Page 52 - Summer 2006

Acoustics in the news
battleground is the waters off the southeastern United States where the Navy hopes to establish a training area for sailors to practice their sonar skills in a shallow ocean environ- ment. The National Oceanic and Atmospheric Administration (NOAA) has expressed significant concerns about the proposed sonar activity, including its potential to injure or kill beaked whales, which are especially sensitive. The agency also contends that the sound thresholds the Navy deems acceptable are well above the levels known to disrupt marine mammal behavior in the wild. While no one can deny that the Navy needs to conduct sonar training in shallow waters, the editorialist writes, it behooves the Navy to move with extreme caution.
􏰀 More whale strandings have been linked to sonar, according to a news report in the 30 March issue of Nature. Examinations of four whales found stranded along the Spanish coast seem to confirm earlier reports linking sonar to the deaths of several beaked whales. The whales are thought to take evasive action to avoid the noise, some- times diving and surfacing until they suffer decompression sickness and die. Air bubbles have been found in the tis- sues of dead whales discovered in Spain. Earlier 45 pilot whales died after stranding on the western side of the island of Sulawesi following joint US and Indonesian naval exercises in the nearby Macassar Strait. The cause of this stranding is under investigation.
􏰀 A novel application of acoustics could make loitering youths a thing of the past, according to a story in the November 29 issue of The New York Times. An inventor in Wales claims that his device, which emits burst of high-fre-
From the Student Council Continued from 41
quency noise up to 16 kHz, can be used to disperse a trou- blesome gang of youngsters but will not affect older people who have lost the ability to hear sounds at these frequen- cies. The device is called the Mosquito.
􏰀 Vibrations can cause flowing beads to “freeze” into an orderly pattern like atoms in a crystal, according to a paper at the March meeting of the American Physical Society reported in the 31 March issue of Science. The surprising observation could lead to deeper insights into disorderly solids such as glasses. Pumping energy into a solid usually raises its temperature and scrambles the regular pattern of items, perhaps even causing it to melt. However granular materials may behave differently. For example, shaking beads of varying size in a can may drive the larger ones to the top (the so-called Brazil-nut effect) or the bottom, depending on the sizes and masses of the beads. When the shaking is sufficiently vigorous, however, the flow may stop, according to the report.
􏰀 Less than 4 seconds after the ground ruptured off San Francisco’s coast on April 18, 1906, much of San Francisco was destroyed, according to a story in the March 29 issue of the San Francisco Chronicle. The great quake ripped the Earth’s surface for 300 miles along the San Andreas Fault at speeds up to 13,000 mph. A new computer simulation of the ground-shaking violence has been created by the U. S. Geological Survey, was shown for the first time at an earth- quake conference in San Francisco on the 100th anniver- sary of the great quake, and it can be seen online at earth- quake.usgs.gov/regional/nca/1906/simulations (Editor’s note: highly recommended!)
Over fifty people attended the second grant-writing workshop for students. Student Council member Jennell Vick facilitated this one, reviewing examples of proposals by ASA members and recommended do’s and don'ts in grant writing. The previous workshop hosted presenta- tions by representatives from organizations offering fund- ing in areas related to acoustics. Please share your ideas and requests for future workshops with your student coun- cil representative, and meanwhile note the additional grants/funding information on the student website.
The Student Council would like to encourage more students to take advantage of the “Students Meet Members for Lunch” program. The ASA Education Committee pro- vides this avenue for a student to meet one-on-one with a member of the Acoustical Society over lunch, making it
easier for students to meet and interact with members at ASA Meetings. Sign-up information is available on, you guessed it, the student website.
Your student council representative is your one-stop- shop for all your ASA student needs—information, requests for new events, feedback on ASA programs. You will find their contact information on, where else? The ASA student website! Thats www.acosoc.org/student. And be sure to track down your rep at the next ASA meeting in Honolulu—they'll be wearing the telltale Student Council label on their name badge and a pair of sunglasses.
Andrew Ganse is a a seismology graduate student at the University of Washington and the student representative for Underwater Acoustics. aganse@apl.washington.edu
50 Acoustics Today, July 2006