‘Seismic hums’ detected near Iceland

Researchers have identified a ‘seismic hum’ in the ocean expanse between Iceland and the Labrador Sea, according to Nature.com.

Under certain conditions in which waves collide and emit vibrations down to the ocean floor, a hum is created that is detectable for thousands of kilometres. The new research gives weight to the old notion that oceans have the capacity to generate strong seismic activity.

These seismic hums, or ‘microseisms’, are normally created near coastlines or in stormy seas. Seismologists detect them by installing seismometers that detect the slow vibrations.

The North Atlantic has long been suspected of housing a significant number of microseisms. Seismologist Sharon Kedar and a team from the Jet Propulsion Laboratory in Pasadena, California, employed buoys and satellite information to find a connection between the ocean activity and the vibrations on land. They finally located the area between the Labrador Sea and Iceland as a hotbed for microseismic activity.

Kedar said this was the first true confirmation of this scientific model. “Until now, we didn’t have a good understanding of where that noise is coming from,” Kedar said. “People had the expectation that the sources were random in place and time, but they are not. The work could help advance growing efforts to track changes in the Earth’s structure with microseisms.”