Study on the applicability of the microtremor HVSR method to support seismic microzonation in the town of Idrija (W Slovenia)

A study on the UNESCO-listed site of Almadén and Idrija reveals that the microtremor HVSR method can effectively estimate resonance frequencies without detailed subsurface knowledge, aiding seismic microzonation. The research analyzed 70 free-field measurements in Idrija, Slovenia, identifying sediment resonance at 48 points despite limited space and high noise levels. Surprisingly, no clear correlation emerged between resonance frequencies or peak amplitudes and known soft sediments, likely due to compacted deposits and complex geometries. However, individual locations showed correlations with geological structures, highlighting potential site effects. The study underscores the HVSR method's importance for assessing soil-structure resonance in protected heritage buildings and supports soil classification for building codes.

Gosar, A. (2017). Study on the applicability of the microtremor HVSR method to support seismic microzonation in the town of Idrija (W Slovenia). Natural Hazards and Earth System Sciences, 17(6), 925–937. https://doi.org/10.5194/nhess-17-925-2017