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Oceans images

Oceans

 

 

The largest reservoir of water on Earth is the ocean.  

So that will be the first unit in our hydrosphere unit.

It also makes up the majority of Earth's surface and is home to the majority of life.

 

 

So what is an ocean?

How many are there?

 

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The 7 seas?

 

 

So what makes an ocean an ocean?

Salinity?

Size?

 

 

Profile of an ocean:

Image result for profile of ocean

Image result for profile of ocean

Light penetrates only so far.  That means that heat and photosynthesizers can only be so deep.  Oxygen levels also drop with depth.  pH changes as does salinity.  So pH, temperature, light, salt and oxygen levels all play a part in what can live where in the ocean.  These factors also change with the current and ocean.

The mixed layer has constant temp. and O2 levels due to sunlight and wave action.

The thermocline gets cold fast.

The abyss gets no light.

Image result for temperature profile of ocean

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So, as you can see from these: the temperature and salinity varies with the layer.  There are distinct layers.  

Image result for ocean floor features

There are marginal features as well as abyssal features.  One of my favorites is the atoll:

Image result for atoll

Image result for atoll

Image result for atoll

Image result for atoll

 

 

Some features of oceans are tides, currents, and waves.  Let's look closer at waves:

Image result for wave

Image result for wave diagram

Image result for wave diagram

What we see is a wave that has tripped and is falling over.

Winds are created by the wind.

 

If the winds blow at an angle to the shore, you get swash:

Image result for swash wave diagram

This results in a longshore current:

Image result for swash wave diagram, longshore current

 

Sometimes that longshore current deposits sand in sandbars (not always visible) and the backwash gets funneled through these narrows / shallows which speeds them up.  We call these riptides:

Image result for swash wave diagram, riptides

Image result for riptides

These look like dark patches:

Image result for riptides

 

These are not true currents.  Real currents are:

Image result for currents

The wind coupled with temperature and salinity differences makes water move.  The coriolis effect turns the currents clockwise in the Northern hemisphere and counterclockwise in the Southern hemisphere.

 

Tides are periodic rising and falling of the ocean due to the pull of celestial objects (mostly the moon).  We will learn more about them when we learn about the moon.  But for now, just know that we get two high tides and two low tides each day.  About 6 hours, 12 and a half minutes from one to the next.  So, 12 hours, 25 minutes between two high tides or two low tides.

Image result for tides

Image result for tides

 

While having nothing to do with tides, the "tidal wave" is actually a tsunami and caused by underwater land movements:

Image result for tsunami

As you can see, the wave out in the ocean is small.  It only gets big close to shore.Image result for tsunami creation

 

 

 

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