Almost every corner of land on Earth has been mapped, but what about the oceans? How can we map what we cannot see?
Scientists tow a long cable line with listening devices called hydrophones on it behind their research vessel. These hydrophones record the echo received back from the ocean floor. Here is an example of scientists in action: http://blogs.ei.columbia.edu/2012/06/23/x-ray-vision-beneath-the-seafloor/ How else could they use this technology? What was this technology originally developed and used for?
- Hydrophones are used by the U. S. Navy to detect submarines: http://www.dosits.org/people/defense/findsubmarines/ How is mapping the ocean floor similar to detecting underwater submarines? How is it different?
- Hydrophones are used to observe animals in the ocean. Here are three different links to hear samples of hydrophone recordings: Listen to the dolphins! Listen to an underwater soundscape! Listen to the whales! Brainstorm out a list of other potential uses for this tool.
- Build your own hydrophone! http://www.dosits.org/files/dosits/hydrophone_instruc_w_image.pdf
The Earth Institute. Columbia University. http://blogs.ei.columbia.edu/2012/06/23/x-ray-vision-beneath-the-seafloor/
Discovery of Sound in the Sea. Office of Marine Programs. University of Rhode Island. http://www.dosits.org/people/defense/findsubmarines/
Pacific Wild Organization. You Tube. http://youtu.be/QdkdjsnmVlc
The British Library. http://sounds.bl.uk/Environment/Soundscapes/022M-W1CDR0000635-3400V0