Coasts, Beaches, And Estuaries Chapter.10 Exam Questions 3e

Investigating Oceanography, 3e (Sverdrup)

Chapter 10 Coasts, Beaches, and Estuaries

1) An abrupt change in the beach slope caused by the cutting action of waves at normal high tide is known as a beach ________.

2) The beach face can have a low region that remains flooded at low tide. This is called a ________.

3) A drowned river valley is also known as a ________ coast.

4) Climate change can result in a worldwide ________ change in sea level.

5) The beach is the portion of the coastal zone that extends from the low water line to the coastline.

6) Primary coasts are coasts that have features created by marine processes.

7) A coast made regular and linear by wave erosion is a secondary coast.

8) Beaches gain sand under severe, high-energy winter waves and lose sand under the milder, low-energy summer waves.

9) Waves that approach the shore at an angle produce a longshore current that flows parallel to the beach.

10) Rip currents move water toward the beach.

11) Accumulated lag deposits protect a beach from continuing erosion.

12) The coastal zone includes both water areas and land areas.

13) A low-tide terrace is most likely exposed on a neap tide.

14) At present, sea level is decreasing around the world's coasts.

15) The net seaward flow of water in a partially mixed estuary is nearly uniform over depth.

16) A partially mixed estuary generally has a two-layered flow that moves inward at depth and seaward at the surface.

17) Tidal currents in an estuary are primarily responsible for mixing.

18) If sea level is to remain constant, the water budget of an estuary requires that all inputs of water equal To.

19) A semienclosed sea at 30°N is most likely resupplied with seawater at depth.

20) Transport of dissolved materials out of an estuary can be estimated from the net T0 transport and its concentration of dissolves materials.

21) An estuary with a short-flushing time will usually have less carrying capacity for pollutants than an estuary with a long-flushing time.

22) Pollutants that adhere to suspended particles in an estuary are usually flushed from the estuary by the net circulation.

23) In an estuary, To is always larger than Ti.

24) During the last glacial period, sea level was approximately 100 feet lower than today.

25) A sea stack is formed from the deposition of sediment.

26) Barrier Islands are common features along the coasts of the southeast United States.

27) A winter berm tends to be farther inland than a summer berm.

28) Beaches tend to be wider in winter and narrower in summer.

29) A coast with fjords is classified as a(n) ________.

A) primary coast

B) secondary coast

C) sinking coast

D) rising coast

E) equilibrium coast

30) An example of a ria coast is ________.

A) the mouth of the Mississippi River

B) San Francisco Bay

C) Delaware Bay

D) the Gulf of Mexico

E) southeast Alaska

31) A coral reef coast is a product of ________.

A) volcanism

B) erosion

C) a change in current direction

D) living organisms

E) wave action

32) A low-tide terrace forms ________.

A) seaward of the offshore bar

B) below the beach face

C) between high and low water

D) along the trough

E) next to the lower beach scarp

33) The higher berm found on a beach is formed ________.

A) when large waves occur at low tide

B) during winter storm conditions

C) from the slumping of cliffs in the backshore

D) during periods of low-energy waves in the summer

E) when neap tides occur during the spring and summer

34) A sand spit formed between an offshore island or rock and the mainland is called a(n) ________.

A) offshore spit

B) inshore spit

C) barrier spit

D) sandbar

E) tombolo

35) A beach that is fed by mixed sizes of rocks and particles but shows only large rocks on its surface is ________.

A) an erosional beach

B) subjected to high waves and strong currents

C) an armored beach

D) All of these are correct.

E) None of these is correct.

36) High-energy waves of winter storms ________.

A) move sand from bars onto the beach

B) move sand from the beach out to bars

C) build sand spits and tombolos

D) hold sand on the beach and keep the beach stable

E) All of these are correct.

37) A beach in dynamic equilibrium

A) loses sand to the offshore area.

B) gains sand.

C) gains and loses sand in equal quantities.

D) builds sand spits and tombolos.

E) gains sand in the low tide terrace.

38) A coastal circulation cell includes ________.

A) longshore transport

B) rip currents

C) onshore transport

D) All of these are correct.

E) None of these is correct.

39) Chesapeake Bay is a ________.

A) shallow, well-mixed estuary

B) deep, well-mixed estuary

C) shallow, fjord-type estuary

D) deep, partially mixed estuary

E) salt wedge estuary

40) Sand dunes are found along coasts in which the sand is transported ________.

A) from the beach toward the sea

B) from the beach toward inland areas

C) from inland areas toward the sea

D) from the beach toward inland areas and from inland areas toward the sea

E) from the beach toward the sea, from the beach toward inland areas, and from inland areas toward the sea

41) A scarp is ________.

A) an underwater sandbar

B) an abrupt change in beach slope

C) a beach fault line

D) the high-water mark on a beach

E) another name for a berm

42) The beach face ________.

A) is the same as the low-tide terrace

B) lies under the surf zone

C) is found between high-tide and low-tide levels

D) appears between an offshore bar and a low-tide terrace

E) is found between the summer and the winter berm

43) In order for an embayment to qualify as an estuary, it must have both ________ and ________.

A) high evaporation; circulation

B) dilution; no physical isolation from the oceans

C) high evaporation; some degree of isolation

D) dilution; some degree of isolation

E) equal evaporation and dilution; no isolation

44) In a well-mixed shallow estuary, the net seaward flow occurs at ________.

A) the surface only

B) depth only

C) middle depths

D) all depths

E) slack water only

45) In a shallow, well-mixed estuary such as Delaware Bay, the inward transport of salt is controlled by ________.

A) density

B) diffusion

C) advection

D) waves

E) tides

46) In a deep fjord with a shallow entrance sill, the deep-basin water is probably ________.

A) low in oxygen and high in nutrients

B) low in salinity and high in oxygen

C) high in oxygen and low in nutrients

D) high in salinity and high in oxygen

E) high in salinity and low in nutrients

47) The salt wedge in a river estuary is steeper and more sharply defined during ________.

A) ebb tides

B) flood tides

C) low water

D) high water

E) slack water

48) If tidal currents are slight in an estuary but river flow is very large, which type of estuary is most likely to occur?

A) a partially mixed estuary

B) a salt wedge estuary

C) a fjord

D) a well-mixed estuary

E) None of these are correct; it is impossible to tell from the information given.

49) The influx of seawater at depth in an estuary ________.

A) supplies water to make up for net surface water outflow

B) supplies salt to compensate for dilution by river water

C) supplies water to maintain the estuary's water level

D) All of these are correct.

E) None of these is correct.

50) Which combination holds true in a partially mixed estuary?

A) Evaporation – precipitation + runoff = transport in

B) Evaporation – precipitation + runoff = transport in – transport out

C) Transport in – evaporation + precipitation + river runoff = transport out

D) Evaporation – precipitation + runoff = transport in and Evaporation – precipitation + runoff = transport in – transport out

E) Evaporation – precipitation + runoff = transport in – transport out and Transport in – evaporation + precipitation + river runoff = transport out

51) If To equals the net flow rate of mixed surface water out of an estuary, the estuary volume divided by To yields the ________.

A) salt flow

B) water flow

C) flushing time

D) salt residence time

E) freshwater flow

52) If the salinity of ocean water at the entrance to an estuary is 30 percent and the average salinity of the estuary is 20 percent, what fraction of the volume of water in the estuary is fresh water?

A) 1/2

B) 1/3

C) 1/4

D) 16

E) 1/8

53) If the seawater available to an estuary has a salinity of 30 percent and the seaward-flowing mixed water has a salinity of 20 percent at the estuary entrance, the net volume transport seaward is ________ units per day if the river input is 10 units per day.

A) 5

B) 10

C) 20

D) 30

E) 50

54) Calculations of flushing times assume that none of the outflowing water is recycled into the estuary. If this assumption is not correct, the actual flushing time is ________ the calculated flushing time.

A) less than

B) greater than

C) the same as

D) not related to

E) None of these is correct.

55) If Si is the average salt content of the incoming seawater and So is the average salt content of the exiting surface water in an estuary, the fresh water in the exiting mixed water is ________.

A) So/(Si – So)

B) Si/(Si – So)

C) (Si – So)/Si

D) (Si – So)/So

E) (So – Si)(Si – So)

56) In a fjord with a shallow entrance sill, the outgoing flow (To) is approximately equal to ________.

A) inflow (Ti)

B) freshwater inflow (R)

C) tidal flow

D) estuary volume

E) All of these are correct.

57) In a temperate latitude, estuary ________.

A) evaporation exceeds precipitation

B) precipitation exceeds evaporation

C) precipitation equals evaporation

D) winds and tides control the estuary circulation

E) tides only control the estuary circulation

58) Which of the following coastal engineering structures is built parallel to the shoreline?

A) Jetty

B) Breakwater

C) Groin

D) Seawall

E) None of these is correct.

59) An estuary that is found within the mouth of a river where freshwater flows out to sea at the surface while seawater flows upstream along the bottom is ________.

A) a fjord

B) partially mixed

C) well mixed

D) a salt wedge

E) All of these are correct.

60) An estuary with strong tidal mixing and low river input is ________.

A) a fjord

B) partially mixed

C) well mixed

D) a salt wedge

E) All of these are correct.

61) Which part of the beach includes the area between the high- and low-tide shorelines?

A) Foreshore

B) Backshore

C) Offshore

D) Coastline

E) Berm

62) Inverse estuaries are generally found between ________.

A) 30°N and 30°S

B) 10°N and 10°S

C) 50°N and 50°S

D) 70°N and 70°S

E) 5°N and 5°S

63) The circulation of water in an inverse estuary is characterized by ________.

A) bottom water flowing in at the surface and seawater flowing out to the sea

B) water flowing into the inverse estuary at all depths

C) bottom water flowing out to the sea and seawater flowing in at the surface

D) water flowing out of the inverse estuary at all depths

E) None of these is correct

64) An example of a fault coast is ________.

A) the mouth of the Mississippi River

B) Hanauma Bay, Oahu, Hawaii

C) Delaware Bay

D) the Gulf of Mexico

E) southeast Alaska

65) The backshore ________.

A) is the same as the low-tide terrace

B) lies under the surf zone

C) is found between high- and low-tide levels

D) is part of the foreshore

E) is the high and dry part of the beach

66) The low-tide terrace ________.

A) is the same as the backshore

B) lies above the surf zone

C) is found between high- and low-tide levels

D) is part of the foreshore

E) is the high and dry part of the beach

67) Which of the following coastal engineering structures is built perpendicular to the shoreline?

A) artificial dune

B) breakwater

C) groin

D) seawall

E) None of these is correct.

68) In a partially mixed shallow estuary, the net seaward flow occurs at ________.

A) the surface only

B) depth only

C) middle depths

D) all depths

E) slack water only

69) Which type of estuary is characterized by the least variation in salinity with depth at any given point along its axis?

A) a partially mixed estuary

B) a salt wedge estuary

C) a fjord

D) a well-mixed estuary

E) None of these is correct; it is impossible to tell from the information given.

70) If the salinity of ocean water at the entrance to an estuary is 35 and 63 percent of the volume of water in the estuary is ocean water, what is the average salinity of the estuary?

A) 0 percent

B) 13 percent

C) 22 percent

D) 35 percent

E) 63 percent

71) If, in a partially mixed estuary, the seaward flow is 15 units per day and the river input is 11 units per day the net saltwater flow is ________ units per day.

A) 4

B) 8

C) 11

D) 15

E) 26

72) If, in an inverse estuary, the inflow of seawater of 35-percent salinity is 21 units per year and the outflow is 18 units per year, the salinity of outflowing water is ________.

A) 30 percent

B) 35 percent

C) 38 percent

D) 41 percent

E) 65 percent

73) If the volume of an estuary is 2.1 km3, and the net flow rate of mixed surface water out of the estuary is 7.5 million m3 per day, the flushing time of the estuary is ________.

A) 1 day

B) 3.5 days

C) 35 days

D) 280 days

E) 350 days