BIRRESBORN (DE)
Quarry blast23 April 2021
- Magnitude
- 2.0ML
- Depth
- –
- Belgian time
- 10:54:572021-04-23
- UTC
- 08:54:572021-04-23
Main parameters
| Date and time | 2021-04-23 08:54:57 UTC 2021-04-23 10:54:57 Belgian time |
|---|---|
| Magnitude | ML 2.0 |
| Epicentral coordinates | 50.191° N, 6.641° E Uncertainty ± 2.5 km |
| Event ID | ROB 13210 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-04-23 17:59:11 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
- 9
- Epicentral distance
- 39.4 – 146.7km
- Mean velocity, P wave
- 6.1km/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: 7 measurements, root-mean-square deviation 0.21 s. S wave: 7 measurements, root-mean-square deviation 0.88 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)8 stations | |||||
| KLBKalborn | 39.4 | 255 | 08:55:03.64+6.44 s | 08:55:09.02+11.82 s | 5.38 |
| VIAVianden | 42.4 | 228 | 08:55:04.13+6.93 s | 08:55:10.03+12.83 s | 5.90 |
| HOUHouvegnez | 48.9 | 292 | 08:55:05.23+8.03 s | 08:55:11.66+14.46 s | 6.43 |
| MRGMont Rigi | 53.8 | 312 | 08:55:06.19+8.99 s | 08:55:15.03+17.83 s | 8.84 |
| CLAClavier | 98.7 | 285 | 08:55:13.71+16.51 s | 08:55:25.69+28.49 s | 11.98 |
| GESGesves | 112.9 | 282 | 08:55:15.91+18.71 s | 08:55:31.71+34.51 s | 15.80 |
| MRDMaredsous | 134.2 | 276 | 08:55:19.89+22.69 s | 08:55:35.95+38.75 s | 16.06 |
| DOUDourbes | 146.7 | 267 | 08:55:22.17+24.97 s | 08:55:40.31+43.11 s | 18.14 |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 81.3 | 322 | 08:55:11.13+13.93 s | 08:55:20.55+23.35 s | 9.42 |