This mysterious rhythm happens roughly every 26 seconds, which is incredibly slow when compared to a human heartbeat that can pump up to 100 times per minute. It’s a very unusual and puzzling pattern.
The odd pulses were first noticed back in the early 1960s by geologist Jack Oliver. He suggested that these tiny tremors might be coming from somewhere in the southern or equatorial Atlantic Ocean, but he couldn’t say for sure at the time.
Years later, these odd pulses were detected once again by Mike Ritzwoller, a seismologist at the University of Colorado in the United States, along with his research team.
While discussing Oliver’s early discovery of this unusual ‘heartbeat’ of the Earth, Ritzwoller shared with Discover Magazine: “Jack didn’t have the resources in 1962 that we had in 2005 – he didn’t have digital seismometers, he was dealing with paper records.”
Another researcher, Garrett Euler, has also been working to solve this geological mystery.
While speaking at the Seismological Society of America conference in 2013, Euler explained that he’d managed to trace the pulse back even further. He had narrowed it down to a spot in the Gulf of Guinea, a region known as the Bight of Bonny.
He explained that as waves move across the surface of the ocean, the changing pressure in the water typically doesn’t disturb the ocean floor too much. But once these waves hit the continental shelf—where the ocean floor is much closer to the surface—the increased pressure starts to bend and move the seafloor. This movement ends up creating seismic pulses that mirror the motion of the waves above.
Still, not everyone agrees with this idea. In a research paper that came out later that same year, Yingjie Xia from the Institute of Geodesy and Geophysics in Wuhan, China, proposed a different theory. Xia argued that the real cause might not be waves at all, but volcanoes.
He also noted that there is another place in the world where a volcano creates a similar kind of microseism—the Aso Volcano in Japan. This added weight to his argument that volcanoes might be behind the recurring pulse.
So, why haven’t scientists reached a clear answer yet? It seems one of the reasons is that this specific mystery isn’t considered a high-priority topic in the field of seismology. Even though many researchers are curious, their focus tends to be elsewhere.
“We want to determine the structure beneath the continents, things like that. This is just a little bit outside what we would typically study [since] it doesn’t have anything to do with understanding the deep structure of the Earth.”
Taking all of that into account, Ritzwoller told the magazine that solving the riddle of the Earth’s strange ‘heartbeat’ might end up being a task for future scientists to figure out.
