Water on Earth
Hydrologic Cycle
The Science of the
Water Cycle
HydrologicCycle
Composition of Sea Water
The Oceans of the world
Water Everywhere!
Is water a matter?
-What is matter?
It has Mass and Volume.
Water is …
a chemical compound (H2O)
comprising two atoms of
hydrogen and one atom of
oxygen, in liquid state ...
Two hydrogen atoms share their electrons with
one oxygen atom to
- - form the electrically
+ + polarized water
molecule
- -
- - +
- - - -
+ +
+ + + +
- -
+ + - -
-
- - +
- - -
When water freezes to
- - ice, the angle of
- - +
- hydrogen bonding
+ + expands from 105° to
- ++ 105°
109°.
-
- - +
- - -
- +
As the space taken by - -
27 water molecules is + +
now used by 24 - ++ 109°
molecules, the density of
ice is less than the - - -
density of water, i.e., - +
water freezes over.
Hydrogen bonding of these electrically
polarized
molecules
gives water
the
properties
of cohesion,
adhesion
and
dissolving
power.
3 States of Water
Gas – Water
Vapor
Solid – ice
Liquid -water
3 States of Water
Solid- molecules packed together and
vibrating very slowly
Liquid -Molecules loosely packed and
sliding past each other
Vapor (gas) - Molecules are spread far
apart and moving fast
3 States of Water
https://phet.colorado.edu/en/
simulation/states-of-matter
Where does this “energy” come from to
change the state the water is in?
This process is driven by the sun and its
energy
Hydrologic Cycle
https://edpuzzle.com/assignments/
5f9340c91ac80f40a274fbf3/watch
What is the Water Cycle?
the pathway of water as it moves in its
various phases to the atmosphere, to the
earth, over and through the land, to the
ocean and back to the atmosphere”.
Water Cycle- Evaporation
The sun heats up liquid water
and turns it into water vapor (gas)
Water vapor is invisible
The “smoke” we see
is from the vapor
condensing…
Evaporation animation
Water Cycle- Transpiration
Do plants sweat?
Well, sort of.... people perspire (sweat) and plants
transpire.
Transpiration is the process by which plants
lose water out of their leaves.
Transpiration gives evaporation
a bit of a hand in getting the water
vapor back up into the air.
Water Cycle- Condensation
Water vapor in the air gets cold and
changes back into liquid, forming clouds
Condensation animation
Water Cycle- Precipitation
The solid or liquid water that
Falls from the air to the surface
-rain, snow, sleet, hail…
Water Cycle- Runoff
Water that flows across land and
collects in rivers, streams, and
eventually the ocean
Water Cycle- Groundwater
Water
located
within the
rocks below
the Earth’s
surface
Review
Conservation of Matter
Water cannot be created, nor destroyed.
It cycles. It changes state (remember
the 3 phases- solid, liquid, gas) it never
decreases or increases in total amount.
We do not have more or less water now
than we did millions of years ago!!
The Water Cycle just keeps going, and
going, and going, and going……
Composition of
Seawater
What are the components of
Seawater?
1. Go to www.menti.com
2. Use the code to answer 20 46 862
3. or you can also use the link
https://www.menti.com/id5yixqh6t
Common
salt (NaCl)
thus
dissolves
in water
most
readily. It is
the ocean’s
most
abundant
constituent,
therefore.
Major Components of Seawater
dissolved salts - hydrated anions and
cations (Table 7.1;, f. 7.3)
dissolved gases - nitrogen, oxygen, carbon
dioxide
organic and inorganic - dissolved organic
materials suspended particulate matter
Major Ions in Typical Seawater
Ion Parts per thousand by weight ‰ (ppt)(Table 7.1)
Cl- 18.98
SO4-2 2.649
HCO3- 0.140
Na+ 10.556
Mg2+ 1.272
Ca+ 0.400
K+ 0.380
Major constituents of Seawater at
Constituent 3.5% Salinity
Water:
85.8%
Oxygen (O) only 2% of Cl in
Hydrogen (H) 10.7% seawater could
The most abundant ions have come from
land sources
Chloride (Cl-) 1.9%
1.1%
Sodium (Na+)
0.3%
only 20% of sulfur in
Sulfate (SO42-) 0.1% seawater could
Magnesium (Mg2+) 0.04% have come from
0.04% land sources
Calcium (Ca2+)
0.01%
Potassium (K+)
-
Salt brought in by run-off from
land can explain only ~2% of Cl
and ~20% of S in the seawater
The World’s Oceans
71% of the Earth’s surface is covered by
water.
The oceans contain 97% of the earth’s
water.
All the oceans and seas are actually one
continuous body of water.
Oceanographers are scientists who study
the ocean and its processes.
Importance of Oceans
• Oceans affect all
living things—
even those far
from the shore.
• Oceans provide
a place for many
organisms to
live.
How were the oceans formed?
When Earth was still a young planet,
many active volcanoes existed. As
they erupted, lava, ash, and gases
were released from deep within the
Earth.
One of these
gases was
water vapor.
Ocean or Sea, What’s the Big Deal?
SEAS
Delineated by land masses
Doesn’t matter if they’re largely enclosed
Also “communicate” with the ocean
Europe
Strait
Unitedof States
Gibralter
Black Sea
Gulf of Mexico
Mediterranean Sea
Africa
Mexico
Oceans
The oceans are the
Atlantic
Pacific
Indian
Arctic.
Around the World Arctic
in 4SeaSlides…
Mediterranean Sea
Gulf of Mexico
Caribbean Sea
Begins at 60°S
Around the World in 4 Slides…
Bering Sea
Gulf of Alaska
Sea of Japan
Begins at 60°S
Around the World
Persian Gulf
in 4 Slides…
Red Sea Arabian Sea
Begins at 60° S
Around the World in 4 Slides…
“Defined” in 2000
Begins at 60° S
Bragging Rights…
Which ocean is the biggest?
OCEAN SURFACE AREA [km2] OF ALL
OCEANS…
Atlantic 90,818,000 27.1%
Indian 68,556,000 20.4%
Pacific 155,557,000 46.4%
Southern 20,327,000 6.1%
Bragging Rights…
Which ocean has the most
coastline?
OCEAN COASTLINE LENGTH [km]
Atlantic 111,866
Indian 66,526
Pacific 135,663
Southern 17,968
