Yellow Submarine

Revelations 8:8-9

"Then the second angel sounded his trumpet, and something like a great mountain burning with fire was thrown into the sea. A third of the sea turned to blood, a third of the living creatures in the sea died, and a third of the ships were destroyed."

Given that over 90% of the earth's crust is made of silicates the force of an asteroid hitting the earth may be equivalent to 50 billion nuclear bombs going off at once.  What happens when you heat sand, also known as silicon dioxide? 

A glassy sea!

If the scripture suggests an impact sufficient to wipe out a third of the fish and ships it is likely that one face of the planet will have the most damage.  Is it the Pacific?  Atlantic?  Arctic?

While Elon Musk is busy tasking about Mars and Moon colonies the highest yield safe domain about us is ocean.  While Mars has neither atmosphere nor heat the waters of earth are a shield and a store.

All of the earth's crust is subject to deformation from an impact event.  More than likely a tsunami would engulf much coast but if there is to be a glassy sea above one prefers the deep.

Underwater currents are rivers with known trajectories and abundant spin for turbines and  electricity.  Water desalination is one research key as will be pressure standards.  Growing food from deep ocean tiles miles high will increase efficiencies manifold.

The Marianas Trench is the deepest part of the ocean at nearly 7 miles and 1000 atm of pressure requiring the top engineering to fit for colonies but offering one of several key safety reserves in case of doomsday.

The asteroid - if it lies as do most solar system bodies in the ecliptic plane - could be best avoided at the poles.  The equator presents the largest surface area from an an angle of attack parallel to the equator while the poles present the smallest surface area to the angle of attack.  

The cold will provide a good shield against impact meltdown too.  Under the ice may in fact prove safest.  Like the ancient Greenland Sharks living over 400 years have found.

https://en.m.wikipedia.org/wiki/Greenland_shark

The Greenland Shark produces a compound like nitrous oxide - which likely forms when divers are under awhile and causes giddiness.  NO has been associated with long life.  Water and depth pressure may prove more useful than we know.

Yellow Submarine!