Earthquake nucleation with heterogeneous physical properties.
Ray, Sohom.
2019
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Seismological and
geodetic studies permit an inference of fault's frictional properties (or normal stress)
to be nonuniform. However, studies on slip instabilities and dynamic ruptures on faults
often consider physical properties to be uniform, or nearly so. I examined how
nonuniform physical properties, affects the dynamics of slip instabilities. I found that
the evolution of slip is almost ... read moreidentical in the limit of very small (highly
heterogeneous) and large (almost homogeneous) wavelengths of property variations.
However, faults' frictional heterogeneities matter most when the wavelengths are close
to elasto-frictional length scales. In that case, slip instabilities are attracted to
special sites on the fault purely dictated by the properties' spatial distributions.
Further, I found that certain heterogeneities can promote blow-up solutions to lose
stability. When all the blow-up solutions on the fault are unstable, an accelerating
slip oscillates in time as well as along the fault and may create spatially distributed
tremors. Owed to the nature of the slip evolution on model faults, I found that the
problem of earthquake nucleation on faults with variable frictional properties can be
seamlessly approached from a nonlinear-dynamics point of
view.
Thesis (Ph.D.)--Tufts University, 2019.
Submitted to the Dept. of Civil Engineering.
Advisor: Robert Viesca.
Keyword: Geophysics.read less - ID:
- fb494n703
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