explosive eruptions, a suspension of gas and pyroclasts rises rapidly within a conduit. Here, we have analysed textures preserved in the walls of a pyroclastic feeder dyke of the AD 1886 Tarawera basaltic Plinian fissure eruption. The samples examined consist of basaltic ash and scoria plastered onto a conduit wall of a coherent rhyolite dome and a welded rhyolitic dome breccia. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-016-1006-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4913976PMC
February 2016
9 Reads

Complex circular subsidence structures in tephra deposited on large blocks of ice: Varða tuff cone, Öræfajökull, Iceland.

Bull Volcanol 2016 1;78(8):56. Epub 2016 Aug 1.

2School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, M13 9PL UK.

Several broadly circular structures up to 16 m in diameter, into which higher strata have sagged and locally collapsed, are present in a tephra outcrop on southwest Öræfajökull, southern Iceland. The tephra was sourced in a nearby basaltic tuff cone at Varða. The structures have not previously been described in tuff cones, and they probably formed by the melting out of large buried blocks of ice emplaced during a preceding jökulhlaup that may have been triggered by a subglacial eruption within the Öræfajökull ice cap. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-016-1048-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175720PMC

Transitions between explosive and effusive phases during the cataclysmic 2010 eruption of Merapi volcano, Java, Indonesia.

Bull Volcanol 2016 18;78(8):54. Epub 2016 Jul 18.

1School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK.

Transitions between explosive and effusive activity are commonly observed during dome-forming eruptions and may be linked to factors such as magma influx, ascent rate and degassing. However, the interplay between these factors is complex and the resulting eruptive behaviour often unpredictable. This paper focuses on the driving forces behind the explosive and effusive activity during the well-documented 2010 eruption of Merapi, the volcano's largest eruption since 1872. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-016-1046-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175738PMC

Uncertainty analysis of a model of wind-blown volcanic plumes.

Bull Volcanol 2015;77(10):83. Epub 2015 Sep 7.

School of Mathematics, University of Bristol, University Walk, Bristol, BS8 1TW UK.

Mathematical models of natural processes can be used as inversion tools to predict unobserved properties from measured quantities. Uncertainty in observations and model formulation impact on the efficacy of inverse modelling. We present a general methodology, history matching, that can be used to investigate the effect of observational and model uncertainty on inverse modelling studies. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-015-0959-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4610681PMC
September 2015
3 Reads

First recorded eruption of Nabro volcano, Eritrea, 2011.

Bull Volcanol 2015;77(10):85. Epub 2015 Sep 7.

Global Resources Development Consultants, Asmara, Eritrea.

We present a synthesis of diverse observations of the first recorded eruption of Nabro volcano, Eritrea, which began on 12 June 2011. While no monitoring of the volcano was in effect at the time, it has been possible to reconstruct the nature and evolution of the eruption through analysis of regional seismological and infrasound data and satellite remote sensing data, supplemented by petrological analysis of erupted products and brief field surveys. The event is notable for the comparative rarity of recorded historical eruptions in the region and of caldera systems in general, for the prodigious quantity of SO emitted into the atmosphere and the significant human impacts that ensued notwithstanding the low population density of the Afar region. Read More

View Article

Download full-text PDF

Source
https://www.researchgate.net/profile/G_Ogubazghi/publication
Web Search
https://link.springer.com/content/pdf/10.1007%2Fs00445-015-0
Web Search
http://link.springer.com/10.1007/s00445-015-0966-3
Publisher Site
http://dx.doi.org/10.1007/s00445-015-0966-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4562108PMC
September 2015
19 Reads

Fracture and compaction of andesite in a volcanic edifice.

Bull Volcanol 2015;77(6):55. Epub 2015 Jun 3.

Équipe de Géophysique Expérimentale, Institut de Physique de Globe de Strasbourg (UMR 7516 CNRS, Université de Strasbourg/EOST), 5 rue René Descartes, 67084 Strasbourg cedex, France.

The failure mode of lava-dilatant or compactant-depends on the physical attributes of the lava, primarily the porosity and pore size, and the conditions under which it deforms. The failure mode for edifice host rock has attendant implications for the structural stability of the edifice and the efficiency of the sidewall outgassing of the volcanic conduit. In this contribution, we present a systematic experimental study on the failure mode of edifice-forming andesitic rocks (porosity from 7 to 25 %) from Volcán de Colima, Mexico. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-015-0938-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4551152PMC
June 2015
2 Reads

An objective method for the production of isopach maps and implications for the estimation of tephra deposit volumes and their uncertainties.

Bull Volcanol 2015;77(7):61. Epub 2015 Jun 17.

School of Earth Science, University of Bristol, Queens Road, Bristol, BS8 1RJ UK.

Characterization of explosive volcanic eruptive processes from interpretation of deposits is a key for assessing volcanic hazard and risk, particularly for infrequent large explosive eruptions and those whose deposits are transient in the geological record. While eruption size-determined by measurement and interpretation of tephra fall deposits-is of particular importance, uncertainties for such measurements and volume estimates are rarely presented. Here, tephra volume estimates are derived from isopach maps produced by modeling raw thickness data as cubic B-spline curves under tension. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-015-0942-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4498447PMC

Spatial analysis of Mount St. Helens tephra leachate compositions: implications for future sampling strategies.

Bull Volcanol 2015;77(7):60. Epub 2015 Jun 13.

Department of Earth and Environmental Sciences, Ludwig Maximilian University, Thereisenstrasse 41/III, 80333 Munich, Bavaria Germany.

Tephra particles in physically and chemically evolving volcanic plumes and clouds carry soluble sulphate and halide salts to the Earth's surface, ultimately depositing volcanogenic compounds into terrestrial or aquatic environments. Upon leaching of tephra in water, these salts dissolve rapidly. Previous studies have investigated the spatial and temporal variability of tephra leachate compositions during an eruption in order to gain insight into the mechanisms of gas-tephra interaction which emplace those salts. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-015-0945-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4498446PMC
June 2015
4 Reads

The frequency of explosive volcanic eruptions in Southeast Asia.

Bull Volcanol 2015;77(1). Epub 2015 Jan 22.

Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore.

There are ~750 active and potentially active volcanoes in Southeast Asia. Ash from eruptions of volcanic explosivity index 3 (VEI 3) and smaller pose mostly local hazards while eruptions of VEI ≥ 4 could disrupt trade, travel, and daily life in large parts of the region. We classify Southeast Asian volcanoes into five groups, using their morphology and, where known, their eruptive history and degassing style. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-014-0893-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4470363PMC
January 2015
19 Reads

Charge structure in volcanic plumes: a comparison of plume properties predicted by an integral plume model to observations of volcanic lightning during the 2010 eruption of Eyjafjallajökull, Iceland.

Bull Volcanol 2014;76(8):828. Epub 2014 Jul 20.

School of Geosciences, University of South Florida, 4202 E. Fowler Ave, Tampa, FL 33620 USA.

Observations of volcanic lightning made using a lightning mapping array during the 2010 eruption of Eyjafjallajökull allow the trajectory and growth of the volcanic plume to be determined. The lightning observations are compared with predictions of an integral model of volcanic plumes that includes descriptions of the interaction with wind and the effects of moisture. We show that the trajectory predicted by the integral model closely matches the observational data and the model well describes the growth of the plume downwind of the vent. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-014-0828-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4456075PMC
July 2014
2 Reads

Sulfur as a binding agent of aggregates in explosive eruptions.

Bull Volcanol 2014;76(10):871. Epub 2014 Sep 24.

Ludwig Maximilian University, Theresienstr. 41, 80333 Munich, Germany.

Understanding the mechanisms that govern ash aggregation is of critical importance in volcanology. Aggregation reduces the residence time of ash (≤2 mm) in the atmosphere strongly, by enhancing the sedimentation of finer-grained material generated during explosive eruptions. To date, experimental studies have focused on the expectation that water provides the strongest bonds between particles to form spherical to oblate aggregates (typically less than or equal to a few mm, occasionally up to several cm) preserved in pyroclastic deposits. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-014-0871-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4456069PMC
September 2014
3 Reads

Sedimentology and geomorphology of the deposits from the August 2006 pyroclastic density currents at Tungurahua volcano, Ecuador.

Bull Volcanol 2013;75(11):765. Epub 2013 Oct 24.

Earth & Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.

The deposits of the pyroclastic density currents from the August 2006 eruption of Tungurahua show three facies associations depending on the topographic setting: the massive, proximal cross-stratified, and distal cross-stratified facies. (1) The massive facies is confined to valleys on the slopes of the volcano. It contains clasts of >1 m diameter to fine ash material, is massive, and interpreted as deposited from dense pyroclastic flows. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-013-0765-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4456066PMC
October 2013
8 Reads

Dune bedforms produced by dilute pyroclastic density currents from the August 2006 eruption of Tungurahua volcano, Ecuador.

Bull Volcanol 2013;75(11):762. Epub 2013 Oct 13.

Earth & Environmental Sciences, Ludwig-Maximilians-Universität (LMU), Munich, Germany.

A series of pyroclastic density currents were generated at Tungurahua volcano (Ecuador) during a period of heightened activity in August 2006. Dense pyroclastic flows were confined to valleys of the drainage network, while dilute pyroclastic density currents overflowed on interfluves where they deposited isolated bodies comprising dune bedforms of cross-stratified ash exposed on the surface. Here, the description, measurement, and classification of more than 300 dune bedforms are presented. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-013-0762-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4456068PMC
October 2013
4 Reads

Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano, Chile.

Bull Volcanol 2012;74(2):511-531. Epub 2011 Sep 27.

Departamento de Geofísica, Universidad de Chile, Santiago, Chile.

Unconsolidated pyroclastic flow deposits of the 1993 eruption of Lascar Volcano, Chile, have, with time, become increasingly dissected by a network of deeply penetrating fractures. The fracture network comprises orthogonal sets of decimeter-wide linear voids that form a pseudo-polygonal grid visible on the deposit surface. In this work, we combine shallow surface geophysical imaging tools with remote sensing observations and direct field measurements of the deposit to investigate these fractures and their underlying causal mechanisms. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00445-011-0545-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4456076PMC
September 2011
1 Read
  • Page 1 of 1