LESSINES (BE)
Quarry blast25 February 2020
- Magnitude
- 1.2ML
- Depth
- –
- Belgian time
- 17:25:552020-02-25
- UTC
- 16:25:552020-02-25
Main parameters
| Date and time | 2020-02-25 16:25:55 UTC 2020-02-25 17:25:55 Belgian time |
|---|---|
| Magnitude | ML 1.2 |
| Epicentral coordinates | 50.717° N, 3.855° E Uncertainty ± 1.8 km |
| Event ID | ROB 9335 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-02-25 17:31:57 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
- 12
- Epicentral distance
- 1.0 – 152.9km
- Mean velocity, P wave
- 5.4km/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: 9 measurements, root-mean-square deviation 0.54 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 | 1.0 | 233 | 16:25:55.45+0.14 s | 16:25:55.61+0.30 s | 0.16 |
| SKQSteenkerque | 17.6 | 115 | 16:25:58.28+2.97 s | – | – |
| RQRRonquières | 28.9 | 115 | 16:26:00.08+4.77 s | – | – |
| BRQBracquegnies | 32.9 | 143 | 16:26:01.21+5.90 s | – | – |
| MRDMaredsous | 79.5 | 125 | 16:26:09.70+14.39 s | – | – |
| OSTBOostende | 86.6 | 312 | 16:26:10.01+14.70 s | – | – |
| DOUDourbes | 86.9 | 142 | 16:26:11.47+16.16 s | 16:26:21.69+26.38 s | 10.22 |
| GESGesves | 94.8 | 112 | 16:26:13.60+18.29 s | – | – |
| DSLBDessel | 102.5 | 56 | 16:26:13.57+18.26 s | – | – |
| MEMSMembach | 152.9 | 94 | 16:26:21.39+26.08 s | – | – |
| MEMHMembach | 152.9 | 94 | 16:26:21.39+26.08 s | 16:26:39.49+44.18 s | 18.10 |
| Dutch seismic network (KNMI)1 station | |||||
| HGNHeimansgroeve | 146.7 | 87 | 16:26:20.28+24.97 s | 16:26:37.33+42.02 s | 17.05 |