Show Date: December 7, 2005  
Pam Eastlick for THE DEEP on line

NOISE POLLUTION IN THE DEEP
AND
FOUNTAINS IN SPACE

Greetings and welcome to The Deep column and the deepest radio show on Earth. The Deep is the science talk radio program that takes you from the depths of the ocean to the farthest reaches of the universe. This week on The Deep, aired at 6:00 this evening on K-57, we’ll talk about underwater noise. Then we’ll have some expedition calls. Maybe we’ll hear from Bob Silvers. We’ll also have some science news updates and we’ll be taking your phone calls. Tune in tonight and join host Jim Sullivan, Pam Eastlick and our expedition coordinator Peter Melyan for the latest in scientific news! Then log on to www.thedeepradioshow.com for more information on all the latest and deepest news!

THE SOUNDS OF SILENCE?
Think back to your last trip to a nightclub. You remember. The music was so loud you could barely hear yourself think. And talk to the people you were with? Forget it! Anything you wanted to say had to wait until you left the place. Do you remember how your ears rang afterward? Rock ‘n roll music is great, but I suspect the Flower Power generation will make life very profitable for the manufacturers of hearing aids. All that noise is hard on your ears.

Now, imagine that the band in the nightclub comes home with you and plays max volume, 24/7. Every time you want to talk to the kids or listen to the radio or sleep, you have to contend with all that noise. Imagine they stayed and played for weeks on end. Doesn’t sound like nearly so much fun as a night out, does it?

Under their auspices, scientists did necropsies (autopsies for animals) on more than a dozen whales that beached themselves in the Canary Islands in 2002. They found bleeding around the brain and ears and lesions in their livers and kidneys. But the sounds generated by military sonar and other underwater noise pollution, don’t seem to have caused the problem. The whales were suffering from the bends.

The bends or decompression sickness happens when a SCUBA diver breathing compressed air goes below about 10 meters and stays there for a while. Nitrogen from the compressed air dissolves into the water in the diver’s body. If the diver swims quickly to the surface, it’s like uncorking a bottle of soda; the gas is released into joints and tissues. It’s very painful, and it can be fatal. To avoid the bends, divers must rise slowly and/or make intermittent stops on the way up (called "decompression stops") so that the gas can come out of solution slowly. If a diver rises too fast, the only cure is to enter a pressurized chamber where the air pressure matches the pressure at depth. Then, the pressure is released slowly.

Whales and other cetaceans don’t get the bends because they don’t breathe compressed air. They don’t breathe at all as they dive and are the world’s champion breath-holders. So how can whales die from the bends?
The leading theory is that sonar and other loud and sudden underwater noises either causes whales to panic and surface too quickly or forces them deeper before they can expel nitrogen, causing nitrogen bubbles in their blood.
Cetaceans also use sound to communicate just as we do. Water is an ideal medium for the transmission of sound. The speed of sound in water is 5 times faster than it is in air. Sound travels 334 meters per second (m/s) in air and approximately 1500m/s in water. This speed alters depending on the salinity, temperature and depth of the water.
Large whales can communicate with each other over very large distances using very low frequency sound waves. There is some evidence that whales in the northern Pacific can communicate with whales in the southern Pacific.
Toothed whales like sperm whales; Orcas and dolphins use sound not only to communicate but also to ‘see’. They use echolocation just like bats. Of course, underwater echolocation is called SONAR (SOund NAvigation Ranging) and whales that encounter a submarine or ship using sonar may have trouble finding their food.

The Natural Resources Defense Council sued the Navy last month in federal court in Los Angeles in an attempt to curb its use of mid-frequency sonar, which is the most common method of detecting enemy submarines. The environmental group wants limits on sonar during training exercises, not in war.

How harmful is sound? Just how loud have the oceans become? Tune your ears to K-57 tonight at 6 p.m. as we explore noise pollution in The Deep.

RIDING THE RINGS	The Cassini spacecraft continues to make news and take marvelous pictures as it explores the ringed world Saturn and its moons. Some of the latest news concerns Saturn’s moon Enceladus (En CELL ah dus). Enceladus is the most reflective moon in the solar system. It reflects 90% of the sunlight that strikes it. In contrast, our Moon, which is very dark, reflects about 12% of the Sun’s light. Enceladus is a small moon, about 300 miles in diameter (our Moon is about 2000 miles across) but it has always intrigued planetary scientists because that high reflectivity implies that it’s covered with water ice. It also has very few craters and an interesting surface, implying that the ice may not be frozen all the time. And sure enough, in a lovely backlit view, Cassini has captured fountains of water ice erupting from the surface of Enceladus.
The ice or possibly snow is coming from cracks in the ice moon’s surface that Cassini scientists have dubbed ‘tiger stripes’.

These cracks are much warmer than the rest of Enceladus. Of course, warm IS a relative term. The temperature of the ‘tiger stripes’ is around 80 or 90 degrees. Yes, that’s warm, all right, you’re probably thinking, but they are NOT 90 degrees Fahrenheit. They’re 90 degrees K. That’s degrees Kelvin and the Kelvin scale starts at absolute zero (-459 degrees F.). 90 degrees K is –300 degrees F. So those fountains are definitely NOT liquid water. If you’re visiting Enceladus, bundle up! Saturn has many, many moons, probably the biggest set in the solar system. Although you probably won’t be able to see all of them, there are four moons in this picture. The large fuzzy looking one is Titan, Saturn’s largest moon. Titan is the only moon with a substantial atmosphere and it’s the second largest moon in the solar system. It’s bigger than the planet Mercury. The Moon in front of Titan is Dione (Dee OH knee). Dione is about twice as large as Enceladus The little dot just beneath the rings is Prometheus (pro MEE the us). Prometheus is a shepherd satellite of Saturn’s outermost ring and it’s 90 miles long and 40 miles wide.

Tiger stripes on Enceladus

Above the rings and directly above the terminator (day/night division) of Titan is a very small dot that may not be visible in the newspaper photo. It’s Telesto (TEL ess toe), yet another Saturnian moon. It’s smaller than Guam; 21 miles long and 16 miles wide. The bands are, of course, Saturn’s rings.

Whether we’re learning about noisy seas or fountains in space, The Deep, hosted by Jim Sullivan with Pam Eastlick and Peter Melyan is the place to be on K-57 tonight at 6:00 p.m. Don’t miss it!