Speaker
Description
The Einstein Telescope (ET) will be Europe's next-generation underground interferometric gravitational wave detector. The extreme target sensitivity that these detectors should attain requires underground placement to shield the apparatuses from the ambient noise. A quiet environment in a geologically stable area away from major faults and industrial activities also helps to maximise the duty cycle of the machine.
Among the competing European sites, Italy - recently supported by other partner countries - has proposed northeastern Sardinia as a candidate site. The island's current geodynamic stability, exceptionally low seismicity, and minimal anthropogenic seismic noise make it an ideal setting for high-precision experiments. In this contribution, we provide an update on the geological exploration results relevant to the selection of the ET configuration.
Two geometries are under consideration: a new triangular layout with 11 km of sides, and an L-shaped design with arms of 15 km length. Since 2019, extensive studies have been carried out in the area through academic research; a public tender has been launched in 2024 to expand these efforts. These investigations include a dozen drill holes and geophysical surveys over a crystalline basement with rugged topography reaching elevations of up to 1000 meters. Combined with geological mapping and hydrogeological data, these surveys will support the development of a 3D geological model, including subsurface water circulation and hydrogeochemical and isotopic characterization.
In order to assess also the fourth dimension of long-term geological risks such as seismic faulting, magmatic activity and ground movement, this study also includes geochronological, thermochronological and ground motion characterization analyses.
