Doors slamming in Earth’s crust?
Earthquakes; Tennant Creek, Au
Earthquakes; Tennant Creek, Au [0:19 · download]


Another recording of ground motion, as recorded in central Australia.

No, those ker-chunk sounds are not from subterranean hallway doors slamming shut. They mark the arrivals of the primary (P) and secondary (S) body waves from earthquakes about 1,000km away.

Technical note

Time-acceleration = 646 (1 second = ~10 minutes Earth time; this 19-sec recording captures almost 3 hours of real Earth time).