2. Chemical Oceanography

Lets take a quiz to see how much you know!

http://ga.water.usgs.gov/edu/sc3.html (1) Water contracts (gets smaller) when it freezes.

(2) Water has a high surface tension.

(3) Condensation is water coming out of the air.

(4) More things can be dissolved in sulfuric acid than in water.

(5) Rainwater is the purest form of water.

(6) It takes more energy to heat water at room temperature to 212o F than it does to change 212o F water to steam.

(7) If you evaporate an 8-inch glass full of water from the Great Salt Lake (with a salinity of about 20% by weight), you will end up with about 1 inch of salt.

(8) Sea water is slightly more basic (the pH value is higher) than most natural fresh water.

(9) Raindrops are tear-shaped.

(10) Water boils quicker at Denver, Co. than at the beach.

What is Chemical Oceanography and why are

we learning it now?IT IS: “The study of the interactions

between the elements and the world’s oceans”

What’s so special about seawater?1) Every element naturally occurring on

earth can be found in seawater! 2) Seawater contains about 3.5% (35ppt)

saltImportant Note: The Principle of Constant Proportions states that: the concentrations (amounts) of seawater

ions don’t change! What does this mean?

Other Cool Stuff You Should Know About Ocean Water:

3) Water Temperature, Salinity, and Density change with Depth

**LOOK OUT!!! Very Important Vocab Below!**

More Important Water Stuff to Consider!Think about what these mean!!! Ask

questions!!!

4) Water has a high heat capacity

5) What happens to salinity when ice forms in seawater? How does this affect the density of the seawater? (Great Test Questions!)

Tools Frequently Used For Chemical Oceanography

• Secchi Disk• CTD Rosette• Niskin Bottles• Hydrometer• Refractometer

Secchi Disk

• Measures turbidity (cloudiness) of the water

• What can make water turbid?– Plankton– Sediment– Pollution (i.e. sewage)

How do we collect water to sample?

Primary Sampling Gear for Chemical Oceanography:

CTD Rosette-a collection of water sampling bottles

Niskin Bottles Collect water from various depthsCan be used on a Rosette or alone

The “messenger”- triggers the Niskin to shut at both ends

messenger

Once you have the water sample, then what?Devices to Measure Salinity

Indirectly-hydrometer Directly-refractometerProvides density, use a chart Provides salinity by lookingto convert density to salinity at sample placed on the lens

What types of problems do chemical oceanographers study?

Hypoxia – low DO (dissolved oxygen)

**why is this a problem? Hint: take a deep breath and think about it!

Dead Zones!

What does the picture above have to do with the picture to

the left?