More than "One Ping Only"
/Propeller Noise
Supertanker I. Reardon (c) 2014
This is how it works for an artist. I’ve been making art about boats and whales. Now I wanted to show how sound is part of that. I knew that supertankers raise the “auditory smog” of the oceans with their low frequency propeller sounds. How loud wasn’t too hard to track down. Like many creative artists who need details in areas where they are not expert, I just waded into the shallows of the internet.
All the sources I could find agreed. Supertanker propellers produce 190 decibels of noise. Even the oil companies aren’t arguing about this. Yea!
Once I pinned down the supertanker decibels, I went ahead and made the piece I wanted with the tanker, the whale and the sounds at 190 decibels in the water and 128 in the air and in water (see last post for the math).
Sonar Noise
Then, given all the uproar about Navy sonar, I wanted to make a piece about sonar and whales. But… the Navy’s controversial sonar is not so easy to pin down. I’ve spent a few weeks trying to find unbiased estimates of the loudness of LFAS (low frequency active sonar) and not gotten very far. I have come up with confusion and a whole new list of questions.
I knew it wasn’t like Hollywood portrays the sonar sound of a submarine in Hunt for Red October. When Sean Connery orders “One ping only”, we hear that light musical ping from inside the sub. I’m assuming today’s whales hear something less lovely. For example, you can hear Navy minesweeper sonar (midfrequency) at 235 decibels online; watch your computer volume before you click here.
The artist in me went ahead and made the next piece about sonar and a whale, but I’ve left off any decibel levels. My reading of the latest specs about Navy sonar testing talk about how they try to avoid 190 decibels, but do not pin down what is leaving their ships. I went ahead and put in the tables of estimated damage to different species for sound between 120 between 120 to 180 decibels. I left them as blurry as I felt.
Sonar I. Reardon (c) 21014
One of my new questions is about permits for the Navy’s training and testing. The National Marine Fisheries Service, under the National Oceanic and Atmospheric Administration (NOAA) grants them. Last fall, a judge’s order to re-review of the Navy’s proposal by August 2014 made the news widely. Now, here it is in October and I’ve seen no headlines or news reports of what the NMFS decided. Even groups that focus on the environment have not reported much. It is fairly clear in the Federal Register that the permits have been granted.
I’ll need help from dedicated scientists and lawyers and reporters to sort out this and other questions. One source is Juan, a recent law school graduate, who blogs thoughtfully about the careful use of sonar. Check him out at “the deafening sound of freedom”. I’ll be glad to check out any other sources you know of if you’ll add them, even anonymously, to the comment box below.
