? ALDENHOVEN (DE)

Earthquake26 April 1992

Magnitude
–
Depth
15.0km ± 4.7
Belgian time
03:45:021992-04-26
UTC
01:45:021992-04-26

Main parameters

Date and time1992-04-26 01:45:02 UTC
1992-04-26 03:45:02 Belgian time
Magnitude–
Epicentral coordinates50.877° N, 6.290° E
Uncertainty ± 5.2 km
Depth of hypocenter15.0 ± 4.7 km
Event IDROB 3647

Data source : ROB (Royal Observatory of Belgium)
Last update : 2024-04-24 12:46:37 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 15 km below the surface. The point on the surface right above it is the epicentre (50.877° N, 6.290° 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

287 other earthquakes in the catalogue since 1879. 253 of them occurred after this one.

Latest earthquakes before this one

DatePlaceMagnitudeIntensityDistance km
1992-04-20ESCHWEILER(D)ML 2.2–8.3
1992-04-17? ESCHWEILER, STADT (DE)––6.8
1992-04-17? NOTHBERG (DE)––8.8
1992-04-17? STOLBERG (DE)––8.5
1992-04-16? ESCHWEILER, STADT (DE)––6.1

Largest known earthquakes

DatePlaceMagnitudeIntensityDistance km
2002-07-22ESCHWEILER - ALSDORF (DE)ML 4.965.9
1992-04-14GEREONSWEILER(D)ML 3.7–9.5
2002-04-22DUERWISS (DE)ML 3.3–5.0
2002-01-07DUERWISS (DE)ML 2.9–6.2
1992-04-14KINZWEILER(D)-WEISWEILER(D)ML 2.8–6.2
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
14
Epicentral distance
15.0 – 148.4km
Mean velocity, P wave
7.7km/s
Mean velocity, S wave
4.5km/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. Hypocenter at a depth of 15.0 km. P wave: 11 measurements, root-mean-square deviation 2.13 s. S wave: 9 measurements, root-mean-square deviation 3.07 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)7 stations
MEMSMembach35.721401:45:08.34+6.23 s––
ROBRobertville48.819501:45:10.54+8.43 s01:45:15.91+13.80 s5.37
MEUMeuville64.921501:45:13.01+10.90 s01:45:20.00+17.89 s6.99
WIBWibrin89.020701:45:17.24+15.13 s01:45:26.64+24.53 s9.40
WLFWalferdange135.318401:45:25.00+22.89 s01:45:41.00+38.89 s16.00
SNFSeneffe147.525501:45:25.55+23.44 s––
DOUDourbes148.423501:45:25.50+23.39 s01:45:42.30+40.19 s16.80
Dutch seismic network (KNMI)3 stations
KRNKERKRADE15.026901:45:06.01+3.90 s01:45:08.53+6.42 s2.52
EPNEPEN28.624501:45:07.36+5.25 s01:45:10.65+8.54 s3.29
VKBValkenburg35.626801:45:12.84+10.73 s––
Bensberg seismic network (University of Cologne, Germany)2 stations
STBSteinbachtalsperre50.012901:45:11.96+9.85 s01:45:17.91+15.80 s5.95
BNSBensberg63.18101:45:06.96+4.85 s01:45:10.03+7.92 s3.07
Network JCK2 stations
GSHGrosshau16.915801:45:06.57+4.46 s01:45:09.33+7.22 s2.76
OLFOleftalsperre43.616801:45:10.00+7.89 s01:45:15.05+12.94 s5.05
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