https://doi.org/10.1140/epjp/s13360-023-04395-2
Regular Article
Array analysis of seismic noise at the Sos Enattos mine, the Italian candidate site for the Einstein Telescope
1
Sezione di Pisa, Istituto Nazionale di Geofisica e Vulcanologia, Via Cesare Battisti 53, Pisa, Italy
2
Dipartimento di Scienze della Terra, Universita degli Studi di Firenze, Florence, Italy
3
Sezione di Roma, Istituto Nazionale di Fisica Nucleare, Rome, Italy
4
Department of Chemical, Physical, Mathematical and Natural Sciences, Università degli Studi di Sassari, Sassari, Italy
5
Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania, Italy
6
Sezione di Cagliari, Istituto Nazionale di Fisica Nucleare, Cagliari, Italy
7
Dipartimento di Fisica, Università degli Studi di Cagliari, Cagliari, Italy
8
Osservatorio Astronomico di Cagliari, Istituto Nazionale di Astrofisica, Cagliari, Italy
9
Sezione di Perugia, Istituto Nazionale di Fisica Nucleare, Perugia, Italy
10
Dipartimento di Fisica, Università degli Studi di Napoli ‘Federico II’, Naples, Italy
11
Dipartimento di Fisica, Università degli Studi di Milano–Bicocca, Milan, Italy
12
EGO, European Gravitational Observatory, 56021, Cascina, Italy
13
Sezione di Napoli, Istituto Nazionale di Fisica Nucleare, Naples, Italy
14
GSSI, Gran Sasso Science Institute, 67100, L’Aquila, Italy
15
Laboratori Nazionali del Gran Sasso, Istituto Nazionale di Fisica Nucleare, L’Aquila, Italy
16
Dipartimento di Fisica, Universitá di Roma La Sapienza, Rome, Italy
17
Sezione di Bologna, Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy
18
Sezione di Pisa, Istituto Nazionale di Fisica Nucleare, Pisa, Italy
19
Dipartimento di Fisica, Università di Pisa, 56127, Pisa, Italy
Received:
19
February
2023
Accepted:
16
August
2023
Published online:
8
September
2023
The area surrounding the dismissed mine of Sos Enattos (Sardinia, Italy) is the Italian candidate site for hosting Einstein Telescope (ET), the third-generation gravitational wave (GW) observatory. One of the goals of ET is to extend the sensitivity down to frequencies well below those currently achieved by GW detectors, i.e. down to 2 Hz. In the bandwidth [1,10] Hz, the seismic noise of anthropogenic origin is expected to represent the major perturbation to the operation of the infrastructure, and the site that will host the future detector must fulfill stringent requirements on seismic disturbances. In this paper we describe the operation of a temporary, 15-element, seismic array deployed in close proximity to the mine. Signals of anthropogenic origin have a transient nature, and their spectra are characterized by a wide spectral lobe spanning the [3,20] Hz frequency interval. Superimposed to this wide lobe are narrow spectral peaks within the [3,8] Hz frequency range. Results from slowness analyses suggest that the origin of these peaks is related to vehicle traffic along the main road running east of the mine. Exploiting the correlation properties of seismic noise, we derive a dispersion curve for Rayleigh waves, which is then inverted for a shallow velocity structure down to depths of 
150 m. This data, which is consistent with that derived from analysis of a quarry blast, provide a first assessment of the elastic properties of the rock materials at the site candidate to hosting ET.
© The Author(s) 2023
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