A symphony of underwater sounds in Antarctica
Deploying the second hydrophone off Livingston Island. Image courtesy of NOAA/Vents, Korea Polar Research Institute (KOPRI).
A team of scientists has used hydrophones – like a special “ear” for listening to sounds underwater – to learn more about earthquakes, ice sheets and marine life in Antarctica.
For example, here’s the crooning of a humpback whale .
And here’s the sound of an underwater earthquake . Robert Dziak leads the team from Oregon State University and the National Oceanic and Atmospheric Administration. They deployed several hydrophones in the frigid water off western Antarctica in late 2005. A year later, they returned to retrieve the data – which by then contained a year of recordings.
Dziak said the specific region they studied in Antarctica is the only volcanically and seismically active area at either pole. He mentioned large icebergs and ice sheets melting at both poles due to increased ocean temperatures. And he said he wanted to find out whether volcanic activity and earthquakes in the area could also be contributing to the ice breakup.
Data from the underwater sound sensors suggest that large sea floor earthquakes near the ice sheets do produce pressure waves in the water. These pressure waves from earthquakes might indeed contribute to breakup of the nearby ice sheets.
Our thanks today to NOAA.
In addition, Dziak said: “We are still in the preliminary stages of data analysis. However, some early interesting finds have been detecting an incredibly loud ‘hum’ produced by an iceberg as it was moving through the ocean, scraping the sea floor. The hum went on for several days, and was so loud we were able to use it to locate the iceberg some 10 miles away. We were able to confirm the ~10-kilometer-long iceberg was the source of the sound because we found the iceberg on a satellite image.”
He said his team has detected sounds that might be a volcanic eruption from a deep (~1800 meter) volcano at the bottom of the Bransfield Strait, but added that more work is needed to confirm this.
The project is a component of the National Oceanic and Atmospheric Administration’s (NOAA) Ocean Explorer program.
Sounds of the Antarctic Revealed: Earthquakes, Icebergs and Pygmy Whales
Sounds of the Antarctic Revealed: Video and Photo Archive
Our thanks to:
Robert Dziak
Geophysicist
Pacific Marine Environmental Laboratory
NOAA and Oregon State University
Additional Teacher Resources
NOAA: Moored Autonomous Hydrophones
Information on how NOAA monitors remotes areas of the world ocean using hydrophones. It includes video and audio of earthquake sound traveling to a hydrophone.
NOAA: Acoustic Monitoring Home Page
One way NOAA monitors the global ocean is through underwater acoustics. Since 1991, NOAA has been monitoring ocean noise including noise from underwater earthquakes and volcanoes, whale songs, and the effect of man-made and natural noise on marine life.
