15.1 Worksheet
1.
In chemistry, the word “salt” doesn’t just refer to the thing we sprinkle on our food (NaCl).
What kinds of things are included when we say “salt”?
2.
Salinity = the total amount of dissolved solids in water. What is the average salinity of ocean
water?
3.
What is the most common “salt” contained in sea water?
4.
What is the most common source of dissolved solids in sea water? What is the 2nd most
common source?
5. The salinity of the ocean is calculated with a simple ratio:
Amount of dissolved solids = salinity
Amount of fresh water
The ocean is very well-mixed and the processes that add dissolved solids remain relatively
constant. Therefore, it’s not likely that salinity would change by adding or taking away dissolved
solids. This leaves only one alternative: salinity can be changed be adding or taking away
amounts of fresh water. Below, make a list of the processes that will:
ADD fresh water, DECREASING salinity
REMOVE fresh water, INCREASING salinity
6.
The ocean’s surface waters will change temperature with the amount of solar radiation
(sunlight received). As you learned at the beginning of the year, the amount of sunlight the
Earth receives varies with latitude. Use the data from figure 3 to fill out the table below and
make a summary statement
Latitude
60 North
Approx. Surface Temp.
Summarize the relationship between
temperature and latitude:
30 North
0 (Equator)
30 South
60 South
7.
The sun can’t reach very far into the ocean. Because of this, the temperature begins to quickly
drop as you increase depth in the ocean. This rapid change in temperature with depth is called
the thermocline. Why is there no thermocline in the high latitude diagram below?
8.
Density = mass/volume (or how much stuff is in a given space). Density of sea water will change
based upon two factors:
a. Temperature. (Liquid) water expands when heated. Based upon this info, fill in the
blank below
Temperature increase = density ___________________
b.
Salinity. As you dissolve more solids into the same volume of water, you are putting
more “stuff” in the same space. Based upon this info, fill in the blank below
Salinity increase = density ______________________
9.
Based changes in salinity and temperature, the density of sea water will vary at different
latitudes and depths. This change in density with depth is called the pycnocline. What is the
single most important factor affecting density in this graph?
______________________________________________________________________________
______________________________________________________________________________
10. Why is density in sea water such an important factor?
11. Summarize the key differences between the following ocean layers
a. Surface zone
b. Transition zone
c. Deep zone
12. The diagram below shows a cross-section of the world’s oceans and how they vary by latitude.
Why do we ONLY see deep zone water at high latitudes?
Why do we see a large transition zone between 40N and 40S?