Transcript Fields of Science

Chapter 22 Test Review
Place these notes in your
Meteorology Notebook.
Something to Think About:
"Our planet is invested with two great oceans;
one visible, the other invisible; one underfoot,
the other overhead; one entirely envelopes it,
the other covers about two thirds of its
surface."
Matthew F. Maury
From The Physical Geography of the
Seas and Its Meteorology, 1855
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Read the quote two or three times. What are
the two great oceans Maury mentions?
Why are both important to mariners?
SONAR
Water Molecules
Compared to the average elevation of the
continents, the average depth of the
ocean in about four times as great.
Elevation of continents = 1
Depth of the oceans = 4
The density of water at 4°C is 1.0 g/cm3.
The density of ice at 0°C is 0.92 g/cm3.
Many of the basic tools of modern
oceanography were developed to meet
military needs during World War II.
The average mass of dissolved salts in
1000 grams of seawater is around 35
grams. That’s approx. (3.5%)
Evaporation and freezing of sea water are
two factors that cause salinity of the sea
water to increase.
Water temperature and salinity are two
factors used to identify a water mass.
The most abundant ion in seawater is
chloride.
Sample A is 100 grams of water from the ocean
surface in the North Atlantic.
Sample B is 350 grams of water from the
ocean surface in the South Pacific.
Truths:
Both samples contain about the same
percentage of chloride ions.
Both samples contain the same types of ions.
Both samples contain magnesium ions.
Not True:
Both samples contain the same mass of
dissolved solids.
Magnesium can be removed in usable
quantities from seawater.
Gold and silver are not mined from sea
water because gold and silver can be
mined more cheaply on land.
If ½ of the solar energy that strikes the
ocean surface is absorbed in the first
meter, and ½ of what remains is
absorbed in the second meter, and so
on, 1/8 of the original sunlight reaches a
depth of three meters.
About 2% of the ocean’s volume is made
up by the mixed layer.
Strong wind is one factor that causes heat
to be mixed evenly in the mixed layer.
The thermocline is the zone in which
seawater temperatures change rapidly.
The Straits of Gibraltar prevent polar
water from entering the Mediterranean
Sea.
Salinity tends to be above average in hot
areas.
Diatoms are one of the most abundant
types of phytoplankton.
Diatom shells settle to the ocean floor
after diatoms die mixing with the
sediment.
The deep waters of the ocean tend to be
poor in oxygen and rich in carbon
dioxide.
Smokers are vents in the sea floor that
emit smoke that is black due to fine
particles of iron sulfide.
http://www.oceanfootage.com/vi
deo_clips/AG38_019
What process is responsible for raising
the salinity above 35 parts per
thousand?
High levels of evaporation .
At what latitudes would we expect to find ocean
surface salinities exceeding 35 ppt?
From about 15° to 35° north and 15° to 40°
south .
At what latitudes is the melting of sea ice most likely to
be important in decreasing salinity below 33 ppt?
Between 60° and 90° north. Low salinities between
about 0°and 10° south are due to several large rivers
entering the ocean and not due to melting of sea ice.
Explain how electrical conductivity could be used to
determine the mass of calcium ions in a sample of
seawater when the mass of the whole sample is
known.
As salinity increases, electrical conductivity also
increases. Conductivity is used to measure total
salinity. Salinity is then used to calculate the total
mass of ions present. The various ions in seawater
exist in constant proportion relative to each other.
The mass of calcium ions is therefore determined
by multiplying the total mass of ions by the
percentage of seawater that consists of calcium
ions.
Compare the food source of a clam that lives in
shallow water near the shoreline with the food
source of a clam that lives near a black
smoker vent in the deep sea.
The base of the food chain in shallow water is
phytoplankton that get their energy for
photosynthesis from sunlight. Near black
smoker vents, the base of the food chain is
bacteria that get their energy for
chemosynthesis from dissolved hydrogen
sulfide gas released from the vent.