TOURNAI (BE)
Quarry blast18 May 2021
- Magnitude
- 2.1ML
- Depth
- –
- Belgian time
- 13:01:192021-05-18
- UTC
- 11:01:192021-05-18
Main parameters
| Date and time | 2021-05-18 11:01:19 UTC 2021-05-18 13:01:19 Belgian time |
|---|---|
| Magnitude | ML 2.1 |
| Epicentral coordinates | 50.644° N, 3.403° E Uncertainty ± 2.9 km |
| Event ID | ROB 13465 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-05-19 10:38:05 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
- 32.0 – 201.8km
- Mean velocity, P wave
- 6.2km/s
- Mean velocity, S wave
- 3.4km/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 0.22 s. S wave: 4 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)11 stations | |||||
| LESLessines | 32.0 | 76 | 11:01:26.09+6.20 s | 11:01:30.11+10.22 s | 4.02 |
| BOUBougnies | 47.8 | 126 | 11:01:28.52+8.63 s | – | – |
| SKQSteenkerque | 47.9 | 89 | 11:01:28.22+8.33 s | 11:01:34.25+14.36 s | 6.03 |
| BRQBracquegnies | 55.0 | 109 | 11:01:29.47+9.58 s | – | – |
| RQRRonquières | 58.3 | 94 | 11:01:29.99+10.10 s | – | – |
| SNFSeneffe | 64.1 | 103 | 11:01:30.76+10.87 s | – | – |
| TGATangissart | 79.3 | 93 | 11:01:33.11+13.22 s | 11:01:43.33+23.44 s | 10.22 |
| DOUDourbes | 104.5 | 125 | 11:01:37.79+17.90 s | 11:01:51.22+31.33 s | 13.43 |
| GESGesves | 122.9 | 103 | 11:01:40.62+20.73 s | 11:01:56.61+36.72 s | 15.99 |
| RCHRochefort | 140.6 | 112 | 11:01:43.23+23.34 s | 11:02:00.72+40.83 s | 17.49 |
| KLBKalborn | 201.8 | 106 | 11:01:52.58+32.69 s | 11:02:15.61+55.72 s | 23.03 |