The Ocean as a Sound Channel
Renowned oceanographer and geophysicist Walter Munk talks about differences in the ways sound travels in the ocean as compared to through the air. He observes that the ocean is an ideal medium through which sound can travel.
Spreading
Renowned oceanographer and geophysicist Walter Munk observes that spreading decreases the energy of sound as it travels. Energy loss due to spreading is proportional to the square of the distance from the source.
Using Sound to Measure Ocean Warming
Renowned oceanographer and geophysicist Walter Munk talks about efforts to measure ocean warming through the use of sound--a process known as dark acoustic thermometry. Professor Munk notes that since the speed of sound increases in the ocean with t...
Noise Pollution and Marine Life
Renowned oceanographer and geophysicist Walter Munk talks about the impact of sound on marine animals. He discusses the campaign of environmental groups to cut down on noise pollution in the ocean--a campaign which Professor Munk argues resulted in ...
Marine Animals and Sound
Renowned oceanographer and geophysicist Walter Munk talks about the use of sound by marine animals. Professor Monk observes that while scientists don't fully understand all the ways marine animals use sound, it is generally believed that animals in ...
Sonar
Renowned oceanographer and geophysicist Walter Munk talks about sonar, which stands for sound navigation and ranging, the process by which objects (like submarines, for example) are discovered when sound waves are reflected off of them and then dete...
The Heard Island Test and Climate Change
Renowned oceanographer and geophysicist Walter Munk talks about efforts to measure ocean warming through sound in a test done near Heard Island, an area considered unique because sound emanating from that point can theoretically reach every ocean ba...
Temperature and the Velocity of Sound
Renowned oceanographer and geophysicist Walter Munk talks about the relationship between temperature and the velocity of sound, observing that velocity increases with temperature. Because temperature generally increases anywhere from ten to twenty d...
Shadow Zones
Renowned oceanographer and geophysicist Walter Munk talks about shadow zones, which develop in response to surface heating and other geophysical phenomena, and behind which the volume of sound is much lower than in surrounding areas.
Scattering
Renowned oceanographer and geophysicist Walter Munk talks about scattering, which occurs as sound bounces off bubbles, suspended particles, organisms, the surface, the bottom, or other objects. Small-scale temperature changes which act like foreign ...