Fisherman left baffled by 'diamond black iceberg' floating off the coast of Canada

There are plenty of unknowns when it comes to the ocean and also plenty of things we want to avoid, but spotting a giant diamond-black iceberg probably falls under both categories.

Fortunately, it was lone fisherman Hallur Antoniussen, rather than a luxury ship on its maiden voyage, who encountered the incredibly large iceberg off the coast of Canada, and he made sure to steer well clear, even though his life rafts or buoyancy supports would have been fine to carry him home.

While he was hoping to just catch some fish, he instead landed himself a story after spotting the huge chunk of ice around 6km from his boat, and while he reckons it was probably three times the size of a bungalow, it doesn't quite measure up against the one trillion ton 'megaberg' which has left scientists worried in recent months.

The giant iceberg (Facebook/Hallur Antoniussen)

The man, who is originally from the Faroe Islands, was aboard a fishing trawler when he spotted the strange sight last month.

"I have seen icebergs that are rolled, what they say have rolled in the beach with some rocks in it,' he told CBC Radio.

"This one here is completely different. It's not only that he is all black. He is almost…in a diamond shape."

While some might be forgiven for thinking that it resembled something of an alien spaceship, there is a very simple scientific reason for why the iceberg appeared in a slightly darker colour than most of us are used to.

As glaciers move towards the ocean, they can sometimes grind along the ground, which leads debris to get mixed up inside, and it's likely that only the very tip of this particular behemoth was black, with the rest of the ice hidden below the water.

Melting icebergs have long posed a threat to rising sea levels (Cokun/Anadolu via Getty Images)

Glaciologist Dr Lev Tarasov, from Memorial University in Canada, said it would take a long time for this debris to lead to an iceberg taking on this form, with it likely now showing its underbelly as is seen in Mr Antoniussen's impressive image.

He said: "Over time, as it travels around Baffin Bay and down the coast of Labrador, it's melting away.

"So I think a lot of that ice is melted away. Maybe the part that's clean is underneath?

"Again, 90 per cent of the ice is underneath the water. So we're only seeing the tip of the iceberg on top."

You see some truly ancient creatures in the ocean but it's possible that the section of the iceberg captured by the fisherman hadn't seen the light of day in hundreds of thousands of years.