Honshu Japan Mw 9.0 Earthquake:
March 11, 2011
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. These insights help us gauge the size and scale of other submarine earthquakes and volcanic eruptions we record that were not detected by other sensor networks. 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.
Below are 2 sound files and an example spectrogram from hydrophones that recorded the seismic and acoustic arrivals for the Honshu Japan Mw 9.0 earthquake. The first sound file is from a hydrophone located in the central north Pacific, the second sound file and spectrogram is from a hydrophone located near the Aleutian Islands.
View YouTube movie about the undersea hydrophone and listen to the event:
Listen to the earthquake (sound has been sped up 16 times):
P-wave sound (sendai-pwave-sound.wav)
P and T-wave sounds: (sendai-ptwave-sound.wav)
The P-wave is the initial burst visible on the image above (left half) and the T-wave follows
in time (right half).