LESSINES (BE)
Quarry blast5 August 2021
- Magnitude
- 1.7ML
- Depth
- –
- Belgian time
- 12:40:462021-08-05
- UTC
- 10:40:462021-08-05
Main parameters
| Date and time | 2021-08-05 10:40:46 UTC 2021-08-05 12:40:46 Belgian time |
|---|---|
| Magnitude | ML 1.7 |
| Epicentral coordinates | 50.713° N, 3.845° E Uncertainty ± 4.1 km |
| Event ID | ROB 14195 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-08-06 18:30:35 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
- 10
- Epicentral distance
- 0.3 – 174.8km
- Mean velocity, P wave
- 5.7km/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: 8 measurements, root-mean-square deviation 0.42 s. S wave: 4 measurements, root-mean-square deviation 0.70 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)10 stations | |||||
| LESLessines | 0.3 | 208 | 10:40:46.34+0.13 s | – | – |
| SKQSteenkerque | 18.1 | 113 | 10:40:48.99+2.78 s | 10:40:51.83+5.62 s | 2.84 |
| RQRRonquières | 29.4 | 114 | 10:40:50.98+4.77 s | – | – |
| BRQBracquegnies | 33.0 | 141 | 10:40:52.03+5.82 s | – | – |
| DOUDourbes | 87.0 | 142 | 10:41:01.64+15.43 s | 10:41:11.52+25.31 s | 9.88 |
| GESGesves | 95.3 | 112 | 10:41:02.89+16.68 s | 10:41:15.73+29.52 s | 12.84 |
| CLAClavier | 108.3 | 107 | 10:41:04.39+18.18 s | 10:41:18.00+31.79 s | 13.61 |
| RCHRochefort | 116.2 | 122 | 10:41:07.27+21.06 s | – | – |
| MEMHMembach | 153.5 | 93 | 10:41:11.87+25.66 s | 10:41:31.04+44.83 s | 19.17 |
| KLBKalborn | 174.8 | 112 | 10:41:15.17+28.96 s | 10:41:35.79+49.58 s | 20.62 |