TOURNAI (BE)
Quarry blast23 February 2023
- Magnitude
- 1.8ML
- Depth
- –
- Belgian time
- 12:59:372023-02-23
- UTC
- 11:59:372023-02-23
Main parameters
| Date and time | 2023-02-23 11:59:37 UTC 2023-02-23 12:59:37 Belgian time |
|---|---|
| Magnitude | ML 1.8 |
| Epicentral coordinates | 50.683° N, 3.346° E Uncertainty ± 8.7 km |
| Event ID | ROB 18870 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2023-02-25 15:39:02 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
- 52.0 – 206.9km
- Mean velocity, P wave
- 5.8km/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: 7 measurements, root-mean-square deviation 0.24 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 | |||||
| SKQSteenkerque | 52.0 | 94 | 11:59:46.51+9.02 s | 11:59:53.01+15.52 s | 6.50 |
| BRQBracquegnies | 60.3 | 112 | 11:59:47.92+10.43 s | – | – |
| RQRRonquières | 62.8 | 98 | 11:59:48.22+10.73 s | – | – |
| SNFSeneffe | 69.1 | 106 | 11:59:48.97+11.48 s | 11:59:58.45+20.96 s | 9.48 |
| TGATangissart | 83.6 | 96 | 11:59:51.59+14.10 s | – | – |
| MRDMaredsous | 109.5 | 112 | 11:59:56.11+18.62 s | – | – |
| DOUDourbes | 110.3 | 126 | 11:59:56.82+19.33 s | 12:00:10.09+32.60 s | 13.27 |
| KLBKalborn | 206.9 | 107 | 12:00:11.13+33.64 s | – | – |