Name: ________________________________ Per. _______ Date: _____________________

AICE Marine – Unit 7 Test Questions/ Study Guide (ANSWERS)

1. (a) Explain how an area of low pressure develops into a tropical cyclone.1. sea (surface) min. temperature 26°C ; A – 79 OF2. ref. evaporation ;3. warm moist air / water vapour rises;4. ref. condensation / heavy rain / precipitation ;5. releases heat / energy / correct ref. latent heat ;6. low wind shear ;7. (thunder)storms develop / formed / merge ;8. system / cyclone rotates / spiral winds ;9. ref. Coriolis effect / earth rotation ; [5]

Fig. 6.1 shows an image of a tropical cyclone taken from space.

(b) State two features of a tropical cyclone visible in Fig. 6.1.1 eye ; I – description of eye2 (eye) wall ; 3 spiral pattern of clouds ; A – circular pattern of clouds [2]

Fig. 6.2 shows the wind speed and air pressure of a number of tropical low pressure systems.A tropical low pressure system is classified as a tropical cyclone when the wind speed reaches

118 km per hour and the air pressure is 980 millibars or lower.

(c) State the relationship between air pressure and wind speed. as air pressure increases wind speed falls / ora ; A – inverse relationship [1]

(d) State the number of tropical cyclones shown on Fig. 6.2.28 ; [1]

Name: ________________________________ Per. _______ Date: _____________________

(e) Explain how tropical cyclones may have beneficial effects on human coastal communities.1. ref. to water / nutrients / named example ;2. to crops / ref. to agriculture benefitting ;3. improved productivity of (inshore) sea ;4. prevent desertification / revives arid land / prevents droughts ; [3]

2. An investigation was carried out into the relationship between depth and the salinity of water in an estuary.

For each depth, the salinity was measured at five different sites. The results are shown in Table 2.1.

(a) Complete Table 2.1 by calculating the mean salinity at a depth of 2 m.

20.94 ; [1]

(b) Using the information in Table 2.1, describe the relationship between depth and salinity.as depth increases, salinity increases / ORA ; A – more saline at 12 m than at

2 m

credit a manipulated quantitative reference, e.g. overall increase in salinity of 9.14 ‰ / reference to greater change between 6 m and 8 m ;

[2]

(c) Suggest an explanation for this relationship.1. idea of freshwater and seawater in an estuary ;2. freshwater is less dense than seawater / converse ;3. (therefore) freshwater floats A – lower salinity water floats on

top / ORA(on top of seawater) / sea water sinks A – less dense water floats on top /

ORA(below freshwater) ;

[2]

3. (a) Describe how tropical cyclones develop.any 4 of:warm water / 26.5 °C + ; I – high temperaturelow pressure area ;evaporation (of water) / water vapour rises ;

Name: ________________________________ Per. _______ Date: _____________________

water condenses ;releases heat / energy ;system / cyclone rotates / owtte ;reference to Earth’s rotation / Coriolis effect ; I – winds and clouds

[4]

Fig. 4.1 shows the air pressure at different distances from the centre of a tropical cyclone.

(b) With reference to Fig. 4.1, calculate the difference between the maximum and minimum air pressure.

64 / 65 millibars / mb ; [1]

Table 4.1 shows the wind speed at different distances from the centre of the same cyclone as in Fig. 4.1.

(c) Plot a graph of these data on Fig. 4.1.Use the right-hand y-axis for your scale.

Name: ________________________________ Per. _______ Date: _____________________

axis scaled and labelled ; I – if left axis usedline (labelled / key) ;plots ± 1 / 2 square ; - 1 for any incorrectsmooth or straight line ; R – thick / wavy / double line

line must go through plots [4]

(d) State the relationship between wind speed and distance from the centre of a cyclone.Suggest an explanation for this relationship.

relationship wind speed increases then decreases as distance from centre increases / ora ;ref. 40 km (from centre) ;

explanation (due to low) pressure in eye increasing with distance from centre / pressure

gradient increases with distance from centre ; [3]

4. Fig. 5.1 shows the relationship between depth and water temperature in a water column in the Indian Ocean.

(a) Between 100 m and 200 m depth there is a large fall in the temperature.State the name given to this part of the water column.

thermocline ; [1]

(b) On Fig. 5.1, sketch another line to show how you would expect the temperature of the water in the Arctic Ocean to vary.

line falling to left throughout ;

below 10 and not touching existing line at any point ; [2]

Name: ________________________________ Per. _______ Date: _____________________

(c) The density of sea water varies with depth.On Fig. 5.1, label with a line and the letter D, the position where the sea water has the greatest

density. State a reason for your choice. D at bottom of column / touching x-axis ;

density greatest when water coldest ; [2]

(d) State two factors that decrease the salinity of sea water.any 2 of:rainfall / precipitation ;less evaporation ;fresh water inflow / melting ice / owtte ;

[2]

(e) Explain why the dissolved oxygen concentration varies in the surface waters of the oceans.any 3 of:less oxygen with high temperature / ora ;solubility of oxygen decreases with increasing temperature ;increases due to mixing by waves / winds / turbulence ;increases / produced by photosynthesis (of phytoplankton / algae) ;decreases due to respiration ; [3]

5. (a) Outline the effects of evaporation and precipitation on the salinity of sea water.evaporation increases salinity ;

precipitation decreases salinity ; [2]

(b) Describe how salinity gradients form in water columns.salinity increases with depth / water with low salinity is above water with high

salinity ;(overall) change in salinity is small ;saltier water is more dense / ora ;denser water at bottom of ocean / ora ;reference to halocline / large, rapid change in vertical salinity gradient ; [3]

Fig. 6.1 shows an estuary.

Name: ________________________________ Per. _______ Date: _____________________

(c) On the axes below sketch a line to show how the salinity of the water changes as it flows from point A to point B. [1]

(d) Explain the shape of your line.fresh water at A with low salinity ;fresh water mixes with sea water at mouth of river / estuary ;gives low salinity at mouth of river / estuary ;salinity increases with distance from river ;normal sea water salinity in open sea / B ;

[4]

6. (a) Describe the features of a hurricane.low pressure area ;thunderstorms ;strong winds / wind speed of 74 mph / 119 kph ;heavy rain ; [4]

Table 7.1 shows some data about different categories of hurricane.

Name: ________________________________ Per. _______ Date: _____________________

(b) State the relationship between hurricane category and central pressure.

lower pressure, higher category / ora ; [1]

(c) Suggest the meaning of the term storm surge.

rise of sea water above mean sea level caused by severe weather system / owtte ; [1]

(d) Suggest how hurricanes can be beneficial.water to deserts / owtte ;fills reservoirs ;replace soil nutrients ;brings nutrients to sea surface / reference to upwelling ;named nutrient* ; * anywherereference to increased productivity ;reference to increased / faster crop growth / owtte ; [3]

7. (a) Describe how temperature and salinity gradients form in the oceans.increase in temperature decreases density / converse ;(therefore) warm water floats on top of cold ;temperature decreases as depth increases ;reference to thermocline in correct context ;as salinity decreases, density decreases / converse ;(therefore) less saline water floats on top of more saline ;salinity increases as depth increases ;reference to halocline in correct context ;

[6]

(b) The concentration of dissolved oxygen in sea water varies.Suggest and explain what effect each of the following would have on the concentration of dissolved oxygen:

an increase in wave action concentration of dissolved oxygen will increase ;reference to mixing of water with air ; [2]

an increase in the temperature of water in a shallow lagoonconcentration of dissolved oxygen will decrease ;reference to decreased solubility of oxygen as temperature increases ;

[2]

(c) Explain why India may experience heavy rainfall during the months of June until September.idea that air over land heats up ;air (becomes less dense and) rises ;this draws in cooler air from the Indian Ocean ;from SW direction ;air from the Indian Ocean is saturated with water vapour ;this air rises and cools further ;water vapour condenses and falls as rain ;

[5]

Name: ________________________________ Per. _______ Date: _____________________

8. Fig. 2.1 shows the oxygen concentration at different temperatures in fresh water.

(a) State the change in oxygen concentration between 5 °C and 15 °C.

decreases / - (symbol);2.4 mg per dm3 / falls from 12.4/5 to 10.0; At – 2.4 – 2.5

[2]

(b) Use Fig. 2.1 to estimate the oxygen concentration at a temperature of 45 °C.

4.6 mg per dm3; A – 4.7 – 4.9 [1]

Table 2.1 shows the oxygen concentration in sea water at different temperatures.

(c) Plot these data on Fig. 2.1.plots;; -1 each incorrectline; A – dot to dot / line of best fit

+/- ¼ squareline labelled / key; [4]

(d) Describe the differences between the oxygen concentrations in fresh water and in sea water.fresh water higher at all temperatures / is always higher / lower at same

temperature;reference to difference at particular temperature e.g. at 0oC tolerance

of 0.2difference is 3.0 / 11.4 to 14.4;greatest difference at 0oC / smallest difference at 35oC;

[3]

Name: ________________________________ Per. _______ Date: _____________________

9. (a) Explain how atmospheric dissolution of one named gas affects the chemical composition of sea water.

any 3 of:named gas (dissolves in sea water);new compounds formed / named;appropriate consequence e.g. pH changed;

[3]

Fig. 7.1 shows how rainfall, evaporation and changes in temperature affect salinity, density and rising and sinking of sea water.

(b) Draw an arrow in box A to show the change in salinity. Explain your answer.

[2]

(c) Complete box B to show whether the water rises or sinks. Explain your answer.

Name: ________________________________ Per. _______ Date: _____________________

[2]

(d) By means of an annotated diagram, describe how a salinity gradient forms in a water column.

annotated diagram showing 2 of the following points:salinity at surface (stated e.g. low) or shown) v different salinity at ocean bottom

(stated e.g. high or shown);reference to halocline;

+ any 2 of:reference to wind causing evaporation of water;leaving saltier water;thus increase in density;dense water sinks; max 2

[3]

10. Fig. 1.1 shows how the temperature and the concentration of dissolved oxygen vary with depth in the Arabian Sea.

Name: ________________________________ Per. _______ Date: _____________________

(a) State the term used to describe the region in which the gradient of temperature change is greatest.

Thermocline ;Accept ‘discontinuity layer’

[1]

(b) Use Fig. 1.1 to find each of the following.the temperature at a depth of 1000 m

8 °C ; [1]

(c) the depth at which the concentration of dissolved oxygen is 20 μmoles per dm3

500 m ; [1]

(d) Describe the change in the concentration of dissolved oxygen as the depth increases from 0 m to 100 m. Suggest an explanation for this change.

Any three of:1. Reference to decrease ;2. Reference to high concentration near surface ;3. Due to oxygen dissolving from atmosphere ;4. High because of photosynthesis ;5. Decreases due to respiration ;6. Rate of respiration greater than rate of photosynthesis ;

[3]

11. (a) Explain how the alignment of the Sun and the Moon affect the tidal range.Any seven from:1. Reference to tides due to gravitational effects of Sun and Moon ;2. Neap tides smaller range / spring tides greater range ;3. Neap tides when Sun, Earth and Moon form a right angle / eq ;4. Neap tides occur when there is a crescent / half moon / eq ;5. Reduced (gravitational) effect ;6. Spring tides when Sun, Earth and Moon are in a straight line / eq ;

Name: ________________________________ Per. _______ Date: _____________________

7. When there is a full Moon / new Moon ;8. Combined / greater (gravitational) effect ;

[7]

(b) Suggest what effect each of the following would have on the tidal range.a decrease in wind speed

Reduced tidal range ; [1]

an increase in atmospheric pressure Reduced tidal range ; [1]

an increase in the size of a body of water.Increased tidal range ; [1]

(c) Explain how wind and the shape of the sea bed produce ocean currents and upwelling.Any five from:1. Idea that water is blown in direction of wind ;2. Displaced water replaced with deeper water ;3. This causes upwelling ;4. Sea floor ridge / eq ;5. Deflects water upwards ;6. This also causes upwelling ; [5]

12. (a) State what is meant by the term salinity. total quantity of salt(s)/ions/minerals (dissolved) in (sea) water/ocean;

[1]

Table 3.1 shows some of the ions present in fresh water and sea water.

(b) Use the information in Table 3.1 to calculate the difference in the sodium chloride content of fresh water and sea water.

70.07; [1]

Name: ________________________________ Per. _______ Date: _____________________

Fig. 3.1 shows how rainfall and salinity vary with latitude.

(c) Use Fig. 3.1 to find each of the following.the rainfall at 70° North

21 / 22 (cm); [1]

the range of salinity 32.6 to 35.6 / 3.0; [1]

(d) Describe the changes in salinity between 40° North and 40° South.falls;(rapid) rise;any correct figures; e.g.(falls) 33.10 to 32.6 by 0.5

Name: ________________________________ Per. _______ Date: _____________________

(rise) 32.60 to 35.10 by 2.5 [3]

(e) State the relationship between salinity and rainfall at latitudes 0° to 80° North. salinity falls as rainfall increases/ora/inverse relationship;

[1]

(f) State two factors, other than rainfall, that affect the salinity of seawater.evaporation;underwater volcanoes/vents;fresh water inflow/glacial/icebergs melting/owtte; R - runoff

[2]

(g) Suggest how global warming may affect the salinity of the oceans. Give an explanation for your answer.

any 4 of:temperature rise of air/water/warmer;melting icebergs;release of (fresh) water; fall in salinity;(alternative)temperature rise;increased evaporation;rise in salinity;

[4]

13. (a) Give two factors required for the development of a tropical cyclone.any 2 of:low pressure;warm air/sea (above 26 °C);moist/humid air; R - humidityrising air;low wind shear; [2]

Table 4.1 shows the relationship between the distance from the centre of a cyclone and the amount of rainfall.

(b) Use the information in Table 4.1 to describe the relationship between the distance from the centre of the cyclone and rainfall.

as distance increases, rainfall decreases/ora;any correct reference to figures;

[2]

Name: ________________________________ Per. _______ Date: _____________________

(c) Estimate the rainfall at 340 km from the centre of the cyclone.

figure between 12 and 26; [1]

(d) State two features, other than rainfall, of tropical cyclones.

any 2 of:high winds;circular wind patterns/cyclic movement of storm;low air pressure;thunderstorms/lightning;warm air; [2]

(e) Tropical cyclones develop over the sea. State three destructive effects that can occur when a cyclone reaches land.

any 3 of:damage to buildings/property/infrastructure/e.g. flooding;changes to coastline/erosion/e.g.;removal of vegetation/destruction of habitats;deaths/reference to disease explained; [3]

(f) Suggest one beneficial effect that may occur when a cyclone reaches land.

any 1 of:rain to desert/dry areas;increase fertility/qualified reference to nutrients in soil;ovp; [1]

14. (a) State two biological reasons why the concentration of oxygen in seawater varies.any 2 of:respiration uses up oxygen;photosynthesis produces oxygen;reference to number of organisms; (must be linked to 1 of above) decomposition; [2]

(b) State three physical reasons why the concentration of oxygen in seawater varies.any 3 of:temperature;salinity;pressure;depth;reference to turbulence/owtte; [3]

Table 5.1 shows the oxygen concentration at different depths in the sea at three different locations.

Name: ________________________________ Per. _______ Date: _____________________

(c) Calculate the mean oxygen concentration at a depth of 200 metres. Write your answer in Table 5.1.

(200 metres) 6.13; [1]

(d) Suggest why the measurements taken at each depth at each location were repeated several times.

any 2 of:rule out anomalies/owtte;rule out errors;improve reliability; [2]

15. (a) Explain what is meant by the term ocean current.continuous/directional;movement of sea water; [2]

(b) State one factor that is involved in the formation of surface ocean currents.

wind/upwellings/rivers; [1]

(c) Explain how temperature and salinity gradients form in water columns to produce layers in deep oceans.

any 4 of:reference to wind;fall in temperature/cooling of sea water;evaporation of water;increase in salinity/owtte;increase in density*;dense water sinks below less dense;

*accept once only with reference to temperature or salinity accept converse points [4]

(d) Explain what is meant by the term upwellings.any 3 of:wind-driven;movement of dense water;movement of cooler water;

Name: ________________________________ Per. _______ Date: _____________________

towards the ocean surface;brings nutrients to the surface; [3]

16. Fig. 5.1 shows a comparison between normal conditions and El Niño conditions in the Pacific Ocean. The arrows indicate the wind and current directions.

(a) Use Fig. 5.1 to describe three differences between normal conditions and El Niño conditions.any 3 of:reduced wind;smoother seas;increased rain over sea/less rain over land masses;lack of/reduced upwelling;lower water levels;increased flow of warm water to east; [3]

(b) Explain how El Niño conditions affect the fish populations near the coast of South America.any 3 of:lack of nutrients from deep water;less phytoplankton;less food for fish;fish population reduced; [3]

(c) In El Niño conditions some parts of the oceans may become warmer than usual. Suggest how this may affect coral growing in these regions.

any 3 of:higher water temperature kills zooxanthellae;coral bleaching;coral dies;warmer water allows coral growth where it was not possible previously; [3]

17. Tropical cyclones are also known as hurricanes and typhoons.(a) State three features of a tropical cyclone.

any 3 of:low pressure;with high winds;thunderstorms;cyclic winds;heavy rain; [3]

Name: ________________________________ Per. _______ Date: _____________________

(b) State two conditions necessary for the formation of a tropical cyclone.any 2 of:water temperature above 26 °C/warm water;high level of evaporation of sea water;spiral wind pattern;low pressure;heat/energy from condensation of water vapour;

[2]

Fig. 7.1 shows the number of different categories of hurricane from 1970 to 2004 at 5-year intervals.

(c) State the total number of category 4 and 5 hurricanes in the period 1990–1994.

96 ; [1]

(d) Describe the changes in the number of category 4 and 5 hurricanes from 1970 to 1994.increases;by 56 / from 40 to 96;

[2]

18. (a) By what other name are tropical cyclones known?

hurricane/typhoon; [1]

Fig. 6.1 shows a section through a tropical cyclone.

Name: ________________________________ Per. _______ Date: _____________________

(b) State the minimum temperature at A. 26 °C;

[1]

(c) Give the letter of the point at which the winds are strongest.E;

[1] (d) Name the process that provides the latent energy for the development of the cyclone.

evaporation; [1]

(e) State what happens to the air pressure as the air rises from A to D.falls; [1]

(f) Describe three possible effects of cyclones on coastal communities.

Any 3 of:death/injury;damage to homes/buildings;damage to infrastructure;loss of power supplies;destruction of crops;spread of disease;financial costs;loss of employment;

[3]

19.Fig. 2.1 shows the surface salinity of the world’s oceans. The figures are in parts per thousand. The measurements were taken in August.

Name: ________________________________ Per. _______ Date: _____________________

(a) With reference to Fig. 2.1, describe how surface salinity varies with distance from land.

salinity increases with greater distance from land ; [1]

(b) Suggest an explanation for the pattern that you have described.

rivers flow in from land ;dilution ;evaporation removes water (but not salt) ;

[2]

Fig. 2.2 shows the difference between evaporation and precipitation, measured in cm, at latitudes between 40°N and 50°S.

(c) Surface salinity tends, in general, to be slightly lower at high latitudes and the Equator than at intermediate latitudes.

Name: ________________________________ Per. _______ Date: _____________________

Use the information in Fig. 2.2 to explain this relationship between surface salinity and latitude.

salinity affected by precipitation – evaporation ;the greater this difference the lower the salinity/vice versa ;difference (between p and e) is greatest at around 20º N or S/lowest near equator ;

[3]

(d) Mangrove trees are able to survive in saline water. Describe two environmental factors, other than salinity, that may lead to the development of mangrove forest along a shore, rather than another type of ecological community.

type of sediment (require relatively small particle size) ;depth of sediment (require fairly deep sediment) ;exposure (require fairly sheltered shore) ;temperature (tropical or subtropical) ; [2]