Why is the surface salinity of the ocean higher in the subtropics than in equatorial regions ?

On the ocean basin profile in the figure, label the following: continental shelf, continental slope, abyssal plain, seamounts, mid-ocean ridge, and deep-ocean trench.

Given your understanding of the relationship between ocean water temperature, salinity, and density, where would you expect surface water to sink and initiate a deepwater current flow in the Atlantic Ocean? Explain your choice.

Explain how an echo sounder is used to determine the bathymetry of the ocean floor.

Summarize the results of the salinity-density experiment (Activity 11.4A) and the temperature-density experiment (Activity 11.5A).

Salinity-density experiment:

Temperature-density experiment:

Processes that decrease seawater salinity include freshwater runoff and melting of icebergs and sea ice, while processes that increase seawater salinity include formation of sea ice and evaporation of seawater. Below each image in Figure 11.13, state whether the salinity of the seawater shown is increasing or decreasing.

Refer to the salinity-density experiment you conducted in Activity 11.4A. Did solution A or B have the greatest density? Solution had the greatest density.

Complete each of the following statements with the correct response. a. Does an increase in the salinity of seawater result in an increase or decrease in density? An increase in the salinity of seawater results in a(n) ____ in density. b. Does a decrease in the temperature of seawater cause its density to increase or decrease? A decrease in the temperature of seawater causes a(n) ____ in density. c. Are the highest surface salinities found in polar, subtropical, or equatorial regions? The highest surface salinities are found in ____ regions. d. Does temperature or salinity have the greatest influence on the density of seawater? ____ has the greatest influence on the density of seawater. e. Would warm or cold seawater, with high or low salinity, have the greatest density? ____ seawater with ____ salinity has the greatest density.

Summarize the results of the salinity–density and temperature–density experiments. Salinity–density experiment: _________________________________________________________________________________________________ Temperature–density experiment: _____________________________________________________________________________________________

Are the following statements true or false? Circle your response. If the statement is false, correct it to make is true. T F a. The Atlantic Ocean covers the greatest area of all the world’s oceans. T F b. Continental shelves are part of the deep-ocean floor. T F c. Deep-ocean trenches are located mostly in the middle of ocean basins. T F d. High evaporation rates in the subtropics (about $30^{\circ}$ latitude) cause the surface-ocean water to have a lower-than-average salinity.

Write a brief statement comparing the distribution of land and water in the Northern Hemisphere to the distribution in the Southern Hemisphere .

Explain how an echo sounder is used to determine the topography of the ocean floor.

Complete the following statements with the correct response. a. Does an increase in the salinity of seawater result in an (increase or decrease) in density? An increase in salinity results in a(n) _________________________________ in density. b. Does a decrease in the temperature of seawater cause its density to (increase or decrease)? A decrease in temperature causes a(n) _________________________________ in density. c. Are the highest surface salinities found in (polar, subtropical, or equatorial) regions? The highest surface salinities are found in ___________________________________ regions. d. Does (temperature or salinity) have the greatest influence on the density of seawater? ____________________________ has the greatest influence on the density of seawater. e. Would (warm or cold) seawater with (high or low) salinity have the greatest density? ______________ seawater with ______________ salinity has the greatest density.

In winter, sea ice forms in the polar latitudes. The water in this ice is essentially salt-free freshwater. How does the formation of sea ice influence surface salinity in polar regions? Show this change by sketching a line on Figure 11.9.