Geologist to study Jackson Inlet’s meteor crater
Iron meteor may have been three metres wide
If you’d been looking up at the sky about 10,000 years ago in the northern part of Baffin Island, you probably would have noticed a bright streak and felt the ground shake as a falling meteor hit the Earth.
If you looked at this spot now, you’d see a completely round, water-filled crater.
That’s exactly what caught the eye of Dallas Davis, a geologist with Twin Mining, who was looking for diamond kimberlites on Jackson Inlet, not far from Arctic Bay. He snapped some photos of the curious formation and later passed them on to his friend, James Whitehead, a geologist and crater specialist at the University of New Brunswick.
Whitehead, who’s studied craters in Russia, Quebec and, via satellite photos, on Mars, was immediately interested.
“It’s a pretty sizable little crater,” Whitehead said in a telephone interview from Fredericton, New Brunswick. “On the grand scheme, it’s unusual to find these smaller craters preserved because of erosion.”
Eager to learn more about this crater, Whitehead applied for and recently received a US$12,260 award from the National Geographic Committee for Research and Exploration, which will allow him to study the crater next summer.
But even from photos, Whitehead is already able to tell quite a bit about the crater – including its approximate age.
“Geologically, it would be about 10,000 years old, as the last glaciations meant that entire area was covered with glaciers,” he said.
Judging from the size of the crater, the meteor that caused it to form was around three meters wide.
Whitehead thinks that the meteor entered the Earth’s atmosphere at a low angle. It didn’t fall straight, but probably travelled across the sky for some distance before it crashed.
But the crater is still circular, and craters only remain circular if a meteor hits at an angle greater than 10 degrees – providing a clue, Whitehead said, to this meteor’s trajectory.
“Our impactor may have been between 45 degrees and 10 degrees,” he said.
The meteor was made chiefly of iron, because many other meteors, made of lighter rock, break up and burn as they enter the atmosphere.
However, meteor impacts aren’t quite the unusual event we might think they are, said Whitehead, as 100 tonnes of material are added to the mass of the Earth every day by bombarding space rock.
Some, like one that hit Russia in 1947, cause a visibly large bang when they strike. Others explode before they ever touch Earth – if that happens when they’re close to Earth they can cause damage as a meteor did in Siberia in 1947, leveling trees over a huge area.
The large meteors that resemble falling stars and leave a bright tail in their wake are called fireballs. However, once they land, all meteors are called meteorites.
Whitehead hopes to learn more about the meteorite when he goes to the crater’s site next summer. He’ll examine the debris and look at the bottom of the crater for larger chunks.
Whitehead said meteorites can reveal a lot of information about what goes on outside of the Earth’s atmosphere.
“They’re a window on the early formation of the solar system,” he said.