TOURNAI (BE)
Quarry blast30 July 2020
- Magnitude
- 1.9ML
- Depth
- –
- Belgian time
- 12:46:382020-07-30
- UTC
- 10:46:382020-07-30
Main parameters
| Date and time | 2020-07-30 10:46:38 UTC 2020-07-30 12:46:38 Belgian time |
|---|---|
| Magnitude | ML 1.9 |
| Epicentral coordinates | 50.622° N, 3.447° E Uncertainty ± 2.2 km |
| Event ID | ROB 10575 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-07-30 14:27:54 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
- 29.7 – 198.1km
- 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: 8 measurements, root-mean-square deviation 0.20 s. S wave: 4 measurements, root-mean-square deviation 0.45 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 | |||||
| LESLessines | 29.7 | 70 | 10:46:43.85+5.64 s | 10:46:47.80+9.59 s | 3.95 |
| BOUBougnies | 43.8 | 126 | 10:46:46.25+8.04 s | – | – |
| SKQSteenkerque | 44.9 | 86 | 10:46:45.88+7.67 s | 10:46:52.15+13.94 s | 6.27 |
| BRQBracquegnies | 51.3 | 108 | 10:46:47.16+8.95 s | – | – |
| RQRRonquières | 55.1 | 92 | 10:46:47.57+9.36 s | – | – |
| MRDMaredsous | 100.3 | 110 | 10:46:55.30+17.09 s | – | – |
| DOUDourbes | 100.5 | 125 | 10:46:55.56+17.35 s | 10:47:07.66+29.45 s | 12.10 |
| GESGesves | 119.3 | 102 | 10:46:58.38+20.17 s | 10:47:14.36+36.15 s | 15.98 |
| CLAClavier | 133.5 | 99 | 10:47:00.66+22.45 s | 10:47:17.39+39.18 s | 16.73 |
| RCHRochefort | 136.8 | 112 | 10:47:01.27+23.06 s | 10:47:18.51+40.30 s | 17.24 |
| KLBKalborn | 198.1 | 106 | 10:47:10.43+32.22 s | 10:47:33.81+55.60 s | 23.38 |