Another 90 metres of material were deposited by ocean water flowing back into the vast crater: the tsunami backwash.

Despite huge advances in anti-submarine search techniques, the nature of the ocean water mass continues to assure their invulnerability.

Life, mostly algae, cyanobacteria and other bacteria, somehow persisted in the small ice-free pockets of ocean water.

Ocean water contains seven times more salt than the human body can safely ingest.

It contained too much deuterium (heavy hydrogen) and could not, therefore, have provided our ocean water.