On February 1^st 2022, a M 4.1 earthquake near Andorra was recorded by the recently deployed RaspberryShake-4D sensors in the Pyrenees (Test-Bed 2). The epicentre was located at around 75 km from the 5 stations deployed in Bagnères-de-Luchon, and at around 120 km from the 6 stations along the high-speed train line between Perpignan and Figueras.

Integrated with the permanent accelerometric network in the area, the RaspberryShake-4D stations were useful to detect and locate the event. While acceleration levels were very weak in Bagnères-de-Luchon (less than 1mg), the accelerometers of the station RE153, located on the floor R+2 of a high-school building, were able to pick up the S waves.

This small earthquake has demonstrated the ability of the deployed stations to detect events in the area. In complement of the other permanent accelerometric stations, the RaspberryShake-4D sensors could then be used to generate more accurate shake-maps in the case of larger seismic events.

• Map of the RaspberryShake-4D network in Test-Bed 2 and epicentre location of the earthquake.