CELLES (BE)
Quarry blast7 July 2021
- Magnitude
- 1.9ML
- Depth
- –
- Belgian time
- 13:02:222021-07-07
- UTC
- 11:02:222021-07-07
Main parameters
| Date and time | 2021-07-07 11:02:22 UTC 2021-07-07 13:02:22 Belgian time |
|---|---|
| Magnitude | ML 1.9 |
| Epicentral coordinates | 50.698° N, 3.416° E Uncertainty ± 2.0 km |
| Event ID | ROB 13910 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-07-08 10:25:23 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
- 14
- Epicentral distance
- 30.2 – 142.2km
- Mean velocity, P wave
- 6.0km/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: 11 measurements, root-mean-square deviation 0.51 s. S wave: 8 measurements, root-mean-square deviation 0.51 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)14 stations | |||||
| LESLessines | 30.2 | 87 | 11:02:26.51+4.37 s | 11:02:32.31+10.17 s | 5.80 |
| SKQSteenkerque | 47.3 | 96 | 11:02:30.63+8.49 s | 11:02:36.17+14.03 s | 5.54 |
| BOUBougnies | 50.9 | 132 | 11:02:30.61+8.47 s | 11:02:37.52+15.38 s | 6.91 |
| BRQBracquegnies | 56.5 | 115 | 11:02:31.87+9.73 s | – | – |
| RQRRonquières | 58.2 | 100 | 11:02:32.10+9.96 s | 11:02:39.82+17.68 s | 7.72 |
| SNFSeneffe | 64.9 | 108 | 11:02:33.02+10.88 s | – | – |
| UCCBUccle | 67.6 | 80 | 11:02:32.46+10.32 s | 11:02:42.06+19.92 s | 9.60 |
| OSTBOostende | 68.7 | 331 | 11:02:33.98+11.84 s | – | – |
| TGATangissart | 78.9 | 97 | 11:02:36.03+13.89 s | 11:02:45.62+23.48 s | 9.59 |
| MRDMaredsous | 105.6 | 114 | 11:02:40.01+17.87 s | 11:02:54.05+31.91 s | 14.04 |
| DOUDourbes | 107.4 | 128 | 11:02:40.72+18.58 s | 11:02:53.33+31.19 s | 12.61 |
| GESGesves | 123.5 | 106 | 11:02:42.95+20.81 s | 11:02:59.04+36.90 s | 16.09 |
| CLAClavier | 137.2 | 102 | 11:02:45.01+22.87 s | 11:03:04.09+41.95 s | 19.08 |
| RCHRochefort | 142.2 | 114 | 11:02:47.24+25.10 s | 11:03:05.50+43.36 s | 18.26 |