Frictional instabilities exist in many geological settings, including glaciers and tectonic plate boundaries. However, investigations of suggested analogies between stick-slip “icequakes” earthquake faulting have been hampered by the noisy, melt-prone inaccessible nature glacial environments. Here, we reveal details events beneath an Alpine glacier using seismic sensors within a few meters seis...

An analytical model has been developed to study the effect of asperity geometry on abrasive wear behaviour an ellipsoidal sliding through a plastically deforming substrate. The computes penetration depth and profile substrate as function applied load geometry, i.e. asperity's axes sizes orientation relative direction. Also using obtained from numerical-material point method (MPM) simulations, a...

The characteristics of the hydro-thermal flow which occurs when a cold fluid is injected into a hot fractured bedrock depend on the morphology of the fracture. We consider a sharp triangular asperity, invariant in one direction, perturbing an otherwise flat fracture. We investigate its influence on the macroscopic hydraulic transmissivity and heat transfer efficiency, at fixed low Reynolds numb...

University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, England; Now, University of Michigan, Ann Arbor, MI 48109 The work vf Jaeger [l] and Barber [2] indicates that the division of frictional heat between sliding solids should be sensitive to the interfacial boundary conditions. Thus it should provide a guide to the nature of asperity interactions and a more accurate statement of the...

As the size of electronic and mechanical devices shrinks to the nanometre regime, performance begins to be dominated by surface forces. For example, friction, wear and adhesion are known to be central challenges in the design of reliable microand nano-electromechanical systems (MEMS/NEMS). Because of the complexity of the physical and chemical mechanisms underlying atomic-level tribology, it is...

Experimental measurements and modeling predictions were obtained to characterize the electro-mechanical response of two different gold contact radio frequency microelectromechanical system (RF MEMS) switches due to variations in the temperature and applied contact voltage. A three-dimensional surface roughness profile from AFM measurements of the top contact surface of a sample RF MEMS switch w...

All quality teleseismic recordings of the great 1906 San Francisco earthquake archived in the 1908 Carnegie Report by the State Earthquake Investigation Commission were scanned and digitized. First order results were obtained by comparing complexity and amplitudes of teleseismic waveforms from the 1906 earthquake with well calibrated, similarly located, more recent earthquakes (1979 Coyote Lake...

A thermal asperity detection and recovery scheme for a disk-drive read channel is presented. The circuit design and simulation results for two key blocks, the AC coupler and its tuning loop, in a 0.5μm CMOS process are described.