Japan’s Tohoku Earthquake Heard From Space

Jonathan Amos, reporting for the BBC:

It has long been recognised that major quakes will generate very low-frequency acoustic waves, or infrasound – a type of deep rumble at frequencies below those discernible to the human ear. But no spacecraft in orbit has had the capability to record them, until now.

“We’ve looked for this signal before with other satellites and haven’t seen it, and I think that’s because you need an incredibly fine instrument,” said Dr Rune Floberghagen from the European Space Agency (Esa).

This is actual sound, unlike other recordings where the Earth’s electromagnetic radiation is transposed into sound waves.