Horizontal contraction (black) and extension (red) strain
axes directions associated with earthquakes larger than Mw
5.5 between 1963 and 1998, showing the distributed nature of the
deformation around the India-Eurasia collision zone as well as the
spatial variation in the strain field
[Holt et al., 1995]. Focal
mechanisms are for large events with Mw > 7.0; a few large historic
events (pre - 1963) are also shown [Molnar and Deng, 1984].

The minimum root mean square deviatoric stress field that
satisfies force - balance equations, where sources of stress are
potential energy differences inferred assuming local isostatic compensation
of topography in Asia. Open white principal axes represent tensional
stress. Black principal axes are compressional stress.

The best-fit far-field stress contribution from a single
rotation of India relative to Eurasia that defines
the India boundary (shown as open vectors) with three
degrees of freedom. The linear sum of this leading order far-field
stress field and the one associated with potential energy differences
(above) provides the best fit to the style of present-day stress
indicators
is shown in below. Tensional and Compressional principal axes
of stress are represented by open and black arrows, respectively.

Total stress field that is a linear sum of the stress
field contribution from potential energy differences within the
lithosphere (above) and far-field stresses associated with the
best-fit leading-order stress boundary conditions for India-Eurasia
relative motion (above). Tensional stress are open white principal
axes and compressional stress are black principal axes.

Vertically averaged effective viscosity for Asia obtained
by taking the magnitude of vertically averaged total stresses in areas
above and dividing by the magnitude of average strain rates
in same areas. The magnitude of the strain rates from
Holt et al. [2000] were those inferred
from the matching of Quaternary fault slip rates and GPS velocities.

Vertically averaged B-values for Asia obtained by taking
the vertically averaged viscosities the in areas above, the magnitude
of the model average strain rates in same areas from
Holt et al. [2000] ,
and using equation (\ref{eqn_11}), assuming n=3.

Vertically averaged B-values for Asia, as described in
above for n=3, except for the case where n=5.

Forward modeled total stress field assuming an isotropic
Newtonian rheology (n=1) determined by minimizing equation (\ref{eqn_12})
subject to the India-Eurasia velocity boundary condition [DeMets
et al., 1994]. The distribution of \overline{\sigma }_{zz} values
is the same as that used to infer stresses in Figure 2a, and the
distribution of viscosity values is the same as that in Figure 2d.
Format for compressional and tensional stresses is the same as that
used in Figure 2 a-c.
Forward modeled total stress field as described in Figure
3a except for a power law rheology where n=3, and B-values from
Figure 2f. Format for compressional and tensional stresses is the
same as that used in Figure 2 a-c.
The similarity in stress directions
and stress magnitudes in Figures 3a-c with those in Figure 2c indicate
that our estimates of minimum absolute magnitudes of stress in Figure
2c are not sensitive to the actual variations in effective viscosity
in Asia, which are a few orders of magnitude. Furthermore, the stress
is not sensitive to power law exponent (n=1-5).

Self-consistent velocity field associated with dynamic
solution in Figures 3b and 4a, plotted relative to Eurasia. The
velocity field within the interior regions (inside \partial S) closely
resembles the kinematic solution inferred from both GPS observations
and Quaternary slip rates (Figure 1c). The style of deformation
indicators are not used to define the deviatoric stress tensor (and
hence deviatoric strain rate tensor) in the dynamic solution. This
dynamic solution is only defined by the distribution of \overline{\sigma }_{zz},
B-values, and velocity boundary conditions.

last edited 02/17/00 by L. Flesch