NAMUR (BE)
Quarry blast4 May 2021
- Magnitude
- 1.8ML
- Depth
- –
- Belgian time
- 13:35:252021-05-04
- UTC
- 11:35:252021-05-04
Main parameters
| Date and time | 2021-05-04 11:35:25 UTC 2021-05-04 13:35:25 Belgian time |
|---|---|
| Magnitude | ML 1.8 |
| Epicentral coordinates | 50.491° N, 4.963° E Uncertainty ± 0.7 km |
| Event ID | ROB 13300 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-05-05 08:34:06 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
- 13
- Epicentral distance
- 14.7 – 92.5km
- Mean velocity, P wave
- 5.7km/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: 13 measurements, root-mean-square deviation 0.34 s. S wave: 12 measurements, root-mean-square deviation 0.34 s.
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 | |||||
| GESGesves | 14.7 | 143 | 11:35:28.17+2.64 s | 11:35:29.98+4.45 s | 1.81 |
| MRDMaredsous | 25.1 | 213 | 11:35:30.67+5.14 s | 11:35:33.20+7.67 s | 2.53 |
| CLAClavier | 25.4 | 108 | 11:35:29.89+4.36 s | 11:35:33.42+7.89 s | 3.53 |
| TGATangissart | 33.7 | 292 | 11:35:31.72+6.19 s | 11:35:35.42+9.89 s | 3.70 |
| RCHRochefort | 41.8 | 153 | 11:35:33.03+7.50 s | 11:35:37.82+12.29 s | 4.79 |
| LCHLa Chartreuse | 48.0 | 70 | 11:35:33.93+8.40 s | 11:35:39.39+13.86 s | 5.46 |
| DOUDourbes | 51.2 | 211 | 11:35:35.47+9.94 s | 11:35:41.18+15.65 s | 5.71 |
| SKQSteenkerque | 65.0 | 286 | 11:35:36.60+11.07 s | 11:35:44.77+19.24 s | 8.17 |
| MEMSMembach | 75.4 | 80 | 11:35:39.27+13.74 s | 11:35:48.19+22.66 s | 8.92 |
| MEMHMembach | 75.4 | 80 | 11:35:39.32+13.79 s | 11:35:48.15+22.62 s | 8.83 |
| MRGMont Rigi | 79.0 | 88 | 11:35:39.38+13.85 s | – | – |
| KLBKalborn | 92.5 | 118 | 11:35:41.89+16.36 s | 11:35:52.04+26.51 s | 10.15 |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 75.0 | 66 | 11:35:38.88+13.35 s | 11:35:47.75+22.22 s | 8.87 |