TOURNAI (BE)
Quarry blast30 November 2020
- Magnitude
- 1.7ML
- Depth
- –
- Belgian time
- 12:59:312020-11-30
- UTC
- 11:59:312020-11-30
Main parameters
| Date and time | 2020-11-30 11:59:31 UTC 2020-11-30 12:59:31 Belgian time |
|---|---|
| Magnitude | ML 1.7 |
| Epicentral coordinates | 50.617° N, 3.522° E Uncertainty ± 32.2 km |
| Event ID | ROB 11430 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-11-30 14:18:16 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
- 7
- Epicentral distance
- 39.3 – 131.7km
- Mean velocity, P wave
- 5.6km/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: 6 measurements, root-mean-square deviation 0.76 s. S wave: 5 measurements, root-mean-square deviation 0.94 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)7 stations | |||||
| BOUBougnies | 39.3 | 130 | 11:59:38.10+6.55 s | 11:59:44.54+12.99 s | 6.44 |
| SKQSteenkerque | 39.7 | 85 | 11:59:38.02+6.47 s | 11:59:43.57+12.02 s | 5.55 |
| RQRRonquières | 49.8 | 91 | 11:59:38.98+7.43 s | – | – |
| UCCBUccle | 62.5 | 71 | 11:59:43.45+11.90 s | 11:59:49.82+18.27 s | 6.37 |
| DOUDourbes | 95.9 | 127 | 11:59:47.39+15.84 s | 11:59:59.95+28.40 s | 12.56 |
| GESGesves | 114.0 | 102 | 11:59:52.00+20.45 s | 12:00:07.77+36.22 s | 15.77 |
| RCHRochefort | 131.7 | 112 | 11:59:54.38+22.83 s | 12:00:06.19+34.64 s | 11.81 |