Listen to an Earthquake Underwater

April 25, 2011

Contact: Lauren Koellermeier, 206-526-6810

Earthquakes are felt more often than heard, but scientists in the NOAA Vents Program say the sound of the March 11 Japan earthquake alone could help improve our ability to detect earthquakes and volcanic eruptions in the deep ocean.

Scientists with the NOAA Vents Program at Pacific Marine Environmental Laboratory captured the sounds of the earthquake using an underwater microphone near the Aleutian Islands – 900 miles from the quake epicenter.

 "The Japan earthquake was the largest source of ocean sound ever recorded on our hydrophone arrays. This unique record gives us insight into the physics behind how sound is transmitted from the Earth's crust into the ocean and then propagates through the Pacific Ocean basin,” says Robert Dziak, Ph.D., a scientist with the NOAA Cooperative Institute for Marine Resource Studies (CIMRS). CIMRS is a partnership between NOAA and Oregon State University. Dziak is also the principal investigator of the Ocean Acoustic Project in the NOAA Vents Program.

The North Pacific hydrophone belongs to the Navy's Sound Surveillance System, which the NOAA Vents Program has used since the early 1990s to monitor earthquakes and volcanic eruptions that happen underwater.

Vents Program scientists analyze sound recordings as well as other sensor readings of events like the Japan earthquake. What they learn from such studies helps them gauge the size and scale of other underwater earthquakes and volcanic eruptions that are picked up only by underwater microphones and not by any other sensor network.

“We also plan to analyze the hydrophone record for evidence of a pressure signal from the tsunami, which will provide additional information and help our understanding of tsunami propagation in the ocean," says Dziak.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Visit us at www.noaa.gov or on Facebook.

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Online:
Listen to the Japan Earthquake on YouTube: http://www.youtube.com/noaapmel#p/u/0/4rWDrZIucAQ

NOAA Vents Program Japan Earthquake page: http://www.pmel.noaa.gov/vents/acoustics/seismicity/pacific/japanmar2011.html

NOAA Vents Program Ocean Sound page: http://www.pmel.noaa.gov/vents/acoustics.html