TOURNAI (BE)
Quarry blast24 September 2021
- Magnitude
- 2.1ML
- Depth
- –
- Belgian time
- 13:00:292021-09-24
- UTC
- 11:00:292021-09-24
Main parameters
| Date and time | 2021-09-24 11:00:29 UTC 2021-09-24 13:00:29 Belgian time |
|---|---|
| Magnitude | ML 2.1 |
| Epicentral coordinates | 50.620° N, 3.475° E Uncertainty ± 3.7 km |
| Event ID | ROB 14485 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-09-24 18:24:46 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
- 8
- Epicentral distance
- 27.9 – 196.1km
- Mean velocity, P wave
- 6.1km/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: 6 measurements, root-mean-square deviation 0.28 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)8 stations | |||||
| LESLessines | 27.9 | 69 | 11:00:34.69+5.27 s | 11:00:38.31+8.89 s | 3.62 |
| BOUBougnies | 42.1 | 127 | 11:00:37.04+7.62 s | – | – |
| RQRRonquières | 53.1 | 91 | 11:00:38.42+9.00 s | – | – |
| SNFSeneffe | 58.6 | 102 | 11:00:38.95+9.53 s | 11:00:46.32+16.90 s | 7.37 |
| DOUDourbes | 98.8 | 126 | 11:00:46.28+16.86 s | 11:00:59.20+29.78 s | 12.92 |
| GESGesves | 117.3 | 102 | 11:00:49.21+19.79 s | – | – |
| RCHRochefort | 134.9 | 112 | 11:00:52.59+23.17 s | – | – |
| KLBKalborn | 196.1 | 106 | 11:01:00.82+31.40 s | 11:01:24.14+54.72 s | 23.32 |