LESSINES (BE)
Quarry blast21 April 2021
- Magnitude
- 1.7ML
- Depth
- –
- Belgian time
- 14:03:142021-04-21
- UTC
- 12:03:142021-04-21
Main parameters
| Date and time | 2021-04-21 12:03:14 UTC 2021-04-21 14:03:14 Belgian time |
|---|---|
| Magnitude | ML 1.7 |
| Epicentral coordinates | 50.703° N, 3.841° E Uncertainty ± 3.7 km |
| Event ID | ROB 13225 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-04-23 18:00:26 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
- 17
- Epicentral distance
- 0.9 – 174.6km
- Mean velocity, P wave
- 5.5km/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: 13 measurements, root-mean-square deviation 0.60 s. S wave: 4 measurements, root-mean-square deviation 0.62 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)16 stations | |||||
| LESLessines | 0.9 | 7 | 12:03:14.78+0.00 s | – | – |
| SKQSteenkerque | 17.9 | 110 | 12:03:17.61+2.83 s | – | – |
| RQRRonquières | 29.2 | 112 | 12:03:19.34+4.56 s | – | – |
| BRQBracquegnies | 32.3 | 140 | 12:03:20.41+5.63 s | – | – |
| SNFSeneffe | 37.9 | 124 | 12:03:21.07+6.29 s | – | – |
| UCCBUccle | 38.1 | 74 | 12:03:21.45+6.67 s | 12:03:26.13+11.35 s | 4.68 |
| TGATangissart | 49.3 | 103 | 12:03:22.51+7.73 s | – | – |
| MRDMaredsous | 79.4 | 124 | 12:03:30.13+15.35 s | 12:03:38.06+23.28 s | 7.93 |
| DOUDourbes | 86.3 | 141 | 12:03:30.48+15.70 s | 12:03:39.61+24.83 s | 9.13 |
| GESGesves | 95.1 | 111 | 12:03:32.63+17.85 s | 12:03:43.93+29.15 s | 11.30 |
| DSLBDessel | 104.2 | 55 | 12:03:32.84+18.06 s | – | – |
| CLAClavier | 108.2 | 106 | 12:03:33.18+18.40 s | – | – |
| RCHRochefort | 115.8 | 121 | 12:03:35.53+20.75 s | – | – |
| MEMHMembach | 153.7 | 93 | 12:03:40.91+26.13 s | 12:03:59.91+45.13 s | 19.00 |
| MEMSMembach | 153.7 | 93 | 12:03:40.94+26.16 s | – | – |
| KLBKalborn | 174.6 | 112 | 12:03:43.59+28.81 s | – | – |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 147.7 | 87 | 12:03:39.76+24.98 s | 12:03:58.62+43.84 s | 18.86 |