Nicholas (Nick) M Beeler
Science and Products
Strength recovery and sealing under hydrothermal conditions
While there is significant evidence for healing in natural faults, geothermal reservoirs, and lab experiments, the thermal, hydraulic, mechanical, and chemical interactions that influence healing are poorly understood. We present preliminary results of triaxial slide-hold-slide experiments to constrain rates and mechanisms of healing. Experiments...
Jeppson, Tamara Nicole; Lockner, David A.; Kilgore, Brian D.; Beeler, Nicholas M.; Taron, Joshua M. Teleseismic waves reveal anisotropic poroelastic response of wastewater disposal reservoir
Connecting earthquake nucleation in basement rock to fluid injection in basal, sedimentary reservoirs, depends heavily on choices related to the poroelastic properties of the fluid-rock system, thermo-chemical effects notwithstanding. Direct constraints on these parameters outside of laboratory settings are rare, and it is commonly assumed that...
Barbour, Andrew; Beeler, Nicholas M. Evolution of fluid transmissivity and strength recovery of shear fractures under hydrothermal conditions
Geothermal systems rely on the presence of long-lived and high-volume, permeable fracture systems. The creation, reactivation, and sustainability of these systems depend on complex coupling among thermal, hydraulic, mechanical, and chemical (THMC) processes occurring in geothermal reservoirs. In part due to a paucity of experimental data, the...
Jeppson, Tamara Nicole; Lockner, David A.; Kilgore, Brian D.; Beeler, Nicholas M.; Taron, Joshua M.
Characterizing fault roughness—Are faults rougher at long or short wavelengths?
Changes in fault roughness with scale, “scaling,” is the topic of this report; changes are considered using a general power law relation between some measure of surface height, H, and another of length, L, H=kLn, where k is a constant and n is an exponent that characterizes the scaling. Extensive profile measurements of natural fault surfaces show...
Beeler, Nicholas M. Near-fault velocity spectra from laboratory failures and their relation to natural ground motion
We compared near-fault velocity spectra recorded during laboratory experiments to that of natural earthquakes. We fractured crystalline rock samples at room temperature and intermediate confining pressure (50 MPa). Subsequent slip events were generated on the fracture surfaces under higher confinement (300 MPa). Velocity spectra from rock fracture...
Beeler, Nicholas M.; Lockner, David A.; Kilgore, Brian D.; McClaskey, Greg Conversion of wet glass to melt at lower seismogenic zone conditions: Implications for pseudotachylyte creep
Coseismic frictional melting and the production of quenched glass called pseudotachylyte is a recurring process during earthquakes. To investigate how glassy materials affect the postseismic strength and stability of faults, obsidian gouges were sheared under dry and wet conditions from 200°C to 300°C at ~150 MPa effective normal stress. Dry...
Proctor, Brooks P.; Lockner, David A.; Lowenstern, Jacob B.; Beeler, Nicholas M. Rock friction under variable normal stress
This study is to determine the detailed response of shear strength and other fault properties to changes in normal stress at room temperature using dry initially bare rock surfaces of granite at normal stresses between 5 and 7 MPa. Rapid normal stress changes result in gradual, approximately exponential changes in shear resistance with fault...
Kilgore, Brian D.; Beeler, Nicholas M.; Lozos, Julian C.; Oglesby, David The transition from frictional sliding to shear melting in laboratory stick-slip experiments
No abstract available
Lockner, David A.; Kilgore, Brian D.; Beeler, Nicholas M.; Moore, Diane E. Earthquake source properties from instrumented laboratory stick-slip
Stick-slip experiments were performed to determine the influence of the testing apparatus on source properties, develop methods to relate stick-slip to natural earthquakes and examine the hypothesis of McGarr [2012] that the product of stiffness, k, and slip duration, Δt, is scale-independent and the same order as for earthquakes. The experiments...
Thomas, Marion Y.; Mitchell, Thomas M.; Bhat, Harsha S.; Kilgore, Brian D.; McGarr, Arthur F.; Beeler, Nicholas M.; Lockner, David A. Earthquake source properties from pseudotachylite
The motions radiated from an earthquake contain information that can be interpreted as displacements within the source and therefore related to stress drop. Except in a few notable cases, the source displacements can neither be easily related to the absolute stress level or fault strength, nor attributed to a particular physical mechanism. In...
Beeler, Nicholas M.; Di Toro, Giulio; Nielsen, Stefan
Gallery of melt textures developed in Westerly Granite during high-pressure triaxial friction experiments
IntroductionMelting occurred during stick-slip faulting of granite blocks sheared at room-dry, room-temperature conditions in a triaxial apparatus at 200–400 megapascals (MPa) confining pressure. Petrographic examinations of melt textures focused largely on the 400-MPa run products. This report presents an overview of the petrographic data...
Moore, Diane E.; Lockner, David A.; Kilgore, Brian D.; Beeler, Nicholas M. Effective stress, friction and deep crustal faulting
Studies of crustal faulting and rock friction invariably assume the effective normal stress that determines fault shear resistance during frictional sliding is the applied normal stress minus the pore pressure. Here we propose an expression for the effective stress coefficient αf at temperatures and stresses near the brittle-ductile transition (...
Beeler, N.M.; Hirth, Greg; Thomas, Amanda M.; Burgmann, Roland