Now we know why Earth is called
“The Water Planet”!!

• Ok, so we know the Earth’s surface is 70% 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

• 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

• 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

Latitude and Longitude!

• 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

• Earth’s water budget is the total amount of 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

• The sea level, simply put, is the point at which 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?

• 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?

• Since the last ice age, Earth’s climate has 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?

• 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