Researchers have recorded a baffling hum originating from somewhere inside the Earth.
It's been generally acknowledged for quite a long time our planet creates a low frequency vibrational signal however it was just confirmed in 1998 after researchers began attempting to detect the sound in 1959.
Hundreds of attempts have been made to record the sound from that point forward utilizing land based seismometers and now researchers have taken to base of the ocean to record the sound.
"The Earth’s hum is the permanent free oscillations of the Earth recorded in the absence of earthquakes, at periods above 30 [seconds]. We present the first observations of its fundamental spheroidal eigenmodes on broadband ocean bottom seismometers (OBSs) in the Indian Ocean."
The researchers first collected data from 57 seismometer stations located at the base of the Indian Ocean, east of Madagascar, between 2012 and 2013.
After all that they discovered the Earth’s natural vibration peaks at several frequencies between 2.9 and 4.5 millihertz.
Since these vibrations have been found at the bottom of the ocean, and the Earth is 70% shrouded in water, it's trusted the murmur is present across the world.
Martha Deen, leader of the research team from the Paris Institute of Earth Physics, hopes the new data will provide clues to the source of the hum – their investigation so far can just clarify some part of the vibration.