On the relation between Geodetic strain, Seismicity and fault frictional properties

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On the relation between Geodetic strain,
Seismicity and fault frictional properties

• Nepal
• Sumatra
• Taiwan

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Sumatra

• Variability of interseismic coupling (using PCAIM
  on coral data).
• Analysis of strong motion data and high rate GPS
• Analysis of aftershocks
• Modeling of large scale postseismic relaxation
• Cause of earthquake clustering in Sumatra
• Inversion of postseismic data for heterogeneity
  of frictional properties

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Nepal

• Interseismic coupling
• Analysis of temporal variations of seismicity and
  geodesy
• Implications for EQs nucleation

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This model of interseismic strain (1995-2005)
indicates an accumulation rate of deficit of
seismic moment of 4.3 1019 Nm/yr
(Bollinger et al, 2004, Bettinelli et al, 2006)
Mw 7.6 (2005 Kashmir EQ) 7 yr Mw 8.2 (1934
Bihar-Nepal EQ) 100 yr
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(No Transcript)
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Seismicity and Coulomb stress change due to
interseismic strain
(Bollinger et al, JGR, 2004)

1. Seismicity coincides with the area where Coulomb
   stress increases by more than 4kPa/yr.
2. The influence of topography on the seismicity
   distribution show that the deviatoric stresses
   driving deformation are actually low, less than
   about 35 MPa

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Horizontal displacements relative to India
SIM
DAMA
NAGA
GUMB
LHAS
Seasonal variation of Horizontal Displacements
(Bettinelli et al, 2008)
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Seismicity is enhanced in the winter when
shortening rate across the Himalayan is increased.
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Amplitude of seasonal variations of surface
loading derived from GRACE