LESSINES (BE)
Quarry blast16 October 2020
- Magnitude
- 1.9ML
- Depth
- –
- Belgian time
- 11:40:412020-10-16
- UTC
- 09:40:412020-10-16
Main parameters
| Date and time | 2020-10-16 09:40:41 UTC 2020-10-16 11:40:41 Belgian time |
|---|---|
| Magnitude | ML 1.9 |
| Epicentral coordinates | 50.713° N, 3.860° E Uncertainty ± 4.4 km |
| Event ID | ROB 11095 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-10-16 12:50:04 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
- 1.2 – 152.5km
- Mean velocity, P wave
- 5.5km/s
- Mean velocity, S wave
- 3.3km/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 0.67 s. S wave: 4 measurements, root-mean-square deviation 0.60 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 | 1.2 | 259 | 09:40:41.82+0.40 s | 09:40:42.04+0.62 s | 0.22 |
| SKQSteenkerque | 17.1 | 114 | 09:40:44.44+3.02 s | 09:40:46.80+5.38 s | 2.36 |
| RQRRonquières | 28.4 | 115 | 09:40:46.19+4.77 s | – | – |
| BRQBracquegnies | 32.4 | 143 | 09:40:47.49+6.07 s | – | – |
| BOUBougnies | 36.5 | 170 | 09:40:46.25+4.83 s | – | – |
| DOUDourbes | 86.4 | 142 | 09:40:57.03+15.61 s | 09:41:06.28+24.86 s | 9.25 |
| RCHRochefort | 115.3 | 122 | 09:41:02.53+21.11 s | 09:41:16.41+34.99 s | 13.88 |
| MEMHMembach | 152.5 | 94 | 09:41:05.40+23.98 s | 09:41:26.43+45.01 s | 21.03 |