Researchers report first seven-month borehole seismic data from Einstein Telescope Meuse-Rhine site
Researchers report first borehole seismic data from the Einstein Telescope's Euregio Meuse-Rhine candidate site, covering seven months in 2026 across four underground stations and surface sensors. The results catalogue transients, including railway-induced noise, and feed models that predict Newtonian noise for detector siting and mitigation. The work matters because low-frequency gravitational-wave detection depends on controlling ground motion and local human activity.
A preprint by L. D'Onofrio and colleagues reports the first seismic characterization results from a borehole network installed for the Einstein Telescope's Euregio Meuse-Rhine candidate site. The observations cover the first seven months of 2026 and include four underground stations with co-located surface sensors. Two boreholes were placed deliberately near railway infrastructure, allowing researchers to measure how human-made ground motion from trains propagates to depth at different distances from the source.
The team used SiteChar, a Python processing framework developed for the work, to run a common pipeline across different sensors, networks and observation periods. The software processes data in sequential chunks and separates the ambient noise floor from transient events. The preprint presents a catalogue of observed transients and a tentative classification, rather than a final mitigation design. It also links the measurements to three-dimensional geological and wave-propagation models used to predict Newtonian noise.
The Euregio Meuse-Rhine site is being evaluated for the Einstein Telescope, a next-generation gravitational-wave detector whose low-frequency sensitivity depends on quiet ground conditions. Underground placement can reduce ordinary surface vibrations, but local geology and nearby human activity still matter. The railway-proximate boreholes show that the project is testing one of the main practical risks: whether trains and other surface sources can inject noise deep enough to disturb future detectors. The result is a measured baseline, not a decision on site suitability.
The data matter because the Einstein Telescope aims to listen to the universe's most violent events at lower frequencies than current detectors, where ground motion and Newtonian noise, a gravity-gradient disturbance, can set the limit on what can be seen. For scientists and engineers, the borehole network provides concrete evidence for designing vibration isolation and choosing detector placement. For the Meuse-Rhine region, the report documents how future infrastructure planning must account for railways and geology before a major underground laboratory can proceed.
The report gives engineers and physicists measured evidence for how trains and geology may limit a future underground gravitational-wave detector in the Meuse-Rhine region. It affects where and how the Einstein Telescope could be built to detect faint cosmic signals.
Sources (1)
- [1]First results from a borehole network for the seismic characterization of the Einstein Telescope Euregio Meuse-Rhine candidate site(https://arxiv.org/abs/2611.12917)