Limitations of strain estimation techniques from discrete deformation observations

Abstract

Several common classes of model-free strain estimation techniques from geodetic deformation measurements were investigated to assess the systematic computational artifacts introduced into strain estimates from different parameterizations. It is demonstrated that highly structured artifacts, which may be impossible to distinguish from real variations in strain, persistently appear in the strain rate field at and above the spatial scale of the network that samples the deformation field. These computational artifacts are biased by the spatial sampling, and by the orientation of the sampling network with respect to the deformation field. While such aliased strain rate representations provide some gross representation of the underlying real strain rate field, they contain numerous small-scale artifacts. As a result, in the absence of a tectonic model, the interpretation of strain rates from heterogeneous networks have limited direct use for interpreting subtleties in the underlying driving mechanisms. Copyright © 2011 by the American Geophysical Union.