. For many decades, scientists have struggled to understand why Earth is humming. French scientists believe it’s caused by ocean waves colliding. Human ear cannot detect the low-frequency sound. In the late 1990s, seismologists (earthquake researchers) discovered that Earth vibrates continuously at low frequencies even though there is no earthquake. Although the micro-seismic activity may not be visible to animals like elephants and whales, it is detectable. Researchers have proposed that the sound might be due to electromagnetic radiation, or submarine communications. Theorists of conspiracy have suggested many possibilities. These include secret military activities, alien tones that control us or beings trying to reach our attention from other parallels. The most probable culprits for Earth’s constant hum are colliding waves. Ocean waves are now believed to be the main culprit for Earth’s continuous hum. Fabrice Ardhuin from CNRS-Ifremer-UBO-IRD, Lucia Gualtieri and Eleonore Stutzmann, both from the Institut de Physique du Globe (all three in France), used computer models of the seafloor, wind and ocean, and found that ocean waves were able to generate mini-seismic waves when they crashed into each other. Their findings were published in Journal Geophysical Research Letters (citation above). Seismic waves generated by slower ocean waves may have a frequency of 13 up to 300 second. This refers to the time taken for the ripples before it reaches the Earth’s crust. Scientists claim that the longer waves are responsible for most of the mysterious bell-like, ringing “hum” sounds. Ardhuin stated in an interview with Live Science that the scientists’ result was an important step towards the understanding of the mysterious noise. Scientists might also be able generate detailed maps of Earth’s interior as they gain greater insight into the “hum” sound. Scientists aren’t sure just how far down the Earth the seismic waves penetrate. The seismic waves could reach the core. Researchers believe that by studying these sounds’ paths more closely, it may become possible to get a better picture of the structure of the planet. The authors suggested that waves traveling along coastlines could also contribute to this overall effect. Water movement in mountains and at the bottom may also play a role. Citation: “How ocean wave rock the Earth” Fabrice Ardhuin and Lucia Gualtieri, Eleonore Stoutzmann. Geophysical Research Letters. Published 10 February 2015. DOI: 10. 1002/2014GL062782.
Ocean waves are the reason Earth hums
