Earth's mysterious 26-second rhythmic pulse remains unexplained

Since the early 1960s, scientists have investigated a mysterious, periodic vibration known as a microseism that causes the Earth to pulse every 26 seconds. First recorded by geologist Jack Oliver at the Lamont-Doherty Earth Observatory, the signal has been traced to the Bight of Bonny in the Gulf of Guinea.

Researchers have proposed several hypotheses to explain the phenomenon. One theory suggests that the continental shelf in the Gulf of Guinea acts like a drumhead, where ocean waves hitting the shelf create a resonant rhythmic pulse. Another group of researchers suggests the cause may be volcanic, noting that the signal originates near a volcano on São Tomé island.