Estimating site amplification factors from ambient noise

Estimating site amplification factors from ambient noise

[1] We present a methodology to obtain frequencydependent relative site amplification factors using ambient seismic noise. We treat a seismic network or array as a forced damped harmonic oscillator system where each station responds to a forcing function obtained from frequencywavenumber beams of the ambient noise field. A network or array beam is necessary to estimate the forcing function. Tak...

Site Amplification Estimates in the Garigliano Valley, Central Italy, Based on Dense Array Measurements of Ambient Noise

A frequency-domain formulation of the Aki (1957, 1965) autocorrelation method has been applied to seismic noise recorded by a 100-m wide circular array deployed on soft Holocene sediments in the Garigliano river valley, where a large amplification of ground motion during earthquakes was experienced (Rovelli et al., 1988). The application of this method to ambient noise recordings demonstrates t...

Imaging with ambient noise

© 2010 American Institute of Physics, S-0031-9228-1009-030-7 Recent developments in seismology, ultrasonics, and underwater acoustics have led to a radical change in the way scientists think about ambient noise—the diffuse waves generated by pressure fluctuations in the atmosphere, the scattering of water waves in the ocean, and any number of other sources that pervade our world. Because diffus...

Underwater Ambient Noise

Ambient Earth noise and instrumental noise

Introduction The seismic frequency band can be defined from 0.3 mhz to tens or hundreds of hz, in which the lower limit is defined by the period of the gravest observed free mode of the Earth (0s2). Digital seismic recordings in this frequency band always contain noise, which essentially can be attributed to ambient Earth noise and instrumental noise, or self-noise, of the recording system. Ins...