The seismic globe
Earthquakes from all over the world on a globe you can turn, with the boundaries of the tectonic plates. Choose an earthquake to watch its waves travel through the Earth to the Uccle station.
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193 earthquakes
Drag to turn the globe, use the wheel or two fingers to zoom, then choose an earthquake.
Source: Euro-Mediterranean Seismological Centre (EMSC-CSEM, seismicportal.eu). EMSC data, not reviewed by the Observatory. Data read on 11 November 2026 at 00:18. · Data policy
What the waves show
P waves (compressional) are the fastest: they cross the whole Earth, liquid core included, and arrive first.
S waves (shear) are slower: 3,300 km from the epicentre, they arrive about five minutes after the P waves. They do not cross the outer core, which is liquid.
Rayleigh waves travel along the surface. They are the slowest, but at large distances they are often the strongest on a seismogram.
Between about 98° and 144° from the epicentre (11,000 to 16,000 km), no direct P wave arrives: the core bends them away. This shadow zone allowed Beno Gutenberg to measure the depth of the core in 1913; the weak waves that still reach it led Inge Lehmann to discover the inner core in 1936.
A front fades where the expected wave becomes weaker than the background noise of a station such as Uccle.
Sources and method
Earthquakes: European-Mediterranean Seismological Centre (EMSC-CSEM), data not reviewed by the Observatory. Body-wave travel times: IASP91 model (Kennett and Engdahl, 1991), tables computed with TauP (ObsPy). Rayleigh waves: group velocities of the GDM52 model (Ekström, 2011), along each path. Plate boundaries: PB2002 model (Bird, 2003). Countries: Natural Earth. The fronts show where each wave reaches the surface at a given moment, not its amplitude; ellipticity corrections and the Earth’s heterogeneities are not included (a few seconds).