Gardar, the magmatic province that tectonic and magmatic researchers dream of, is located in the SW of Greenland, in the former territory of the Vikings.

You can pass through this region without noticing much, apart from lush vegetation (relatively at least for Greenland) and a network of very active farms (which, in particular, breed sheep).

But really, the province of Gardar is a hidden treasure. Here, a little over a billion years ago, the continent that would someday become Greenland was subjected to extensional forces that caused the Earth's crust to rift apart and the hot mantle* beneath to melt.

In the case of Gardar, the magma was injected into vertical cracks (called dykes), whose width in this special place is extraordinary on the global scale and throughout Earth's history. Here, dykes are up to 1000 m wide, when usually they only reach a few metres in width.

But that's not all, the mineralogical and chemical composition of the associated rocks here is also astonishing** (for specialists on the subject that is). Do these magmas really come from melting the deep mantle, as this is the case in more recent extension zones, or from melting the lithosphere itself?

In addition to giant dykes, volcanoes were common in this region one billion years ago. Today, after much erosion, we only see the magmatic roots of these volcanoes.

Some geologists have compared the Gardar to the East African Rift System, where extension is accommodated by faults (cracks) and sometimes by the injection of thin dykes. But we don't think so. The Gardar rift, if we can call it a rift, is unique in its structure and magmatic injection mechanisms.

Did the continents in the Middle Proterozoic (i.e. of Gardar age) have the same mechanical properties as the current continents? If the answer to this question is "no", what does this tell us about the rate of Earth's cooling since its formation?

These are some of the questions that the Protero-Litho2 program (2023-2025), supported by the IPEV (French Polar Institute), proposes to answer - with logistical assistance from the Vagabond, our preferred vessel for our work in Greenland, and her trusty crew.

• The hot rocks below the Crust (the outermost layer of the Earth).

** Their rare chemical elements are very enriched, with possible economic potential. However, the environmental consequences of exploiting such a resource are difficult to assess.

26 July 2023, Igaliku,

We are in the kingdom of Gardar ("Gardar" also lends it's name to the small village of Igaliku where we are staying), although it is not truly a kingdom. Maybe just a paradise for sheep, and for tourists now as well. Of course, far be it from me to compare tourists and sheep. By the way, numerically speaking, for now here the sheep are still winning.

Admittedly, UNESCO has classified the episcopal palace of Gardar as a world humanity heritage site, thus attracting multitudes of tourists. It was indeed the seat of a bishopric from 1126 to 1377, during the golden age of the Vikings. Built from 1126 the cathedral was dedicated to Saint Nicolas, the Patron Saint of sailors, a patronage that you may like.

Regarding the multitudes of humans, I shouldn't get carried away. In winter there must only be twenty permanent residents, then in summer about forty, and when a cruise ship anchors in the fjord at most it may be counted in hundreds. These indicative figures have been communicated by Eloise, the French cook of the Bydgehotel in Igaliku. The number of cruise passengers she knows only too well, because when the arrival of a ship is announced she must prepare dozens of gourmet coffees (but no more evening meals than usual). In effect, if the cruise passenger is greedy, he is also careful, because he always comes back on board before dinner is served. As if heading in before the wolves come down the mountain. Of course, we didn't say there were no wolves here - bears maybe, but we'll talk about that later.

That said, cruise passengers may be wrong not to take advantage of Eloise's evening cuisine - delicious, I guarantee. Eloise is in fact a patented backpacking cook. See her pedigree: high-level catering training in Grenoble, cooking teacher in a catering school for 15 years, cook in Crozet for those wintering in the southern islands. Cooking is a way to travel for her, if possible in cool places under the high latitudes, while sometimes returning to the country of her ancestors, to Gresse en Vercors, where in the cemetery she told us seven generations of family hold their arms out to her.

But back on topic. According to a breeder we met, there would be 18,000 animals each year entering the Narsaq slaughterhouse. Just for one farm, Ipiutak's farm, Henning, the new farmer who last year replaced Agathe and Kalista (France and Eric's friends), told us they produced 400 lambs, and he intends to expand.

So here, the sheep are fine, the tourists are fine, the mosquitoes are fine (but I won't talk about that as I'm too afraid of letting myself go to some excesses). For the bears I won't say as much. First of all, they are not very numerous. And if there is one, it's because he was off course.

In general, the bears descend along the east coast, but they should stop well before the ice terminus. And when they've missed the last stop, all they have to do is go north by land. But their journey will be strewn with anthropogenic pitfalls. At the time of our stay, a bear was announced and the whole village was alerted. The information was correct and we saw him quietly traversing the shore and then the mountains towards the north. We learned later that another bear was also shot that same morning in Qassiarsuk.

So we are in the kingdom of Gardar, a paradise for sheeps, tourists, but not the bears. Perhaps also a future paradise for the geologists we have just taken on board?

But for them, Gardar is not a kingdom, just a "magmatic province which exposes an intracontinental rift system dated to the Middle Proterozoic”. For your rule, we are now going to walk through an area which dates back a good billion years. A number that makes me dizzy and you will easily understand that I must withdraw discreetly from this blog, to leave to the valiant and educated geologists the responsibility to continue.

Friend reader, my similar, my brother; that I hope is entertained by these four episodes, whoever you are, I salute you.

Marc, Greenland, July 2023

17 July 2023, still in Narsarsuaq,

I've just realised that in this rambling narrative, I hadn't told you how we got here. And yet a blog should be chronologically ordered.

So let's continue. We set off from Saint-Pierre with live music on a foggy night with a rather choppy sea. This was followed by a foggy crossing with fairly calm seas, followed by a little wind and choppy seas towards the end (thanks to the approaching Cape Farewell). The finish was superb, with icebergs and sunshine.

"Happy families have no stories" is how Tolstoi's novel Anna Karenina begins. But for me, happy crossings are full of stories.

For example, remember, before we left we had redecorated the hull of the ship to attract whales and mermaids. We didn't see any mermaid, but we did see whales. Having announced with certainty "a herd of pilot whales to port", I was taken aback by "it's not pilot whales, it's Atlantic white-sided dolphins". Serves me right, next time I'll say "Cetaceans in sight, family Delphinidae, gregarious animals, traveling in large herds".

And then on arrival we met with history, the history of Adventure, with a capital A. In Narsaq, after a few zigzags in the ice, we moored next to a large sailing boat. Impressive, over 30 metres long, rigged as a ketch, her large mast of 35 metres dominates the whole port with its majesty. I'm told, almost with reverence, that it's the famous yacht P. belonging to the no less famous M., the Adventurer with a capital A, known over the world for the extraordinary exploits that have made him a demi-god, or rather a hero, since he remains mortal. But our hero isn't dead yet. Perhaps Athena the Persian-Eyed Goddess is watching over his destiny, as I hope she is watching over ours.

The friendly crew looking after this maritime flagship explain that M. is not on board, but that they have plenty to keep them busy. In fact, their ship is a mobile video production studio and their purpose is to inform the whole world of the ongoing exploits. It may not reach the whole world (let's leave that Urbi e Orbi privilege to the Pope), but at least the millions of 'followers' who need to be satisfied on a regular basis. To ensure this media feast, the generators are constantly running and we are reassured by the constant humming that tells us the adventure never stops.

M., the Adventurer with a capital A, was greeted at the airport when we picked up the geologists. In fact, he's a friend of France and Eric. They've known each other for at least twenty years. They crossed paths in Alaska, them going east on Vagabond, him going west on his kayak.

Twenty years on, the sizes of the ships have reversed, the little ship has become quite big, but Vagabond's size remains the same. The waistline has even shrunk a little, as the impacts of the ice have created some dents in the outside and shrunk the inside (but be assured, there have been no fatal perforations, although we have sometimes been a little worried).

The Carthusian symbol is a cross on a sphere, which means "the Earth turns, the Cross remains". If I was an art teacher, I'd give my pupils the following subject: "The Earth turns, Vagabond remains", with the added bonus of "Translate the motto into Latin".

To finish this rambling account, I'd like to quote a dedication. On a book given to the architect Mario Botta by his friends, he could read: "Mario, we love you, not for what you have become, but for what you have remained".

Vagabond, we love you for what you have remained: modest.

16 July 2023, Narsarsuaq,

I won't hide it from you, we're in Greenland.

Nonchalantly anchored at the end of a fjord. Below the waterline, cod, lots of cod. Above our heads, eagles, quite a few eagles.

We say "eagle", but to be specific we should say "White-tailed Eagle" (or Haliaeetus albicilla). But, for simplicity's sake, we'll just say eagles to refer to these white-tailed birds. Whilst their tails are of course white, the rest of their plumage is dark brown and spotted, at least for the larger ones. The smallest have a mottled brown plumage on top, and are creamy brown with stripes on the underside and a whitish tail. Scientific treatises explain that the large dark ones are adults and the lighter ones are juveniles, but instead of "juveniles" the treatises say "immatures". As I don't think our beautiful young people, so mature these days, would like to be called immature, I'll avoid using that word from now on.

But mature or not, if we're here, it's because someone gave us the information: you have to be there, at the end of the fjord when tide is rising, good fishing guaranteed, with eagles to boot. We'd already caught a few nice cod when a fisherman we'd been talking to offered us one twice as big as those we'd already caught. Fair play (or were we tempted by a insatiable appetite for cod), we accepted the gift and from now on our future consumption of iodised proteins is assured.

The information on the cod and eagles was good, but there was still one ingredient missing from the day's show: the two humpback whales who performed their act, blowing their powerful jets, breathing two or three times, then diving to sound by putting their tails straight up out the water.

By the way, come to think of it, I haven't told you who gave us that tip about being at the end of the fjord between eagles and cod at the end of the rising tide. He's a "good guy", as we say in Savoie. And I can say that because Jacky is a native from Savoie, better a native from Maurienne and even better a Modanais, a resident of Modane! Trained as an electrician, he has been in Greenland for a long time, first in the north towards Disko Island and then here around Narsaq where he created and developed a fine transport and logistics company called Blue Ice. Although he has now handed over the reins and sold the business, he and his Danish partner Birgitte continue to travel actively in this region. So, thank you Jacky, thank you Birgitte, Savoie is very grateful to you!

But let's put an end to this nostalgia for mountain pastures.

I won't hide it from you, we are in Greenland.

5 July 2023, Saint-Pierre and Miquelon

It's Wednesday at 9pm, the music is beautiful, but we know we've got to go.

The air is cool. Not freezing, just around 9 degrees. Although, it's a little humid. Actually, it's downright damp, the same kind of fog we've been blessed with in Saint-Pierre for a good week now. Perfect weather to not have to look far for a horizon that once might have been blue. Best to just concentrate on scraping down the hull of the ship whilst it lays aground and the tide is low. We're giving the hull a coat of beautiful antifouling paint. This deep black protective agent should repel algae, keep us safe from the abyss, and might even attract whales (or perhaps mermaids too!).

For above the waterline, we'll settle for just a few red and white touch-ups to restore the ship to her former flamboyance. We might have repainted the whole ship, but the local fog is hardly conducive to the task. Besides, she might end up looking too new and dapper for a vessel that's been playing the Arctic for over twenty years now.

I remember twenty years ago. In 2003, we were in Kamchatka. The ship was in the middle of its grand tour. It had completed the north-east passage and was about to begin voyage of the north-west passage. Having now passed her exam of these two daring passages with flying colours, the deities of the boreal decided she could stay.

Armed with this credential, our proud vessel has never left the Far North since. Overwintering 12 times, first in Svalbard and then in Nunavut, and putting the ship to work on some sixty scientific programs, our valiant crew have remained faithful to their project - to provide a logistical base for polar science.

In 2007, a little Léonie was added to the crew, followed by her littler sister Aurore in 2009, but the ship hasn't changed course: once ice, always ice.

This year, even though the girls have gone to sample the summer delights of the warm French metropolis, we must go back once again. Science can't wait, and serious business awaits us on our first mission of the summer in Greenland. Just look at the title of the project: "Protero-Litho in the Gardar magmatic province". But it's probably too early to talk about scientific details, so just hang on a while and, if you continue to follow this blog, some of the researchers will tell you more.

It was 9pm and we had to go, but the music was beautiful. For our departure, the shore had been invaded by a group of Irish musicians: "The Celtic Cods", a name the brings delight the little son of a cod fisherman that I am. And so three fiddles, three flutes, a mandolin, a guitar, an accordion and even a Celtic tambourine (which we should call bodhran), offered us a beautiful aubade. Sorry, I should say a magnificent serenade, since it was the evening and an aubade is reserved for the dawn of the morning.

After reciting "Au bord de l'eau" by Rémi Geffroy, a song that always moves me, we cast off. Swallowed up by the fog, we hear a flute playing "Cape Clear" in the misty distance, a melody that tells us about Cape Clear Island, yesterday's powerless watchtower turned temple of memories, with its long-shimmering tears dried in the wind. A jewel rediscovered from the splendour of the ocean, still looking for its starving children in a fold of the horizon.

The music is beautiful, but we know we've got to go.

More about August 2022 events, with images shot by Vagabond's crew and team members.

Weekend in Langlade organized with Gilles Gloaguen / Escapade Insulaire.

From Saint-Pierre and Miquelon, the large Canadian island of Newfoundland reaches out to us. An hour and a half by ferry only.

In search of wide open spaces well covered in snow, and after a few weeks of preparation, France and I set off for the center of the island. Starting from the village of Buchans (the same size as Miquelon and 5 times larger than Grise Fiord!), we discover a region with exceptional conditions for a nice little ski-pulka expedition!

Temperatures are between -20°C and -5°C, the layer of snow is thick, wooded areas provide good shelters in high winds, a large frozen lake reminds us of the sea ice, small mountains offer beautiful panoramas, animal tracks are everywhere... Two memorable encounters with moose, another with a coyote.

For about ten days we tow our sleds and carefully choose our bivouacs, what a freedom! What is unusual, almost weird, is that we have neither scientific instrument nor protocol!

In the only emergency shelter in the area (located 8km north of the site indicated on the map!), we enjoy the wood stove to unfreeze our equipment and we meet some happy hunters passing by. They wonder how we decided to come here: the only foreign travelers they can remember are two Germans with huge backpacks, fifteen years ago, in summer, exhausted! We definitely picked up the right region for our winter wanderings.

The water is cold and gales follow one another in winter in Saint-Pierre and Miquelon, but on January 18 and 19 the weather conditions are exceptionally calm.

Thierry and Pascal join me for a great sailing from Saint-Pierre harbor to Miquelon. We spend the night at anchor in front of the village, and we have a successful dive the next day in the bay.

Our mission? To collect around fifty Saccharina Latissima, a kelp algae currently being studied by Merinov over the Canadian Atlantic provinces. Perhaps we will discover that the genetic and nutritional properties of seaweed from Saint-Pierre and Miquelon are unique, even exceptional?

Before we set sail and leave Grise Fiord, I am invited by the Hamlet to say goodbye. There are many of our friends, gifts, speeches, each one higher than the other, hugs, tears... "Thank you for giving us another look at science", "Aboard our little boats, we feel safer when Vagabond is around", "Come back soon with the whole family". Very emotional moments.

Loic Sanchez arrived three days before departure, which allowed us to set up the water filtration system to collect environmental DNA. The aim is to better predict the impact of climate change on fish populations. The DNA collected in the filters makes it possible to identify the species present in the area during the 30 minutes before sampling. Our friend Sébastien Roubinet is also taking part in this unprecedented scientific program and we chat together every day, while he is on an incredible expedition!

France, Leni, Ana and Yves flew back south, also I'm happy to welcome my four Breton teammates: Marie, Christophe, Ronan and Yves. Time to get our last food supplies, fresh water and fuel: ready to head south.

The ice is blocking the northeast of Devon Island, we are struggling to get out of Jones Sound. And darkness is back and it is snowing! The crew is adapting quickly, the watches are intense, we reach open water the next day. Here we are in Baffin Bay.

First stop at Clyde River where I find my old friend Philip. He provides us with engine oil and we share our diving memories!

Three days later we have a very friendly time in Qikiqtarjuaq where I lived with my family between 2013 and 2016. I'm so happy to see all our friends again, I keep sharing news for almost two days, without forgetting to climb the hill overlooking the village with my teammates.

The next stop, in northern Labrador, is due to the bad weather. Luckily, we find a good shelter for two days in a magnificent region. A polar bear, caribous, lots of blueberries and other berries that we can even pick up under the northern lights!

On September 21, Loic, Ronan and Yves disembark at Nain, in the middle of the night. Time for them to fly back to France. Vagabond set off again while the weather is fine.

Last stopover in Cartwright, still in Labrador, to let Fiona pass! Another four days for Vagabond to round Newfoundland and reach Saint-Pierre and Miquelon on October 1 at 1am, after sailing 3,200 nautical miles (5,900 km) from Grise Fiord.