TOURNAI (BE)
Quarry blast22 March 2021
- Magnitude
- 1.9ML
- Depth
- –
- Belgian time
- 13:00:552021-03-22
- UTC
- 12:00:552021-03-22
Main parameters
| Date and time | 2021-03-22 12:00:55 UTC 2021-03-22 13:00:55 Belgian time |
|---|---|
| Magnitude | ML 1.9 |
| Epicentral coordinates | 50.605° N, 3.494° E Uncertainty ± 6.4 km |
| Event ID | ROB 12825 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-03-22 19:44:39 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
- 27.4 – 194.4km
- Mean velocity, P wave
- 7.3km/s
- Mean velocity, S wave
- 3.8km/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: 11 measurements, root-mean-square deviation 2.08 s. S wave: 4 measurements, root-mean-square deviation 0.77 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 | 27.4 | 64 | 12:01:03.61+8.32 s | – | – |
| BOUBougnies | 40.0 | 127 | 12:01:08.77+13.48 s | – | – |
| SKQSteenkerque | 41.8 | 83 | 12:01:02.01+6.72 s | 12:01:07.76+12.47 s | 5.75 |
| BRQBracquegnies | 47.6 | 107 | 12:01:03.03+7.74 s | – | – |
| RQRRonquières | 51.8 | 90 | 12:01:03.21+7.92 s | – | – |
| SNFSeneffe | 57.0 | 100 | 12:01:04.45+9.16 s | – | – |
| UCCSUccle | 64.9 | 70 | 12:01:04.89+9.60 s | – | – |
| UCCBUccle | 64.9 | 70 | 12:01:05.91+10.62 s | 12:01:14.02+18.73 s | 8.11 |
| TGATangissart | 72.8 | 90 | 12:01:07.79+12.50 s | 12:01:16.88+21.59 s | 9.09 |
| DOUDourbes | 96.7 | 125 | 12:01:11.90+16.61 s | 12:01:23.99+28.70 s | 12.09 |
| GESGesves | 115.7 | 102 | 12:01:14.46+19.17 s | – | – |
| CLAClavier | 129.9 | 98 | 12:01:17.77+22.48 s | – | – |
| KLBKalborn | 194.4 | 106 | 12:01:26.39+31.10 s | – | – |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 173.2 | 83 | 12:01:24.36+29.07 s | – | – |