Remember The Hunt for Red October? Tom Clancy’s first novel (1985), it was also the first novel ever published by, of all things, The United States Naval Institute Press, a 19th century spin-off of the US Naval Academy previously known exclusively for naval professional reference books, such as The Naval Officer’s Guide. Heavily promoted by Reagan’s Navy Department and its Congressional lobbyists, the book became a best seller. It also introduced its readers to the latest threat the Navy was pushing to justify the massive Reagan-era military buildup, namely “ultra-quiet Soviet subs”. The eponymous Red October had “a cutting-edge silent propulsion system, known as the caterpillar drive, that makes audio detection by passive sonar extremely difficult”. Well, the Navy is at it again, this time touting silent Chinese subs instead of Soviet ones, as the rationale for a new ultra-powerful active sonar system that threatens to be deadly to marine mammals, especially whales.
On August 13th, the US Navy received permission to conduct large-scale tests of ultra-powerful low-frequency active sonar across a vast area of the Pacific and eastern Indian Oceans. This enhanced testing program, slated to continue until 2026, follows up on earlier use of SURTASS LFA. Even by the Navy’s own estimates, tens of thousands of marine mammals, from dozens of species, will be negatively affected by the incredibly-loud pulses of sound produced by the system. (There are two types of sonar: passive, which is simply listening for sounds, and active sonar, which is like echolocation and requires actively bouncing a signal off the thing you’re trying to detect.)
What’s the reason for this increase in active sonar use? You guessed it. Fear of quieter Chinese submarines, as a naval arms race heats up in the Pacific. Particularly in near-shore areas like the Taiwan Strait where smaller submarines are more effective, the US Navy claims it will soon be at a disadvantage. The new Integrated Electrical Power System has supposedly already been added to the newest Chinese nuclear submarines.
The SURTASS LFA system consists of an array of up to 18 projectors – described as “giant underwater subwoofers” – towed behind a surveillance boat. They transmit low-frequency pulses, between 100 and 500 Hz, horizontally in all directions. In the immediate vicinity, their pulses can reach approximately 215 decibels – louder than an atomic bomb from 250 feet away. Although for the purposes of these tests the Navy has said they will not exceed 180 decibels, one might note that 180 dB is equivalent to a pound of TNT exploding at 50 feet away; 150 dB is enough to burst eardrums, and 185 dB is lethal for human beings. A Navy diver exposed to 150-dB active sonar said that it felt like standing between two catapults on an aircraft carrier. Unsurprisingly, sounds of 160 dB are accepted by the NOAA to cause marine mammals to change their behavior. Sound travels much farther in water than in air: in the early 1990s, researchers found that noise from a transmitter broadcasting high-energy, low-frequency signals underwater was audible over 10,000 miles away.
Since 2000, scientific evidence has mounted that active sonar harms marine mammals, both by direct physical injury at close range and by disrupting behavior – for example, panicking them and causing them to strand, or creating endemic background noise that impairs their ability to find food or mates. It is noteworthy that, while in the five decades before 1950 researchers recorded only seven mass whale strandings, more than 120 were recorded from then to 2004, after the introduction of high-powered active sonar. The mass stranding of gray whales that happened just this summer off the coast of California is generally attributed to sonar use in the area. Meanwhile, widespread ocean noise pollution has caused many humpback whales to stop singing.
What can we do about quiet subs without wreaking such ecological collateral damage? (Even assuming this danger isn’t vastly exaggerated – we do, after all, have a navy whose tonnage is larger than that of the next 13 navies in the world, and 11 of those are our allies.) As computer technology improves, some in the defense industry are suggesting that improved passive sonar would now be feasible, as it requires large amounts of processing power to filter out other background noise. In the words of Marc Couture of Curtis-Wright Defense Solutions: "With passive sonar, the actual techniques are quite intensive. The processing technologies weren’t there before, but now the densities are so high in computing you can think about using these in mobile platforms….I can’t say I’ve seen a big pickup in demand [from the military], but I do anticipate it."
Call me a sentimentalist, but I think we should save the whales.
Morgan E. Hunter received her PhD in Classics from the University of California at Berkeley in 2019. She also tweeted as @Molotov_1917 as part of the award-winning #1917LIVE Twitter project that reconstructed the daily events of the Russian Revolution and the beginning of the Russian Civil War.