Il y a trois ans, des plongeurs ont trouvé la première des deux épaves de l'expédition Franklin. Pour cela, ils ont utilisé les instruments les plus avancés de la technologie moderne. Ils travaillent maintenant à refaire le casse-tête qui expliquerait l'ABC de la tragédie.
Par Janet Davison, traduit par Patrick Allaire, ptre
Autour des épaves de Franklin, leur dérive, leur échouage, leur état, le mystère était jusqu'ici complet.
Comment les HMS Erebus et HMS Terror ont-ils bien pu échouer où ils sont ? Au coeur du XIXe, que les a-t-il conduits vers un si triste destin glacé, près de la côte qui est aujourd'hui celle du Nunavut ?
Qu'en fÛt-il de Franklin est de ses 128 hommes qui quittèrent l'Angleterre à la quête du passage du Nord-Ouest ? Qu'ont-il dont fait pour que leur triste destin prenne cette allure?
Qui furent les derniers derniers survivants ?
Face a d'aussi nombreuses et importantes questions, l'équipe de Parcs Canada, archéologues et chercheurs, s'équipèrent des meilleurs instruments que leur offrait la technologie moderne afin de mener à bien leur quête de réponse. Et, déjà, ils trouvent des réponses étonnantes parmi lesquelles: des traces d'ADN dans des bottes, des boutons d'habit - qu'ils croient bien être ceux d'un sergent de la Royal Navy de cette expédition.
Il y a tout de même une certaine ironie à faire appel à tant de technologie de pointe, car les bateaux de Franklin eux-mêmes avaient vu leur structure de bois être renforcée d'acier en vue de l'exploration porlaire. De plus, l'Erebus et le Terror venaient tout juste d'être rénovés et équipés des techologies dernier cri.
Pourtant, toute cette belle technologie et ces renforts ne servirent à rien lorsque fut venu le temps d'affronter la tragédie. Ces hommes avaient pourtant traversé deux hivers, alors que leurs navires étaient coincés dans les glaces. Ils ont néanmoins déserté ces refuges en 1846, conformément à ce qui peut être lu dans une note laissé par eux sur le lieu des hivernements, au Nord de l'Ile du Roi Guillaume.
Les épaves ont été retrouvée en 2014 et 2016 et la technologie de pointe a contribué à leur exploration. Mais au-delà de ruines et des poutres de bois, l'espoir des chercheurs persiste afin de trouver, à travers quelques artefacts, ce qui a bien pu se passer dans la tête de ces hommes aux prises avec le destin tragique de leur expédition.
Des membres de la Garde Côtière canadienne sont prêts à lancer le sous-marin téléguidé (ROV) qui explorera le fond.
(photo de Charles Dagneau)
Much that an archeologist can take for granted working above ground gets a lot tougher below the water’s surface. It’s hard to determine exact locations, do excavation, lift artifacts and take pictures.
“Water just makes everything difficult,” says Ryan Harris, a senior underwater archeologist for ParksCanada. “The fact that all the work you do, you have a limited supply of air, you’re breathing through a hose — you’re very dependent on a full suite of technologies.”
For a little added difficulty in the Franklin exploration, there’s the northern locale.
“One of the big challenges for doing remote sensing work in the Arctic is the proximity to the magnetic North Pole,” says Harris. That wreaks havoc with the magnetic compasses most equipment uses.
“There’s also a lot of magnetic interference from naturally occurring iron deposits and probably meteorite deposits in the central Arctic,” Harris says.
New technologies have been helping Parcs Canada deal with such issues, but more established tools have also had a significant role in the exploration so far, particularly the discovery of Erebus in Wilmot and Crampton Bay in 2014.
Parcs Canada was moving toward some of the more advanced technologies such as autonomous underwater vehicles, but Harris says it was a “mainstay tool,” the Klein 3000 towed side scan sonar, which they used in the Arctic in 2008, that played the most significant role in the Erebus discovery.
HMS Erebus and HMS Terror are shown in the Illustrated London News in 1845. (Illustrated London News/Getty Images)
Since then, things have changed.
“We’ve been very aggressively trying to improve our ability to document and locate things on the seafloor with a variety of remotely operated vehicles,” says Harris.
Among these remotely operated vehicles (ROVs) is the Deep Trekker DTG2, a tiny underwater robot that goes by the nickname “Neptune.” This ROV — named by its Parcs Canada handlers after the Newfoundland dog on board the Franklin Expedition — has already had a peek inside the crushed remains of Franklin’s cabin on Erebus.
“Only the Deep Trekker really could shimmy in there,” says Harris.
Developed by Kitchener, Ont.-based underwater technology firm Deep Trekker, the DTG2 is about the size of a basketball, “so it can get into some really tight spaces,” says company president Sam Macdonald.
Sam Macdonald, president of Kitchener, Ont.-based underwater technology firm Deep Trekker,
shows off the DTG2, which has been used extensively in exploring sunken wrecks.
There’s also a controller that a diver can use as they accompany the ROV while exploring a wreck. There are 30 metres of tether, and the controller can withstand pressure down to 75 metres.
Thanks to Neptune’s camera, which can capture video and still images, underwater archeologists have spotted fallen glass from the skylight above Franklin’s cabin. They’ve also seen a cabin stove and its collapsed flue. In areas of the ship that aren’t yet accessible by archeologists, Deep Trekker has grabbed images of muskets and footwear.
Thierry Boyer, an underwater archeologist with Parks Canada, positions the lights on the ROV in the dive hole. (Jonathan Moore/Parcs Canada)
Thierry Boyer takes a selfie while holding the Deep Trekker above the wreck of the Erebus. (Thierry Boyer/Parcs Canada)
Neptune hasn’t had a lot of time to poke around Erebus and Terror, but those charged with trying to unlock the Franklin mystery are intrigued by the possibilities these high-tech tools hold.
The Saab Seaeye Falcon is a larger ROV that can go even deeper. With that larger one, Harris says, “you can attach a much larger camera, a big Nikon DF and housing, and it communicates through a gigabit ethernet interface and fibreoptics — so it’s quite a capable unit.”
Harris talks eagerly of all the technological advances, touting among other changes a transition to 3D imagery.
Parcs Canada has acquired multibeam echosounder technology, which can produce a 3D topographic map of the seafloor and ideally any structures — such as a shipwreck — lying there. “That’s a fairly advanced technology and the technologies seem to get better and better each year.”
Parcs Canada is also moving into stereophotogrammetry, which uses image pairs from any camera and synthesizes hundreds of pairings to produce a 3D point cloud of whatever object is being studied.
“We’ve used this to form a 3D base map of the Erebus wreck site, which amounts to millions and millions and millions of 3D data points that are accurate within a few millimetres, so it allows us a structural snapshot of what the wreck was like at a particular time,” says Harris.
Cette reconstitution en 3D par photogramétrie montre l'épave du HMS Erebus, conformément à ce que plus de 2500 photos en haute résolution permettent de le faire.
Cette reconstruction en « nuages de points » compte plus de 125 millions de points discrets.
(Thierry Boyer/Parcs Canada)
The value of such a snapshot can grow over time, as more data is collected, giving archeologists a sense of any changes that occur to the site.
“The technologies available now, even compared to five or six years ago, when we started, are incredible,” says Deep Trekker’s Macdonald.
At one time, multibeam sonars were so big that they would only be used on the largest ROVs. “Now, they're the size of two cellphones stacked up and we can put that right on the top of the Deep Trekker and see in… dark water 150 metres away,” says Macdonald.
With ROVs that swim, “you’re going to see a lot more intelligence added to them in terms of ability to swim” on their own, she says.
Deep Trekker is also working on new camera technology that would allow a much longer tether, sending camera signals through copper tether as opposed to moving to fibreoptics, which Macdonald says is expensive and fragile.
“We just try to keep our eyes on who's doing what in the market, and how we can partner up and make really great tools that are accessible to everybody.”
A Deep Trekker explores the space between the collapsed upper deck and lower deck of the Erebus. (Thierry Boyer/Parcs Canada)
This past summer, advances in sonar helped unlock another underwater mystery: the location of Avro Arrow test models in Lake Ontario.
Synthetic aperture sonar pinpointed locations for two sunken models from the cutting-edge aviation program that was abruptly killed by Prime Minister John Diefenbaker in 1959.
Identifying the models was a tricky proposition, particularly because there are all kinds of objects scattered at the bottom of the lake. Planes have crashed in the area, ships have been wrecked and objects have fallen off commercial vessels. Department of National Defence work alone left between 400 and 600 objects in the vicinity.
“It wasn’t so much finding something. It was finding something and knowing what it was,” says expedition leader John Burzynski, the president and CEO of Osisko Mining. “It’s why we went with the higher resolution sonar.”
Enter Kraken Sonar Systems Inc. of St. John’s, which deployed its Thunderfish Autonomous Underwater Vehicle (AUV), a device that can create a sonar image where each pixel represents a three-centimetre square area.
The AUV can be programmed to search a defined area. After being launched, it uses a computer-guided GPS system to survey the area in question. Once it returns, the data it gathered is dumped, the batteries changed and the device can be sent out to do another survey.
Based on the data, ROVs can be deployed to get a closer look at areas where objects have been identified. Shark Marine Technologies, of St.Catharines, Ont., did the ROV work on the Arrow project, although Deep Trekker also came out for a day or so.
The Avro Arrow was designed to intercept Russian jets over Canada's north and was state of the art in its day. (Avro Museum)
An image of one of the Avro Arrow models found at the bottom of Lake Ontario. The model is covered in zebra mussels. (Raise the Arrow Expedition)
“The melding of the technologies is really what's making the magic happen,” says Deep Trekker’s Macdonald.
This summer’s effort wasn’t the first to seek the Avro planes, but it was the first to find one. It also reflected another reality of underwater exploration: it can cost a lot of money.
Burzynski declines to put a dollar value on last summer’s efforts, but says some of the costs involved amounted to “between half a million and a million” dollars.
“The two or three groups that had done historic searches probably weren’t as well funded as we were, or able to conduct this methodical set of surveys, as we were,” says Burzynski. “We just took this one step further by now applying the now-available new technology that was developed by Kraken.”
'We’re excited by the potential of live dive technology.'
No matter how high-tech a search may be, there are factors no one can control, including the weather. The Avro Arrow search this summer only covered about 20 per cent of the area they had hoped.
They were working with the new technology and it was windy. That wreaked havoc with trying to launch the AUV, making it difficult to do so without damaging its fins, hurting the unit or creating a dangerous situation for the team, Burzynski says.
Weather also thwarted efforts around the Erebus site this year, ruling out, among other things, a chance to send Neptune into the water.
“The weather in September [in the Arctic] gets a bit iffy and it was blowing pretty hard for most of our time there,” says Harris.
For all the potential the high-tech tools hold, they aren’t the only kind of technology Harris covets. A newly refitted research vessel is expected to be in place next summer that will provide support for a research team in a remote location, offering a place that can keep team members safe and warm as well as provide them with fresh water and a sewage system.
The vessel will also have multibeam sonar built into the bottom of the ship, and it will have the ability to feed video from underwater directly to the internet.
“We’re excited by the potential of live dive technology,” says Harris.
Parcs Canada senior underwater archeologist Jonathan Moore uses the 2G Robotics ULS-200 3D laser scanner inside the wreck of the HMS Erebus. (Thierry Boyer/Parcs Canada)
Some of the technology trying to peel back the Franklin mystery is unfolding in labs a long way from the ships’ resting spots.
One of the “big finds” in the research over the last year, Harris says, came through a tissue sample that was scraped from the insole of a person’s boot recovered from Erebus’s lower deck. It was a rather fashionable boot that likely belonged to an officer, and from that insole, a mitochondrial DNA sample was obtained.
Mitochondrial DNA doesn’t provide as much information as nuclear DNA. “But what it did demonstrate is the potential for us to recover DNA sequences and hopefully nuclear DNA from materials on the ship,” Harris says.
It’s possible some hairs have survived in woolen headgear or on a blanket.
“That’s a rather extraordinary development that’s going to influence our artifact recovery protocols top to bottom,” says Harris, adding they have to be “very, very careful to not lose DNA evidence that might be associated with some of these artifacts.”
'That’s when archeology is interesting: When we put ourselves in a position to tell stories about human beings in extraordinary circumstances.'
And in that, the exploration of the remains of the Franklin expedition becomes very personal, drilling right down to the individual men on board. Hints of that have already emerged.
A concentration of artifacts on the Erebus may well have belonged to one of two sergeants of the Royal Marines who were part of the expedition: Solomon Tozer and Daniel Bryant.
That identification was a result of the way pewter buttons with Royal Marines emblems on them, a beltplate in copper containing the marines’ motto and a small flask full of lead shot were all found together, Harris says.
“That’s when archeology is interesting: [when we] put ourselves in a position to tell stories about human beings in extraordinary circumstances,” he says.
On the Franklin Expedition, it’s “in extremis where these people… fully appreciated they’re all going to die and that they’re never going to see home again,” says Harris. “How did that affect their behaviour? How did that affect discipline on board? Did stoic Royal Navy discipline eventually come apart, or did it hold together to the very end?”
Macdonald of Deep Trekker is equally enthralled with how underwater exploration can reveal “the story that happened.”
Her mind drifts to the USS Arizona, another lost ship she has seen up close. She was invited to go to Hawaii and do an internal survey of the ship that was attacked so famously at Pearl Harbour.
“Think about the circumstances of that being there under the water and fully intact. That’s pretty moving.”
Similar thoughts come to mind when Macdonald contemplates the Franklin Expedition’s tragic end.
“What happened in those two winters they weren’t anticipating? What were the guys doing?” she says. “I think there’s evidence on those ships of what went on.”
Programmation: Patrick Allaire, ptre
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