TOURNAI (BE)
Quarry blast11 May 2021
- Magnitude
- 1.6ML
- Depth
- –
- Belgian time
- 13:51:442021-05-11
- UTC
- 11:51:442021-05-11
Main parameters
| Date and time | 2021-05-11 11:51:44 UTC 2021-05-11 13:51:44 Belgian time |
|---|---|
| Magnitude | ML 1.6 |
| Epicentral coordinates | 50.639° N, 3.375° E Uncertainty ± 19.1 km |
| Event ID | ROB 13420 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-05-11 17:07:55 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
- 8
- Epicentral distance
- 34.0 – 124.7km
- Mean velocity, P wave
- 5.8km/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 0.49 s. S wave: 4 measurements, root-mean-square deviation 0.63 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 | |||||
| LESLessines | 34.0 | 76 | 11:51:50.65+6.48 s | 11:51:54.60+10.43 s | 3.95 |
| BOUBougnies | 49.0 | 124 | 11:51:52.80+8.63 s | – | – |
| SKQSteenkerque | 49.9 | 88 | 11:51:52.66+8.49 s | – | – |
| BRQBracquegnies | 56.7 | 108 | 11:51:52.97+8.80 s | – | – |
| SNFSeneffe | 65.9 | 102 | 11:51:54.93+10.76 s | 11:52:02.48+18.31 s | 7.55 |
| MRDMaredsous | 105.7 | 110 | 11:52:02.27+18.10 s | 11:52:15.79+31.62 s | 13.52 |
| DOUDourbes | 105.8 | 124 | 11:52:02.64+18.47 s | 11:52:15.45+31.28 s | 12.81 |
| GESGesves | 124.7 | 102 | 11:52:05.42+21.25 s | 11:52:21.66+37.49 s | 16.24 |