Transcript Chapter 15 Lesson 1 Powerpoint

The Water Planet
Now we know why Earth is called
“The Water Planet”!!
The Water Planet
• Ok, so we know the Earth’s surface is 70%
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water
The oceans surround landmasses called
continents, which make up the remaining 30%
The continents divide the oceans up into 4
major parts: The Atlantic Ocean, The Pacific
Ocean, The Indian Ocean, and The Arctic Ocean
Seas
• Where two continents lie close together, a
smaller part of an ocean called a sea is
formed
• An example is the Caribbean sea – it
connects to the Atlantic ocean
Seas
• In fact, all of Earth’s oceans and seas are
connected and flow into one another
• So, Earth’s surface (partly) is made up of
one continuous body of water
How are geographical areas
located on Earth?
Latitude and Longitude!
Mapping the Earth
• Our planet is mapped by using lines of
latitude and longitude
• Today, in class, we will do an activity that
will help us remember how Lat and Long
works
• So, have a pencil handy
The Water Budget
• Earth’s water budget is the total amount of
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water contained in and on the planet
The oceans contain about 97% of all water on
Earth!
The Pacific Ocean is the largest ocean
Only 3% of water on Earth is freshwater
About only 1/3 of all freshwater on Earth is
found as liquid in lakes, rivers, and groundwater
Sea Level
• The sea level, simply put, is the point at which
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the ocean surface touches the shoreline
So, the amount of water in the oceans must
determine sea level!
Over Earth’s long geologic history, the sea level
has definitely changed
About 12,000 years ago, during the last ice age,
the sea level was about 100m lower than it is
today
Why?
Climate Change!
• Back then, Earth’s climate was much
colder, there was increased snowfall, and
as a result• Much of Earth’s water was frozen in the
form of glaciers and polar ice caps
• When water freezes, less is available for
the oceans and sea level drops
• What about today?
Present Day
• Since the last ice age, Earth’s climate has
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warmed significantly, causing much of this ice to
melt
This melting ice has added water to the oceans
(through rainfall and runoff)
So, sea level has risen because now with less
frozen water, more is available to the oceans
What does this mean for us?
Global Warming?
The Water Cycle!!
The Water Cycle
• Earth’s water cycle is the continuous
movement of water from the oceans to
the atmosphere and back to the surface
again
• It occurs through the processes of
evaporation, condensation, and
precipitation