12,800 years ago, the last deglaciation has been interrupted during thousands of years : no more ice melting, no more sea level rise, global temperatures decreased again. Despite we can easily explain the origin of this cold event through interhemispheric balance, ice dynamics and oceanic currents shutdown, recent discoveries indicate an iron asteroid hit Earth in the early stages of Younger Dryas, thus enhancing harsh climate conditions.
Watch here how looked this impact in real time, and what ancient humans noticed during this event.

----- TIMECODE -----
0:00 Introduction
1:34 Impact
5:54 Twice more powerful than Yellowstone
7:39 Fireball faded
11:10 The earthquake reaches northermost human settlements
16:30 The ejectas fall upon northermost human settlements
21:53 The earthquake is to weak to be felt by humans anymore
32:33 No more ejectas beyond this point
1:01:40 Timelapse of the air blast
1:03:00 Discussion about climate change during Younger Dryas

----- SOURCES -----

The simulation is based on Impact! Earth algorithm
Simulator : https://impact.ese.ic.ac.uk/ImpactEar...
Equations : https://impact.ese.ic.ac.uk/ImpactEar...
Impact on ice : https://arxiv.org/ftp/arxiv/papers/21...
Evidence of heavy elements in ice-cores: https://www.pnas.org/content/110/32/1...
Crater formation :    • Hiawatha impact crater, 1.5 km pre-im...  
Impact debris fields : https://www.researchgate.net/publicat...
And Wikipedia, of course

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