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STRASBOURG (FR)

Known induced event4 December 2020

Magnitude
3.0ML
Depth
4.0km
Belgian time
11:10:252020-12-04
UTC
10:10:252020-12-04

Main parameters

Magnitude and intensity

Two numbers often confused, with the values of this earthquake and of the Observatory’s catalogue.

Preparing the animation…

1Magnitude: the size of the earthquake

The magnitude (ML 3.0) measures the size of the earthquake at its source, from the amplitude of the waves recorded by seismographs: a single value for the whole earthquake. Since 1985, 96 % of the 3,122 earthquakes with a magnitude in the Observatory’s catalogue have a smaller one.

Animation drawn from the page and the Observatory’s catalogue (tectonic earthquakes since 1985, ML or MW magnitudes); short descriptions of the European Macroseismic Scale EMS-98.

Date and time2020-12-04 10:10:25 UTC
2020-12-04 11:10:25 Belgian time
MagnitudeML 3.0
Epicentral coordinates48.626° N, 7.871° E
Uncertainty ± 2.0 km
Depth of hypocenter4.0 km
Event IDROB 11485

Data source : ROB (Royal Observatory of Belgium)
Last update : 2020-12-04 18:10:13 Belgian time

Location map

Where and when the earthquake began

The focus, the epicentre and their uncertainties, with this earthquake’s values.

Preparing the animation…

1Focus and epicentre

An earthquake starts at depth, at the focus (or hypocentre): here 4 km below the surface. The point on the surface right above it is the epicentre (48.626° N, 7.871° E), the one the map shows.

Values from the page and the Observatory’s catalogue (tectonic earthquakes since 1985).

  • Epicentre
  • Station that recorded the event

Seismic activity in the area

Known earthquakes around the epicentre, from the catalogue of the Royal Observatory of Belgium.

Within 10 km of the epicentre

12 other earthquakes in the catalogue since 2020. 8 of them occurred after this one. By magnitude, it is the joint 4th largest of the 13 earthquakes of known magnitude in the area.

Latest earthquakes before this one

DatePlaceMagnitudeIntensityDistance km
2020-12-04STRASBOURG (FR)inducedML 3.6–1.0
2020-11-11STRASBOURG (FR)inducedML 2.6–3.8
2020-11-09STRASBOURG (FR)inducedML 1.9–6.2
2020-10-28STRASBOURG (FR)inducedML 3.0–4.6

Largest known earthquakes

DatePlaceMagnitudeIntensityDistance km
2021-06-26STRASBOURG (FR)inducedML 4.2–5.4
2020-12-04STRASBOURG (FR)inducedML 3.6–1.0
2021-01-22STRASBOURG (FR)inducedML 3.5–2.0
2020-10-28STRASBOURG (FR)inducedML 3.0–4.6
2020-12-04This earthquakeinducedML 3.0––
Notes and method

Tectonic and induced earthquakes from the Observatory’s catalogue, suspected ones included; quarry blasts, explosions and other events are not counted. Epicentral distances on the WGS84 ellipsoid.

Municipality: 2025 municipal boundaries (Statbel), applied to every earthquake, including those before the merger of municipalities. For an epicentre outside Belgium, only the circular area is given. Each earthquake’s name is the catalogue’s: it may refer to a place near the epicentre.

Magnitude: the one given on each earthquake’s page (ML preferably, otherwise MW or MS); magnitudes of different types are compared as they are.

The epicentres of historical earthquakes are only known to within a few kilometres, sometimes more: whether they fall in the area is indicative. Small earthquakes have only been recorded as the station network grew: the area’s older earthquakes are mostly the largest ones, and recent activity looks more frequent.

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
11
Epicentral distance
9.0 – 292.1km
  • P wave
  • S wave

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)7 stations
VIAVianden189.632110:10:56.57+31.11 s10:11:16.49+51.03 s19.92
KLBKalborn208.032310:10:59.53+34.07 s10:11:22.27+56.81 s22.74
MEMHMembach258.332910:11:05.62+40.16 s10:11:34.00+68.54 s28.38
CLAClavier272.731810:11:05.02+39.56 s10:11:39.11+73.65 s34.09
GESGesves280.931510:11:07.33+41.87 s10:11:41.04+75.58 s33.71
DOUDourbes288.630610:11:08.24+42.78 s10:11:42.79+77.33 s34.55
MRDMaredsous292.131110:11:08.77+43.31 s10:11:43.47+78.01 s34.70
Network STR2 stations
STRStrasbourg9.023910:10:27.79+2.33 s10:10:30.03+4.57 s2.24
WLSWelschbruch44.923810:10:32.82+7.36 s10:10:38.33+12.87 s5.51
Dutch seismic network (KNMI)1 station
HGNHeimansgroeve275.933010:11:07.07+41.61 s10:11:39.85+74.39 s32.78
Network ROM1 station
TUEStuetta263.915510:11:05.77+40.31 s10:11:33.67+68.21 s27.90
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