Dear Atikul Haque Farazi:

The HVSR (known as H/V for "horizontal-to-vertical methodology") uses a single, broad-band three-component seismometer to record ambient seismic noise. It is considered a "passive" seismic technique because it does not require an artificial seismic source, such as an explosive charge or vibration trucks as you would need for the search of oil and gas. HVSR method measures a vertical (V) and two horizontal (H1 and H2) components of ambient seismic noise, which could include microtremors induced by wind and anthropogenic activity. The ratio of the averaged of the spectrum of frequency V/H1/H2 you can used to estimate the fundamental site resonance frequency, which can be interpreted with regression equations to guesstimate sediment thickness and depth to bedrock.

I think that your question should not be related to "regional structure using HVSR method" because this is an application for local scale mapping, e.g.: bedrock geometry, Quaternary geology; near surface buried valleys, channels, and faults. Maybe, the word "regional" means tens kilometers profiles, but not such as 3D seismic for E&P.

On the other hand:

1) The depth coverage: because it is a seismic method, remember that you need a good relative acoustic impedance (velocity and density) contrast between the layers, e.g., sediments and underlying rock. In general it is the weathering or low-velocity layer (LVL). At this point, it looks like the seismic method for searching for hydrocarbons, since in 2D or 3D prospection it is necessary to know the thickness and speed of the weathering or LVL to make the “static corrections”, which tend to cancel or eliminate their effect and allow us to measure the TWT (two-way travel time) to a common reference plane. So, it means that the depth of coverage is in order of tens of meters (30 / 50 m) to hundreds (200 / 300 m). It means: it is in order of the seismic refraction method for E&P.

2) The window length, frequency range, etc. for such works. Please, see the paper that I attached: Lane, J.W., Jr., White, E.A., Steele, G.V., and Cannia, J.C., 2008, “Estimation of bedrock depth using the horizontal-to-vertical (H/V) ambient-noise seismic method”, in Symposium on the Application of Geophysics to Engineering and Environmental Problems, April 6-10, 2008, Philadelphia, Pennsylvania.

Best wishes, Mario E. Sigismondi

Thanks a lot.