Open AccessInformation on subsoil geological structure in the city of Catania (Eastern Sicily) from microtremor measurements
Author(s) -
Elisabetta Giampiccolo,
S. Gresta,
Marco Mucciarelli,
Giorgio De Guidi,
Maria Rosaria Gallipoli
Publication year - 2001
Publication title -
annals of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 60
eISSN - 2037-416X
pISSN - 1593-5213
DOI - 10.4401/ag-3606
Subject(s) - microtremor , geology , subsoil , seismology , frequency band , shear (geology) , soil water , bandwidth (computing) , soil science , petrology , computer network , computer science
Nakamuras technique, or the H/V spectral ratio method, has been applied to microtremor measurements carried out in the urban area of Catania (Eastern Sicily) to obtain information on the geological structure of some sites,and to make a hypothesis on their seismic response. In general, sites located on soft soils or anthropic debris fillings have shown greater amplification at high frequencies (above 1 Hz). However, a strong lateral variation was observed in the frequency band, thus a denser grid of measurement points is necessary for a precise mapping of the resonant frequencies. In the low frequency range, between 0.1 and 1 Hz, a common peak around 0.2 Hz was observed. The fundamental resonant frequency inferred from the main peak in the H/V spectrum has been used to calculate the depth of the interface between the clays and the main reflector on the basis of the shear-wave velocity: it has been estimated as about 700 m