TOURNAI (BE)
Quarry blast15 April 2021
- Magnitude
- 1.7ML
- Depth
- –
- Belgian time
- 13:00:192021-04-15
- UTC
- 11:00:192021-04-15
Main parameters
| Date and time | 2021-04-15 11:00:19 UTC 2021-04-15 13:00:19 Belgian time |
|---|---|
| Magnitude | ML 1.7 |
| Epicentral coordinates | 50.601° N, 3.354° E Uncertainty ± 7.7 km |
| Event ID | ROB 13150 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-04-15 14:58:45 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
- 51.6 – 203.8km
- Mean velocity, P wave
- 5.5km/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 0.35 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 | 51.6 | 84 | 11:00:28.69+8.98 s | 11:00:36.09+16.38 s | 7.40 |
| BRQBracquegnies | 57.0 | 103 | 11:00:30.16+10.45 s | – | – |
| RQRRonquières | 61.6 | 89 | 11:00:30.29+10.58 s | – | – |
| SNFSeneffe | 66.6 | 98 | 11:00:31.39+11.68 s | – | – |
| TGATangissart | 82.7 | 89 | 11:00:33.81+14.10 s | – | – |
| DOUDourbes | 104.7 | 122 | 11:00:38.73+19.02 s | 11:00:50.15+30.44 s | 11.42 |
| GESGesves | 125.3 | 100 | 11:00:38.85+19.14 s | 11:00:57.78+38.07 s | 18.93 |
| KLBKalborn | 203.8 | 105 | 11:00:52.08+32.37 s | 11:01:14.88+55.17 s | 22.80 |