LESSINES (BE)
Quarry blast5 August 2021
- Magnitude
- 1.3ML
- Depth
- –
- Belgian time
- 14:57:232021-08-05
- UTC
- 12:57:232021-08-05
Main parameters
| Date and time | 2021-08-05 12:57:23 UTC 2021-08-05 14:57:23 Belgian time |
|---|---|
| Magnitude | ML 1.3 |
| Epicentral coordinates | 50.713° N, 3.845° E Uncertainty ± 9.3 km |
| Event ID | ROB 14200 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-08-06 18:30:54 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
- 9
- Epicentral distance
- 0.3 – 174.8km
- Mean velocity, P wave
- 5.5km/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 0.27 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)9 stations | |||||
| LESLessines | 0.3 | 208 | 12:57:23.74−0.08 s | – | – |
| SKQSteenkerque | 18.1 | 113 | 12:57:26.51+2.69 s | 12:57:28.80+4.98 s | 2.29 |
| RQRRonquières | 29.4 | 114 | 12:57:28.26+4.44 s | – | – |
| BRQBracquegnies | 33.0 | 141 | 12:57:29.52+5.70 s | – | – |
| DOUDourbes | 87.0 | 142 | 12:57:39.03+15.21 s | – | – |
| GESGesves | 95.3 | 112 | 12:57:40.17+16.35 s | 12:57:53.96+30.14 s | 13.79 |
| CLAClavier | 108.3 | 107 | 12:57:43.09+19.27 s | 12:57:56.17+32.35 s | 13.08 |
| RCHRochefort | 116.2 | 122 | 12:57:44.60+20.78 s | – | – |
| KLBKalborn | 174.8 | 112 | 12:57:52.54+28.72 s | 12:58:12.71+48.89 s | 20.17 |