PECQ (BE)

Quarry blast22 December 2020

Magnitude
2.1ML
Depth
–
Belgian time
13:00:022020-12-22
UTC
12:00:022020-12-22

Main parameters

Date and time2020-12-22 12:00:02 UTC
2020-12-22 13:00:02 Belgian time
MagnitudeML 2.1
Epicentral coordinates50.662° N, 3.364° E
Uncertainty ± 24.4 km
Event IDROB 11605

Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-12-22 14:57:03 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
10
Epicentral distance
34.3 – 144.0km
Mean velocity, P wave
6.0km/s
Mean velocity, S wave
3.5km/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 0.47 s. S wave: 5 measurements, root-mean-square deviation 0.66 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.

Table of measurements

Station measurements

P- and S-wave arrivals and ground displacement measured at each station. Click a column heading to change the order.

km°UTCUTCs
Belgian seismic network (Royal Observatory of Belgium)10 stations
LESLessines34.38112:00:09.15+6.80 s12:00:12.84+10.49 s3.69
SKQSteenkerque50.79112:00:11.16+8.81 s12:00:17.20+14.85 s6.04
BOUBougnies51.212612:00:10.79+8.44 s––
BRQBracquegnies58.311012:00:11.46+9.11 s––
TGATangissart82.29412:00:16.26+13.91 s12:00:24.98+22.63 s8.72
MRDMaredsous107.411112:00:20.55+18.20 s12:00:34.04+31.69 s13.49
DOUDourbes107.912512:00:20.73+18.38 s12:00:34.06+31.71 s13.33
GESGesves126.010312:00:24.01+21.66 s12:00:40.78+38.43 s16.77
CLAClavier140.010012:00:26.31+23.96 s12:00:43.88+41.53 s17.57
RCHRochefort144.011212:00:27.58+25.23 s12:00:44.89+42.54 s17.31
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