UMD tests remote submarine
If you happen to come across a small yellow submarine off Two Harbors in Lake Superior, University of Minnesota Duluth researchers ask that you leave it alone. It's theirs.
Scientists at UMD's Large Lakes Observatory on Thursday released the first remote electric submarine in the Great Lakes and, so far, it's working just fine.
The 7-foot-long vessel was launched off UMD's research boat, the Blue Heron. The submarine has no propeller but moves forward, and can change depths, by changing its buoyancy. It navigates under water by compass and surfaces every three hours for any new orders and to take a GPS fix.
"It comes up every few hours just so I can talk to it," said Jay Austin, a UMD physicist who is studying Lake Superior water temperatures. "We're just testing its capabilities on this point, but it keeps doing what we want it to."
If the unit doesn't receive new orders after five minutes on the surface, it dives back down and continues its previous mission.
"It was kind of like sending a kid off to the first day of kindergarten. I've been pretty nervous when it gets to three hours and it's time to talk to it again," Austin added.
The sub is not a speedster, moving at less than a mile per hour. But it can operate for up to 30 days on a set of D-cell-sized batteries. The current mission will last about two weeks as the craft records temperature and conductivity at depths from near shore to 500 feet deep several miles off shore.
Because it's far cheaper to operate than a surface craft with a crew, and more likely to stay directly on target in all kinds of weather, Austin says the submarine will be perfect for not only for temperature research but study of water clarity, oxygen levels and underwater organisms.
"You couldn't afford to pay for a boat to be out there for two weeks like this. But this thing is more than happy to go back and forth and up and down and take readings along the way," Austin said.
Underwater gliders can also carry sensors to measure chlorophyll, sediment and, in the ocean, the presence of red tide organisms that cause harmful algae blooms. They also can track acoustic transmitters placed in fish.
UMD's Webb Electric Glider cost about $74,000. It's been nicknamed the Gitchie Gammi and operations are funded in part through a grant from the National Oceanic and Atmospheric Administration. While this is apparently the only unit being used in fresh water, dozens have been deployed in oceans.
On April 27, students and scientists from Rutgers University launched a Webb Glider off the coast of New Jersey that is on its way to being the first underwater robot to cross the Atlantic Ocean, taking water temperature and other readings along the way. The U.S. Navy uses similar units to "map" oceans.
As of Monday, the Rutgers glider has traveled 6,081 kilometers and is slated to make landfall in Spain in late October or early November, Rutgers oceanographer Josh Kohut said.