BRAINE-LE-COMTE (BE)
Quarry blast20 May 2021
- Magnitude
- 1.6ML
- Depth
- –
- Belgian time
- 14:10:522021-05-20
- UTC
- 12:10:522021-05-20
Main parameters
| Date and time | 2021-05-20 12:10:52 UTC 2021-05-20 14:10:52 Belgian time |
|---|---|
| Magnitude | ML 1.6 |
| Epicentral coordinates | 50.594° N, 4.092° E Uncertainty ± 1.6 km |
| Event ID | ROB 13500 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-05-21 16:51:38 Belgian time
Location map
- Epicentre
- Station that recorded the event
Arrival times at the stations
Each station first records the P wave, the fastest, then the S wave. The farther a station is from the epicentre, the later the waves reach it and the wider the gap between the two.
- Stations
- 13
- Epicentral distance
- 6.1 – 135.8km
- Mean velocity, P wave
- 5.8km/s
- Mean velocity, S wave
- 3.3km/s
- P wave
- S wave
- Curve fitted to the measurements
Notes and method
Curves: travel time of a direct wave in a homogeneous medium. The velocity of each wave and an origin-time shift, common to both, are fitted to the measurements by least squares. Depth not determined: hypocenter placed at the surface for the calculation. P wave: 10 measurements, root-mean-square deviation 0.29 s. S wave: 6 measurements, root-mean-square deviation 0.31 s.
Stations farther than 120 km are left out of the fit: the first waves to reach them have travelled beneath the crust, through the mantle, where they propagate faster.
Station measurements
P- and S-wave arrivals and ground displacement measured at each station. Click a column heading to change the order.
| km | ° | UTC | UTC | s | |
|---|---|---|---|---|---|
| Belgian seismic network (Royal Observatory of Belgium)12 stations | |||||
| SKQSteenkerque | 6.1 | 352 | 12:10:53.64+1.08 s | 12:10:54.82+2.26 s | 1.18 |
| RQRRonquières | 9.5 | 82 | 12:10:54.31+1.75 s | – | – |
| BRQBracquegnies | 13.0 | 166 | 12:10:54.24+1.68 s | – | – |
| SNFSeneffe | 16.4 | 124 | 12:10:55.20+2.64 s | – | – |
| UCCBUccle | 29.4 | 40 | 12:10:57.81+5.25 s | 12:11:01.66+9.10 s | 3.85 |
| TGATangissart | 30.4 | 88 | 12:10:57.71+5.15 s | 12:11:01.63+9.07 s | 3.92 |
| DOUDourbes | 66.1 | 147 | 12:11:04.04+11.48 s | 12:11:12.60+20.04 s | 8.56 |
| GESGesves | 74.3 | 108 | 12:11:05.87+13.31 s | 12:11:15.06+22.50 s | 9.19 |
| CLAClavier | 88.0 | 102 | 12:11:07.39+14.83 s | – | – |
| RCHRochefort | 94.4 | 121 | 12:11:08.99+16.43 s | 12:11:20.31+27.75 s | 11.32 |
| MEMSMembach | 135.8 | 89 | 12:11:16.20+23.64 s | – | – |
| MEMHMembach | 135.8 | 89 | 12:11:16.20+23.64 s | 12:11:33.83+41.27 s | 17.63 |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 131.4 | 81 | 12:11:15.17+22.61 s | – | – |