For most humans, sight is our dominant sense. We use our eyes to monitor our surroundings, get around, observe and connect with other people, find and prepare food, learn about the world, and much more. Common phrases like “seeing is believing” and “a picture is worth a thousand words” are testament to our reliance on sight. But some animals, such as whales and dolphins (called cetaceans by biologists), rely much more heavily on sound and the sense of hearing.
Sound is a wave (a traveling disturbance) that moves through a medium like air or water. Underwater, sound travels much faster and farther than light, allowing animals to communicate over long distances and to sense and navigate their surroundings even in dark or murky water where sight is not very helpful. Too much noise or sudden, unexpected sound waves can startle and confuse marine animals–in some cases causing injuries or endangering their lives. That’s why scientists at the National Oceanic and Atmospheric Administration (NOAA) have been working to map human-made sounds in the sea, such as shipping traffic, oil and gas exploration, and military sonar.
Our image of the week is a visualization of just one type of underwater sound that scientists have mapped: the noise caused by shipping traffic in the Atlantic Ocean. As shipping and other human activities have increased over the last several decades, the ocean has become a noisy place, and researchers are working to better understand the effects of that noise on marine life.
For more about the science of waves and how they travel, visit our module Waves and Wave Motion: Describing Waves.
To understand the underlying math of wave motion, check out our module Wave Mathematics: Trigonometric Functions.
For more in-depth information on how noise in the ocean effects marine life, browse the Discovery of Sound in the Sea website. You can also listen to audio clips of natural and human-made sounds from whale songs to torpedoes.
Written by Christine Hoekenga
Christine is a freelance writer, editor, and content strategist, specializing in science and nature. She holds an Bachelor's degree in Environmental Science and Media Studies and a Master's of Science Writing. She has been working in science communication and education for nearly a decade as a journalist, an organizer for conservation groups, and a museum educator. Before joining the Visionlearning team, she served as the New Media and Online Community Manager for the Webby award-winning Smithsonian Ocean Portal. Christine is assisting Visionlearning with developing new modules and glossary terms, managing the blog, and outreach through social media.