Is The Aspen Anomaly A Wet Pipe off the 410-km Seismic Discontinuity?

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Is The Aspen Anomaly A Wet Pipe off the 410-km
Seismic Discontinuity?

• John Jasbinsek
• Ken Dueker
• University of Wyoming

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RISTRA Array
Gao et al., 2004 (JGR)
South of CREST
CD-ROM
Yuan Dueker, 2005
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Water Pipe
Smith et al., 2004 (G-Cubed)
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410-water-filter model Incompatible elements
partition into melt dynamically create MORB OIB
Seismically seen as a low-velocity
layer 410-LVL
olivine
0.1 wt
Hydrous silicate melt
410 km
wadsleyite
0.2-2 wt
660 km
(modified from) Leahy Bercovici 2007 (JGR)
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Adding water to the Transition Zone
Surface Wave Tomography Bedle van der Lee, 2007
(Earthscope Meeting Poster)
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North of CREST Evidence of the 410-water-filter
(410-LVL)
P-S receiver functions
Jasbinsek Dueker (in press, G-Cubed)
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RISTRA Array Evidence of a 410-LVL
Southwest of CREST
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Density of hydrous silicate melt
It is possible for hydrous melt to rise in the
upper mantle
Mastukage, Jing Karato (Nature, 2005)
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CREST/Earthscope Seismic DataFill in gap between
N and S

• Data quality/coverage compared to previous
  arrays?
• Discriminate between temperature/plume
  water/wet-pipe?
• P-wave, S-wave velocity (tomography)
• P/S velocity ratio
• Transition Zone thickness
• 410,660 km seismic discontinuity sharpness
• Seismic attenuation
• Gravity

• Petrology 36-5 Ma Post-Laramide magmatism
• San Juan Mountains, 39-Mile Volcanic Field

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• Hypothetically, an excessively buoyant region of
  past entrainment that is enriched with water and
  trace elements could develop into a source for a
  mantle plume
• Leahy Bercovici (JGR, 2007) On the dynamics of
  a hydrous melt layer above the transition zone.