Nicholas (Nick) M Beeler
Science and Products
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.
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. The role of fluid pressure on frictional behavior at the base of the seismogenic zone
To characterize stress and deformation style at the base of the seismogenic zone, we investigate how the mechanical properties of fluid-rock systems respond to variations in temperature and strain rate. The role of fluids on the processes responsible for the brittle-ductile transition in quartz-rich rocks has not been explored at experimental...
Hirth, Greg; Beeler, Nicholas M.
Earthquake forewarning in the Cascadia region
This report, prepared for the National Earthquake Prediction Evaluation Council (NEPEC), is intended as a step toward improving communications about earthquake hazards between information providers and users who coordinate emergency-response activities in the Cascadia region of the Pacific Northwest. NEPEC charged a subcommittee of scientists with...
Gomberg, Joan S.; Atwater, Brian F.; Beeler, Nicholas M.; Bodin, Paul; Davis, Earl; Frankel, Arthur; Hayes, Gavin P.; McConnell, Laura; Melbourne, Tim; Oppenheimer, David H.; Parrish, John G.; Roeloffs, Evelyn A.; Rogers, Gary D.; Sherrod, Brian; Vidale, John; Walsh, Timothy J.; Weaver, Craig S.; Whitmore, Paul M. Direct measurement of asperity contact growth in quartz at hydrothermal conditions
Earthquake recurrence requires interseismic fault restrengthening which results from solid state deformation in room-temperature friction and indentation experiments. In contrast exhumed fault zones show solution-transport processes such as pressure solution and contact overgrowths influence fault zone properties . In the absence of fluid flow,...
Beeler, Nicholas M.; Hickman, Stephen H. A robust calibration technique for acoustic emission systems based on momentum transfer from a ball drop
We describe a technique to estimate the seismic moment of acoustic emissions and other extremely small seismic events. Unlike previous calibration techniques, it does not require modeling of the wave propagation, sensor response, or signal conditioning. Rather, this technique calibrates the recording system as a whole and uses a ball impact as a...
McLaskey, Gregory C.; Lockner, David A.; Kilgore, Brian D.; Beeler, Nicholas M. Slip-pulse rupture behavior on a 2 meter granite fault
We describe observations of dynamic rupture events that spontaneously arise on meter-scale laboratory earthquake experiments. While low-frequency slip of the granite sample occurs in a relatively uniform and crack-like manner, instruments capable of detecting high frequency motions show that some parts of the fault slip abruptly (velocity >100...
McLaskey, Gregory C.; Kilgore, Brian D.; Beeler, Nicholas M.