how was the sea created? – Ruthenium Zone

Question: how was the sea created?
- Keywords:
  sea
Asked by jonahbwhite to Ed, Hayley, Jason, Nathan, Sophie on 18 Mar 2013.
- Hayley Evers-King answered on 18 Mar 2013:
  
  There are a number of theories for possible sources (it could be a combination of all these things):
  – Water formed from outgassing as the Earth cooled down.
  – Water synthesised by early chemosynthetic (like extreme bacteria) and photosynthetic (like plants) life.
  – From collisions with ice rich comets/meteorites/protoplanets.

Question: how was the sea created?