Interferometric detectors for gravitational waves are very sensible instruments so they need special careful about every possible source of noise. When ambient seismic waves pass near and under an interferometric gravitational-wave detector, they induce density perturbations in the earth, which in turn produce fluctuating gravitational forces on the interferometer’s test masses. These forces mimic a background of gravitational waves and thus constitute a noise source. It is therefore mandatory to study and characterize this type of noise in order to subtract it from gravitational data. In this work both data analysis techniques and numerical simulations are of primary importance, as these are the principal tools that will be learned and used in this work.