F16 Sonic Booms
When loud “bangs” are reported to us, sometimes this is related to a F16 (most frequently used military airplane around Belgium) breaking through the sound barrier. The location can be estimated from the records of our seismic stations and is usually confirmed by the people reporting the event in our online DYFI system. This was for instance the case above Liège on 8 February 2013 (5 testimonies) and above Walloon Brabant on 17 August 2015 (11 testimonies).
Explosions related to construction works or accidents
On 18 February 2011 14:21:20 (Belgian Time) a controlled explosion to demolish a building inside the European quarter in Brussels led 42 people to respond to our inquiry.
On 3 January 2014 13:26:22 (Belgian Time) an accidental explosion occurred near the town of Euskirchen (Germany). From the 301 inquiries, 235 observations were geocoded to the street level or better for those addresses for which the respondents provided their house number. Distribution of individual macroseismic observations proved to be much better suited to interpret the macroseismic spread than if intensity data was grouped per community. Hinzen (2014) concluded that strong directivity of this felt event (all responses came from a northeasterly direction to the blast) was related to source directivity of the air blast, population density, effects of the wind field and topography.
On Sunday 28 February 2016 at 21:36:51 (Belgian time) an explosion related to local construction works in Antwerp mislead people in thinking it was an earthquake. Seismology.be was alerted due to an abnormally-high number of online visitors on the website and through its Twitter account. Rapid seismic data analysis confirmed that was not an “earthquake” effect and this information was spread rapidly through our Twitter and Facebook accounts. 54 people submitted their perception to Seismology.be. The distribution shows that this event has been perceived/heard further to the SW due to a NE wind that evening.
Figure 7: Felt and heard testimonies to the Antwerp construction explosion on 28 February 2016. Sources: Seismologie.be, Twitter and Facebook.
References
- Hinzen, K.G., 2014. Seismic Analysis of the Accidental WWII Bomb Explosion in Euskirchen, Germany, on 3 January 2014. Seismological Research Letters 85, 825-835.