Total Kill: why working together matters.

on the Burckoe impact map there is a larger impact predating it. 

Multiple shelf collapses, bay excavations, even erosion of mountainous landmass as indicated by the sumatra debris field. That kind of damage is monstrous compared to the minor damage of the Burckle impact near the same location.

Now lets say that Apophis which will impact off North America in the Pacific is somewhere inbetween those extreems. The tidal waves will collapse various shelves. Erode coastline forming bays. And push mountainous lands into the sea- particularly those of soft volcanic ash.. Hawaii, Taiwan, Japan, Philipines, .. gone.

Its time to build a three billion population city on the south-west coast of Australia. Mass produced and modular. Move the human race to safety, and stockpile billions of tons of vegemits as a nutritional supplement.
 Because agriculture is going to take a hit.