AUDIO: Hear what the Japan earthquake sounded like

Published On Wed Mar 07 2012

A ship brought ashore by the March 2011 magnitude 9.0 earthquake and tsunami is seen among debris in Kesennuma, north Japan, March 17, 2011.

KIM KYUNG-HOON/REUTERS

Debra Black Staff Reporter

It sounded almost like thunder, then like popcorn popping and finally like fireworks going off.

That's how one seismologist describes the sounds of last year's 9.0 magnitude March 11earthquake off the northeast coast of Japan.

Zhigang Peng, an associate professor from Georgia Institute of Technology's School of Earth and Atmospheric Sciences and his team converted the seismic data from the earthquake into audio files by playing it much faster than its true speed and then added a video element — an animated bar graph of the seismic data.

The seismic data was taken from various monitoring stations including one 144 kilometres from the Japanese earthquake's epicentre, another near the coastline between the Fukushima Daiichi nuclear reactor and Tokyo and another near the San Andreas Fault in the U.S.

Peng and his team first converted the seismic data in 2011. Their work was published in the March/April edition of Seismological Research Letters.

"As seismologists it is important that we effectively convey information about catastrophic earthquakes, like this recent Japan event, to others who many not necessarily be well versed in the language and methods of earthquake seismology," the authors write in the journal.

Peng hopes the audio clips will help convey scientific information about the earthquake to the public in a more understandable way. He also hopes it will assist scientists studying how earthquakes interact with each other.

The seismologist, who grew up in the Sichuan province in southwest China, became fascinated with earthquakes and made them his life's work after he experienced them as a young child.

The different sounds in the seismologists' work provide scientists with interesting tidbits about the main shock and the aftershocks from the earthquake, Peng told the Toronto Star.

For example, in the first clip — taken from data 144 kilometres from the epicentre — one hears two groups of noise, Peng explained.

"This corresponds to the fact that there are a least two patches of fault that are broken during the earthquake. But we also found at around 90 seconds or so a pop," he said.

What that pop represents is a mystery, Peng said. It's something his team is still trying to understand.

The second clip — taken from data obtained between Fukushima and Tokyo — provides audio from the main event as well as aftershocks. What is surprising here is that some of these aftershocks clearly heard in the compressed files weren't reported by Japanese monitoring agencies, Peng said. They were perhaps too small, he hypothesizes.

The third clip reveals the subtle movements in the San Andreas Fault. First there is a sound like distant thunder which corresponds to the main shock in Japan. Then a continuous high pitch sound – representing the tremor activity in the San Andreas Fault.