Massive crater under Greenland's ice points to climate-altering impact
 

Massive crater under Greenland's ice points to climate-altering impact in the time of humans.

That would explain the submerged and lost advanced civilizations that could have been flourishing. :yes:

The 31-kilometer-wide Hiawatha crater may have formed as recently as 12,800 years ago when a 1.5-kilometer asteroid struck Earth

Of course the "shocked quartz grains" formed could also come from a nuclear blast. :smoking:

https://youtu.be/gg0mAihbm58