Researchers have now ‘heard’ the echo of cyclones whirling ocean waters from all the way on the other side of our planet.
Microseismic waves generated by interactions between the ocean and Earth’s crust might be able to help us peer into otherwise hidden parts of Earth’s geological structure, such as regions left shrouded by a scarcity of high-energy earthquakes in the North Atlantic.
“Our research uses these microseismic phenomena as an alternative data source to study the Earth’s structure beneath Australia,” says seismologist Hrvoje Tkalčić from Australian National University.
Intense storm activity like cyclones over the ocean produces acoustic energy strong enough to ring through the planet.
By the time these vibrations pass through Earth’s core though, they’re incredibly subtle. So Tkalčić and fellow seismologist Abhay Pandey went searching for these seismic waves using sensitive spiral arrays of sensors located in extremely quiet, remote parts of Australia.
“We combined data from multiple days to identify the regions where the signals were strongest, providing insights into the source and transmission of the seismic waves,” explains Pandey.
“The signals are tiny in amplitude and often below the observational threshold of a single sensor, requiring specific instrument designs to record them.”
The researchers were able to trace these signals back to the waters near Greenland and Newfoundland, stirred up by winter storms.
“The Newfoundland basin is a significant and persistent source of microseisms observed on most days during the study period, which is likely linked to the movement of frequent cyclones during the winter months,” Pandey and Tkalčić write in their paper.
This new method of detecting signals through the Earth may also prove useful for exploration of alien worlds.
“We live in the times of interplanetary voyages, and perhaps it is not far-fetched to say that in the not-so-distant future, we might be able to harness the energy of storms to complement the investigations of the interiors of planets and several moons upholding atmospheres,” the researchers conclude.
This research was published in Seismological Research Letters.
