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 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/cm 3. The density of ice at 0°C is 0.92 g/cm 3. 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.

MagnesiumMagnesium 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.

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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.