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Ongoing GeoPrisms Aleutian Volcano Research
Terry Plank, Lamont Doherty Earth Observatory of Columbia
University
Cleveland Volcano, Islands of Four Mountains, Alaska. Photo:
Anna Barth
“Slab to the Surface”
With Contributions From:Daniel Rasmussen (LDEO)Diana Roman
(DTM-Carnegie)John Power & Matt Haney (USGS, AVO)Elizabeth
Cottrell (Smithsonian)
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Alaska Amphibious Community Seismic Experiment (AACSE)
2015-2106GeoPrismsField Programs
AKWd
SH
PV
Veni
Ank
Uga
Katmai
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60
70
80
90
100
-175
-173
-171
-169
-167
-165
-163
Seguam
Bogoslof
Makushin
Akutan
Shishaldin
Bogoslof(132
From Syracuse & Abers (2006) G3
65 km
135 km95
km
white lines are slab contours
Cleveland Vsevidof
Westdahl
Okmok
Sh
Wd
Fisher
Fi
AkuMak
Ok
VsCv
Seg
blue circles = historically active
l
Yun
Amkt
Eastern Aleutians: Depth to the Slab Varies Smoothly Along
Strike
Globally Shallow!
Last Eruptedthis year
!1990’s
20081800’s
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NSF/GeoPrisms-AVO/USGS-Deep Carbon Obs. Joint Expeditions
2016 Team on the Maritime Maid with the Maritime Helicopter
(Initial Deployments were in 2015)
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Objectives• Where do M agmas
Stall Prior to Eruption?• Role of Primary
M agma Composition?• Relation to
Eruption/Unrest?
GeoPrisms Project: From the Slab to the Surface: Origin,
Storage, Ascent, and Eruption of Volatile-Bearing MagmasDiana Roman
& Erik Hauri • CarnegieTerry Plank • LDEO
with AVO Partners:Power, Haney, Lyons, Werner, Lopez
2015-17 Samples Collected
Westdahl
ShishaldinFisher
Akutan
Makushin
Okmok
Vsevidof
Cleveland
Bogoslof
12-stationseismic &infrasoundarray (IFM)
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Three Nuggets:
1. The Run-Up to Eruption: Shishaldin 1999
2. The Depth of Magma Stalling: Cleveland 2015/6
3. Connecting the Volcano to the Slab
Cleveland Steams from the Maritime Maid June 12, 2017: Kim
Angeli. AVO Image D t b
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1. The Run-Up to Eruption: Shishaldin 1999
Fo = forsterite composition of olivine= Mg/(Mg+Fe)
Shishaldin 1999
Photo: McGimsey, R. G.
VEI 3 EruptionNo Clear DeformationAbundant Seismicity
“Crystal Clocks”
Chemically Zoned Olivines
Mixing Event: Recharge Magma Drives Crystal to Increase in
Fo
Crystal Resides, Then Erupts
Shape of Profile Reflects Mixing-to-Eruption Timescale
This Olivine CrystalErupted 22 days After a Recharge Event
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Crystal Clocks
Rasmussen, Roman, Hauri, Plank, Bodnar, Power – EPSL in R i
i
1. The Run-Up to Eruption: Shishaldin 1999
Seismicity
OlivineClocks
Seismic EventsRelate toMagma Recharge
Over 9 Monthsof Run-up
Crystal Depths (MI)
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Back-Projection ofLong Period Event3 hours before April 2016
Explosion
Shallower Depthof 2.5 km BSL
Aug 2015Swarm
Spr 2016Eruptions
Seismicity at IFM over GeoP Deployment(Aug 15 – Aug 16)
Cleveland
GeoP Deploymentw/ infrasoundPermanent AVO
2. The Depth of Magma Stalling: Cleveland 2015/6D
epth
(km
BSL
)
10
5
0
VT Earthquakes Cluster at 5-7 kmBeneath Cleveland Volcano
Courtesy of Matt Haney
Courtesy of John Power
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see also Werner et al. (2017) JVGR
2. The Depth of Magma Stalling: Cleveland 2015/6
Re-homogenizing the Melt Inclusion: Accurate Pressure of
Entrapment
see Rasmussen this AGU! Friday 8:45 am V51G
Using Melt Inclusions to Define Depth (P) of Magma Degassing
SO2 emission rate
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Smaller volumes for shallow slab depths
3. Connecting the Volcano to the SlabSlab T Proxy
Mantle-MeltingPressure Proxy
Smaller Volcanoes at Shallower DepthsPlank et al. (2017)
IAVCEI
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3. Connecting the Volcano to the Slab
NEIC Catalog – Events within ~ 30 km Volcano RadiusAVO Stations
on Volcanoes, Including New Cleveland Station (CLES)
Courtesy of Diana Roman
Systematic change in S-P timeMost Reasonably due to Decrease in
EQ Depth to the West
Cat
alog
Dep
th (k
m)
S-P
time
(sec
onds
)
Cleveland
Shishaldin
1400C
50
Moho
100km
100 km
200 km (from trench)
low Si5.0
hi Si5.0hi H2O/K2O
cooler slab fluid
lo H2O/K2Ohotter slab fluid
Bogoslof?
Courtesy of Peter van Keken
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Buldir tephraCredit: Sheppard
• > 2,700 lbs of rock send to AVO, URI, & Smithsonian•
tephra from 8 volcanic islands (1st from Buldir, Segula, &
Kiska)• gas and spring samples @ Kiska, Gareloi, Kanaga; @ L.
Sitkin, Tanaga• 100% maintenance success at 30 seismic
installations• new methods for assessment of hydrous melt inclusion
redox at high flux synchrotron facilities (Cottrell et al., in
revision)
Leg 3 Western Aleutians: The role of oxygen fugacity in
calc-alkaline differentiation & the creation of continental
crust at the Aleutian arc
Project Leads:Katie Kelley &
Liz Cottrell
(see T23I-03: New constraints on subduction inputs and volatile
outputs along the Aleutian Arc. Lopez et al )
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Alaska Amphibious Community
Seismic ExperimentClosing Thoughts
Diana Roman, Carnegie
AK
Wd
SH
PV
Veni
Ank
Uga
Katmai
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Graduate student Janine Andrys operates the new rapid-quench HMC
cold-seal apparatus at NMNH. Credit: Cottrell
• Experimental program to investigate calc-alkaline
differentiation • V11B-0343: Calc-Alkaline Liquid Lines of Descent
Produced Under
Oxidizing Conditions: An Experimental and Petrologic Study of
Basaltic Tephras from the Western Aleutians, AK. Waters, Cottrell
and Kelley.• Conference: Experimental Studies of Subduction Zone
Processes: Washington University in St. Louis, Missouri, June,
2018
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Seguam
Shishaldin
1400C
1200°C
1000°C
800°C
Shallower coupling depth?and ~ vertical transport from slab?
50
Moho
100km
100 km
200 km (from trench)
low Si5.0
hi Si5.0
hi H2O/K2Ocooler slab fluid
lo H2O/K2Ohotter slab fluid
Courtesy of Peter van Keken
Bogoslof?
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ShWe
AkuMak
OkVs
CvYunAmtSe
g
AmliaFractureZone
Bg
Why is Depth to Slab so Shallow in this Sector of the Arc?
GeoMapApp
Trench Sediment Thickness after Ryan et al. (2011); Locked vs
creeping (Freymueller, pers. comm).
But also....Upper Plate (end of shelf)
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