LESSINES (BE)
Quarry blast27 April 2021
- Magnitude
- 1.8ML
- Depth
- –
- Belgian time
- 12:40:092021-04-27
- UTC
- 10:40:092021-04-27
Main parameters
| Date and time | 2021-04-27 10:40:09 UTC 2021-04-27 12:40:09 Belgian time |
|---|---|
| Magnitude | ML 1.8 |
| Epicentral coordinates | 50.712° N, 3.885° E Uncertainty ± 4.9 km |
| Event ID | ROB 13265 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-04-30 15:33:50 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
- 11
- Epicentral distance
- 3.0 – 150.7km
- Mean velocity, P wave
- 5.2km/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: 9 measurements, root-mean-square deviation 0.40 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)11 stations | |||||
| LESLessines | 3.0 | 268 | 10:40:09.57+0.33 s | 10:40:10.05+0.81 s | 0.48 |
| SKQSteenkerque | 15.4 | 117 | 10:40:12.19+2.95 s | – | – |
| RQRRonquières | 26.7 | 116 | 10:40:14.09+4.85 s | – | – |
| BRQBracquegnies | 31.2 | 145 | 10:40:15.36+6.12 s | 10:40:16.53+7.29 s | 1.17 |
| SNFSeneffe | 36.0 | 128 | 10:40:15.85+6.61 s | – | – |
| BOUBougnies | 36.2 | 173 | 10:40:16.43+7.19 s | – | – |
| DOUDourbes | 85.2 | 143 | 10:40:24.84+15.60 s | 10:40:26.88+17.64 s | 2.04 |
| GESGesves | 92.6 | 113 | 10:40:27.72+18.48 s | – | – |
| RCHRochefort | 113.7 | 122 | 10:40:30.59+21.35 s | – | – |
| MEMSMembach | 150.7 | 94 | 10:40:32.98+23.74 s | – | – |
| MEMHMembach | 150.7 | 94 | 10:40:33.00+23.76 s | – | – |