TOURNAI (BE)
Quarry blast30 March 2021
- Magnitude
- 1.7ML
- Depth
- –
- Belgian time
- 13:00:072021-03-30
- UTC
- 11:00:072021-03-30
Main parameters
| Date and time | 2021-03-30 11:00:07 UTC 2021-03-30 13:00:07 Belgian time |
|---|---|
| Magnitude | ML 1.7 |
| Epicentral coordinates | 50.648° N, 3.534° E Uncertainty ± 4.7 km |
| Event ID | ROB 12865 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2021-03-30 14:48:38 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
- 38.6 – 193.0km
- Mean velocity, P wave
- 5.8km/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 0.15 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 | |||||
| SKQSteenkerque | 38.6 | 90 | 11:00:14.52+6.99 s | 11:00:20.08+12.55 s | 5.56 |
| BOUBougnies | 41.0 | 135 | 11:00:14.56+7.03 s | – | – |
| BRQBracquegnies | 46.5 | 113 | 11:00:15.57+8.04 s | – | – |
| RQRRonquières | 49.1 | 95 | 11:00:16.03+8.50 s | – | – |
| SNFSeneffe | 55.2 | 106 | 11:00:16.88+9.35 s | – | – |
| DOUDourbes | 97.4 | 129 | 11:00:24.46+16.93 s | 11:00:37.64+30.11 s | 13.18 |
| GESGesves | 113.9 | 104 | 11:00:27.10+19.57 s | 11:00:42.17+34.64 s | 15.07 |
| KLBKalborn | 193.0 | 107 | 11:00:38.93+31.40 s | – | – |