DOCSLIB.ORG

2. Debris Avalanches

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

lltt.:' : l. Introduction than severalhundred metersacross as a maximum and ll. GeomorphicCharacteristics lessthan a meter acrossas a minimum. lll. InternalFramework debris-avalanchematrix A debris-avalanchematrix is a mix- lV. Frequencyand Magnitude ture of small volcanicclasts derived from variousparts V. Eruption Processes of the source volcano. This faciesis massive,poorly Vl. Flow and EmplacementProcesses sorted,and made of fragmentsof volcaniclasticforma- Vll. Examples tions and occasionallyof fragments of paleosolsand Vlll. Conclusions plants. hummocksCharacteristic topographic fearures for debris avalanchedeposits. The shapeof hummocksis variable and irregular. No overall trend in the alignment of hum- mocksis found. GLoSSARY jigsawcracks Jigsaw cracks are characteristicjoint patterns within a debris-avalancheblock. Jigsaw cracksare typi- cally more irregular than the cooling joints of massive amphitheaterAn arm-chair-shapedlandscape formed at igneousrocks. The joint planesusually remain closed, the sourceof a sectorcollapse. The depth, width, and but many of them open wide due to deformation during height of an amphithearer are variable. Amphitheaters the transport of the debrisavalanche. associatedwith a major debris avalancheat composite sector collapseA destructivevolcanic process volcanoesmay enclosethe summit vent. during the growth history of a volcano.Debris avalanchedeposits debrisavalanche The product of a large-scalecollapse of are the productsof sectorcollapses. a sectorof a volcanicedifice under water-undersaturated conditions.The depositis characterizedby two deposi- tional facies,"block" and "matrix." An amphitheaterat the sourceand hummoclg, topography on the surfaceof the deposit are characteristicropographic features of a SECTOR COLLAPSEof a volcanicedifice pro- debris avalanche. ducesa debrisavalanche. A debrisavalanche is debris-avalancheblock A fracturedand deformedpiece of triggered typically by intrusion of new magma, a phre- the source volcano included within a debris avalanche atic explosion, or an earthquake. A debris avalanche deposit.The sizesof single blocks are variable,more is generated at water-undersaturatedconditions. The Copyright O 2000 by AcademicPress !:.u,t clope d i a of VoI can ou 617 All rights of reproductionin any form reserved. 6ta D Bsnrs Av,q.r-,A.NcHBs deposit is characterizedby two depositional facies, the texture, internal stnrcture, or surface morphology. Sci- debris-avalanche block and the debris-avalanchematrix entists from the United States Geological Survey facies. The debris-avalanche block facies is composed (USGS) analyzed the eruptive processes,flowage, em- oflarge, coherentyet fractured and deformed piecesof placement mechanisms, and depositional structure for the source volcano that formed the debris avalanche the 1980 Mount St. Helens debris avalanche. Other deposit. The debris-avalanche matrix facies is a more researchersthen summarized the general characteristics uniform and fine-grained mixture of volcanic fragments of debris avalanchedeposits. Since this critical eruption, derived from various parts of the source volcano. An research related to debris avalancheshas increased sig- amphitheater at the source and hummocky topography nificantly. It is now clear that the formation of debris on the surface of the deposit are characteristic topo- avalanchesis a common phenomenon within the growth graphic features produced by a debris avalanche. history of many composite volcanoes. I. INTRODUCTIoN I I. GEoMoRPHIc CHARACTERISTIcS Debris avalanchesare recently recognized volcanic phe- Hummoclly topography, natural levees,a marginal cliff, nomena. One of the recent historical events was when a distal cliff, remnants of temporary river channels, and the northern sector of Mount St. Helens collaosed to an amphitheater at the source are characteristic geomor- be emplacedas a debris avalanchedeposit in thi upper phic featuresof a debrisavalanche deposit (Fig. 1).Hum- tributary of Toude River on May 18, 1980. Similar mocky topography is perhaps the most significant geo- processeswere observedand recorded during the 1888 morphic feature. The shape of individual hummocks eruption of Bandai in Japan and the 1956 eruption of is variable and irregular (Fig. 2A). Although parallel Bezymianny in Kamchatka. These eventswere first clas- alignments of the long axes of hummocks have been sified as ultranrlcanian eruptions until their true nature describedin some deposits,no consistentoverall trend was understood. Before the eruption of Mount St. Hel- has been observed.The volume and height of hummocks ens in 1980, most debris avalanchedeposits were inter- are larger in tJre proximal to medial part of the deposit preted as lahar deposits.Some other debris avalanche and decreasetoward the distal end. Sbme glacial termi- deposits have been interpreted aspy"roclastic flow depos- nal moraines show a similar topographic expression. its, lava flows, or moraines, due to the similarities in Due to irregularity in form and composition, it is often Al Longltudinalsection B: Medtattransverse section C: oistaltransverse section Naturallevee Matrix Marginalclitf Matrixfacies I o"bri"-"ualancheblock t t_ \:\. Debris-avalancheblock FIGURE I Schematicsection for a debris avalanchedeposit: (A) a longitudinalsection stretchingfrom the source amphitheater to the distalend; (B) a transversesection of the medialregion; (C) a transversesection for the distalregion. Size of hummocksgradually decreasestoward the distalarea. Debris-avalancheblocks are smallerand scarceat the distalarea. A D -: - ln .t1* : :i--r'' ,,ti;)- F lc U R E 2 Photographsof debrisavalanche features: (A) hummockytopography, 466 B.C.Kisakata debris avalanche deposit, Chokai volcano,northern Japan; (B) natural levee in the medialregion of the 1980Mount St.Helens debris avalanche deposit; (C) amphitheater of the 1980Mount St. Helensdebris avalanche; (D) hummockyterrain and a sourceregion already filled with postavalanchevolcanic deposits,Mount Shasta;(E) a sectionof a debris-avalancheblock, 1980Mount St. Helensdeposit; (F) a jigsawcrack, Owarabi debris avalanchedeposit, Chokai volcano, Japan; (G) a sectionof debris-avalanchemalrix, 466 B.C.Kisakata debris avalanche deposit, Chokai volcano, northern Japan;(H) deformed soft soil fragments(arrow) near the bottom contact of the 1797 debris avalanchedeposic, Unzenvolcano, Japan. 620 Dr,enrs Av.A.r,aNcHEs hard to discriminate debris avalanchedeoosits based on topography alone.Internai depositionalieatores should III. INTERNALFRAMEwoRK be examinedto confirm the origin of a deposit. Similar undulating topography is also known in the case of The internal framework of debris avalanchedeposits small-scale pyroclastic flow deposits. However, their comprises debris-avalancheblocks and a debris-ava- gentle and regularly undulating pattern differs from the lanche matrix. Debris-avalanchebiocks are surrounded hummocky topography of debris avalanchedeposits. by a debris-avalanchematrix. Fracture patternsand fault Naturai levees(Fig. 2B), a marginal cliff, and a distal displacementin debris-avalancheblocks, heterogeneity cliff are other characteristictopographic features in a in the debris-avalanchematrix, and paieomagneticevi- well-preserweddebris avalanchedeposit. Natural levees dence are clues to the mode of emolacement. have been described that rise 40 m above the debris avalanche deposit at Socompa Volcano, in northern Chile. A well-preserued example of a natural levee is the 1792 debris avalanchedeposit of Maluyarna lava A. Debris-Avalanche Blocks dome, Unzen volcano, Japan. Marginal ciiffs (Fig. 1) occur at both the 1792 Ma1,ryamadebris avalanchede- Most debris-avalancheblocks are fragments derived posit and the Zenkoji debris avalanchedeposit of Usu frorn the source volcano (Fig'. 2E). These blocks are volcano, Japan. The height of marginal cliffs is up to fractured and deformed but preseruemany of the pri- 10 m. The cliffs develop at the lower part of a debris mary texturesand geologic structuresof the sourcevol- avalanchecleposit if it is ernplacedon a wide plain.Distal cano. Some debris-avalanche blocks are fragments cliffs are a continuation of the marsinal cliff at the distal eroded from the ground surface during transportation encl of the deposit. The height oflhe distal cliff at the of the avalanche.The size of such debris-avalanche nonvolcanic tslackhawkLandslide, California, is about blocks is generallynot so big as the blocks derived from 20 m. the source volcano. The rnaximum measureddiameter Remnants of temporary river channelsare left on the for a debris-avaiancheblock is 280 m in the Mount surface of the valley-filling debris avalanchedeposits. Shastadebris avalanche deposit. The diameterof smaller Typical exarnplesof this are seenat the Kisakatadebris debris-avalancheblocks may be lessthan 1 m. Fracnrre avalancheof Chokai volcano and the Nirasaki debris patterns called jigsaw cracks are comrnonly observed avalancheof Yatsugatakevolcano in Japan. Such phe- within debris-avalancheblocks (Fig. 2F). Jigsaw cracks nomena lbrm soon afier the emolacementof the debris within a debris-avalancheblock are typically not asregr- avalanche.In the caseof the 1980 Mount St. Helens lar as the cooling joints of massiveigneous rocks. These eruption, stream capture began just after the emplace- joint planes usualiy remain closed, but some of thern ment of the debris avalancheand the river channel had open widely, due to deformation during transport of thr stabilized within several years after
Recommended publications
  • Seismic and Acoustic Signatures of Surficial Mass Movements at Volcanoes

    Seismic and Acoustic Signatures of Surficial Mass Movements at Volcanoes

    UC Santa Barbara UC Santa Barbara Previously Published Works Title Seismic and acoustic signatures of surficial mass movements at volcanoes Permalink https://escholarship.org/uc/item/2gd0d3wk Journal J. Volcanol. Geotherm. Res., 364 Authors Allstadt, K. E. Matoza, Robin Samuel Lockhart, A. B. et al. Publication Date 2018 Peer reviewed eScholarship.org Powered by the California Digital Library University of California ACCEPTED MANUSCRIPT Seismic and Acoustic Signatures of Surficial Mass Movements at Volcanoes Kate E. Allstadt1, Robin S. Matoza2, Andrew Lockhart3, Seth C. Moran3, Jacqueline Caplan- Auerbach4, Matthew Haney5, Weston A. Thelen3, Stephen D. Malone6 1) U.S. Geological Survey Geologic Hazards Science Center, Golden, CO 2) Department of Earth Science and Earth Research Institute, University of California, Santa Barbara, CA 3) U.S. Geological Survey Cascades Volcano Observatory, Vancouver, WA 4) Western Washington University, Bellingham, WA 5) U.S. Geological Survey Alaska Volcano Observatory, Anchorage, AK 6) University of Washington, Seattle, WA Abstract Surficial mass movements, such as debris avalanches, rock falls, lahars, pyroclastic flows, and outburst floods, are a dominant hazard at many volcanoes worldwide. Understanding these processes, cataloging their spatio-temporal occurrence, and detecting, tracking, and characterizing these events would advance the science of volcano monitoring and help mitigate hazards. Seismic and acoustic methods show promise for achieving these objectives: many surficial mass movements generate observable seismic and acoustic signals, and many volcanoes are already monitored. Significant progress has been made toward understanding, modeling, and extracting quantitative information from seismic and infrasonic signals generated by surficial mass movements. However, much work remains. In this paper, we review the state of the art of the topic, covering a range of scales and event types from individual rock falls to sector collapses.
  • Consequences of Volcano Sector Collapse on Magmatic Storage Zones: Insights from Numerical Modeling Virginie Pinel, Fabien Albino

    Consequences of Volcano Sector Collapse on Magmatic Storage Zones: Insights from Numerical Modeling Virginie Pinel, Fabien Albino

    Consequences of volcano sector collapse on magmatic storage zones: insights from numerical modeling Virginie Pinel, Fabien Albino To cite this version: Virginie Pinel, Fabien Albino. Consequences of volcano sector collapse on magmatic storage zones: insights from numerical modeling. Journal of Volcanology and Geothermal Research, Elsevier, 2013, 252, pp.29-37. 10.1016/j.jvolgeores.2012.11.009. ird-00782222 HAL Id: ird-00782222 https://hal.ird.fr/ird-00782222 Submitted on 29 Jan 2013 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. *Manuscript Click here to view linked References Consequences of volcano sector collapse on magmatic storage zones: insights from numerical modeling V. Pinela, F. Albinob aISTerre, Universit´ede Savoie, IRD, CNRS, F73376 Le Bourget du Lac, France bNordic Volcanological Center, Institute of Earth Sciences, University of Iceland, 101 Reykjavik, Iceland Abstract Major volcano flank collapses strongly affect the underlying magmatic plumb- ing system. Here, we consider the magma storage zone as a liquid pocket embedded in an elastic medium, and we perform numerical simulations in two-dimensional axisymmetric geometry as well as in three dimensions in order to evaluate the consequences of a major collapse event.
  • The Effect of Giant Lateral Collapses on Magma Pathways and the Location of Volcanism

    The Effect of Giant Lateral Collapses on Magma Pathways and the Location of Volcanism

    Originally published as: Maccaferri, F., Richter, N., Walter, T. R. (2017): The effect of giant lateral collapses on magma pathways and the location of volcanism. ‐ Nature Communications, 8. DOI: http://doi.org/10.1038/s41467‐017‐01256‐2 ARTICLE DOI: 10.1038/s41467-017-01256-2 OPEN The effect of giant lateral collapses on magma pathways and the location of volcanism Francesco Maccaferri1, Nicole Richter1 & Thomas R. Walter1 Flank instability and lateral collapse are recurrent processes during the structural evolution of volcanic edifices, and they affect and are affected by magmatic activity. It is known that dyke intrusions have the potential to destabilise the flanks of a volcano, and that lateral collapses may change the style of volcanism and the arrangement of shallow dykes. However, the effect of a large lateral collapse on the location of a new eruptive centre remains unclear. Here, we use a numerical approach to simulate the pathways of magmatic intrusions underneath the volcanic edifice, after the stress redistribution resulting from a large lateral collapse. Our simulations are quantitatively validated against the observations at Fogo vol- cano, Cabo Verde. The results reveal that a lateral collapse can trigger a significant deflection of deep magma pathways in the crust, favouring the formation of a new eruptive centre within the collapse embayment. Our results have implications for the long-term evolution of intraplate volcanic ocean islands. 1 German Research Centre for Geosciences (GFZ), Potsdam, 14473, Germany. Correspondence and requests for materials should be addressed to F.M. (email: [email protected]) NATURE COMMUNICATIONS | 8: 1097 | DOI: 10.1038/s41467-017-01256-2 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/s41467-017-01256-2 specially tall and active volcanoes are prone to flank observed at numerous volcanic ocean islands15,29,34,35, including – Einstability which may lead to failure and sector collapse1 3.
  • Triggering of Major Eruptions Recorded by Actively Forming Cumulates SUBJECT AREAS: Michael J

    Triggering of Major Eruptions Recorded by Actively Forming Cumulates SUBJECT AREAS: Michael J

    Triggering of major eruptions recorded by actively forming cumulates SUBJECT AREAS: Michael J. Stock*, Rex N. Taylor & Thomas M. Gernon GEOCHEMISTRY PETROLOGY National Oceanography Centre, Southampton, University of Southampton, Southampton SO14 3ZH, U.K. SOLID EARTH SCIENCES VOLCANOLOGY Major overturn within a magma chamber can bring together felsic and mafic magmas, prompting de-volatilisation and acting as the driver for Plinian eruptions. Until now identification of mixing has been Received limited to analysis of lavas or individual crystals ejected during eruptions. We have recovered partially 15 August 2012 developed cumulate material (‘live’ cumulate mush) from pyroclastic deposits of major eruptions on Tenerife. These samples represent ‘‘frozen’’ clumps of diverse crystalline deposits from all levels in the Accepted developing reservoir, which are permeated with the final magma immediately before eruptions. Such events 17 September 2012 therefore record the complete disintegration of the magma chamber, leading to caldera collapse. Chemical variation across developing cumulus crystals records changes in melt composition. Apart from fluctuations Published reflecting periodic influxes of mafic melt, crystal edges consistently record the presence of more felsic 12 October 2012 magmas. The prevalence of this felsic liquid implies it was able to infiltrate the entire cumulate pile immediately before each eruption. Correspondence and he Las Can˜adas volcano on Tenerife, Canary Islands, generated at least seven major explosive eruptions requests for materials during the Quaternary1–3. These events resulted in widespread deposition of pyroclastic material, with an should be addressed to estimated volume of .130 km3 (ref. 1,4). Despite considerable scientific interest in the volcano and assoc- T 5 6 R.N.T.
  • Dome Growth, Collapse, and Valley Fill at Soufrière Hills Volcano, Montserrat, from 1995 to 2013: Contributions from Satellite Radar

    Dome Growth, Collapse, and Valley Fill at Soufrière Hills Volcano, Montserrat, from 1995 to 2013: Contributions from Satellite Radar

    Research Paper GEOSPHERE Dome growth, collapse, and valley fill at Soufrière Hills Volcano, Montserrat, from 1995 to 2013: Contributions from satellite radar GEOSPHERE; v. 12, no. 4 measurements of topographic change doi:10.1130/GES01291.1 D.W.D. Arnold1, J. Biggs1, G. Wadge2, S.K. Ebmeier1, H.M. Odbert3,*, and M.P. Poland4 1COMET (Centre for Observation and Modeling of Earthquakes, Volcanoes and Tectonics), School of Earth Sciences, University of Bristol, Queen’s Road, Bristol BS8 1RJ, UK 4 figures; 5 tables; 1 supplemental file 2COMET (Centre for Observation and Modeling of Earthquakes, Volcanoes and Tectonics), Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading RG6 6BB, UK 3School of Earth Sciences, University of Bristol, Queen’s Road, Bristol BS8 1RJ, UK 4U.S. Geological Survey, Cascade Volcano Observatory, 1300 S.E. Cardinal Court, Building 10, Suite 100, Vancouver, Washington 98683-9589, USA CORRESPONDENCE: david .arnold@ bristol .ac.uk CITATION: Arnold, D.W.D., Biggs, J., Wadge, G., ABSTRACT Fink, 1996; Fink and Griffiths, 1998; Watts et al., 2002; Hutchison et al., 2013). In Ebmeier, S.K., Odbert, H.M., and Poland, M.P., 2016, Dome growth, collapse, and valley fill at Soufrière steady state, lava effusion rate can constrain the volume and pressure change Hills Volcano, Montserrat, from 1995 to 2013: Contri- Frequent high-resolution measurements of topography at active vol- of shallow magma reservoirs (e.g., Dvorak and Dzurisin, 1993; Harris et al., butions from satellite radar measurements of topo- canoes can provide important information for assessing the distribution and 2003, 2007; Anderson and Segall, 2011), while long-lived volcanic eruptions graphic change: Geosphere, v.
  • Abrupt Climatic Changes As Triggering Mechanisms of Massive Volcanic Collapses

    Abrupt Climatic Changes As Triggering Mechanisms of Massive Volcanic Collapses

    Journal of Volcanology and Geothermal Research 155 (2006) 329–333 www.elsevier.com/locate/jvolgeores Short communication Abrupt climatic changes as triggering mechanisms of massive volcanic collapses Lucia Capra Instituto de Geografía, UNAM, CU Coyoacan, 04510, Mexico DF, Mexico Received 7 March 2006; received in revised form 31 March 2006; accepted 19 April 2006 Available online 5 June 2006 Abstract Abrupt climate change can trigger volcanic collapses, phenomena that cause the destruction of the entire sector of a volcano, including its summit. During the past 30 ka, major volcanic collapses occurred just after main glacial peaks that ended with rapid deglaciation. Glacial debuttressing, load discharge and fluid circulation coupled with the post-glacial increase of humidity and heavy rains can activate the failure of unstable edifices. Furthermore, significant global warming can be responsible for the collapse of ice-capped unstable volcanoes, an unpredictable hazard that in few minutes can bury inhabited areas. © 2006 Published by Elsevier B.V. Keywords: volcanic collapse; global warming 1. Introduction Wyk de Vries et al., 2001; Clavero et al., 2002). Several analogue experiments have been performed to demon- Although climate changes have been considered to be strate how faults can deform volcanoes that finally a triggering mechanism for large eruptions (Rampino et collapse (Van Wyk de Vries and Borgia, 1996; Lagmay et al., 1979; McGuire et al., 1997), they have not, so far, al., 2000; Acocella, 2005; Norini and Lagmay, 2005). been related to the collapse of volcanoes. Unstable This is probably a very common mechanism, but it is volcanoes, whatever the origin of their instability, can spatially localized and can occur in an indeterminate collapse from the same triggering mechanism (McGuire, period of time.
  • Article Is Part of the Special Issue Bris Avalanche Emplacement and Formation of Hummocks

    Article Is Part of the Special Issue Bris Avalanche Emplacement and Formation of Hummocks

    Nat. Hazards Earth Syst. Sci., 18, 429–444, 2018 https://doi.org/10.5194/nhess-18-429-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 3.0 License. Characteristics of debris avalanche deposits inferred from source volume estimate and hummock morphology around Mt. Erciyes, central Turkey Yuichi S. Hayakawa1, Hidetsugu Yoshida2, Hiroyuki Obanawa3, Ryutaro Naruhashi4, Koji Okumura5, Masumi Zaiki6, and Ryoichi Kontani7 1Center for Spatial Information Science, The University of Tokyo, Kashiwa, 277-8568, Japan 2School of Arts and Letters, Meiji University, Tokyo, 101-8301, Japan 3VisionTech Inc., Tsukuba, 305-0045, Japan 4Earthquake Research Institute, The University of Tokyo, Tokyo, 113-0032, Japan 5Department of Geography, Graduate School of Letters, Hiroshima University, Hiroshima, 739-852, Japan 6Department of Economics and Business, Faculty of Economics, Seikei University, Tokyo, 180-8633, Japan 7Department of Contemporary Sociological Studies, Faculty of Literature, Notre Dame Seishin University, Okayama, 700-8516, Japan Correspondence: Yuichi S. Hayakawa ([email protected]) Received: 23 March 2017 – Discussion started: 23 March 2017 Revised: 5 December 2017 – Accepted: 13 December 2017 – Published: 7 February 2018 Abstract. Debris avalanches caused by volcano sector col- indicating that the compressional regime of the flow con- lapse often form characteristic depositional landforms such tributed to the formation of hummocks. These indicate that as hummocks. Sedimentological and geomorphological anal- the flow and emplacement of the avalanche were constrained yses of debris avalanche deposits (DADs) are crucial to by the topography. The existing caldera wall forced the initial clarify the size, mechanisms, and emplacement of debris eastward flow to move northward, and the north-side caldera avalanches.
  • University of Birmingham the Evolution of Volcanic Systems Following Sector Collapse

    University of Birmingham the Evolution of Volcanic Systems Following Sector Collapse

    University of Birmingham The evolution of volcanic systems following sector collapse Watt, Sebastian DOI: 10.1016/j.jvolgeores.2019.05.012 License: Creative Commons: Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) Document Version Peer reviewed version Citation for published version (Harvard): Watt, S 2019, 'The evolution of volcanic systems following sector collapse', Journal of Volcanology and Geothermal Research, vol. 384, pp. 280-303. https://doi.org/10.1016/j.jvolgeores.2019.05.012 Link to publication on Research at Birmingham portal Publisher Rights Statement: Checked for eligibility: 25/06/2019 General rights Unless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law. •Users may freely distribute the URL that is used to identify this publication. •Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research. •User may use extracts from the document in line with the concept of ‘fair dealing’ under the Copyright, Designs and Patents Act 1988 (?) •Users may not further distribute the material nor use it for the purposes of commercial gain. Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.
  • Science for a Changing World

    Science for a Changing World

    science for a changing world Cover photograph Mount Rainier, Washington, with the flood plain of the Puyallup River in the foreground, 50 kilometers downstream from the volcano. The flood plain is a pathway for debris flows (lahars) from the volcano, most recently by the Electron Mudflow about 500 to 600 years ago. (Photograph by David Wieprecht, U.S. Geological Survey.) Catastrophic Debris Flows Transformed from Landslides in Volcanic Terrains: Mobility, Hazard Assessment, and Mitigation Strategies By Kevin M. Scott, Jose Luis Macias, Jose Antonio Naranjo, Sergio Rodriguez, and John P. McGeehin U.S. Geological Survey Professional Paper 1630 U.S. DEPARTMENT OF THE INTERIOR GALE A. NORTON, Secretary U.S. GEOLOGICAL SURVEY CHARLES G. GROAT, Director Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Reston, Virginia 2001 For sale by the U.S. Geological Survey, Information Services Box 25286, Federal Center Denver, CO 80225 Library of Congress Cataloging-in-Publication Data Scott, Kevin M., 1935- Catastrophic debris flows transformed from landslides in volcanic terrains: mobility, hazard assessment and mitigation strategies I by Kevin M. Scott ... [et al.]. p. em.- (U.S. Geological Survey professional paper; 1630) Includes bibliographical references and index. 1. Debris avalanches. 2. Lahars. 3. Catastrophes (Geology). I. Scott, Kevin M., 1935- 11. Series QE75.P9 no. 1630 [QE599.A2] 557.3 s-dc21 [551.3'07] 2001058484 ISBN 0-607-98578-X CONTENTS
  • Numerical Modeling of Volcanic Slope Instability and Related Hazards at Pacaya Volcano, Guatemala

    Numerical Modeling of Volcanic Slope Instability and Related Hazards at Pacaya Volcano, Guatemala

    ARMA 12-438 Numerical modeling of volcanic slope instability and related hazards at Pacaya Volcano, Guatemala Schaefer1, L.N., Oommen1, T., Corazzato2, C. and Tibaldi2, A. and Rose1, W.I. 1Michigan Technological University, Houghton, MI, USA 2Università degli Studi di Milano-Bicocca, Milan, Italy Copyright 2012 ARMA, American Rock Mechanics Association This paper was prepared for presentation at the 46th US Rock Mechanics / Geomechanics Symposium held in Chicago, IL, USA, 24-27 June 2012. This paper was selected for presentation at the symposium by an ARMA Technical Program Committee based on a technical and critical review of the paper by a minimum of two technical reviewers. The material, as presented, does not necessarily reflect any position of ARMA, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of ARMA is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgement of where and by whom the paper was presented. ABSTRACT: This study uses numerical modeling to determine the possibility of an edifice collapse at the active Pacaya Volcano in Guatemala. Stability analyses using the Limit Equilibrium Method (LEM) and the Finite Element Method (FEM) were performed on the south-western flank using the physical-mechanical material properties of Pacaya’s intact rocks and rock mass characteristics based on field observations and laboratory tests. The Hoek and Brown failure criterion was used to calculate the friction angle, cohesion, and rock mass parameters in a determined stress range.
  • Influence of Substrate Tectonic Heritage on the Evolution of Composite

    Influence of Substrate Tectonic Heritage on the Evolution of Composite

    Available online at www.sciencedirect.com Global and Planetary Change 61 (2008) 151–174 www.elsevier.com/locate/gloplacha Influence of substrate tectonic heritage on the evolution of composite volcanoes: Predicting sites of flank eruption, lateral collapse, and erosion ⁎ Alessandro Tibaldi a, , Claudia Corazzato a, Andrey Kozhurin b, Alfredo F.M. Lagmay c, Federico A. Pasquarè d, Vera V. Ponomareva b, Derek Rust e, Daniel Tormey f, Luigina Vezzoli d a Università degli Studi di Milano-Bicocca, Dipartimento di Scienze Geologiche e Geotecnologie, Milan, Italy b Institute of Volcanology and Seismology, Petropavlovsk-Kamchatsky, Russia c National Institute of Geological Sciences, Quezon City, Philippines d Università degli Studi dell'Insubria, Dipartimento di Scienze Chimiche e Ambientali, Como, Italy e School of Earth and Environmental Sciences, University of Portsmouth, UK f ENTRIX Inc., Ventura, California, USA Received 30 January 2007; accepted 23 August 2007 Available online 9 October 2007 Abstract This paper aims to aid understanding of the complicated interplay between construction and destruction of volcanoes, with an emphasis on the role of substrate tectonic heritage in controlling magma conduit geometry, lateral collapse, landslides, and preferential erosion pathways. The influence of basement structure on the development of six composite volcanoes located in different geodynamic/geological environments is described: Stromboli (Italy), in an island arc extensional tectonic setting, Ollagüe (Bolivia–Chile) in a cordilleran extensional setting, Kizimen (Russia) in a transtensional setting, Pinatubo (Philippines) in a transcurrent setting, Planchon (Chile) in a compressional cordilleran setting, and Mt. Etna (Italy) in a complex tectonic boundary setting. Analogue and numerical modelling results are used to enhance understanding of processes exemplified by these volcanic centres.
  • Volcano Instability: a Review of Contemporary Themes

    Volcano Instability: a Review of Contemporary Themes

    Downloaded from http://sp.lyellcollection.org/ by guest on September 26, 2021 Volcano instability: a review of contemporary themes W. J. McGUIRE Department of Geography & Geology, Cheltenham and Gloucester College of Higher Education, Francis Close Hall, Swindon Road, Cheltenham GL50 4AZ and Department of Geological Sciences, University College London, Gower Street, London WCIE 6BT, UK Abstract: Active volcanoes are revealed to be dynamically evolving structures, the growth and development of which are characteristically punctuated by episodes of instability and subsequent structural failure. Edifice instability typically occurs in response to one or more of a range of agencies, including magma emplacement, the overloading or oversteepening of slopes, and peripheral erosion. Similarly, structural failure of a destabilized volcano may occur in response to a number of triggers of which seismogenic (e.g tectonic or volcanic earthquakes) or magmagenic (e.g. pore-pressure changes due to magma intrusion) are common. Edifice failure and consequent debris avalanche formation appears to occur, on average, at least four times a century, and similar behaviour is now known to have occurred at volcanoes on Mars and Venus. Realization of the potential scale of structural failures and associated eruptive activity has major implications for the development of monitoring and hazard mitigation strategies at susceptible volcanoes, which must now address the possibility of future collapse events which may be ten times greater than that which occurred at Mount St Helens in 1980. Since the spectacular landslide which triggered Labazuy this volume), Martinique (Semet & the climactic eruption of Mount St Helens during Boudon 1994), Stromboli (Kokelaar & Romag- May 1980 (Lipman & Mullineaux 1981), con- noli 1995), Augustine Island (Beg& & Kienle siderable attention has been focused upon the 1992), and the Canary Island volcanoes (Hol- unstable nature of volcanic edifices, and their comb & Searle 1991; Carracedo 1994, this tendency to experience structural failure.