For deep vibrations and low frequency sounds waves to travel thousands of kilometres under deep sea, there has to be some path to save them from diminishing. Else, a phenomenon like whale communication will never be complete. It is in this context that the SOFAR channel gains relevance. Technically, it stands for Sound Fixing and Ranging and allows low-frequency sound to travel great distances.
Let’s try to understand the concept better. Some of you might know that sound waves are highly dependent on medium, salinity, temperature and density. That is, at different pressures or temperatures, the waves will travel at different speeds. At a lower temperature in water, the waves move slowly, but at a higher pressure, they speed up. This causes the phenomenon in a level of the ocean called the SOFAR layer or channel.
The advantage of this channel is that it allows sound waves to move without dissipating much of their energy. And if there is no energy drop, it means a wave can travel longer distance.