Chapter 16
The image is a map of bathymetric features in the North Atlantic off the eastern coast of North America. Which correctly identifies the numbered bathymetric features marked on the map? http://www.geo.hunter.cuny.edu/~fbuon/GEOL_180/GEOL180_S2018_Ch3.pdf
(Use the two maps of ocean bathymetry (left) and ocean age (right) of the NE Pacific Ocean. Notice that there are uppercase AND lower case letters on the map = d > e > c > a)
Which is characteristic of submergent coasts?
Fjords Submergent coastlines are stretches along the coast that have been inundated by the sea by a relative rise in sea levels from either isostacy or eustacy. Features of a submergent coastline are drowned river valleys or rias and drowned glaciated valleys or fjords. Estuaries are often the drowned mouths of rivers. The Western Coastal Plains of the Indian subcontinent are examples of submergent coastline. The ancient city of Dvārakā, which is mentioned in the great epic Mahabharata, is now under water. The coastline also forms the estuaries of the Narmada and the Tapti Rivers.
Which is characteristic of emergent coasts?
Terraces Emergent coastlines have experienced a relative fall in sea levels, are a result of local tectonic uplift of the land surface or a fall in the elevation of sea level because of a reduction in the water volume of ocean basins. Quite often, emergent coasts have rocky coastlines with cliffs and nearly flat platforms that extend inland where older coastal plains have been tectonically raised and are now elevated above the modern land and water interface.Ex: the west coast of North America, parts of the Scandinavian coastline (Sweden and Norway)
at which location would high tide be the highest?
Where the earth is tipped toward the moon, the highest high tides occur. In Canada (Bay of Fundy) and in Anchorage Alaska for the USA
When sea level rises and floods a glacially carved valley, the area is called a(n) a. fjord. b. wetland. c. estuary. d. reef.
a. fjord
The process of reef bleaching occurs when a. reefs lose their color and die in response to the warming of seawater. b. reefs lose their color following large storms. c. reefs are exposed to too much sunlight. d. over fishing causes a decrease in species diversity.
a. reefs lose their color and die in response to the warming of seawater.
Coastal landforms are constantly changing because the a. sand is constantly moving. b. tides are getting stronger. c. sand is moved by developers. d. storms are getting stronger.
a. sand is constantly moving.
The balance between sediment supplied and sediment removed on a beach is known as a. sediment budget. b. wave erosion. c. wave refraction. d. longshore drift.
a. sediment budget
The timing and magnitude of tides in a given location is LEAST likely to be influenced by the a. size of the waves. b. ocean-basin shape. c. moon's orbit. d. shape of the shoreline.
a. size of the waves
Barrier islands are constantly moving in the direction of a. the longshore drift. b. the high tide. c. down welling. d. the Coriolis effect.
a. the longshore drift
The difference between sea level at high tide and low tide for a given location is known as a. tidal reach. b. swash. c. continental shelf. d. tidal bore.
a. tidal reach.
The active continental margin is located at the a. west coast of North America. b. east coast of North America. c. west coast of Africa. d. east coast of South America.
a. west coast of North America
The entire state of Florida is composed of fossiliferous limestone (indicative of a coral reef environment). This implies that in the recent past, Florida was a. covered with caves. b. a submergent coast. c. an emergent coast. d. in the mountains.
b. a submergent coast.
The shape of the seafloor is called a. topography. b. bathymetry. c. marine geology d. oceanography
b. bathymetry
Gently sloping fringes of sediment along the shore are known as a. tidal flats. b. beaches. c. lagoons d. inlets.
b. beaches.
Swamps and marshes are examples of a. estuaries. b. coastal wetlands. c. fjords. d. swashes
b. coastal wetlands.
The tide-generating force is a combination of the __________ and __________ . a. gravitational attraction of the Moon; centrifugal force caused by the revolution of the Earth-Moon system b. gravitational attraction of the Moon and the Sun; centrifugal force caused by the revolution of the Earth-Moon system c. gravitational attraction of the Moon; the gravitational attraction of the Sun d. centrifugal force caused by the revolution of the Earth-Moon system; the Coriolis effect
b. gravitational attraction of the Moon and the Sun; centrifugal force caused by the revolution of the Earth-Moon system
Which of the following features is characteristic of a rocky coast? a. sand spits b. sea stacks c. lagoons d. accretionary prisms
b. sea stacks
If sea level continues to rise and covers the city of Miami, the Florida coast will become a(n) a. emergent coast. b. submergent coast. c. continental slope. d. abyssal plain.
b. submergent coast.
Which of the following scenarios is most likely to result in an emergent coast? a. global sea level rise b. uplift associated with active margin tectonics c. subsidence of the shoreline caused by near-shore removal of groundwater d. the formation of a near-shore coral reef
b. uplift associated with active margin tectonics
The movement of sand along a beach can cause a landform called a spit. If the spit grows to completely block the entrance to an estuary or bay it is called a
baymouth bar
A coast that grows seaward as a result of regular sedimentation is a(n) a. active continental margin. b. erosional coast. c. accretionary coast. d. coastal plain.
c. accretionary coast
Many rocky coasts occur along active margins. This is because a. active margins are associated with larger storms, which cause more erosion of sediment, leading to fewer beaches. b. subduction along active margins consumes coastal sediments. c. active margins often experience repeated uplift, and thus the waves have not had sufficient time to erode the land surface down to sea level. d. active margins tend to have far fewer streams that feed sediment to the oceans; thus, there is not enough sand to create beaches.
c. active margins often experience repeated uplift, and thus the waves have not had sufficient time to erode the land surface down to sea level.
Structures—like jetties, groins, and breakwaters—that are designed to prevent beach erosion a. are permanent solutions that protect erosional beaches. b. must be built in conjunction with beach nourishment. c. are a temporary solution that decreases the rate of beach erosion. d. have the added benefit of allowing organic coasts to develop.
c. are a temporary solution that decreases the rate of beach erosion.
Some beaches are maintained by artificially increasing the rate of sediment supply using a procedure known as a. beach protection. b. sand swash. c. beach nourishment d. tidal bore.
c. beach nourishment
A(n) __________ is a vegetated, flat-lying stretch of coast that floods at high tide, becomes particularly exposed at low tide, and does not feel the impact of strong waves. a. marine terrace b. coral reef c. coastal wetland d. estuary
c. coastal wetland
When the sea level rises, an ocean may invade a river valley, producing a nearshore body of water of mixed and variable salinity, which is termed a(n) a. atoll. b. lagoon. c. estuary d. jetty.
c. estuary
The production of tides is NOT affected by Earth's a. gravitational attraction with the sun. b. gravitational attraction with the moon. c. gravitational interaction with Mars. d. centrifugal force caused by the revolution of the Earth-Moon system.
c. gravitational interaction with Mars.
Along beaches, groins have a. solved the problem of beach drift. b. increased erosion rates immediately up current from the groin. c. increased erosion rates immediately down current from the groin. d. increased depositional rates immediately down current from the groin.
c. increased erosion rates immediately down current from the groin.
Sea floor spreading is associated with a. active continental margins. b. passive continental margins. c. mid-ocean ridges d. abyssal plains.
c. mid-ocean ridges
Which type of coastline would most likely contain estuaries or fjords? a. subductive b. emergent c. submergent d. divergent
c. submergent
The __________ is the generally twice-daily rise and fall of sea level. a. wave b. swash c. tide d. tidal bore
c. tide
Which of the following is MOST true of beach nourishment as a solution to coastal erosion? a. It is a permanent solution that will protect an erosional beach. b. The flux of sediment from beach nourishment will change a beach from erosional to accretionary. c. It is a temporary, but inexpensive, solution to coastal erosion. d. It is costly and may only provide a temporary solution.
d. It is costly and may only provide a temporary solution.
Building a dam across a river can lead to __________ because sediment becomes trapped behind the dam. a. pollution b. beach nourishment c. reef bleaching d. beach erosion
d. beach erosion
A coastline characterized by steep-sided cliffs and associated with an active margin is likely to be a. accretionary. b. submergent. c. passive. d. emergent.
d. emergent.
Which of the following is LEAST likely to result in reef bleaching? a. pollution b. changes in seawater salinity c. changes in water temperature d. gradual sea level rise
d. gradual sea level rise
Which of the following is the BEST example of an organic coast? a. gently sloping, well-developed beach b. wave-cut platform c. shoreline that has just received beach nourishment d. shallow coral reef
d. shallow coral reef
During a rising tide, the a. coast is emergent. b. coast is submergent. c. shoreline moves seaward. d. shoreline moves inland.
d. shoreline moves inland.
What is formed when layers of turbidites accumulate? a. accretionary prisms b. submarine canyons c. continental margins d. submarine fans
d. submarine fans
the localized rise in sea level under a storm is called
storm surge
Mangroves are an important part of coastal wetlands because
their roots prevent shoreline erosion
The strongest tides are during
a new moon and full moon
Sea level is currently rising at 3.2 mm/yr, and scientists predict that global warming could cause a rise in sea level of 7 m if left unabated. How long will it take the sea to rise 7 m at the current rate? a. 2,121 years b. 0.0004 year c. 2.121 years d. 0.47 year
a. 2,121 years
Passive continental margins a. are characterized by broad continental shelves. b. tend to be seismically active. c. tend to be volcanically active. d. are characterized by the presence of a deep-sea trench.
a. are characterized by broad continental shelves.
Active continental margins a. are characterized by narrow continental shelves. b. are characterized by gradual continental slopes. c. lack accretionary prisms. d. are characterized by the presence of a spreading center immediately off shore.
a. are characterized by narrow continental shelves.
Seamounts
are hot-spot volcanoes whose peaks lie below sea level.
an artificial structure built parallel to the shoreline to stabilize the shore is called a
breakwater
Understanding threats to organic coasts is important because globally, between 20% and _____ of coastal wetlands have been destroyed in the last century.
70%
Subduction at convergent boundaries results in the formation of a a. passive margin. b. submarine canyon. c. deep-sea trench. d. well-developed beach.
c. deep-sea trench.
A coral reef would MOST likely be found a. in an expansive, warm-water tropical tidal flat. b. in clear, shallow waters at high latitudes. c. in the shallow waters surrounding a volcanic tropical island. d. along the coasts of active margins.
c. in the shallow waters surrounding a volcanic tropical island.
The width of the intertidal zone depends on the tidal a. reach. b. bore. c. reach and the slope of the seafloor surface. d. bore and the slope of the seafloor surface.
c. reach and the slope of the seafloor surface.
Submarine canyons
can transport sediment to form turbidites deep, steep-sided valleys cut into the continental slope
The tidal reach
is the difference between sea level at high and low tide. elevation change between high and low tides
Currents that move sediment along the beach parallel to shore are called
longshore currents
bathometry
shape of the sea floor measurement of ocean depth and seafloor topography
trenches
border continental and island volcanic arcs