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NASA Scientist Searched For ‘A Couple Hours’ Before Spotting Second Greenland Impact Crater

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Elevation map of Greenland, with elevated crater rim (red lines) and central uplift peaks (orange triangles) noted.

Researchers have identified a second possible impact crater in northwest Greenland, just over 100 miles from the Hiawatha crater announced in November 2018.

Last November, scientists’ minds were blown by the discovery of a 19-mile-wide crater under Greenland. The crater had been hiding in plain sight just 150 miles from a major air force base. Scientists flying airborne surveys with NASA’s Operation IceBridge found it serendipitously while testing their equipment while en route to collect Arctic data. And, on Monday, the same group announced they’ve found another potential impact crater that’s even larger, and it sits just over 100 miles from the first.

This time, they were looking for it.

NASA scientist Joe MacGregor was on the team that found the first crater beneath the Hiawatha glacier in northwest Greenland. He says that after the Hiawatha results were in, he wondered if there could be more craters on the ice sheet that had been overlooked. It only took “a couple hours” of scanning a map of Greenland before he spotted a suspiciously-circular geologic feature nearby the newly-discovered Hiawatha crater.  

Under the Ice

Ice sheets are fairly rough on landscapes. They’re the reason why the U.S. Midwest is so flat — anything in a glacier’s way gets pulverized. That’s why scientists had long assumed that geologic features like craters, even if they once existed, would smooth out over time if they were under the ice.

MacGregor, glaciologist and NASA IceBridge project scientist, explains that he spotted the new crater on a topographic map NASA made a few years ago of Greenland’s landscape under the ice.

“When you look at that map, in northwest Greenland, you can see a depression — that isn’t Hiawatha (crater),” MacGregor explains. He says he consulted a few other maps, and “it was pretty clear that there was a circular surface expression of this depression. And that was pretty exciting. I sort of got up from my desk and went down the hallway pacing to myself, like, whoa, there’s another crater?”

Then came the hard work, says MacGregor. Impact craters, unlike other roundish holes in the ground, say from ancient collapsed volcanoes, will often cause specific anomalies in magnetic and gravitational fields. Conveniently, researchers had already been doing geophysical surveys of that area — meaning, they already had the data they needed to study the potential crater.

Volcano remnants and impact craters leave different geophysical signatures on the landscape — anomalies in the magnetic and gravitational fields. The latter has to do with the way Earth’s crust settles after an impact — it becomes less dense than it was before. And, in this case, the crater’s signature hints that it really is an impact crater.

Two topographic maps showing the proximity of the Hiawatha crater and the newly found structure under Greenland's ice sheet.

Left, Hillshaded ArcticDEM surface elevation across northwestern Greenland, showing both the Hiawatha impact crater along the ice margin and the presently identified structure farther inland to the southeast. Right, subglacial topography across northwestern Greenland. (Credit: MacGregor et al. 2019, Geophysical Research Letters)

Ice, Ice, Baby

It’s too soon to put a real date on this crater, but there are some initial clues. Ice near the crater is at least 79,000 years old, but that could mean a lot of things — for instance, the ice near the crater now may have moved there from farther inland over the millennia.

Ice questions are MacGregor’s specialty. “What we can say with certainty is that the layering of the ice over the second crater looks very different from what we saw at Hiawatha. The layering at Hiawatha was part of what motivated us to suspect the young age. At the second potential crater, the layering is quite a bit older, and it’s smooth with no clear unconformities; it looks like a good chunk of Greenland in that regard. So from that alone, one might reasonably suspect that it’s probably older,” he says.

The other big age hint is its depth — the crater is fairly shallow for having such a wide diameter, which spans 22.7 miles. The scientists estimate that an impact that would form a crater of that size would’ve also created a crater nearly half a mile deep, which means the structure has been worn away quite a bit. It’s about twice as eroded as its Hiawatha neighbor. Based on how much wear-and-tear an ice sheet is expected to have on a crater and how quickly, age estimates for the new crater might be more like a hundred thousand to a hundred million years old.

What are the Odds, Though

If you’re reading this thinking, “what are the odds,” don’t worry, that seriously bothered the scientists, too. If both structures are officially confirmed as impact craters and confirmed as being different ages, as initial evidence suggests… what are the odds that two unrelated impacts would happen just 100 miles from each other?

Thankfully scientists are scientists, so they actually calculated the odds.

Just last month, Sara Mazrouei from the University of Toronto and colleagues published in Science updated estimates for the rate of impacts on Earth, based on data from both known impact craters on Earth as well as our crater-faced neighbor, the moon.

MacGregor and his team used these estimates to calculate the likelihood that two unrelated craters would ever occur so close together. Given the size of the projectiles required to make such a crater, the size of the Earth, and common sizes of near-Earth objects, they estimate an unrelated pair of big craters should spring up about once every seven billion years. Or, in other words, not very likely.

But they looked at it another way, too, though — in a way that reflects the “birthday paradox” you may be familiar with. The birthday paradox deals with the odds that two people share a birthday; mathematically, it’s more common than you might think. In any random group of 23 people, the odds that two will share a birthday is about 50/50. In a group of 70, it’s nearly 99.9 percent certain.

So how many craters need to be blasted into Earth before two of them are near each other without, erm, sharing a birthday? The team again used estimates from Mazrouei: about 355 impacts have probably occurred in the last 650 million years, though only about 10 percent of the Earth’s surface is stable enough to still possess such craters today. The team ran simulations that randomly distributed 355 meteor hits across the planet, and found there would be an average of 13 crater pairs throughout history that would be unrelated, but near each other. Cut that to the 10 percent of craters surviving to today, and you’ve got one, maybe two crater pairs.

Two such crater pairs have already been discovered: one in Quebec, and one in the Ukraine. But that doesn’t mean a third pair is outside the realm of possibility — sometimes three coin flips all come up “heads” even when you’d expect at least one “tails.”

More to Learn; Expect Skeptics

“Both Hiawatha and this second possible crater fall into an unusual category of impact craters,” says MacGregor. “They are on Earth, but they’re covered by ice, which makes them relatively hard to sample in all the ways that one would like to.”

To truly confirm a crater as an impact crater, MacGregor explains, the terrestrial impact geology community is going to need a lot more than a gravity anomaly. But the info they need is under a mile of ice.

“Maybe a different way to think about it is that it takes about 10 seconds to convince a planetary scientist that these are impact craters,” jokes MacGregor, “but it’ll probably take 10 years to convince the terrestrial impact geologists.”

MacGregor says there’s talk of the type of laborious expedition that would be required to study the craters, but no firm plans yet. For now, he’s not quitting his day job with Operation IceBridge, despite his new track record studying craters.

“It’s a lot of fun, but I’ll remain a glaciologist,” says MacGregor. “For hopefully clearly many good reasons, we still want to know a lot more about what ice is going to be doing in the future.”

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Ecology

Yukon and Northern BC First Nations tackle climate change using Indigenous knowledge and science

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YUKON, June 18, 2021 /CNW/ – The Government of Canada is working together in partnership with Indigenous and Northern communities in finding solutions to adapt to the impacts of climate change in the North.

Today, Minister of Northern Affairs, Daniel Vandal, along with Parliamentary Secretary to the Minister of Economic Development and Official Languages (Canadian Northern Economic Development Agency), Larry Bagnell, highlighted progress on three unique, Indigenous-led projects that are helping communities in Yukon and Northern British Columbia adapt to the challenges posed by climate change.

The Minister and Parliamentary Secretary met virtually with Carcross/Tagish First Nation (C/TFN) to learn about their community-led climate change monitoring program. C/TFN has partnered with Tsay Keh Dene Nation (TKDN) and Chu Cho Environmental of Prince George, British Columbia, to build a community-led monitoring project that examines environmental data and Indigenous knowledge to create a holistic picture of how the climate is changing across C/TFN and TKDN traditional territories. The project combines tracking of current and historical climate trends with knowledge shared by Elders while also providing opportunities for youth mentorship and climate change awareness.

The Taku River Tlingit First Nation (TRTFN) is also leading a unique project to assess the impacts of climate change within their traditional territory. Climate change is causing many of the culturally significant ice patches to melt, exposing organic artifacts to oxygen and leading to rapid deterioration. The TRTFN ice patch mapping project will involve performing archaeological assessments to prevent the degradation of artifacts. Research will be guided by traditional knowledge, Elders and oral histories, when available, and heavily involve community, Elders, youth and Knowledge Keepers.

The Pelly Crossing Selkirk Development Corporation is leading the Selkirk Wind Resource Assessment project through the installation of a Sonic Detection and Ranging (SODAR) system. The initiative includes a feasibility study leading up to the construction of a renewable energy facility, including wind, solar and battery energy storage. Expanding clean energy within the region will have direct benefits for communities, including reduced reliance on diesel, job creation and revenue generation for Selkirk First Nation. 

These projects are delivering important environmental, social and economic benefits that lead to healthier, more sustainable and resilient communities across Yukon and Northern British Columbia. They also build community clean energy capacity and help to avoid the impacts of climate change.

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Ecology

Atlantic Provinces Ready For Aquaculture Growth

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Aquaculture is an important economic driver for rural, coastal and Indigenous communities, and Atlantic Canada is well positioned to increase aquaculture production as global demand for sustainably sourced seafood grows.

That is why the ministers responsible for aquaculture in the Atlantic provinces have agreed to the ongoing development and management of their industries based on common principles. A new memorandum of understanding has been signed by the four ministers, which extends the previous agreement signed in 2008.

“In a time when food security is especially important, it is good to see our aquaculture industry has grown steadily and is poised for continued growth in 2021 based on environmentally responsible, science-based policies and practices,” said Keith Colwell, Minister of Fisheries and Aquaculture for Nova Scotia. “Our Atlantic partnership continues to help the industry grow sustainably.”

Cooperation between the provinces and the aquaculture industry has led to improvements in pest management, environmentally sustainable aquaculture methods, aquatic animal health and policies to support the shared use of marine and freshwater resources. It also aims to align regulation and policy between the provinces to make the regulatory requirements easier to understand by industry and the public.

Each province has a comprehensive and robust legislative and regulatory framework to ensure environmental sustainability, economic prosperity and public accountability. The provinces update their legislation and regulations regularly. Nova Scotia revamped its regulatory framework in 2015; New Brunswick received Royal Assent for a new Aquaculture Act in 2019 and is working on the supporting regulations; Newfoundland and Labrador completely revised its aquaculture policy in 2019; and Prince Edward Island has recently drafted a new Aquaculture Act.

The ministers have agreed to continue to use science-based evidence for management decisions, thereby increasing public and investor confidence in the Atlantic Canadian aquaculture industry.

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Ecology

COMING SOON: A Healthy Environment and a Healthy Economy 2.0

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We all want the same thing: a clean and responsible energy future for our children and future generations while continuing to enjoy a high standard of living.

On December 11, 2020, the Prime Minister announced a new climate plan which he claimed will help achieve Canada’s economic and environmental goals.

The proposed plan by Environment and Climate Change Canada (ECCC) entitled “A Healthy Environment and a Healthy Economy” will have an initial investment of $15 billion of taxpayer’s money. It is built on 5 pillars of action:

  1) Making the Places Canadians Live and Gather More Affordable by Cutting Energy Waste

2) Making Clean, Affordable Transportation and Power Available in Every Community

3) Continuing to Ensure Pollution isn’t Free and Households Get More Money Back

4) Building Canada’s Clean Industrial Advantage

5) Embracing the Power of Nature to Support Healthier Families and More Resilient Communities  

In my paper, “A Healthy Environment and a Healthy Economy 2.0” I will objectively critique each pillar in the government’s new climate plan and provide alternative solutions to the same issues.

  This is an alternative plan that supports workers, protects lower income earners and creates economic growth while respecting the environment and focusing on the dignity of work.

  This plan abandons virtue-signaling projects and relies on Canadian ingenuity to build our economy and restore Canada’s role of responsible leadership in the world.

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