Seismic noise measurement with the H/V spectral quotient technique.
Overview of seismic noise measurement with the array technique
Field data observation. Left) Distribution of measurement points on a 1:250000 orthophoto (ICGC, 2019) of the study area. The limit of the study area is marked in blue and the location of the Absolute Gravimetric Base used in this campaign is marked with a red circle. As can be seen in the image, the density of measurement points is greater on the North-West side of the study area. Right) Relative gravimeter CG-6 (Scintrex) and differential GPS (Trimble R8s) working at the same point.
Results of a gravimetric modeling. The upper graph corresponds to the fit between the observed gravimetric data (circles) and the calculated ones (black line), where the error (0.445; red line) is also shown. Each color of the geological section (lower graph) represents a formation (Fm.) with a differentiated density (D).
Simple diagram of how electromagnetic induction works:
- Hp, primary magnetic field.
- Hs, secondary magnetic field.
Example of measurement and control of vibrations produced by a blasting operation.
Left: time record of the three components of the ground movement (blue: longitudinal, green: vertical, red: transverse).
Right: comparison between the speed peaks and the UNE 22381 prevention criterion.