One earthquake, heard by 113 seismometers
On 19 August 2018 a magnitude 8.2 broke 600 km beneath Fiji — deep enough that nobody was hurt and nothing was damaged, big enough that the whole planet rang. This is the hour that followed at 113 seismometers, one trace each, stacked at the station's true angular distance from the epicentre. Press play. The wiggles do not start at random: the ground first moves at Monasavu in Fiji, 3.6° away, 1 min 24 s after the rupture, and last in the Canary Islands, 160.4° away and most of the way round the world, 18 min 59 s after. In between the onsets lie on a curve that flattens as it goes — the first 45° of arc cost 6.0 minutes, the next 45° cost 4.5, and the 45° after that only 3.5, because a wave crossing a longer arc dives deeper and the rock down there carries it faster. Every trace is scaled to its own largest swing, so the nearest station and the furthest are drawn the same height: what this shows is timing, not size. Nothing is modelled — there is no predicted curve over the data. Tap or hover any trace.