CEE Fall 2016 Seminar: Assistant Professor, Fatemeh Pourahmadian, University of Colorado Boulder

Title: Sounding of Heterogeneous Fractures in Geomaterials. Geometric and interfacial properties of fractures and related features such as faults in rock are the subject of critical importance to a wide spectrum of scientific and technological facets of our society including natural gas and geothermal energy, mining, seismology, environmental protection, hydrogeology, and waste disposal. More specifically, the fracture's linearized interfacial condition - that could be probed by seismic waves - has been linked to i) the stability of rock masses, ii) fluid transport through natural and hydraulically-induced fractures, and iii) progressive shear failure along rock discontinuities. In general, however, the fracture's response to given seismic excitation is equally driven by its (often non-planar) shape, whose geometric reconstruction poses a major challenge in its own right. This talk highlights the development of a next-generation seismic imaging paradigm targeting the holistic characterization of partially-closed fractures in rock - that is capable of unveiling both their geometric and (heterogeneous) contact characteristics. First, two non-iterative approaches to the geometric reconstruction of fractures from the full-waveform seismic data are considered in the context of inverse scattering......