TOURNAI (BE)
Quarry blast21 September 2020
- Magnitude
- 2.2ML
- Depth
- –
- Belgian time
- 12:59:592020-09-21
- UTC
- 10:59:592020-09-21
Main parameters
| Date and time | 2020-09-21 10:59:59 UTC 2020-09-21 12:59:59 Belgian time |
|---|---|
| Magnitude | ML 2.2 |
| Epicentral coordinates | 50.655° N, 3.460° E Uncertainty ± 2.8 km |
| Event ID | ROB 10925 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-09-22 00:06:45 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
- 11
- Epicentral distance
- 43.9 – 198.3km
- 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: 8 measurements, root-mean-square deviation 0.35 s. S wave: 5 measurements, root-mean-square deviation 0.20 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)11 stations | |||||
| SKQSteenkerque | 43.9 | 91 | 11:00:07.39+7.61 s | 11:00:13.24+13.46 s | 5.85 |
| BOUBougnies | 45.4 | 131 | 11:00:07.77+7.99 s | – | – |
| BRQBracquegnies | 51.7 | 112 | 11:00:08.73+8.95 s | – | – |
| RQRRonquières | 54.4 | 95 | 11:00:08.89+9.11 s | – | – |
| UCCBUccle | 65.5 | 76 | 11:00:11.91+12.13 s | 11:00:19.80+20.02 s | 7.89 |
| MRDMaredsous | 100.8 | 112 | 11:00:17.32+17.54 s | 11:00:29.75+29.97 s | 12.43 |
| DOUDourbes | 102.0 | 127 | 11:00:17.34+17.56 s | 11:00:29.96+30.18 s | 12.62 |
| GESGesves | 119.2 | 104 | 11:00:19.84+20.06 s | 11:00:34.85+35.07 s | 15.01 |
| CLAClavier | 133.2 | 101 | 11:00:22.44+22.66 s | 11:00:39.01+39.23 s | 16.57 |
| RCHRochefort | 137.4 | 113 | 11:00:22.84+23.06 s | 11:00:40.56+40.78 s | 17.72 |
| KLBKalborn | 198.3 | 107 | 11:00:31.93+32.15 s | 11:00:54.37+54.59 s | 22.44 |