Newly Discovered Recent Impact Crater In Greenland

Map via Gizmodo Australia
University of Kansas

About 10 years ago a group of researchers from various fields proposed a theory. This theory set out to explain the onset of the Younger Dryas (YD) episode of our current interglacial period. Their theory proposed a huge impact event as the trigger for the YD episode. Their comprehensive claims included a 4km wide impact object, massive continent wide wild fires across the Northern Hemisphere, and extensive global flooding. Of course their evidence was ruthlessly debunked by their critics, most of which was valid due to the extravagance of their claims. (4)

Before and since the question of what caused the Younger Dryas episode has remained largely unanswered. Since the end of the last Ice Age (~3 - 2.5 million YAG) climatologists have concluded that the Earth has experienced approximately 25 brief cooling periods or cycles, referred to as Dansgaard-Oeschger (D-O) events. One argument of critics against any impact triggering theory is that they consider the Younger Dryas as nothing more than another one of the D-O cycles. This is in spite of the fact that known and accepted data singles out the Younger Drays as the most significant climate period in recent history, up to our own time. The Younger Dryas returned climate to almost ice age norms, with average global temps dropping 8ᵒC. The extreme of the Younger Dryas from climatological norms implies that there is more to the story than just another D-O cyclonic event.

The Ice Layers over the suspected impact crater.
Graphic: C. Bikel/Science via science.sciencemag.org

Fast-forward to 3 years ago, when researchers from University of Copenhagen noticed an anomaly about 19 miles wide and 1000ft deep on images from NASA's Operation Icebridge. (1) They wondered if it might be a 31km wide crater, that could have been created when an iron object up to 1.5km wide slammed into Greenland within recent history, geologically speaking.(4) The last 3 years have been spent seeking the cause of the anomaly. This was done using a more specialized German research plane equipped with special radar, as well as, putting boots on the ground to make field observations and collect runoff samples.(1)

So what did their 3 years of subsequent research yield?

The ice is perfectly layered over the past 11,700 years, then it becomes disturbed during a range consistent with the Younger Dryas period. The collected samples contained "shocked quartz" and 'glass' that was forged at temps higher than those found in volcanic activity.(4) The collected "shocked quartz" samples' profiles identified an enrichment of rhodium and palladium along with a depletion of platinum, usually associated with impacts of unique iron objects. The signatures are similar to the iron meteorite fragments previously recovered from various locations in the region, collectively known as the Cape York fragments, which are dated to 10,000 YAG.(2)

The Cape York fragments include "Agpalilik" (Inuit for "the man") a 20 ton piece of iron meteorite on display in the courtyard of the National Museum of Natural History in Copenhagen. The American Natural History Museum states their "Ahnighto" fragment, which is 34 tons, and also part of the Cape York impact, struck Earth approximately 10,000 YAG. Their display information goes on to state that the piece was either a break away part of a larger object or part of a collection of multiple objects impacting simultaneously.

"Ahnighto" fragment via ANHM website.

In addition, the German research plane, collected images from their specialized radar that can penetrate ice sheets and map the terrain beneath. The images were studied and revealed the probable existence of a circular formation with 1000ft rim and central upwellings in the floor suggesting the anomaly being the result of an impact event.(1)

From the above data, the logical theory suggests that a significant object between 1/2 and 1 mile across impacted Greenland within the last 100,00 years  releasing 700megatons of energy and creating the Hiawatha crater. (1,4)

"The impact would have been a spectacle for anyone within 500 kilometers. A white fireball four times larger and three times brighter than the Sun would have streaked across the sky. If the object struck an ice sheet, it would have tunneled through to the bedrock, vaporizing water and stone alike in a flash. The resulting explosion packed the energy of 700 1-megaton nuclear warheads, and even an observer hundreds of kilometers away would have experienced a buffeting shock wave, a monstrous thunder-clap, and hurricane-force winds. Later, rock debris might have rained down on North America and Europe, and the released steam, a greenhouse gas, could have locally warmed Greenland, melting even more ice." (4)

Due to the nature of glacial ice the logical conclusion would be that the impact would have to date closer to 12,000 YAG than to the 3million year mark. "The crater is exceptionally well-preserved, and that is surprising, because glacier ice is an incredibly efficient erosive agent that would have quickly removed traces of the impact," Kurt H Kjær (1)

In addition, in an attempt to disprove the YD Impact Theory, mentioned in the first paragraph, which is connected to the new research out of the University of Copenhagen, that this article focuses on, there was a study of ice core samples in 2013 that did not succeed. This study actually gives indirect supporting evidence to the new research being an impact crater. The 2013 study revealed a similar platinum spike as the crater samples. That being said, 'significant' multiple samples have been lacking.(4)

Paris fits inside the crater. NASA imaging
via Australian Broadcasting Corporation

Consideration should be given to Brandon Johnson, Brown University, who leads research using iSALE model to study the impact event on icy moons and objects. The iSALE model suggests that an impact occurring when the ice is 1.5 ~ 2km thick would significantly inhibit the typical debris eruption showers seen in wholly terrestrial impacts.(4) Thus it could be supposed that the lack of 'significant' multiple supporting or confirming ice core samples could be the result of a smaller debris field that while being ice could be vaporized and melted into flash run off carrying the evidence with it into other areas and or dispersing it in unnoticeable remnants in unrelated or non-local areas.

Retired geophysicist, Allen West, explains that an ice sheet impact could result in significant (immediate) climate issues. These could include increased rainfall due to vaporization and change in ocean temps due to disturbance discharge in the forms of ice cleavage and runoff.(3) In addition, Dr. Mathieu Morlighem (UC-Irvine) explains that impact craters could be hidden under current ice sheets. This possibility would make locating and dating challenging, not to mention that the erosive actions of glacial movement would erase their presence before their discoveries as well.(2)

The new research has many critics, such as Ludovic Ferriere (Natural History Museum in Vienna) who told National Geographic, it could just be a natural depression and he would want ultimate proof in the form of crater floor sediment samples.(1) Similarly, J. Severinghaus, Scripps Institution of Oceanography in San Diego, cites lack of supporting evidence in other ice core samples dating to 100,000YAG for doubting the research conclusions stating, "You really ought to see something."(4) However, just because you do not see something you think you ought to see, does not mean that it does not exist.

Then J. Melosh, Purdue Univeristy, doubts that if the crater is an impact event, that it could be from the 12,000~100,000YAG time range based solely on a statistical belief that large impacts ONLY occur every few millions of years. Melosh goes on to imply that Science's reporting on this is reckless, "You're aware you're going to set off a firestorm?"(4)

66million YAG an object hit Earth creating the 200km Chicxulub crater; then 35.5million YAG another object struck the Chesapeake Bay area leaving a 85km scar; now there is evidence suggesting that between 100,000 and 12,000YAG a smaller, but still significant object struck Greenland giving us the 31km Hiawatha crater. Based on these stated examples and taking into account the hypothesis that as the Universe has aged the chaos regarding debris impact risks has lessened, the possibility of the accuracy of the Hiawatha impact theory increases to probability.

Once again we see the same problem occurring; when someone makes up their mind that something completely is or isn't it is virtually impossible to change their opinion, not matter the truth. This trait is especially detrimental to science! The reality is that some even when provided with a preponderance of evidence, in some cases the very evidence that they demanded needed as proof, they will still deny the logical conclusion and demand even more proof. Fulfilling their demands is of course futile as their demands will only become absurd. The tragedy is when these obtuse individuals hold positions of respect and authority (ex. tenure) on such level as to suppress new information from being openly and intelligently discussed and analyzed and judged on its own factual merit alone.

If the Hiawatha impact crater can be accepted by the science community, it would be one of the 25 largest impacts known.(1)

References:

1. @jasondaley608, F. and Daley, J. (2018). Massive Impact Crater Found Under Greenland's Ice. [online] Smithsonian. Available at: https://www.smithsonianmag.com/smart-news/massive-impact-crater-found-under-greenlands-ice-180970829/ [Accessed 16 Nov. 2018].

2. Amos, J. (2018). Greenland ice hides huge 'impact crater'. [online] BBC News. Available at: https://www.bbc.com/news/science-environment-46181450 [Accessed 16 Nov. 2018].

3. Groves, A. (2018). Impact crater beneath Greenland could help explain Ice Age. [online] Astronomy.com. Available at: http://www.astronomy.com/news/2018/11/massive-impact-crater-beneath-greenland-could-explain-ice-age-climate-swing [Accessed 16 Nov. 2018].

4. Voosen, P. (2018). Massive crater under Greenland’s ice points to climate-altering impact in the time of humans. [online] Science | AAAS. Available at: https://www.sciencemag.org/news/2018/11/massive-crater-under-greenland-s-ice-points-climate-altering-impact-time-humans [Accessed 16 Nov. 2018].

5. YouTube. (2018). Younger Dryas Impact Crater Discovered in Greenland? | Ancient Architects. [online] Available at: https://www.youtube.com/watch?v=DvkD-sQe-nc [Accessed 16 Nov. 2018].

6. Kjær, K., Larsen, N., Binder, T., Bjørk, A., Eisen, O., Fahnestock, M., Funder, S., Garde, A., Haack, H., Helm, V., Houmark-Nielsen, M., Kjeldsen, K., Khan, S., Machguth, H., McDonald, I., Morlighem, M., Mouginot, J., Paden, J., Waight, T., Weikusat, C., Willerslev, E. and MacGregor, J. (2018). A large impact crater beneath Hiawatha Glacier in northwest Greenland. [online] Science Advances. Available at: http://advances.sciencemag.org/content/4/11/eaar8173/tab-pdf [Accessed 16 Nov. 2018].

7. Johnson, B., Silber, E., Bjonnes, E., Kjaer, K., Wiggins, S., MacGregor, J. and Larsen, N. (2018). Formation of terrestrial craters on thick ice sheets. [online] AGU - AGU Fall Meeting 2018. Available at: https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/448365 [Accessed 18 Nov. 2018].

8. Lpi.usra.edu. (1963). The Meteoritical Bulletin No 28.. [online] Available at: https://www.lpi.usra.edu/meteor/docs/mb28.pdf [Accessed 18 Nov. 2018].

9. En.wikipedia.org. (2018). Cape York meteorite. [online] Available at: https://en.wikipedia.org/wiki/Cape_York_meteorite [Accessed 18 Nov. 2018].