Spectrum of the seismic-electromagnetic and acoustic waves caused by seismic and volcano activity

Seismic noise emission induced by seismic waves

The in situ rock undergoing different kinds of deformation accumulates elastic energy that can be released spontaneously o r under artificial effect. Triggering of energy can also be performed by means of a dynamic excitation caused by elastic waves. W e carried out special field investigations with the use of seismic vibrators (Vibroseis-like sources) to study the effect of the energy release ...

Northridge earthquake damage caused by geologic focusing of seismic waves

Despite being located 21 kilometers from the epicenter of the 1994 Northridge earthquake (magnitude 6.7), the city of Santa Monica experienced anomalously concentrated damage with Mercalli intensity IX, an intensity as large as that experienced in the vicinity of the epicenter. Seismic records from aftershocks suggest that the damage resulted from the focusing of seismic waves by several underg...

Seismic Surface Waves

Investigation of the Detection of Shallow Tunnels Using Electromagnetic and Seismic Waves

Multimodal detection of subsurface targets such as tunnels, pipes, reinforcement bars, and structures has been investigated using both ground-penetrating radar (GPR) and seismic sensors with signal processing techniques to enhance localization capabilities. Both systems have been tested in bi-static configurations but the GPR has been expanded to a multi-static configuration for improved perfor...

Seismic velocity structure in and around the Naruko volcano, NE Japan, and its implications for volcanic and seismic activities

Geofluids is important for understanding volcanic and earthquake generation processes. In this study, we obtained a detailed seismic velocity structure in and around the Naruko volcano, northeastern Japan, using data from a dense seismic observation network. We found a distinct seismic low-velocity zone (LVZ) beneath the Naruko volcano, with a diameter of nearly 10 to 20 km in the lower crust. ...