Seismometers worldwide continue to detect a rhythmic pulse occurring every 26 seconds. This microseism, undetectable by humans, has puzzled scientists since its initial observation in the 1960s. The signals are most evident in West Africa, North America, and Europe.
The pulse's origin has been traced to the Gulf of Guinea, off the coast of West Africa. Researchers rediscovered the signal in 2005 using digital seismic data, pinpointing its consistent and persistent nature. Despite ongoing investigations, the exact cause remains unknown.
Theories range from ocean waves impacting the continental shelf to potential volcanic activity near Sao Tome Island. Some scientists propose that fluid flowing through fractal fissure networks in sediments under the seafloor could be the cause. The mystery continues to intrigue seismologists in 2025, driving further research into this unexplained phenomenon.