The seismic network of the Royal Observatory of Belgium (ROB) measured 31 natural earthquakes in the country during 2021, though none were felt by the public.
The largest natural quakes occurred on 20 June in Dampremy near Charleroi and on 28 August in Baelen near the German border in the province of Liège, Belga News Agency reports. Both quakes had a magnitude of 1.7.
Just across the border in Germany, around the village of Rott in Bavaria, a total of 126 quakes were recorded in 2021.
The magnitude of those varied widely, with most not being felt by the local population. But some of the strongest quakes, notably the one in January with a magnitude of 2.6, were felt as far away as Eupen in Belgium.
The Royal Observatory recorded 257 natural earthquakes in and around Belgium.
“The increased seismic activity is mainly related to the occurrence of several earthquake swarms along faults in the Rottal valley [of Bavaria], Germany,” geologist Koen Van Noten explained.
“These swarms occurred in Rott (Germany), Eschweiler (Germany) and Voerendaal (the Netherlands).”
There were also 12 man-made quakes in 2021 (most of them in connection with a deep-earth heating project in Dessel in the province of Antwerp), 367 explosions in stone quarries and at least six controlled explosions at sea by the Belgian, Dutch or French navy to destroy bombs from the World Wars.