LESSINES (BE)
Quarry blast14 July 2020
- Magnitude
- 1.5ML
- Depth
- –
- Belgian time
- 14:31:262020-07-14
- UTC
- 12:31:262020-07-14
Main parameters
| Date and time | 2020-07-14 12:31:26 UTC 2020-07-14 14:31:26 Belgian time |
|---|---|
| Magnitude | ML 1.5 |
| Epicentral coordinates | 50.716° N, 3.855° E Uncertainty ± 2.4 km |
| Event ID | ROB 10480 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-07-14 17:14:18 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
- 1.0 – 152.8km
- 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 0.24 s. S wave: 4 measurements, root-mean-square deviation 0.50 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 | |||||
| LESLessines | 1.0 | 238 | 12:31:26.61+0.17 s | 12:31:26.77+0.33 s | 0.16 |
| SKQSteenkerque | 17.6 | 115 | 12:31:29.41+2.97 s | 12:31:31.37+4.93 s | 1.96 |
| RQRRonquières | 28.9 | 115 | 12:31:31.19+4.75 s | – | – |
| BRQBracquegnies | 32.8 | 143 | 12:31:32.48+6.04 s | – | – |
| DOUDourbes | 86.8 | 142 | 12:31:41.97+15.53 s | 12:31:52.35+25.91 s | 10.38 |
| CLAClavier | 107.7 | 107 | 12:31:45.13+18.69 s | 12:32:00.10+33.66 s | 14.97 |
| MEMHMembach | 152.8 | 94 | 12:31:52.19+25.75 s | 12:32:11.57+45.13 s | 19.38 |