Thanks to all who tried to guess the answer of a recent Guess the Creature feature!
Humpback whales are baleen whales that can grow to lengths of 40-50 feet (about the size of a school bus) and weights of 20-30 tons. One of the most noticeable characteristics of the whale on this image, and humpbacks in general, is their long flippers, or pectoral fins. These fins can grow to 15 feet in length.
How does sonar work? Sonar is an acronym for SOund, NAvigation and Ranging. Side-scan sonar uses a device that sends out pulses of sound. These pulses are bounced-back by the ocean bottom and the objects that lie there. The sonar device uses the travel time and amplitude of the returned pulses to create images that are continually stitched together into a "video" of the ocean bottom and surrounding objects. I wonder if it was a surprise to the sonar technician to see this humpback whale on the sonar footage?
Image courtesy NOAA Office of Coast Survey/NMAO