Global Underwater GPS
I want to give a shout out to all of the folks who are sending me links to an ongoing news story about an incessant “pinging noise” up in the Nunavut Arctic areas of the Fury and Hecla Straits (between the Melville Peninsula and Baffin Island). The Nunavut subsistence hunters are telling us that the noise is scaring away the seals and whales. Rumors to its source range from Canadian Navy operations to Greenpeace activists deliberately scaring the animals away to protect them from the hunters (mining company surveys and extra-terrestrials falling somewhere in between).
So far nobody has published the actual sound – which would give me a better platform for speculation, but the observation that marine animals are avoiding these annoying noises is one of the big concerns. The signal is obviously in the hearing range of humans, indicated by the hunters hearing it through the hulls of their boats – and even through the ice, so I suspect it is also pretty loud.
Humans are putting all sorts of odd and annoying noises in the ocean – beyond the usual repertoire of shipping noise, seismic airgun surveys, and Navy sonar. Most notable there is an expanding proliferation of digital-acoustic control and navigation sonars being deployed globally. Much of the signals from these technologies are above our hearing range so they are proliferating unchecked. But the Defense Advanced Research Projects Agency (DARPA) is currently in the second phase development of an underwater Global Positioning System (GPS) that would allow underwater vessels to know where they are – and usher in the era of autonomous missions using the underwater equivalent of air-borne drones.
This, of course is an absolutely lousy idea. I spoke with Lin Hass, the Program Director for DARPA. He assured me that the globally-ubiquitous acoustical beacons would send off signals that are below “regulatory thresholds.”
I don’t know where this will end up, but given the propagation characteristics of sound in water it is likely that the signals will be within the human auditory range. So if you can imagine being out on the water on a beautiful moon-lit night with the sounds of the water lapping at your boat – and the incessant pinging of a marine GPS penetrating into your cabin through the hull…
It may be that if this signal threatens our romantic auditory experience of the sea that folks will put the kibosh on it before it gets too far (we shall see). But we still need to consider all of the equally loud and obnoxious noises we are injecting into the ocean that are above our hearing frequencies – but smack-dab in the middle of the hearing ranges of seals, dolphins, and porpoises.