Prof. Laura J. Pyrak-Nolte

Laura J. Pyrak-Nolte
Distinguished Professor of Physics & Astronomy
College of Science
Purdue University

“The Formation & Function of Fracture Geometry in Rocks”

Abstract:  The success or failure of subsurface energy production and the secure storage of anthropogenic fluids are often controlled by mechanical discontinuities.  From cracks to fractures to faults, mechanical discontinuities are easily perturbed and cause dramatic changes in fluid permeability that affect the injection and withdrawal of fluids from the subsurface.  How fractures form and propagate in rock determines the geometry of the voids and the contact area that define the fluid flow paths. In this presentation, three topics related to fracture formation and the functional response of fractures will be examined:  (1) a hydro-mechanical scaling function that provides a link between fluid flow and the seismic response of a fracture; (2) identification of a geophysical precursor for a system transitioning from meta-stability to unstable behavior with specific focus on crack nucleation, propagation and coalescence; and (3) the competition between layering and mineral texture in the formation of fracture surface roughness with preferential flow directions. These studies advance current understanding of the importance of the coupled microscopic properties and processes that affect fracture formation and behavior over time.

Acknowledgment: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Research Program under Award Number (DE-FG02-09ER16022).

BIO: Dr. Laura J. Pyrak-Nolte is a Distinguished Professor of Physics & Astronomy, in the College of Science, at Purdue University. She holds courtesy appointments in the Lyle School of Civil Engineering and in the Department of Earth, Atmospheric and Planetary Sciences, also in the College of Science. She is the Vice-President for North America for the International Society of Rock Mechanics and Rock Engineering.  Prof. Pyrak-Nolte is a member of the National Academy of Engineering, a fellow of the American Association for the Advancement of Science, a Fellow of the American Geophysical Union, recipient of the Reginald Fessenden Award from the Society of Exploration Geophysicists, and a Fellow of the American Rock Mechanics Association. Her interests include applied geophysics, experimental and theoretical seismic wave propagation, laboratory rock mechanics, micro-fluidics, particle swarms, and fluid flow through Earth materials.