A destructive earthquake (Mw 6.1) struck Pasaman, West Sumatra, Indonesia, on 25 February 2022, resulting in at least 18 deaths and damage to 1765 buildings. Our relocated foreshock, mainshock, aftershocks their source mechanisms reveal a previously unknown ∼20 km long segment of the Sumatran Fault as result dextral strike-slip motion (strike N132oE dip 72oSW) along what we have called Kajai Fa...

We investigate the impact of source-side 3D velocity structure on teleseismic travel-time in back projection (BP) analysis large earthquakes. use data events recorded by Hi-Net array to reveal how errors vary with source location. In a area few hundred km, where error varies dominantly linearly, we propose new interpolation scheme using earthquakes located around mainshock rupture calibrate err...

The paper presents results obtained using a transient analysis technique for point contact elastohydrodynamic lubrication (EHL) problems based on a formulation that couples the elastic and hydrodynamic equations. Results are presented for transverse ground surfaces in elliptical point contact that show severe film thinning and asperity contact at the transverse limits of the contact area. This ...

The traction developed between a thin flexible web, wrapped around a non-vented, rotating cylindrical roller is studied experimentally and theoretically. A series of eight webs representing a wide range of surface roughness characteristics are traction-tested against the same roller over a wide speed range. A mathematical model that couples air film pressure, web deflection, and asperity deform...

A hybrid slip model combined an Asperity model and k model for predicting near-field strong ground motion is proposed in this paper. Firstly, the asperity model charactering lower wave number of slip distribution is estimated based on works of Wang (2004), Wang and Tao (2004a, b). Secondly, k square slip model charactering higher wave number of slip distribution was determined based on research...

This paper presents an analysis of the interaction energy and various forces between two surfaces, and the microscopic study of friction. Atomic-scale simulations of dry sliding friction and boundary lubrication are based on the classical molecular dynamics (CMD) calculations using realistic empirical potentials. The dry sliding of a single metal asperity on an incommensurate substrate surface ...

We have inverted the teleseismic P waveforms recorded by stations of the Global Digital Seismograph Network for the 8 July 1986 North Palm Springs, California, the 28 October 1983 Borah Peak, Idaho, and the 19 September 1985 Michoacan, Mexico, earthquakes to recover the distribution of slip on each of the faults using a point-by-point inversion method with smoothing and posiUvity constraints. I...

where the expression following the first equality is the force in the spring and that following the second is the frictional resistance to sliding of the block (both expressed for a block of unit area). The load point velocity vo is the product of the imposed rate of tectonic strain rate γ̇ in the crustal block and the characteristic length of the block. The effective spring stiffness k is the s...