TOURNAI (BE)
Quarry blast3 August 2021
- Magnitude
- 2.1ML
- Depth
- –
- Belgian time
- 13:00:192021-08-03
- UTC
- 11:00:192021-08-03
Main parameters
| Date and time | 2021-08-03 11:00:19 UTC 2021-08-03 13:00:19 Belgian time |
|---|---|
| Magnitude | ML 2.1 |
| Epicentral coordinates | 50.607° N, 3.490° E Uncertainty ± 2.9 km |
| Event ID | ROB 14165 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-08-06 18:24:53 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
- 40.4 – 194.7km
- Mean velocity, P wave
- 6.0km/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: 7 measurements, root-mean-square deviation 0.14 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 | |||||
| BOUBougnies | 40.4 | 127 | 11:00:27.01+7.09 s | – | – |
| SKQSteenkerque | 42.0 | 83 | 11:00:27.26+7.34 s | 11:00:32.82+12.90 s | 5.56 |
| BRQBracquegnies | 47.9 | 107 | 11:00:28.56+8.64 s | – | – |
| RQRRonquières | 52.0 | 90 | 11:00:28.82+8.90 s | – | – |
| SNFSeneffe | 57.3 | 100 | 11:00:29.74+9.82 s | – | – |
| UCCBUccle | 65.0 | 71 | 11:00:31.26+11.34 s | 11:00:39.25+19.33 s | 7.99 |
| GESGesves | 116.0 | 102 | 11:00:39.68+19.76 s | 11:00:54.50+34.58 s | 14.82 |
| RCHRochefort | 133.4 | 111 | 11:00:42.17+22.25 s | 11:00:58.87+38.95 s | 16.70 |
| KLBKalborn | 194.7 | 106 | 11:00:51.76+31.84 s | 11:01:15.55+55.63 s | 23.79 |