During the early 1980s, the phenomenon of acoustic-to-seismic coupling was used to detect buried objects or mines. In these early measurements, large 2 Hz geophones measured the low frequency (50-300 Hz) normal component of the soil particle velocity over buried targets. Several different, naturally-occurring ground types were studied in these measurements, including grass-covered ground; bare,...

The interest in dynamic behavior of railway bridges has increased in recent years with the introduction of high speed trains. Higher speeds of the trains have resulted in larger and more complicated loads than earlier, producing significant dynamic effects. The dynamic aspects are of special interest and have often shown to be the governing factor in the structural design. Dynamic analysis of r...

Passing seismic waves released by large-magnitude earthquakes may affect geological systems located thousands of miles far from the epicenter. TheM9.0 Tohoku earthquake struck on 11 March 2011 in Japan. We detected local seismic activity at the Larderello-Travale geothermal field, Italy, coinciding with the maximum amplitudes of the Rayleigh waves generated by the Tohoku earthquake. We suggest ...

There is a general consensus that 3D reference models can be used to isolate effects of wave propagation and thus help in improving characterization of seismic sources. Advances in computation and numerical method have made it possible to capture increasingly broadband, full wave generation and propagation in 3D earth models. The main objectives of this project are to construct hierarchical, mu...

in exploration seismology, migration refers to a multi-channel processing step that attempts to spatially re-position events and improve focusing. before migration, seismic data is usually displayed with traces plotted at the surface location of the receivers and with a vertical time axis. this means that dipping reflections are systematically mispositioned in the lateral coordinate and the ver...

We review the resolution currently available with seismic tomography, in particular the ability of seismic waves to image mantle plumes, and discuss frequently asked questions about artifacts, interpretation and possible systematic errors. These aspects are discussed in more detail for two case histories offering different problems in the tomographic interpretation: Iceland and Hawaii. Regional...

S U M M A R Y Converted phase (CP) elastic seismic signals are comparable in amplitude to the primary signals recorded at large offsets and have the potential to be used in seismic imaging and velocity analysis. We present an approach for CP elastic wave equation velocity analysis that does not use source information and is applicable to surface-seismic, microseismic, teleseismic and vertical s...

The inversion of seismic reflection data is challenging due to the oscillatory nature of the seismic data, the nonlinear relation between the data and the Earth’s model parameters, and the relative sensitivity of the different subsets of the data to the model parameters. Full-waveform inversion solves this inverse problem in the data space but is known to have shortcomings, especially because o...

crustal velocity structure model has a significant role in truly understanding of seismicity and also in relocating earthquakes. on the other hand, it can be used for recognizing major and potential seismic sources which is very critical for seismicity and earthquake hazard assessment studies. seismic parameters simultaneous inversion modeling is one of the most prevalent methods in the study o...