Download 06B - El Camino College

Shorelines Lecture Notes (Topic 6B) – 1
Shorelines Lecture
Estuaries: bodies of ocean water partially surrounded by land
The water in estuaries is often fresher (less salty)
than the coastal water outside the estuary. Why?
Where is there more life, in estuaries or near the coast outside of estuaries?
There is (A)________________ life in estuaries than along the coast outside estuaries,
because there are (B) ________________ nutrients in estuaries than along the open coast.
Nutrients are found in the soil on land, and are mainly carried in the ocean
by (C)______________________.
Estuaries get (A) ________________ nutrients from the land than the open coast.
In addition, nutrients that enter estuaries tend to stay inside estuaries instead of drifting away.
An estuary is a body of water that is (D)_________________________ surrounded by land,
so nutrients can only drift out through the exit, not in all directions as happens along open
coast. Moreover, there is (A)________________ water motion in estuaries than along the
open coast, so nutrients tend to stay in place in the estuary instead of spreading out.
Nutrients can and do leave estuaries. The main cause of water motion into and out of
estuaries is (are) (E)___________. Water flows out of estuaries each day when sea level
is going (F)______________ in the ocean.
A: more, less
C: currents, rain, tides, waves, wind
E: rain, tides, waves, wind
B: more, fewer
D: completely, partially, not
F: up, down
Shorelines Lecture Notes (Topic 6B) – 2
Why do estuaries get more nutrients from land
than the open coast?
Nutrients in the soil on land are washed off the land
and into the ocean by (A)_________________________.
Since the estuary has land on 2 or more sides,
the estuary gets nutrients from (B)__________ or more directions.
The open coast gets nutrients only gets nutrients from (B)__________ direction.
Why is there more water motion
or less water motion in estuaries
than along the open coast?
There is (C) _________ water motion in estuaries
than along the open coast, because the land
around the estuaries blocks (A)___________________
from some directions from getting into the estuaries.
Explain how and why the amount of nutrients in the water affects how abundant ocean life will
be in an environment. Discuss both animals and algae.
(D)______________________ like phytoplankton grow abundantly in nutrient-rich water,
because they use the nutrients for photosynthesis. (D)________________________ come
to estuaries to eat the abundant (D)________________________.
What is the major cause(s) of currents in estuaries?
_______________________
How do estuaries benefit humans? How or why do they provide these benefits?
What do we use estuaries for? Why are they good places for these activities?
• Food: Estuaries are good places for ocean animals that we eat to grow up,
because there are (C)___________ nutrients in the estuaries than along the open coast.
Baby animals eat (D)________________, which need nutrients for __________________.
• Harbors/Ports for Ships: Estuaries are good places to load and unload cargo,
because there is (C) _________ water motion in estuaries than along the open coast,
because the land around them blocks (A)______________________ from getting in.
Possible Answers:
A: currents, longshore transport, rain, tides, waves, winds
B: enter a number
C: more, less
D: algae, animals, algae & animals, nutrients
Shorelines Lecture Notes (Topic 6B) – 3
Wetlands
Why are coastal wetlands often “wet” (covered by water)?
_______________________
List the 2 kinds of marine (coastal) wetlands.
(1) ______________________________
(2) ______________________________
Most animals living in wetlands do NOT eat the wetland plants like grasses and trees.
What do most animals living in wetlands eat?
___________________________________
How do wetlands benefit humans? How or why do they provide these benefits?
• Food: Wetlands are good places for ocean animals that we eat to grow up, because
wetland plants and algae absorb nutrients in rainwater runoff, so they grow abundantly.
Baby animals in wetlands eat ________________________________________________.
• Cleaner Ocean: Wetland plants & algae absorb nutrient-rich fertilizers washed off farmers’
fields by rain, keeping it from entering the ocean where it can cause _________________.
In addition, some wetland bacteria can breakdown some toxic chemicals in the runoff.
• Protection from Flooding: Wetland plants absorb water and block the rising ocean from
coming ashore during ______________________________.
• Protection from Coastal Erosion: Wetland plants block __________________________,
and their roots hold onto sediments washed off the land by rain.
Estuaries and Wetlands
How is a wetland similar to an estuary? How is a wetland different from an estuary?
Presence of Vegetation: _____________________
(Grasses & Trees)
Presence of Water: _____________________
Uses of Estuaries and Wetlands
Thick lines
represent
wetlands.
Which one is a better place for a port (harbor)? Why?
Which one keeps the ocean cleaner by filtering out pollutants
in rainwater runoff before it enters the ocean?
__________________
Which one protects us from storm surge?
(Sea level rises beneath storms and floods the land.)
__________________
Shorelines Lecture Notes (Topic 6B) – 4
Waves and Phytoplankton
How do waves affect phytoplankton? Are waves good or bad for phytoplankton?
Deltas: piles of sediments at the end of rivers (mainly mud)
Why do deltas form at the ends of some rivers but not others?
Barrier Islands: long, thin piles of sand parallel to the coast.
Estuary
Estuary
Land
Estuary
● very large river: big rivers carry a ____________________
of sediments
Ocean
Barrier Islands
● direction: _________________ angle with the coast, so
waves push sediments back into the river, not down the coast
y
● small height: ______________blocks the big waves
created by storms near the Poles
ar
tu
Es
Why might waves be unable to take away all the sediments
coming down a river?
Barrier Islands
____________________ take sediments away from the ends of rivers and push them
to beaches far down the coast. Deltas form when sediments pile up at the end of a river
because the sediments are not taken away fast enough.
r
Rive
Where are barrier islands common
along the coast of the United States?
Delta
Shorelines Lecture Notes (Topic 6B) – 5
Wave-Cut Terraces and Marine Terraces
After Uplift & More Erosion
Marine Terrace
Wave-Cut Terrace
Coastal Cliffs
Changes in Sea Level:
Earthquakes and Ice Ages
Coastal
Cliffs
Uplift
Fault
Shorelines Lecture Notes (Topic 6B) – 6
Headlands, Coves, and Sea Stacks
Coves
Land
Headlands
Headland
Sea Arch
Ocean
Sea Stack
Shorelines Lecture Notes (Topic 6B) – 7
Practice Questions
Names of Shoreline Features
1. (a) A body of water filled with vegetation (plants and algae);
sometimes the water leaves.
_______________________
(b) A large body of water partially surrounded by land.
_______________________
(c) A pile of sediments at the end of a river.
_______________________
(d) A long, thin pile of sediments that is just offshore
of the coast and is parallel to the coast.
_______________________
(e) Where land sticks out into the ocean
_______________________
(f) A small body of water partially surrounded by land.
_______________________
(g) A flat area at the bottom of a coastal cliff
_______________________
(h) A flat area at the top of a coastal cliff
_______________________
Benefits of Estuaries and Wetlands
2. Write an “E” next to the major ways in which estuaries benefit humans that we discussed.
(Mark all that apply.)
Write a “W” next to the major ways in which wetlands benefit humans that we discussed.
(Mark all that apply.)
● cleaner ocean for swimming: filter pollutants out of runoff
● drilling for oil and natural gas
● food: good farmland
● food: a place for ocean animals that we eat to grow up
● mining valuable minerals (e.g., gold, silver)
● newly discovered plants and animals are a source of chemicals
for new medicines and other drugs
● ports for ships: good place to load & unload cargo, protected from waves and storms
● produce most of the carbon dioxide that we breathe
● protection from drought: store fresh water
● protection from flooding when it rains
● protection from flooding when sea level rises during storms
● recreation: safer and easier place to sailing and water skiing
● reduce shoreline erosion by blocking waves
● safer food: filter pollutants out of runoff
● safer food: pollutants quickly leave and do not get “trapped”
Shorelines Lecture Notes (Topic 6B) – 8
Waves, Wave Speed, Wave Refraction, and the Direction of Longshore Transport
3. Where is the wave crest moving slower in the map below, at dot A or at dot B? Why?
Explain. What is the direction of longshore transport, to the left (west) or to the right (east)?
Sketching Shoreline Features
4. Sketch a bird’s-eye-view of an estuary and barrier islands in ONE picture.
Label the land, the ocean, the estuary, and the barrier islands.
5. Sketch a bird’s-eye-view of headlands, coves, and sea stacks in ONE picture.
Label the land, the ocean, the headland(s), the cove(s), and the sea stack(s).
6. How are barrier islands different from other kinds of islands and sea stacks?
Shape:
Barrier islands are _________________________________.
Composition (what they are made of)
Barrier island are made of ____________________,
and sea stacks are made of ____________________.
7. Sketch a side-view of a wave-cut terrace, a cliff, and a marine terrace in ONE picture.
Label the land, the ocean, the wave-cut terrace, the cliff, and the marine terrace.