Fluid motions in volcanic conduits: a source of seismic and acoustic signals

249 Pages·2008·11.11 MB·English

by  S. J. Lane

Volcanoes become active when fluids are in motion, and erupt when these fluids escape into the
atmosphere. Volcanic fluids are a mixture of solid, liquid and gas. These mixtures result in a
complex range of flow behaviour, especially during interaction with conduit geometry. These
processes are not directly observable and must be inferred from interpretations of field
observation and measurement. One of the outcomes of this complexity is the generation of
pressure and force transients as high-density phases accelerate and decelerate during unsteady
flow. These transients are one means of flexing the conduit wall, a process that manifests itself as
ground motion and is detectable as volcano seismic signals. On eruption, volcanic fluids interact
with the atmosphere and generate acoustic and thermal signals. In this Special Publication we
present a series of papers based on field, numerical and experimental approaches that seek to
establish links between geophysical signals and fluid motion in volcanic conduits.
Fluid Motions in Volcanic Conduits:
A Source of Seismic and Acoustic Signals
The Geological Society of London
Books Editorial Committee
ChiefEditor
BOB PANKHURST (UK)
SocietyBooksEditors
JOHN GREGORY (UK)
JIM GRIFFITHS (UK)
JOHN HOWE (UK)
PHIL LEAT (UK)
NICK ROBINS (UK)
JONATHAN TURNER (UK)
SocietyBooksAdvisors
MIKE BROWN (USA)
ERIC BUFFETAUT(FRANCE)
JONATHANCRAIG(ITALY)
RETO GIERE´ (GERMANY)
TOM MCCANN (GERMANY)
DOUG STEAD (CANADA)
RANDELL STEPHENSON (NETHERLANDS)
Geological Society books refereeing procedures
TheSocietymakeseveryefforttoensurethatthescientificandproductionqualityofitsbooksmatchesthat
ofitsjournals.Since1997,allbookproposalshavebeenrefereedbyspecialistreviewersaswellasbythe
Society’sBooksEditorialCommittee. Ifthe refereesidentify weaknesses inthe proposal,these mustbe
addressedbeforetheproposalisaccepted.
Once the book is accepted, the Society Book Editors ensure that the volume editors follow strict
guidelineson refereeingand qualitycontrol.Weinsistthatindividualpaperscanonlybeacceptedafter
satisfactoryreviewbytwoindependentreferees.Thequestionsonthereviewformsaresimilartothosefor
JournaloftheGeologicalSociety.Thereferees’formsandcommentsmustbeavailabletotheSociety’s
BookEditorsonrequest.
Althoughmanyofthebooksresultfrommeetings,theeditorsareexpectedtocommissionpapersthat
werenotpresentedatthemeetingtoensurethatthebookprovidesabalancedcoverageofthesubject.Being
acceptedforpresentationatthemeetingdoesnotguaranteeinclusioninthebook.
MoreinformationaboutsubmittingaproposalandproducingabookfortheSocietycanbefoundonits
website:www.geolsoc.org.uk.
Itisrecommendedthatreferencetoallorpartofthisbookshouldbemadeinoneofthefollowingways:
LANE,S.J.&GILBERT,J.S.(eds)2008.FluidMotionsinVolcanicConduits:ASourceofSeismicand
AcousticSignals.GeologicalSociety,London,SpecialPublications,307.
CHOUET,B.,DAWSON,P.&MARTINI,M.2008.Shallow-conduitdynamicsatStromboliVolcano,Italy,
imagedfromwaveforminversions.In:LANE,S.J.&GILBERT,J.S.(eds)2008.FluidMotionsinVolcanic
Conduits: A Source of Seismic and Acoustic Signals. Geological Society, London, Special Publications,
307,57–84.
GEOLOGICAL SOCIETY SPECIAL PUBLICATION NO.307
Fluid Motions in Volcanic Conduits:
A Source of Seismic and Acoustic Signals
EDITED BY
S. J. LANE and J. S. GILBERT
University of Lancaster, UK
2008
Published by
The Geological Society
London
THE GEOLOGICAL SOCIETY
TheGeologicalSocietyofLondon(GSL)wasfoundedin1807.Itistheoldestnationalgeologicalsocietyintheworld
andthelargestinEurope.ItwasincorporatedunderRoyalCharterin1825andisRegisteredCharity210161.
TheSocietyistheUKnationallearnedandprofessionalsocietyforgeologywithaworldwideFellowship(FGS)of
over9000.TheSocietyhasthepowertoconferCharteredstatusonsuitablyqualifiedFellows,andabout2000ofthe
Fellowship carry the title (CGeol). Chartered Geologists may also obtain the equivalent European title, European
Geologist(EurGeol).OnefifthoftheSociety’sfellowshipresidesoutsidetheUK.TofindoutmoreabouttheSociety,
logontowww.geolsoc.org.uk.
TheGeologicalSocietyPublishingHouse(Bath,UK)producestheSociety’sinternationaljournalsandbooks,and
actsasEuropeandistributorforselectedpublicationsoftheAmericanAssociationofPetroleumGeologists(AAPG),
theIndonesianPetroleumAssociation(IPA),theGeologicalSocietyofAmerica(GSA),theSocietyforSedimentary
Geology (SEPM) and the Geologists’ Association (GA). Joint marketing agreements ensure that GSL Fellows may
purchasethesesocieties’publicationsatadiscount.TheSociety’sonlinebookshop(accessiblefromwww.geolsoc.org.uk)
offerssecurebookpurchasingwithyourcreditordebitcard.
To find out about joining the Society and benefiting from substantial discounts on publications of GSL and
other societies worldwide, consult www.geolsoc.org.uk, or contact the Fellowship Department at: The Geological
Society, Burlington House, Piccadilly, London W1J 0BG: Tel. þ44 (0)20 7434 9944; Fax þ44 (0)20 7439 8975;
E-mail:[email protected].
ForinformationabouttheSociety’smeetings,consultEventsonwww.geolsoc.org.uk.Tofindoutmoreaboutthe
Society’sCorporateAffiliatesScheme,[email protected].
PublishedbyTheGeologicalSocietyfrom:
TheGeologicalSocietyPublishingHouse,Unit7,BrassmillEnterpriseCentre,BrassmillLane,BathBA13JN,UK
(Orders: Telþ44(0)1225445046,Faxþ44(0)1225442836)
Onlinebookshop:www.geolsoc.org.uk/bookshop
Thepublishersmakenorepresentation,expressorimplied,withregardtotheaccuracyoftheinformationcontained
inthisbookandcannotacceptanylegalresponsibilityforanyerrorsoromissionsthatmaybemade.
# The Geological Society of London 2008. All rights reserved. No reproduction, copy or transmission of this
publicationmaybemadewithoutwrittenpermission.Noparagraphofthispublicationmaybereproduced,copiedor
transmittedsavewiththeprovisionsoftheCopyrightLicensingAgency,90TottenhamCourtRoad,LondonW1P9HE.
UsersregisteredwiththeCopyrightClearanceCenter,27CongressStreet,Salem,MA01970,USA:theitem-feecode
forthispublicationis0305-8719/08/$15.00.
BritishLibraryCataloguinginPublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary.
ISBN978-1-86239-262-5
TypesetbyTechsetCompositionLtd,Salisbury,UK
PrintedbyMPGBooksLtd,Bodmin,UK
Distributors
NorthAmerica
Fortradeandinstitutionalorders:
TheGeologicalSociety,c/oAIDC,82WinterSportLane,Williston,VT05495,USA
Orders: Telþ1800-972-9892
Faxþ1802-864-7626
E-mail:[email protected]
Forindividualandcorporateorders:
AAPGBookstore,POBox979,Tulsa,OK74101-0979,USA
Orders: Telþ1918-584-2555
Faxþ1918-560-2652
E-mail:[email protected]
Website:http://bookstore.aapg.org
India
AffiliatedEast-WestPressPrivateLtd,MarketingDivision,G-1/16AnsariRoad,DaryaGanj,NewDelhi110002,India
Orders: Telþ91112327-9113/2326-4180
Faxþ91112326-0538
E-mail:affi[email protected]
Acknowledgements
SteveLaneandJennieGilbertthankAngharadHillsandstaffoftheGeologicalSocietyPublishingHouse
fortheirhelpwiththeproductionofthisbook.JennieandStevealsothankthefollowingpeoplewhogave
theirprecioustimetoassistinhelpingtheauthorsimprovethescientificandeditorialqualityofthepapers
submittedtothisSpecialPublication.
PhilLeat
BritishAntarcticSurvey,HighCross,MadingleyRoad,Cambridge,CB30ET,UK
JenniBarclay
SchoolofEnvironmentalSciences,UniversityofEastAnglia,Norwich,NR47TJ,UK
RickAster
DepartmentofEarthandEnvironmentalScienceandGeophysicalResearchCenter,NewMexicoInstitute
ofMiningandTechnology,801LeroyPlace,Socorro,NM87801,USA
MinoruTakeo
EarthquakeResearchInstitute,1-1-1Yayoi,Bunkyo-ku,Tokyo,Japan
LucaD’Auria
IstitutoNazionalediGeofisicaeVulcanologia,OsservatorioVesuviano,UFCentrodiMonitoraggio,Via
Diocleziano,328 – 80124,Napoli,Italy
JeremyPhillips
DepartmentofEarthSciences,UniversityofBristol,WillsMemorialBuilding,QueensRoad,BristolBS8
1RJ,UK
DorkSahagian
EarthandEnvironmentalSciences,LehighUniversity,31WilliamsDr,Bethlehem,PA18015-3126,USA
MieIshihara
EarthquakeResearchInstitute,1-1-1Yayoi,Bunkyo-ku,Tokyo,Japan
JacopoTaddeucci
Istituto Nazionale di Geofisica e Vulcanologia, Dept. of Seismology and Tectonophysics, Via di Vigna
Murata605,00143,Roma,Italy
AmandaClarke
SchoolofEarthandSpaceExploration,ArizonaStateUniversity,Tempe,AZ85287-1404,480-965-6590,
USA
HughTuffen
DepartmentofEnvironmentalScienceandLancasterEnvironmentCentre,LancasterUniversity,Lancaster
LA14YQ,UK
AntonellaLongo
IstitutoNazionalediGeofisicaeVulcanologia,SezionediPisa,viadellaFaggiola32,56126Pisa,Italy
OlegMelnik
InstituteofMechanics,MoscowStateUniversity,1-Michurinskiiprospect,119192,Moscow,Russia
AlisonRust
DepartmentofEarthSciences,UniversityofBristol,WillsMemorialBuilding,QueensRoad,BristolBS8
1RJ,UK
SoniaCalvari
IstitutoNazionalediGeofisicaeVulcanologia,PiazzaRoma2,95123Catania,Italy
MikeJames
DepartmentofEnvironmentalScienceandLancasterEnvironmentCentre,LancasterUniversity,Lancaster
LA14YQ,UK
viii ACKNOWLEDGEMENTS
BernardChouet
USGeologicalSurvey,345MiddlefieldRoad,MS910,MenloPark,California,CA94025,USA
JeffJohnson
DepartmentofEarthSciences,UniversityofNewHampshire,Durham,NH03824,USA
SilvioDeAngelis
MontserratVolcanoObservatory,Flemmings,Montserrat,WestIndies
BruceJulian
USGeologicalSurvey,345MiddlefieldRd,MS977,MenloPark,CA94025,USA
LionelWilson
DepartmentofEnvironmentalScienceandLancasterEnvironmentCentre,LancasterUniversity,Lancaster
LA14YQ,UK
LizParfitt
Cynlais,ConwyOldRoad,Dwygyfylchi,ConwyLL346RB,UK
HarryPinkerton
DepartmentofEnvironmentalScienceandLancasterEnvironmentCentre,LancasterUniversity,Lancaster
LA14YQ,UK
Contents
Acknowledgements vii
GILBERT,J.S.&LANE,S.J.Theconsequencesoffluidmotioninvolcanicconduits 1
KURZON,I.,LYAKHOVSKY,V.,NAVON,O.&LENSKY,N.G.Dampingofpressurewavesin 11
visco-elastic,saturatedbubblymagma
LONGO,A.,BARBATO,D.,PAPALE,P.,SACCOROTTI,G.&BARSANTI,M.Numerical 33
simulationofthedynamicsoffluidoscillationsinagravitationallyunstable,compositionally
stratifiedfissure
RUST,A.C.,BALMFORTH,N.J.&MANDRE,S.Thefeasibilityofgeneratinglow-frequency 45
volcanoseismicitybyflowthroughadeformablechannel
CHOUET,B.,DAWSON,P.&MARTINI,M.Shallow-conduitdynamicsatStromboliVolcano, 57
Italy,imagedfromwaveforminversions
MARCHETTI,E.&HARRIS,A.J.L.TrendsinactivityatPu’u’O’oduring2001–2003:insights 85
fromthecontinuousthermalrecord
VERGNIOLLE,S.&RIPEPE,M.FromStrombolianexplosionstofirefountainsatEtnaVolcano 103
(Italy):whatdowelearnfromacousticmeasurements?
VERGNIOLLE,S.Fromsoundwavestobubblingwithinamagmareservoir:comparisonbetween 125
eruptionsatEtna(2001,Italy)andKilauea(Hawaii)
JAMES,M.R.,LANE,S.J.&CORDER,S.B.Modellingtherapidnear-surfaceexpansionofgas 147
slugsinlow-viscositymagmas
LENSKY,N.G.,SPARKS,R.S.J.,NAVON,O.&LYAKHOVSKY,V.CyclicactivityatSoufrie`re 169
HillsVolcano,Montserrat:degassing-inducedpressurizationandstick-slipextrusion
OHMINATO,T.SourcemechanismsofvulcanianeruptionsatMt.Asama,Japan,inferredfrom 189
volcanoseismicsignals
LANE,S.J.,PHILLIPS,J.C.&RYAN,G.A.Dome-buildingeruptions:insightsfromanalogue 207
experiments
Index 239
The consequences of fluid motion in volcanic conduits
JENNIE S.GILBERT & STEPHEN J. LANE
1Department of Environmental Science, Lancaster EnvironmentCentre, Lancaster University,
LA1 4YQ,UK (e-mail: [email protected])
Abstract: Whenvolcanoesareactive,therearecharacteristicsignssuchasgroundmovement,
sounds,heatandejectedmaterial.Eachofthesesignsisaresultof,andhenceaninformation
sourcefor,fluidmotioninvolcanicconduits.Herewebrieflyreviewsomeofthelinksbetween
thesesignsandfluidflowprocessesandsuggestfuturedirectionsthatshouldallowadvancement
oferuptionforecastingastheselinksbecomeunderstoodmorefully.Cross-fertilizationbetween
increasinglyrealisticnumericalandexperimentalmodels,diversegeophysicaldatasources,and
chemicalandphysicalevidenceineruptiveproductscanbeachievedbysimultaneouslyapplying
theseapproachestowell-studiedvolcanoes.
Volcanic activity comprises a wide range of 2003; Chadwick et al. 2006), motion of the
phenomena that result from complex non-linear atmosphere in response to eruption (e.g. Matoza
interactions and feedback mechanisms. Processes et al. 2007), thermal signatures (e.g. Ball &
that start in the volcanic plumbing system deter- Pinkerton 2006), and the physicochemical nature
mine the nature of subsequent events and control of ejected material, for example gas chemistry
eruptionstyles.Onemergingfromthevent,volca- (Burton et al. 2007), crystal zonation (Blundy
nicmaterialenterstheatmosphereandtheensuing et al. 2007), and pyroclast morphology (Lautze &
interactionsarekeyindeterminingtheconsequent Houghton 2007). Many of these natural signals
transportofvolcanicdebristhatdefinestheimpact have the same underlying source process, namely
on the environment and on human lives and the motion of gases, liquids and solids within and
infrastructure. Our capability to mitigate volcanic beneath volcanic edifices. The linking of passive
hazards reliesin large part onforecasting eruptive geo-physicochemical signals to the dynamics of
events, and this, in turn, requires a high degree of fluids formed the focus of a Workshop entitled
understanding about the physical and chemical ‘The Physics of Fluid Oscillations in Volcanic
processes operating during volcanism. The ability Systems’, held at Lancaster University on 7 and 8
tointerpretsurfaceobservationsandmeasurements September2006,andseededtheproductionofthis
in terms of subsurface processes is a key step in SpecialPublication.
eruptionforecasting. Fluid flow in volcanoes is a difficult phenom-
The flow of magma in volcanic plumbing enontoobserveinaction,especiallywithincreasing
systems is a prerequisite for surface eruptive volcanic explosivity index (VEI, Newhall & Self
activity.Formagmaflowtotakeplace,forcemust 1982; Pyle 2000). High-VEI eruptions do not
be applied and pressure gradients must exist. happen very often, and the larger the explosion
Forces and pressures in magma systems will the less frequent it is, with, for example, repeat
changewithtimeonarangeofscales,resultingin timescales of order 103 years for VEI 6 events
motion of conduit walls that, if sufficiently large, such as the Krakatau 1883 eruption. This makes
will be measurable. Fluids in motion also exert detailedsyn-eventmeasurementsoflargeexplosive
dragonthewallsofaconduit,variationsofwhich episodes infrequent on the timescale of con-
willcreategroundmotion(e.g.Greenetal.2006). temporaryscience;aneventlikeKrakatauin1883
Changes in force, pressure and drag may also has never been monitored by modern methods.
couple into a range of resonant or other cyclical Medium-VEI events such as vulcanian explosions
processes.Thissuggeststhatamajorsourcemech- frequentlydestroynear-fieldobservationequipment
anism of ground motion at active volcanoes is (e.g. Voight et al. 1998), suggesting that proximal
magma flow, and that this ground motion may, measurements during high-VEI eruptions are very
therefore, be interpreted in terms of fluid flow difficult to obtain even when an event does occur.
withintheactivevolcanicconduit. Processesthatcontributetoanexplosiveeventare
Volcanoes are largely monitored by measure- difficult to access directly; a prime example of
ment of the consequences of fluid flow within this ishowtoobtaindataaboutthe natureofflow
conduit systems, including motion of the ground in the volcanic conduit system during explosive
over a wide range of timescales (e.g. Chouet activity. Direct measurements are not possible,
From:LANE,S.J.&GILBERT,J.S.(eds)FluidMotionsinVolcanicConduits:ASourceofSeismicand
AcousticSignals.GeologicalSociety,London,SpecialPublications,307,1–10.
DOI:10.1144/SP307.1 0305-8719/08/$15.00#TheGeologicalSocietyofLondon2008.