LESSINES (BE)
Quarry blast7 August 2020
- Magnitude
- 1.6ML
- Depth
- –
- Belgian time
- 11:39:482020-08-07
- UTC
- 09:39:482020-08-07
Main parameters
| Date and time | 2020-08-07 09:39:48 UTC 2020-08-07 11:39:48 Belgian time |
|---|---|
| Magnitude | ML 1.6 |
| Epicentral coordinates | 50.713° N, 3.858° E Uncertainty ± 2.0 km |
| Event ID | ROB 10625 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-08-07 13:48:12 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
- 14
- Epicentral distance
- 1.1 – 174.0km
- Mean velocity, P wave
- 5.4km/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 0.44 s. S wave: 6 measurements, root-mean-square deviation 0.26 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)13 stations | |||||
| LESLessines | 1.1 | 258 | 09:39:48.49−0.01 s | 09:39:48.67+0.17 s | 0.18 |
| SKQSteenkerque | 17.2 | 114 | 09:39:51.21+2.71 s | 09:39:53.54+5.04 s | 2.33 |
| RQRRonquières | 28.6 | 114 | 09:39:53.00+4.50 s | – | – |
| BRQBracquegnies | 32.5 | 143 | 09:39:54.21+5.71 s | – | – |
| BOUBougnies | 36.6 | 170 | 09:39:55.18+6.68 s | – | – |
| TGATangissart | 48.5 | 104 | 09:39:56.71+8.21 s | 09:40:02.74+14.24 s | 6.03 |
| MRDMaredsous | 79.1 | 125 | 09:40:02.18+13.68 s | 09:40:11.68+23.18 s | 9.50 |
| DOUDourbes | 86.4 | 142 | 09:40:03.66+15.16 s | 09:40:14.22+25.72 s | 10.56 |
| GESGesves | 94.5 | 112 | 09:40:06.55+18.05 s | 09:40:17.12+28.62 s | 10.57 |
| RCHRochefort | 115.4 | 122 | 09:40:09.22+20.72 s | – | – |
| MEMHMembach | 152.6 | 94 | 09:40:14.17+25.67 s | 09:40:33.50+45.00 s | 19.33 |
| MEMSMembach | 152.6 | 94 | 09:40:14.22+25.72 s | – | – |
| KLBKalborn | 174.0 | 112 | 09:40:17.28+28.78 s | 09:40:38.74+50.24 s | 21.46 |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 146.5 | 87 | 09:40:13.33+24.83 s | 09:40:31.40+42.90 s | 18.07 |