GEOPHYSICAL PROSPECTION

The Nakamura method is well known by geologists since the 1950’s.

Using a 3-C seismic node and performing the Horizontal-to-Vertical Spectra Ratio (HVSR) we can detect changes in seismic impedance in the underground. And we know that a contrast in seismic impedance can mean layering.

The Nakamura method uses the shallow waves and it is a passive geophysical method. It is also called ambient noise or microtremor monitoring.

Our Sentinel-GEO was designed for this purpose: its 3C 4.5 Hz geophones electronically extended to 2 seconds allow to reach deep depth!