Prsentation PowerPoint

1
Dynamics of plume-lithosphere interaction
at Hawaii
Neil M. Ribe Institut de Physique
du Globe de Paris
With the collaboration of
U. Christensen (MPI für Sonnensystemforschung, Kat
lenburg-Lindau, Germany)
L. Cserepes (Eötvös University, Budapest,
Hungary)
now at Laboratoire FAST, Universités de
Paris-6 et 11, Orsay
2
3-D Numerical Model for Plume-Lithosphere
Interaction
(Ribe Christensen
1994, 1999 Moore et al. 1998 Zhong Watts
2002 Van Hunen Zhong 2003)
3
Three-stage modeling approach

• Construct a realistic 3-D model that satisfies
  simultaneously
• a variety of observational constraints
  (topography, geoid, petrology)

2. Formulate a simplified asymptotic model
that reveals the underlying physical
mechanisms

• Determine the ranges of model parameters that are
  compatible
• with the observational constraints

4
Governing equations
5
Hawaiian plume model Temperature and velocity
fields
(Ribe Christensen 1994, 1999)
6
Hawaiian plume model Cross-sections
Potential temperature (oC)
(110 km depth)
Melt depletion ()
(100 km depth)
Potential temperature (oC)
(vertical symmetry plane)
7
Uplift of the Hawaiian swell model vs.
observations
8
Geoid/topography ratio ( GTR )
Examples
9
GTR for Hawaii Observations vs. 3D model
10
Resolution of the GTR paradox effect of
volcanic loading
Idea GTR observations are contaminated by
shallowly compensated volcanic topography
that band-pass filtering fails to remove
completely
Test
11
Petrological stages of Hawaiian volcanism
(Clague Dalrymple 1987)
12
Eruption history of Hawaiian volcanoes model
predictions
(Ribe Christensen 1999)
13
Thin-layer model for plume-lithosphere interaction
(Olson 1990 Ribe Christensen 1994, 1999)
14
3D vs. thin-layer model Quantitative comparison
15
Hawaiian plume parameters Inferences from
scaling laws
Question what ranges of model parameters are
compatible with the
observations?
Approach inversion of scaling laws
16
Array seismic imaging of the Hawaiian plume
SWELL (Laske et al. 1997-98)
8 stations intermediate-period Rayleigh waves
? Lower velocities closer to the chain
PELENET (Russo, Wolfe et al. 1996-1999)
7 stations teleseismic body-wave arrivals
SWS receiver functions
? Low-velocity anomaly beneath Maui/Molokai
PLUME (Laske et al. 2005-)
OBS array 35  inner , 39  outer