the role of multiphase instabilities in nature’s extremes ... · the role of multiphase...
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Fractureorflow?
FRACTURESlidingoverahydrologically
flushedfaultzone
FLOWStabilityofasolidmatrix
experiencingsustainedflow
Generalized model by Cooper Elsworth; see Elsworth and Suckale, 2016
CooperElsworth
Mechanical Model
Ice
yz
g
H
yz
ce
Tillα
W
Slip No Slip
Temperate FrozenForce Balance: Glen’s Law:
Ice
yz
g
H
yz
ce
Tillα
W
Slip No Slip
Temperate FrozenForce Balance: Glen’s Law:
Thermal Model
FullyCoupled
Ice Speed[m/yr]
600
400
200
0
B
C
D
E
F
20 km
A
Data from NSIDC, Scambos et al., 1994
Distance from Margin [km]0510152025
Ice
Spee
d [m
/yr]
0
100
200
300
400
500
600
AB
C
DE
F
Simulations by Cooper Elsworth; see Elsworth and Suckale, 2016
Distance from Margin [km]0510152025
Ice
Spee
d [m
/yr]
0
100
200
300
400
500
600
AB
C
DE
F
SimulationsbyIndraneel Kasmalkar;CollaborationwithAndersDamsgaard andLiran Goren
Indraneel Kasmalkar
Grains:
Water:
Flowchannelization occursfirstattheshearmargin
Mechanical Model
Ice
yz
g
H
yz
ce
Tillα
W
Slip No Slip
Temperate FrozenForce Balance: Glen’s Law:
⌧⇤ = f(�n � p)
freeboundaryGeneralized model by Cooper Elsworth; see Elsworth and Suckale, 2016
CooperElsworth
30
Distance from Stream Center [km]
2030405060700
10
20
Nor
mal
ized
Bas
alSh
ear S
tren
gth
10
duringcontraction,anincreaseintdand/oradecreaseinbasalresistancewouldhavetooccur.Sincechangesintdarelikelytooccuroverlongertimescalesthantheobservedrateofnarrowing,wesuspectthattheresponseofKIStocontractionwasnotfastenoughtocounterinevitableslowdown.
[12]Figure3showsthatwhentheDuckfootstagnated,flowstripesbecamestrandedandshearedastheflowdirec-tionchanged.SimilarfoldsareseenneartheSteersheadIceRiseandinthemouthofMercerIceStreamandarelikelyaresultoflocalizedflowredirection[HulbeandFahnestock,2005].Jacobeletal.[2000]illustratetheformationoftheDuckfootfoldsimilartoourFigure3buthereweusethedatesofmarginshutdownanddeformationlengthtodeter-mineanaveragepaleo-icestreamspeedbetween340and
Figure2.Ice-penetratingradardataacrosstwoKISmargins,clippeddatashowninblack.(a)2MHzradardataacrossbothmarginsalongB-B0.Notethestrongreturnsignalatroughlyhalftheicethicknessisasystemglitch.(bandc)100MHzradaracrossM1andM2alonglineA-A0.Somepickedlayersareshowninblack.
Figure3.SchematicofDuckfootstagnationandflow-stripedeformation.(a)KISpriorto340yearsago.(b)KIS150yearsago.
L14502CATANIAETAL.:KAMBICESTREAMSTAGNATIONL14502
3of4
Migration in <10 years
Shear margin width
Shear margin width
Simulations by Cooper Elsworth; see Elsworth and Suckale, 2016
Surfa
ce V
eloc
ity [m
/yr]
600
400
200
0
30
Distance from Stream Center [km]
2030405060700
10
20
Nor
mal
ized
Bas
alSh
ear S
tren
gth
10
Simulations by Cooper Elsworth; see Elsworth and Suckale, 2016
Water Film
Arterial Channels
Distributed Cavities
Margin Position
Basa
l Stre
ngth
Basa
l Stre
ngth
Basa
l Stre
ngth
Frozen
Temperate
Discontinuous Migration
Stable Margin
Continuous Migration
FigurebyCooperElsworth
Fractureorflow?
FRACTURESlidingoverahydrologically
flushedfaultzone
Flowcreatesapatchyfaultsurface(here:drypatchesactasasperities,lakesarezonesoffreeslip)
Flowintroducesadifferenttimescalethatcanleadtorapidrearrangementoftheslippingzone.
Salt water disposal
Unknown
Enhanced oil recovery
FiguremodifiedfromWalshandZoback,2016
Injection rate in million of barrels (≈108 liter) per month
transfers
CONTROL
VOLUME
CONTINUUM
PHASE FIELDS
LOCAL
SYSTEM
SCA
LE
solid grains (transparent)
liquid films
gas bubbles
fluxesgas
liquid
solid
FigurebyTobiasKeller
3DGPU-basedcodebyLudovic Räss,seeRäss etal.,2018,SketchbyLøseth etal,2011
Ludovic Räss
ObservationModel
Fractureorflow?
FLOWStabilityofcontinuousrockexperiencingsustainedflow
Sustainedflowaltersthestructuralintegrityofarockorgranularmatrix
Top:Figure14.2fromRosi etal.,2013;Left:Figure4fromRipepe etal.,2007
NORMAL STROMBOLIAN EXPLOSIONS:largeinfrasonicpulses (>10Pa)every8-10min
PUFFING:small infrasonicpulses (≈1Pa)every1-2s
PASSIVE DEGASSING: continuousanddistributed
Experimental crystallinity datafromAgostini etal.2013;ComputationsfromSuckaleetal.2016
Crystallinity (%)
Pressure(M
Pa)
Tremor
VLPsignalTiltmeter
Seismic/strain
Subvolcanicmagmastorage
Plagiocla
se
Total
KellerandSuckale,inpreparation;Permeability scaling fromBai etal.,2010
Regime1:Darcyflow
Plug
ΔP
Nooverpressure
Seealso:Michault etal.,2013;RisevelocityfromGaudin etal.,2017
Regime2:Degassingwaves
Gasexpansion Magmacreep
vs
Pressurepulsesevery1-2s
NASAISSImage:StromboliVolcano,Italy;CraterlocationsfromHarrisetal.1996;Suckaleetal.2016
1.9
2.0
2.1
τ[105 Pa]
Suckaleetal.,2016
Mushfailure(normal
explosions)
Degassingwaves
(puffing)
Darcyflow(passivedegassing)
Fractureorflow?
FLOWStabilityofcontinuousrockexperiencingsustainedflow
Sustainedflowaltersthestructuralintegrityofarockorgranularmatrix
Theinterplaybetweenflowandmatrixdeformationresultsinoverpressureandmayentailfailure
Conclusions:
1) Multiphaseinteractionsatthegranularscalecantriggerashiftinthesystem-scaledynamics.
2) Fractureandflowoftenoccursimultaneouslyandinteractmoredynamicallythanweusuallygivethemcreditfor.
3) Studyingextremeevent’sacrossdifferentnaturalsystemswithasimilarmodelincreasesopportunitiestorefute/validatemodels.
Bottom:Arahama,MiyagiPrefecture;Top:Yamada,IwatePrefacture
100outof300kmofseawallsinTohokudestroyed.
Tohokuindarkgreen,source:Wiki
Viscousshallowwaterequations(NUMA2D)
Continuity:
Momentum:
Dynamicdissipationcoefficient:
Wetting&drying:0.1mthreshold
Giraldo etal.,2002;Abdi andGiraldo,2016;Marras etal.,inreview
Switchesviscosityon/off
Bathymetry Freesurface Dynamicdissipation
2Dsolitarywaverunup oncircularisland
Synolakis,1987;Marras etal.,inreview
Unstabilized
Stabilized
Initialcondition
Velocitym/yr
0 1500 3000
−10Gt /yr
+10Gt /yr
AmundsenSea
?
EricRignot,NASAJetPropulsionLaboratory,Paoloetal.,2015;MacGregor etal.,2013
Siple Coast
MangaandStone,1993;Suckaleetal.,2010a;Cliftetal.,2005;QinandSuckale,2017.
LOG M-14
-13
-12
-11
-10
-9-8
-7
-6-5
-4-3
-1
0
1
23
4 56 7 8
SHPERICAL-CAP
WOBBLING
ELLIPSOIDAL
DIMPLEDELLIPSOIDAL-CAP
SKIRTED-2
SPHERICAL
1. Wake formation 2. Settling speed 3. Three-phase coupling
Suckaleetal.,2012a;QinandSuckale,2017;Taneda 1956;Belien etal.,2010.
Re≈80Bo≈105
Rayleigh-Taylor
instability
exponentialgrowth
breakup
PhDthesisbyJennySuckaleandSuckaleetal.,2010a,2010b
Taneda 1956 and Belien et al., 2010; Suckale et al., 2012a,b; Qin and Suckale, in review
1. Wake formation 2. Settling speed 3. Three-phase coupling