Earth’s 26-Second Pulse Mystery

The Earth gives off a faint microseismic pulse every 26 seconds, almost like a planetary heartbeat. Scientists have traced the rhythmic signal to somewhere in the ocean, where it causes tiny tremors that instruments can pick up over and over again. Researchers have studied the pulse for decades and come up with possible explanations that include waves, seafloor activity, and volcanic regions. However, they still don't know exactly what causes it.

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