The Hydrosphere Part II- Ocean & Freshwater Resources

DO NOW 1.What are the major oceans? (list all that you can). 2.Rank the oceans you listed in #1 in terms of their size. – Put a #1 for the largest – End with the highest # for the ocean you think is the smallest. 3. What differentiates ocean water from fresh water?

The World Ocean All oceans collectively

The Earth’s Oceans Ranking from largest to smallest: 1.Pacific 2.Atlantic 3.Indian 4.Southern (Antarctic) 5.Arctic  What differentiates ocean water from freshwater? Salt!  Where does the salt come from? Rocks!  What does the term salinity mean? [dissolved salts]

Think!  What properties of water do you remember from biology and chemistry?  What do you think is the most important function of the world ocean?

Global Temperature Regulation  One of the most important functions of the world ocean is to absorb and store energy from sunlight. -oceans absorbs over ½ of the solar energy that reaches Earth’s surface.  This helps regulate temperatures in Earth’s atmosphere! - Water has a high specific heat capacity! -Absorbs and releases energy slowly! Heats & cools slowly! - Without the oceans, temps on Earth would be too hot for life to exist.

Think!  What is the definition of current?  What do you think is the function of ocean currents?

Ocean Currents  A current is continuous directional movement of ocean water  Currents circulate warm water causing the land areas they flow past to have more moderate temperatures.  Movement of the ocean is influenced by various factors: – The sun (solar heating) – Wind – Gravity

Ocean Currents Surface currents Wind driven Result from global wind patterns May be warm-water currents or cold-water currents Can influence the climate of the land they pass Deep currents Stream-like movement of water that flow very slowly along the ocean floor Always cold Form when cold dense water from poles sinks below warmer, less dense ocean water and flows toward the equator

Freshwater Most of the water on Earth is salt water in the oceans (97%!) Remaining water on Earth is fresh, but of that, most fresh water is in icecaps and glaciers. Very little fresh water is available on land  Why? Where is this freshwater found? In what form?

Where does the readily available fresh water come from?  List any sources you can think of

Where does the readily available fresh water come from? Lakes Rivers (streams and creeks) Wetlands Soil Rock layers below the surface The atmosphere

A River System A river system is a network of surface waters that drain an area of land. It includes the main river and all of its tributaries. A river is surface water finding its way over land from a higher altitude to a lower altitude, due to gravity

Ground Water Ground water: rain or melting snow that trickles down or percolates through the soil and collects in sediment and rock formation  Accounts for only 1% of all water on Earth, but fulfills human need for fresh drinking water, and water for agriculture and industry

Aquifers Aquifer – an underground formation that stores groundwater Upper boundary of aquifer is called the water table Most consist of rock, sand and gravel that have a lot of spaces where water can accumulate Important water source for many cities and agriculture

Do Now: Have you ever dug a hole at the beach and reached water?  What is going on with this phenomenon?  Why did you find water?  If this has NOT happened to YOU, why does it happen to some people?

Do Now: Have you ever dug a hole at the beach and reached water?  What is going on with this phenomenon? You’ve reached the water table!  Why did you find water? You reached the aquifer  If this has NOT happened to YOU, why does it happen to some people? Dug deeper,

Closure Video FNg