chapter 10 oce exam
Of the following statements about groins, which is/are true? Groins add more sediment to the beach. Groins trap sand on their downstream side and cause erosion on their upstream side. Groins can be constructed out of large blocky rocky material (rip-rap) or of sturdy wood pilings. Groins can be singular or many. Groins are built parallel to the coast beyond the surf zone.
Groins can be constructed out of large blocky rocky material (rip-rap) or of sturdy wood pilings. Groins can be singular or many.
the _____ extends inland from the shore as far as ocean-related features can be found
coast
What estuary type forms with sea level rise and subsequent flooding of river valleys?
coastal plain
which of the following estuaries forms when sea level rises and floods an existing river valley?
coastal plain estuary
the boundary between the shore and the coast is known as the
coastline
Southern California beaches would have more sand if __________.
dams were removed from streams flowing to the coast
What feature is formed at the mouth of a river when more sediment is deposited than the longshore current can accommodate?
delta
Features of a depositional coast may include spits, barrier islands, tombolos, and __________.
deltas
large deposits of sediment at the mouths of rivers are called
deltas
Which of the following terms would characterize the East Coast of the United States?
depositional and submerging
what shoreline rises above sea level?
emerging
beaches downcurrent from a groin tend to _______ b/c of beach drift
erode
Which of the following terms would be used to characterize the West Coast of the United States?
erosional and emerging
What would be the expected composition of the beach in an area with a river that drains surrounding lowlands
fine silts
What estuary type has a U-shape and was formed due to flooding of a glaciated valley?
fjord
which state contains mangrove swamps?
florida
the part of the shore that is exposed at low ttide and submerged at high tide is known as the
foreshore
which is responsible for the graph of salinity versus depth for a coastal ocean?
fresh water runof
You own a beachfront lot that has been experiencing erosion due to beach starvation. Your neighbor to the north (up-current) has the same problem, so he gets permission to build a groin just north of your property line. Your response would probably be to __________.
get permission to build a groin of your own near the southern boundary of your propertyhave sand trucked in to rebuild your beach
the photo of the new jersey shore is an example of a _________
groin field
Important plants in a coastal wetland at 45°N latitude are most likely to be __________.
halophytic grasses and pickleweed
Southern California beaches in winter typically are narrow and rocky. That is because __________.
heavy winter wave activity moves the sand out to the longshore bar and uncovers the rocks underneath the sand
which best describes the coastal ocean environment that results in the temperature versus depth graph shown above>
high latitude
coastal wetlands are characterized by
high levels of organic matter in the tidal zone and oxygen-poor muds
An isothermal temperature profile from surface to seafloor may exist in coastal ocean waters __________.
in either low-latitude waters or high-latitude waters
eustatic changes in sea level include
increased glacial melting due to the global warming
When wintertime waves remove sand from the beach, where does the sand go?
it is deposited in longshore bars
what is the name for the body of water between a barrier island and the mainland?
lagoon
after playing in the ocean for a while, tom looks up and sees he has drifted quite a distance from his starting point. why?
longshore current has movement tom parallel to the shore
What feature might cause a wave to break well before it meets the shoreline?
longshore sand bar
the purpose of the pier-like structures is to __________ the beach and prevent erosion
maintain or widen
What is formed during the uplift of an erosional surface?
marine terrace
which of the following occurs during light wave activity?
much of the swash soaks into the beach
an example of relocation iis the movement of cape hatteras lighthouse. where is the lighthouse located?
north carolina
which us coast is considered an emerging shoreline
pacific coast
the pier-like structures are installed ___________ to the shore
perpendicular
Geologic evidence suggests that eustatic (global) sea level rises have been caused by __________.
rapid seafloor spreading at divergent plate boundaries
Narrow currents flowing across the surf zone toward the open ocean are called:
rip currents
what is causing barrier islands to migrate landward?
rising sea level
What supplies the majority of sand in an individual beach compartment?
river inflow
What ecosystem is usually found in the midlatitudes and supports low-lying halophytic plants?
salt marsh
Which of the following describes an estuary located at the mouth of a high-volume river where freshwater flows to the ocean over a layer of dense saline water? Select only one answer.
salt wedge estuary
which of the following zones is located between the low tide line and the highest point on land affected by large storm waves?
shore
the part of the shore that represents the water's edge and migrates back and forth with the tide is known as the
shoreline
______________ is a partially mixed estuary
slightly stratified estuary
the longshore current generally flows which direction along both the atlantic and pacific coasts of the us?
southward
Normally, beaches have the greatest amount of sand on the berm near the end of __________.
summer
San Francisco Bay is a __________ estuary.
tectonic
an estuary produced by faulting or folding of rocks that creates a dropped-down section into which a river flows is called a
tectonic estuary
what has caused the greatest changes in sea level in the past 3000 years?
tectonic movements
which of the following statements about the mediterranean sea is correct
the mediterranean sea is several connected small seas
What is the function of a groin on a beach?
to trap sand on the beach
What is a sand ridge that connects an island to the mainland called?
tombolo
the pier-like structures ______ sand that is moving parallel to the shore
trap
mangrove swamps are restricted to
tropical regions
What is the longshore current?
water forced by waves to move along the shore
Which of the following features would likely be found on a summertime beach?
wide berm
larger, high-energy waves scour sand from the berm and create a
wintertime beach
Which of the following statements regarding a vertically mixed estuary is/are true? -River water mixes evenly with ocean water at all depths in a vertically mixed estuary. -Salinity decreases from the head of the estuary to the mouth in a vertically mixed estuary. -Salinity lines curve due to the Coriolis effect in a vertically mixed estuary. -Vertically mixed estuaries are deep and have a high volume. -salinity is uniform from the top of the water column to the bottom in a vertically mixed estuary.
-River water mixes evenly with ocean water at all depths in a vertically mixed estuary. -Salinity lines curve due to the Coriolis effect in a vertically mixed estuary. -salinity is uniform from the top of the water column to the bottom in a vertically mixed estuary.
Which of the following factors contribute to the direction of longshore current and longshore drift? -wave height -angle tthat waves approach the shore -major offshore storm centers -major ocean surface currents -wave refraction
-angle that waves approach the shore -major offshore storm centers -wave refraction
future sea level rise estimates that approximately _________ of existing us coastal wetlands will be lost
60%
Of the following characteristics or features, which is/are associated with erosional shores?
A coastline with lots of rugged headlands Wave-cut benches and marine terraces Tectonic activity Rocky coasts
an example of a coastal plain estuary is the
Chesapeake Bay
What is the most obvious difference between summertime and wintertime beaches?
During summertime, there is much more sand on the beach.
how many barrier islands are there worldwide?
2150
the approximate boundary between salt marshes and mangrove swamps is _______ latitude
30%
the percentage of the original area of wetlands currently left in the us is approximately _____
50%
How does a sea stack form?
A stack forms when a sea arch collapses, leaving a vertical column of rock offshore.
where does the davidson current develop?
Along the coast of Washington and Oregon
How is an arch formed along a sea coast?
An arch forms when a sea cave breaks through a headland or where two sea caves coalesce as they erode back due to wave action.
Which of the following statements regarding a highly stratified estuary is/are true? Highly stratified estuaries are common along glaciated or previously glaciated coastlines. Highly stratified estuaries are characterized by estuarine circulation, in which river water flows toward the ocean and ocean water flows toward the head of the estuary. Highly stratified estuaries are characterized by a strong halocline. Puget Sound is an example of a highly stratified estuary. Highly stratified estuaries have a mixed zone.
Highly stratified estuaries are characterized by estuarine circulation, in which river water flows toward the ocean and ocean water flows toward the head of the estuary. Highly stratified estuaries are characterized by a strong halocline.
Why is there a distinct difference in surface salinities of the Chesapeake Bay from east to west?
Incoming ocean water is turned to the east due to Coriolis.
With continued sea level rise, what is expected to happen to the total area of wetlands?
It is expected to decrease.
Small waves move sand up the beach face and create a wide, sandy beach
Large waves move sand offshore onto longshore sand bars and create a rocky beach.
What is the difference between longshore current and longshore drift?
Longshore current refers to the movement of water, longshore drift refers to the movement of sediment.
Of the following statements about longshore transport (longshore drift), which is/are true? Longshore transport moves just a small amount of sediment along the shore during a year. Longshore transport moves sediment upcoast or downcoast along the beach. Longshore transport can change direction depending on which direction the waves approach the beach. Longshore transport and rip currents are the same thing. Longshore transport describes the movement of water in the surf zone. Longshore transport moves sediment in a zigzag path.
Longshore transport moves sediment upcoast or downcoast along the beach. Longshore transport can change direction depending on which direction the waves approach the beach. Longshore transport moves sediment in a zigzag path.
Of the following statements about coastal wetlands, which is/are true? Mangrove swamps are a type of coastal wetland that can protect shorelines from erosion. Scientists estimate that, globally, 50% of all coastal wetlands have disappeared in the past century. Salt marshes are a type of coastal wetland found only in the tropics. Coastal wetlands are good at cleansing water of agricultural runoff, toxins, and other pollutants. Coastal wetlands often serve as important nursery areas for many species of fish.
Mangrove swamps are a type of coastal wetland that can protect shorelines from erosion. Scientists estimate that, globally, 50% of all coastal wetlands have disappeared in the past century. Coastal wetlands are good at cleansing water of agricultural runoff, toxins, and other pollutants. Coastal wetlands often serve as important nursery areas for many species of fish.
In the long term, what do beach drift and longshore current do?
Move sediment parallel to the shoreline
Of the following statements about the physical characteristics of coastal oceans, which is/are true? Onshore wind and coastal runoff create geostrophic currents that flow northward along western North America. In low-latitude areas where there is no mixing, surface water temperatures can be very high. In middle-latitude coastal oceans where evaporation is high, a halocline can develop. Most coastal waters have very high salinity due to freshwater runoff.In high-latitude areas, the coastal ocean is isothermal (has a uniformly low temperature from surface to deeper waters).
Onshore wind and coastal runoff create geostrophic currents that flow northward along western North America. In low-latitude areas where there is no mixing, surface water temperatures can be very high. In middle-latitude coastal oceans where evaporation is high, a halocline can develop. In high-latitude areas, the coastal ocean is isothermal (has a uniformly low temperature from surface to deeper waters).
Which of the following statements regarding a slightly stratified estuary is/are true? Salinity increases from the head to the mouth in a stratified estuary. Stratified estuaries have a saltier upper layer and a fresher lower layer. Delaware Bay is an example of a stratified estuary. Stratified estuaries have a mixed zone. Salinity lines curve due to the Coriolis effect in a stratified estuary.
Salinity increases from the head to the mouth in a stratified estuary. Stratified estuaries have a mixed zone. Salinity lines curve due to the Coriolis effect in a stratified estuary.
Which of the following statements regarding a salt wedge estuary is/are true? Fjords are examples of salt wedge estuaries. Salinity is uniform from the top of the water column to the bottom in a salt wedge estuary. Salt wedge estuaries are characterized by estuarine circulation, in which river water flows toward the ocean and ocean water flows toward the head of the estuary. Salt wedge estuaries are common at the mouths of deep, high-volume rivers. Salt wedge estuaries are characterized by a strong halocline.
Salt wedge estuaries are characterized by estuarine circulation, in which river water flows toward the ocean and ocean water flows toward the head of the estuary. Salt wedge estuaries are common at the mouths of deep, high-volume rivers. Salt wedge estuaries are characterized by a strong halocline.
If you built a solid structure perpendicular to the shore, such as a groin, which of the following would occur?
Sand would accumulate on the upcoast side of the structure.
Why does the beach shown in the video look the way that it does during summertime?
Small waves move sand up the beach face and create a wide, sandy beach
What is the net direction of longshore current along the east and west coasts of North America?
South
If caught in a rip current, what should a swimmer do?
Swim parallel to the shore until they no longer feel the current.
Why does the East Coast of the United States have many barrier islands, but the West Coast does not?
The East Coast has a passive continental margin, and the West Coast is an active margin.
Of the following statements about coastal regions and landforms, which is/are true? The berm is affected by storm waves but is typically dry and relatively flat. The berm is located in the backshore area. The beach face is the wet, sloping surface in the foreshore area. Most of the beach face is exposed during the lowest tides and covered during the highest tides. The nearshore is exposed during low tide each day. The area of a beach above the shoreline is often called the recreational beach.
The berm is affected by storm waves but is typically dry and relatively flat. The berm is located in the backshore area.The beach face is the wet, sloping surface in the foreshore area. Most of the beach face is exposed during the lowest tides and covered during the highest tides. The area of a beach above the shoreline is often called the recreational beach.
Of the following characteristics or features, which is/are associated with depositional shores?
The formation of barrier islands A large sand spit High sediment supply A location near a large delta Bay-mouth bars
How does the tide cycle affect erosion along a sea coast?
The tide cycle causes erosion to occur at different elevations along a sea coast.
How is a cave created in a cliff face along a sea coast?
Wave action erodes areas of weakness in rock in a sea cliff.
Of the following statements about global sea level, which is/are true? When seawater warms, it thermally expands and occupies more volume, so global sea level rises. When seawater cools, it contracts and occupies less volume, so global sea level is lowered. Sea level has risen about 120 meters (400 feet) in the past 18,000 years. When the rate of sea floor spreading increases, global sea level is lowered. Sea level is affected by the amount of ice in polar ice caps on land.
When seawater warms, it thermally expands and occupies more volume, so global sea level rises. When seawater cools, it contracts and occupies less volume, so global sea level is lowered. Sea level has risen about 120 meters (400 feet) in the past 18,000 years. Sea level is affected by the amount of ice in polar ice caps on land.
What is an estuary?
a body of water where freshwater and saltwater mix
The coastal wetlands of Louisiana are being lost primarily because of __________.
a combination of subsidence and rising sea level
which of the following describes the trend in ths us wetlands during this century?
a decrease in coastal wetlands and an increase in freshwater wetlands
Of the following types of estuaries, which one has a relatively shallow mouth but is often narrow, long, and extremely deep? Select only one answer.
a drowned glacial valley called a fjord
which of the following would you expect to find on a summertime beach?
a wide, sandy berm
Which way would sediment move if NO beach drift existed?
at an angle to shore
a ______ is a deposit of shore area
beach
Beach joggers prefer to run on the __________.
beach face
which of the following is an alternative to hard stabilization?
beach replenishnent
