Sometimes, the most important sounds are those that cannot be heard.
Take infrasound—acoustic waves below the range of human hearing. Although nuclear weapons blasts, midair meteor explosions, volcanic paroxysms, and angry thunderstorms make plenty of noise people can hear up close, the infrasound these phenomena emanate can also circumnavigate the globe. Even if a scientist is half the world away, their infrasound detector may be able to pick it up.
Despite its promise as a remote sensing technique, you can’t register these sources of infrasound everywhere. The world’s oceans are not only cacophonous, but the absence of land—particularly within the Southern Hemisphere—has made placing detectors a seemingly insurmountable challenge. But for
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