Greenland impact crater support Young Dryas theory?

[Brian G Turner]

The theory that an asteroid impact around 12,000 BC caused a new Ice Age has been given clear support by the discovered of a 30km crater under the Greenland ice-sheet - which has a preferred dating of around 13,000 BC: Greenland ice hides huge 'impact crater'

Phil Plait also wades in on the subject, and highlights some of the range of errors - for example, the impact crater might date from 3 million BC instead: Deep freeze impact: Scientists find a *huge* asteroid impact crater under Greenland’s ice

In the meantime, the Young Dryas theory - which posits an impact caused our most recent ice-age - remains contentious: Younger Dryas impact hypothesis - Wikipedia

Either way, it makes for a very interesting discovery, because if proven true then it could help provide a clearer understanding of prehistory.

 

[Robert Zwilling]

Maybe hitting a thick bed of ice created a massive steam explosion that vaporized whatever was thrown out and maybe straight up into the atmosphere rapidly injecting nothing bigger than dust which stayed up in the sky for a long time. There is fractured sand in the area which must be coming from somewhere, perhaps it was forced downward and never got in the air, not much going sideways.

A layer of ice would completely change the nature of the explosion. The ice might splash out as fast as water would, hanging around an extra second might make for a much worse explosion. A layer of ice backed by thick rock might even make a shaped explosion. A strange feature of nuclear bomb explosions under water is that there is no sign of what happened afterwards. Maybe the cold ice on rock also creates unusual explosions.

There are many routes leading into and out of an ice age, none of them clear cut, but injecting a large amount of fine dust into the upper atmosphere would seem to be one way to trigger a short lived ice age if other conditions were right. The timing of the rising rising waters and glacier formation around 12,000 years ago have been described as pulsed. An ending long term ice age would be bumpy, events could push it temporarily one way or another as it ran out of steam.

We have been entering this current warming period for a long time now. Much longer than realized. Supposedly things like aerosols slowed down the warming up by adding a filtering layer to the atmosphere. All those above ground nuclear bomb test explosions injected a lot of dust into the air, maybe that slowed things down as well. Just have to wait for the crater floor to be examined to find out more, someone will want to do it fairly soon.