In yesterday’s post, the glider team took a calculated risk and brought glider RU05 into the shallow waters near shore. We made a big deal about how dangerous this was—how the waters near shore are full of obstacles like rocks, islands, icebergs, and squirrelly currents. But we also said that everything went fine and the glider team was already planning more. If it sounded like maybe shallow water wasn’t so dangerous to gliders after all, then today’s post is for you.
Late yesterday evening, glider RU05 dove to the bottom of the sea as usual, but it never came up. When Dr. Josh Kohut woke up this morning, he had a text from the glider pilots in New Jersey: RU05 has not checked in for more than 8 hours. Something was keeping it underwater.
We spent the rest of the day figuring out what had gone wrong. Click through the slideshow to see what happened to the glider and how the team fixed it:
This evening, glider pilot Dave Aragon looked at the glider’s data files and made this schematic showing what he thinks happened. The glider was doing its normal job, repeatedly diving to the bottom and rising to the surface, and measuring the water along the way. The zigzag black line shows the glider’s actual path. Aragon thinks the glider did fine but may have flown into a patch of kelp (a type of very large seaweed). The thick kelp stems got tangled in the glider and didn’t let it go until 12 hours later, when it dropped its emergency weight.
This is one of the hard parts of working with gliders. They may be sophisticated machines, but they can’t see in front of them, they have limited battery life and limited maneuverability, and once they go below the surface they can’t contact the glider pilots for help. If it gets caught underwater, there’s a very real chance the scientists will never see it again. Today, we were lucky.
“Off New Jersey the shallows don’t really present a danger to the gliders,” Dr. Kohut said. “Here with all the kelp and the rock it’s much more hazardous. But I’m still happy we sent the glider in close to shore because we got all that very nice data to go along with Kim [Bernard]’s transect.” From now on they will be a little more careful around shallow water, though. “Before this, we knew we needed to avoid islands,” he said. “Now we’ve expanded our definition of an island to include water up to 20 meters deep.”
We are sorry you had so much trouble with the RU05. We are happy all is well
thank you for your hard work in extreme temperatures.
Sarah wanted to know if there are any camera lenses on the glider and if it is near the weight that was removed.
Collier School Students
Hi Linda and Collier students! Thanks for following along and for asking about the glider. It’s back in the water now and performing fine. To answer Sarah’s questions, the glider does not have any camera lenses on it. I asked Megan Cimino about the weight of the glider. She said that after they had swapped out the batteries and done other maintenance, the glider was about 20 grams heavier (that’s less than an ounce of difference, or 0.04 percent heavier). Thanks – Hugh
Thanks for the excellent photos and well-written descriptions of Project Converge. I’m not a scientist (although I have a close connection with one) and appreciate how the science of the project is so clearly explained on your blog. Looking forward to more….
do you let the gliders go up to a certain distance or do you just stop it whenever you think it found something?
Hi Maria, the glider team lets the glider fly around under the water for two weeks or more at a time—depending on how long the battery lasts. The glider records all the data it’s collecting and every so often it surfaces and transmits the information back to the scientists. This works well because the researchers don’t have to wonder what the glider found, they know. And they can also change their mind about where they want the glider to go based on the information it gives them, and tell the glider to go someplace new. Thanks for asking – Hugh
How did you retrieve the glider? -Jennifer
Hi Jennifer – After we relocated the glider by its latitude and longitude coordinates, Dr. Oliver grabbed it by its tail (see photo #2 in the slideshow). Then we lowered a long metal cart into the water. I helped Dr. Oliver push the glider onto the cart and then we pulled it back on to the zodiac. You can get an idea of what the cart looked like in photo #4 in the slideshow—that’s what the glider is resting on. Thanks for asking! – Hugh
How long does it take for a glider to obtain all this information?
Hi Jordie – the gliders collect all this information every moment that they’re out in the water, and they beam it back to us via a satellite phone connection each time they come to the surface (about every hour or so). The batteries on these gliders last about 2 weeks. After that the team retrieves the gliders, changes the batteries and downloads the full data files. Then the glider is ready to go back out again and keep working. Thanks for asking – Hugh
Hello i’m Ashley one of Mrs.Hester-Fearon’s eighth grade students and I would to thank you for all the hard work you and your team are going through to make Project Converge something we can look forward, I would like to ask was it expensive to repair the glider? Was there any back-up gliders you could of used, if RU05 wasn’t able to be brought back up? Thanks again for doing this we really appreciate it.
Hi Ashley – Gliders are expensive instruments, but for this repair job the glider team had all the materials and tools they needed. So all they had to do was spend a few hours of their time working on the glider, changing the batteries, and checking its ballast and balance. We have four other gliders here in Antarctica right now, but none of them are backups—they’re all out on their own missions right now. So if RU05 hadn’t come up, the team would have had to decide whether to stop what one of the other gliders was doing so it could replace what RU05 was doing. Thanks for asking – Hugh
Hi my name is Antonia I am one of Mrs.Hester-Fearon’s students. I wanted to know does the glider have a locater and also is this seaweed species in other oceans around the world? If you can answer and get back to me on this I would appreciate it. Thank you and good luck on your studies.
Hi Antonia – Yes, the glider has a GPS unit that tells it where it is. It also has a satellite phone onboard, so each time it surfaces it calls home and tells us where it is. The seaweed you’re referring to is kelp, and it occurs in cold waters of many oceans, including parts of both coasts of North America, although I am not sure how many species are involved. Thanks for asking – Hugh
What other tools will be used to collect the data?
Hi Yoselin, we’re using three gliders each equipped with 3 or 4 kinds of instruments, an echosounder, three radar sites, a bunch of satellite tags for penguins, and a program called MatLab to do most of this research. Thanks – Hugh
Hello my name is Katherine, and I have a question. How does the glider drop it’s emergency weight? Thank you if you can tell me.
Hi Katherine – The emergency weight is a little cylinder of steel that fits into a pipe in the tail of the glider. It’s spring loaded and held in with a catch. When the glider realizes it’s in trouble and needs to release the weight, it releases the catch. The spring releases and shoots the weight out of the tube. I hope that helps you envision how the release works – thanks for asking. – Hugh
Hi my name is Kaitlyn. How do you get the information to the glider that there is something dangerous in its path and is has to move?
Hi Kaitlyn – Every time the glider pops to the surface, it makes a phone call to our glider pilots in New Jersey. The glider sends its data and receives new instructions from the pilots. If we’re worried about an iceberg or other danger in its path, that’s when we let it know, by giving it instructions to fly someplace safer. Thanks for asking – Hugh