SOIGNIES (BE)
Quarry blast20 August 2021
- Magnitude
- 1.7ML
- Depth
- –
- Belgian time
- 14:00:442021-08-20
- UTC
- 12:00:442021-08-20
Main parameters
| Date and time | 2021-08-20 12:00:44 UTC 2021-08-20 14:00:44 Belgian time |
|---|---|
| Magnitude | ML 1.7 |
| Epicentral coordinates | 50.568° N, 4.067° E Uncertainty ± 0.6 km |
| Event ID | ROB 14285 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-08-23 10:18:49 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
- 5
- Epicentral distance
- 9.1 – 32.5km
- Mean velocity, P wave
- 6.8km/s
- Mean velocity, S wave
- 3.7km/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: 5 measurements, root-mean-square deviation 0.18 s. S wave: 4 measurements, root-mean-square deviation 0.30 s.
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)5 stations | |||||
| SKQSteenkerque | 9.1 | 6 | 12:00:46.66+1.88 s | 12:00:47.98+3.20 s | 1.32 |
| BRQBracquegnies | 10.8 | 153 | 12:00:46.94+2.16 s | – | – |
| SNFSeneffe | 16.6 | 112 | 12:00:47.82+3.04 s | 12:00:50.40+5.62 s | 2.58 |
| LESLessines | 22.5 | 315 | 12:00:49.07+4.29 s | 12:00:51.80+7.02 s | 2.73 |
| TGATangissart | 32.5 | 82 | 12:00:50.32+5.54 s | 12:00:53.86+9.08 s | 3.54 |