TOURNAI (BE)
Quarry blast9 February 2021
- Magnitude
- 2.2ML
- Depth
- –
- Belgian time
- 12:32:282021-02-09
- UTC
- 11:32:282021-02-09
Main parameters
| Date and time | 2021-02-09 11:32:28 UTC 2021-02-09 12:32:28 Belgian time |
|---|---|
| Magnitude | ML 2.2 |
| Epicentral coordinates | 50.650° N, 3.457° E Uncertainty ± 5.0 km |
| Event ID | ROB 12365 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-02-20 18:29:36 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
- 44.1 – 198.3km
- Mean velocity, P wave
- 5.9km/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 0.43 s. S wave: 5 measurements, root-mean-square deviation 0.61 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 | |||||
| SKQSteenkerque | 44.1 | 90 | 11:32:35.77+7.56 s | 11:32:41.43+13.22 s | 5.66 |
| BOUBougnies | 45.2 | 130 | 11:32:36.04+7.83 s | – | – |
| BRQBracquegnies | 51.7 | 111 | 11:32:36.67+8.46 s | – | – |
| RQRRonquières | 54.6 | 95 | 11:32:38.37+10.16 s | – | – |
| UCCBUccle | 65.8 | 75 | 11:32:40.22+12.01 s | 11:32:48.02+19.81 s | 7.80 |
| TGATangissart | 75.5 | 93 | 11:32:41.14+12.93 s | 11:32:49.65+21.44 s | 8.51 |
| DOUDourbes | 101.8 | 127 | 11:32:45.27+17.06 s | 11:32:58.90+30.69 s | 13.63 |
| GESGesves | 119.3 | 104 | 11:32:48.18+19.97 s | 11:33:04.48+36.27 s | 16.30 |
| KLBKalborn | 198.3 | 107 | 11:33:00.03+31.82 s | 11:33:23.24+55.03 s | 23.21 |