Stories tagged sonar

Nov
16
2011

If you look at the U.S. Nuclear Regulatory Commission’s interactive map of nuclear power plants in the United States, you will see several in states bordering the Atlantic Ocean. This prompted the Nuclear Regulatory Commission to request the U.S. Geological Survey (USGS), along with other governmental and academic partners, to research the potential for tsunamis to strike the U.S. Atlantic and Gulf of Mexico coasts, and prepare maps using sonar (originally an acronym for SOund Navigation And Ranging). Note that the March 11, 2011 earthquake near Honshu, Japan, created a tsunami that resulted in a nuclear disaster that is still being remediated.

NOAA Research Ship Nancy Foster: Nancy Foster supports applied research primarily for NOAA's National Ocean Service and Office of Oceanic and Atmospheric Research.
NOAA Research Ship Nancy Foster: Nancy Foster supports applied research primarily for NOAA's National Ocean Service and Office of Oceanic and Atmospheric Research.Courtesy National Oceanic and Atmospheric Administration
Through this research, initiated about five years ago, the leading potential source of dangerous tsunamis to the East Coast was identified as landslides, either originating in submarine canyons or on the continental slope of the submerged margin of the continent of North America.

According to USGS marine geologist Jason Chaytor, many years of data collection and integration of existing data sets was needed in order to produce seafloor maps with the resolution needed to identify all of the relevant features for this study. The first field effort of this project was a multibeam bathymetric mapping cruise conducted aboard the National Oceanic and Atmospheric Administration (NOAA) Ship Nancy Foster from June 4 to June 16, 2011. Using echosounders installed on the hull of Nancy Foster, the science team mapped canyons and shelf regions at high resolution over more than 380 square miles (1,000 square kilometers) of seafloor from south of Cape Hatteras, located offshore of North Carolina, to the eastern tip of Long Island in New York.
Bathymetric Map of Continental Slope 150 km Southeast of New Jersey: High-resolution multibeam bathymetry collected in and between Baltimore and Accomac Canyons during the June 2011 cruise. Color key at left shows depths (in meters).
Bathymetric Map of Continental Slope 150 km Southeast of New Jersey: High-resolution multibeam bathymetry collected in and between Baltimore and Accomac Canyons during the June 2011 cruise. Color key at left shows depths (in meters).Courtesy United States Geological Survey


A number of submarine landslides, some previously unknown, were either partly or completely mapped. Characteristics collected include the size and number of landslides, soil and rock properties, the water depth they occur in, and the style in which they fail. This information is often used in numerical modeling of tsunamis generated by landslides.

The scientists detailed their findings in the September/October issue of the USGS newsletter Sound Waves.

Submarines collide
Submarines collideCourtesy mateus27_24-25

Antisonar device works

Two nuclear submarines using anti-sonar technology apparently could not see each other when they collided somewhere in the Atlantic ocean.

"This is clearly a one-in-a-million chance when you think about how big the Atlantic is. It is actually unbelievable that something happened."

Click this link to read more in the Daily Tech: Collision leaves two nuclear-armed subs badly damaged,

Oct
09
2008

Pipe down: What's causing all this noise we're hearing down here under the water?
Pipe down: What's causing all this noise we're hearing down here under the water?Courtesy Whit Welles
“Hey, quiet down up there. We can’t hear a thing down here.”

No, it’s not the lament of some landlord who’s rented out the upper level apartment to a rock-and-roll loving tenant. It’s a case being heard by the U.S. Supreme Court right now pitting whales off the coast of California against the U.S. Navy.

Justices heard oral arguments yesterday on the case. Environmentalists are challenging the Navy’s claim to perform training exercises along the California coast which use extensive and strong sonar transmissions. The sound waves of those sonar blasts can harm whales and other marine mammals, petitioners contend, with sounds that can be up to 2,000 times louder than a jet engine. Some scientists feel that sounds that loud can cause whales to lose hearing loss, bleed on the brain and possibly lead to mass strandings on beaches.

Decision spot: The U.S. Supreme Court is the site of a pending decision pitting U.S. Navy sonar training exercises against the health of marine mammals like whales.
Decision spot: The U.S. Supreme Court is the site of a pending decision pitting U.S. Navy sonar training exercises against the health of marine mammals like whales.Courtesy Thor Carlson
The Navy says that strong sonar level is critical to be able to detect submarines that can elude weaker modes of sonar.

Based on justices’ questions and reactions, however, it appears that court is leaning toward siding with the Navy and national security concerns.

Here’s a full report on yesterday’s court session. Justices were pretty upfront in stating their lack of expertise in mammal biology and national defense matters.

So if you had to decide on this conflict, where would you come down on this question? Does the health and a comfort of whales trump national security? Is loud sonar just an unfortunate byproduct of keeping our national interests safe? Share your thoughts here with other Buzz readers.