NAMUR (BE)
Quarry blast28 April 2020
- Magnitude
- 1.7ML
- Depth
- –
- Belgian time
- 14:30:422020-04-28
- UTC
- 12:30:422020-04-28
Main parameters
| Date and time | 2020-04-28 12:30:42 UTC 2020-04-28 14:30:42 Belgian time |
|---|---|
| Magnitude | ML 1.7 |
| Epicentral coordinates | 50.492° N, 4.955° E Uncertainty ± 1.4 km |
| Event ID | ROB 9895 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-04-28 14:56:32 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
- 12
- Epicentral distance
- 15.2 – 108.4km
- Mean velocity, P wave
- 5.7km/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: 12 measurements, root-mean-square deviation 0.58 s. S wave: 5 measurements, root-mean-square deviation 0.64 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)9 stations | |||||
| GESGesves | 15.2 | 142 | 12:30:44.47+2.08 s | 12:30:46.72+4.33 s | 2.25 |
| MRDMaredsous | 25.0 | 212 | 12:30:46.99+4.60 s | – | – |
| TGATangissart | 33.2 | 292 | 12:30:48.07+5.68 s | 12:30:52.81+10.42 s | 4.74 |
| RCHRochefort | 42.2 | 153 | 12:30:49.46+7.07 s | 12:30:56.28+13.89 s | 6.82 |
| DOUDourbes | 51.1 | 210 | 12:30:50.80+8.41 s | 12:30:58.34+15.95 s | 7.54 |
| SKQSteenkerque | 64.4 | 286 | 12:30:53.00+10.61 s | – | – |
| MRGMont Rigi | 79.5 | 88 | 12:30:55.78+13.39 s | – | – |
| KLBKalborn | 93.1 | 118 | 12:30:58.36+15.97 s | – | – |
| VIAVianden | 108.4 | 124 | 12:31:01.38+18.99 s | – | – |
| Dutch seismic network (KNMI)2 stations | |||||
| VKBValkenburg | 71.9 | 54 | 12:30:54.92+12.53 s | 12:31:03.56+21.17 s | 8.64 |
| HGNHeimansgroeve | 75.4 | 66 | 12:30:54.60+12.21 s | – | – |
| VITO (Mol)1 station | |||||
| MOL2AMol | 81* | – | 12:30:57.95+15.56 s | – | – |
* Distance from the catalogue, rounded to the kilometre: the coordinates of the station are missing from it.