CELLES (BE)
Quarry blast9 July 2021
- Magnitude
- 1.8ML
- Depth
- –
- Belgian time
- 12:02:332021-07-09
- UTC
- 10:02:332021-07-09
Main parameters
| Date and time | 2021-07-09 10:02:33 UTC 2021-07-09 12:02:33 Belgian time |
|---|---|
| Magnitude | ML 1.8 |
| Epicentral coordinates | 50.692° N, 3.429° E Uncertainty ± 6.5 km |
| Event ID | ROB 13990 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-07-26 11:56:17 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
- 12
- Epicentral distance
- 29.3 – 201.6km
- Mean velocity, P wave
- 6.1km/s
- Mean velocity, S wave
- 3.2km/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: 9 measurements, root-mean-square deviation 0.41 s. S wave: 5 measurements, root-mean-square deviation 0.60 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)12 stations | |||||
| LESLessines | 29.3 | 86 | 10:02:39.19+5.94 s | 10:02:43.05+9.80 s | 3.86 |
| SKQSteenkerque | 46.3 | 96 | 10:02:41.31+8.06 s | 10:02:47.41+14.16 s | 6.10 |
| BOUBougnies | 49.8 | 132 | 10:02:41.50+8.25 s | – | – |
| BRQBracquegnies | 55.3 | 115 | 10:02:42.63+9.38 s | – | – |
| RQRRonquières | 57.1 | 99 | 10:02:43.52+10.27 s | – | – |
| SNFSeneffe | 63.8 | 108 | 10:02:43.73+10.48 s | – | – |
| TGATangissart | 77.9 | 97 | 10:02:47.14+13.89 s | 10:02:57.17+23.92 s | 10.03 |
| MRDMaredsous | 104.5 | 114 | 10:02:50.55+17.30 s | 10:03:06.95+33.70 s | 16.40 |
| DOUDourbes | 106.2 | 128 | 10:02:51.36+18.11 s | 10:03:06.31+33.06 s | 14.95 |
| CLAClavier | 136.2 | 102 | 10:02:56.74+23.49 s | 10:03:14.52+41.27 s | 17.78 |
| RCHRochefort | 141.1 | 114 | 10:02:57.70+24.45 s | 10:03:15.24+41.99 s | 17.54 |
| KLBKalborn | 201.6 | 108 | 10:03:05.65+32.40 s | 10:03:31.37+58.12 s | 25.72 |