Ocean Formation
How did the oceans form??
Formation of the Ocean
 Earth is
approximately 4.6
Billion Years Old
 Oceans formed 2
possible ways:
 Comets
 Volcanism
Comets
 Comets hit the Earth and
released water
 The water filled the ocean
basins over geologic time
Volcanism
 Volcanoes release
Water Vapor, Carbon
Dioxide and other
gases
 Water vapor
condensed to form
water droplets that
formed the oceans
Chemical Properties of Seawater
 96.5% Water
 3.5% Dissolved
salts
 NaCl is most
abundant
Salinity
 Measure of the
amount of dissolved
salts in seawater
 Expressed in ppt
(Parts per thousand)
35 ppt
How Does Water Become
Salty?
 Volcanic gases
contain chlorine and
sulfur dioxide which
dissolve into water
 Weathering of rocks
and minerals
Salt Removal
 Sea Spray
 Evaporite Formation
 Water evaporates
and salt is left
behind
Desalination
 Process that turns saltwater (saline) into
potable (drinkable) freshwater
 Common Methods of Desalination:
 Distillation
 Reverse Osmosis
Distillation
 Saltwater is heated
to boiling point and
creates water vapor
 The heated water
vapor is cooled and
condensed as
freshwater
Reverse Osmosis
 Seawater pressed through semi permeable
membrane that allows water, not NaCl to
pass through
Why would we want to remove salt?
 Humans need freshwater to survive
 Of the 3% of freshwater, most is unavailable to
us! (glaciers)
 In case of drought conditions, water would still
be available
Environmental Concerns
 Loss of Habitat for organisms that live in the
area where the water is taken from
 Waste (salt) disposal
 Higher concentrations of salt being added back to
an environment that is not adapted to those
conditions
 Costs Money and uses Energy
 Greenhouse gas emissions from distillation
plants