NAMUR (BE)
Quarry blast22 April 2021
- Magnitude
- 1.8ML
- Depth
- –
- Belgian time
- 14:28:372021-04-22
- UTC
- 12:28:372021-04-22
Main parameters
| Date and time | 2021-04-22 12:28:37 UTC 2021-04-22 14:28:37 Belgian time |
|---|---|
| Magnitude | ML 1.8 |
| Epicentral coordinates | 50.492° N, 4.968° E Uncertainty ± 2.8 km |
| Event ID | ROB 13215 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-04-23 17:59:32 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
- 14.6 – 92.3km
- 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: 14 measurements, root-mean-square deviation 0.33 s. S wave: 8 measurements, root-mean-square deviation 0.55 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)13 stations | |||||
| GESGesves | 14.6 | 145 | 12:28:40.33+2.50 s | 12:28:42.19+4.36 s | 1.86 |
| CLAClavier | 25.1 | 109 | 12:28:41.97+4.14 s | 12:28:45.62+7.79 s | 3.65 |
| MRDMaredsous | 25.5 | 214 | 12:28:42.55+4.72 s | 12:28:46.40+8.57 s | 3.85 |
| TGATangissart | 34.0 | 292 | 12:28:43.53+5.70 s | 12:28:48.03+10.20 s | 4.50 |
| RCHRochefort | 41.8 | 154 | 12:28:44.89+7.06 s | – | – |
| DOUDourbes | 51.5 | 211 | 12:28:47.14+9.31 s | 12:28:53.66+15.83 s | 6.52 |
| RQRRonquières | 54.1 | 284 | 12:28:47.38+9.55 s | – | – |
| SKQSteenkerque | 65.3 | 286 | 12:28:48.43+10.60 s | – | – |
| MEMSMembach | 75.0 | 80 | 12:28:50.82+12.99 s | 12:29:00.61+22.78 s | 9.79 |
| MEMHMembach | 75.0 | 80 | 12:28:50.87+13.04 s | 12:29:00.67+22.84 s | 9.80 |
| MRGMont Rigi | 78.6 | 88 | 12:28:51.35+13.52 s | – | – |
| TNLTernell | 83.1 | 82 | 12:28:52.31+14.48 s | – | – |
| KLBKalborn | 92.3 | 118 | 12:28:54.00+16.17 s | 12:29:04.19+26.36 s | 10.19 |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 74.6 | 66 | 12:28:50.11+12.28 s | – | – |