This book for children was chosen as one of 1993's best books by School Library Journal. That's all for this report. I'm hoping to have more good news in my next report. This is Anne Smrcina of the Stellwagen Bank National Marine Sanctuary signing off. I guess we only needed to think of one of the basic human needs and transfer that to our aquatic mammal friends.
Sounds are really waves of energy that move through a medium, either water or air.
Because they are waves, they travel forward until they hit something. The waves then bounce back, or are reflected back off of the object they hit. I by the American, British, and French, were used to find both submarines and icebergs. These early units were crude if not effective. During World War II, underwater acoustics made great leaps and enemy submarines could be detected more easily by surface ships as they sent a stronger and better formed sound pulse into the water.