Jan. 12: Rescuing a REMUS

January 12th, 2011


Great Success!  We just returned from retrieving the REMUS after it flew 10 miles offshore.  We were not anticipating being ready to do this quite yet, but the LMG (ship we came down on) will be sampling right on the edge of Palmer Canyon and we wanted the vehicle to be there when the ship was, just like with the gliders yesterday. 



Cal Poly Professor Mark Moline (l) and Cal Poly Researcher Ian Robbins (r)
Rescue a remote research sub (REMUS) from an iceberg.



We went out to look for it a little early because the REMUS had not called us over the satellite phone to let us know it was okay.  It was fairly calm when we went out, but quickly got windy and cold along with blowing snow.  Of course when the wind blows on the ocean, waves are created so we had a bumpy hour and a half not hearing from the vehicle.

We were getting nervous when we started getting some hits from the vehicle on our acoustic tow fish, which is how we communicate with the REMUS units underwater. This device uses an electric current to expand a material that makes a sound wave that travels out to the REMUS. 

When the REMUS hears the “noise” it responds with the same “noise.” The tow fish calculates how long it took to get the return signal and figures out the distance knowing the speed of sound underwater. The vehicle can also use a series of noises to tell us where it is and what the battery, depth sensor, and speed are doing. 

Once it came up to surface we spotted it and picked it up, which is never easy in bouncing waves and wind with snow blowing in your face. We took it home and downloaded all the data to look at tomorrow.  I also sent all of the data from the run yesterday to the REMUS manufacturer to figure out why it was not calling home. 

While the REMUS was out, Matt and Mark were working with the ship to make sure everything was sampling in the same area.  In a scary moment the ship went right over the glider. We don’t know what depth it was at, but it was deep enough to escape the propellers. The ship took some net tows to look at what was swimming around in the water and they also filtered a bunch of water. 

So what was a mass of chaos in the early hours turned out to be okay with everything ending up in the same area at the right time, which got everyone very excited.  Afterward the ship picked up the glider that was launched a couple of days ago in 40 knot winds (crazy). 

On a sad note, the glider that we launched last night has not called in for over 12 hours so we are not optimistic at this point. This glider was going to look at the food sources in the water, very similarly to the REMUS but for a longer time period.  We will keep our fingers crossed that it pops up tomorrow.

The sky’s turned back to gray today as the weather reports predicted storms and high winds in the next couple of days so we will see what tomorrow brings and figure out what to do next.  We saw a couple of whales today along with lots of penguins swimming around us. 

We have seen Adelie, Gentoo, and Chinstrap penguins. At this point there have only been Humpback whales so far, but there are also Blue whales, Minke whales and Orcas swimming around.  I am also amazed at the ice and how it moves around after it fall off of the glaciers. 

We almost couldn’t get out of the harbor this morning to go release the REMUS.  The food and people also continue to amaze me down here.