Lab 14D-1
Name:
Section:
Sandy Shoreline Alternate Site Activity
(45th Street, Manhattan Beach, CA 90266)
The purpose of the sandy shores activity is for you to reflect on how much science there is all
around you at the beach. Hopefully you will learn to look at your visits to the beach in a new
way.
Directions
1. Go west on Manhattan Beach Blvd
or Rosecrans Ave
2. Turn RIGHT onto Highland Ave
3. Turn LEFT onto 45th St
(at the Chevron Gas Station)
4. Go down the steep hill into the parking lot.
Park in the first spot that you find, and walk back
to the entrance (north end) of the parking lot.
Bathrooms are available.
What to Bring
Bring 15 QUARTERS
for the parking meters
(wait until the beginning
of the field trip to put them in)
Appropriate clothing for
walking on the beach
(dress in layers in case it is cold)
Sunscreen
Hat
Lab Manual
Pencil
Lab 14D-2
Activity #1: Sediments
Why is this area
so hilly?
What kind of rock would be formed
from the sediments on this beach?
1. Describe the sediments on the beach.
Size
Shape
Cannot tell
Sorting
Well-Sorted (all have about the same size & shape)
Color
What is special about the black minerals?
What are they called?
2. What is the source of the sediments on the beach? In other worlds,
where did the sediments on this beach come from? How did they get here?
What two processes brought the sediments on this beach?
Look around you at the local area and think about your description of the sediments.
Why is your explanation of the sediments origin above the best one?
What evidence is there that supports this explanation?
3. Why aren’t the beaches of Palos Verdes to
the south (like Bluff Cove) sandy beaches
like this one?
Mountains & Rivers
Santa
Monica
Redondo Canyon
Bluff
Cove
Redondo
Beach
Cabrillo
Beach
Lab 14D-3
Activity #3: Tides
We will skip activity #2, so there is no activity #2 in your notes.
You are not missing any pages.
10. What are tides?
11. Is it high tide now?
__________
What evidence is there that the sea level was higher earlier today? How or why do these
observations support the idea that sea level was higher earlier today?
● Seaweed Location
● Location of Wet and Dry Sediments
Activity #4: Rip Currents
Beach
____________
Why or why not?
Swim this way?
!!!
p
l
He
Rip C
urre
nt
13. If you are caught in a rip current,
should you try to swim directly back
towards the shore?
14. What should you do to survive if you are caught in a rip current? How should you swim?
(Sketch how you should swim into the picture above.)
Lab 14D-4
Activity #5: Waves
15. Why do waves grow
as they approach a beach?
16. Estimate the height of the waves.
(Hint: How high is the average surfer?)
________________________
17. What kind of breakers are present on the beach today,
plunging breakers or spilling breakers?
________________________
Plunging Breakers = crest gets ahead bottom
and curls over the top, forming a “barrel”
Spilling Breakers = water slides down
the front of the wave, creating bubbles
Period = amount of time (seconds)
required for successive wave (swell)
crests to pass a given point
18. What is the period of the waves today?
(Hint: Use the rise and fall of the surfers.)
________________________
19. What creates most ocean waves?
________________________
They do not, of course, always create waves
heading directly towards land.
Beach
Why, then, do waves almost always come
directly into the shore? In other words,
why do waves always bend to match
the shape of the shoreline?
wa
ve
cr
es
t
Lab 14D-5
Activity #6: Longshore Transport
and Hard Stabilization
Motion of
the Sand
20. What causes longshore transport of sand
and the longshore drift of the water
(a.k.a., the longshore current)?
B r e ak
Wave
Direction
________________________
21. What is the direction of longshore transport today?
Beach
in g W
Direction of
Longshore
Transport
ave C
res t s
________________________
22. Describe how we can measure the longshore drift of the water.
23. Estimate the approximate speed of the longshore drift of the water.
(Show your work. Be clear. Circle your answer.)
24. What is a groin? _______________________________________________________
25. Add beach sand to the picture on the right
showing how the size of the beach is
different on each side of the groin.
Write “erodes” in the place without sand.
Put an arrow in the picture in the direction
of the longshore transport and label it
“longshore transport.”
Ocean
Sand
Land
?
Groin
?
Sand
Lab 14D-6
26. Which side of the groin has more sand on it,
the north side or the south side?
________________________
Why is there more sand on one side of the groin?
Why is there less sand on the other side of the groin?
27. What is the typical direction of longshore transport
of sand along this coast, to the north or to the south?
The longshore transport is not always in this direction.
Why not? (Hint: What causes longshore transport?)
________________________
________________________
What is the best evidence that you have seen which supports your belief
about the typical direction of longshore transport along this coast?
28. Why was the groin built along this shoreline?
29. What are the rocks in front of the bike path and power plant called?
In other words, what kind of hard stabilization is this an example of? _______________
Why was it built here?
To protect the power plant from being flooded when sea level rises due to ___________
or smashed and broken down by ________________________.
What harm has this kind of hard stabilization
been known to cause?
__________________________________
Lab 14D-7
Activity #7: Life on a Sandy Beach
30. As you walk along the beach to the groin, look in the surf zone for marine organisms.
What do you see? Complete the table below.
Organism
Characteristics
Status
(dead or alive)
31. Why are many of the living animals on a sandy beach buried in the sand?
Protection from:
•
_______________________________________
•
_______________________________________
•
_______________________________________
32. Where do animals living on a sandy beach get their food from?
Clam
33. Kelp washed up on the beach is a source of food for some beach organisms.
Why is kelp so common along the coast of California?
Why does kelp like to live along the coast? Under what conditions does it grow fast?
Kelp needs ________________ water to _________________________________
and water filled with _______________________
so that kelp can ____________________________________________________.
California has both, because:
Lab 14D-8
Activity #8: Pollution
34. Look offshore. You can often see large ships.
What are they? What are they doing?
__________________________________
35. Why is there tar along the beach?
Where does the tar come from?
___________________________________________
36. Why does the electric power plant
take in water from the ocean?
___________________________________________
37. How does the electric power plant affect the nearby water and ocean life?
38. Was it a good idea to put groin north of the electric power plant? Why or why not?
Look at the modern buildings beyond the candy-striped smokestacks to the north.
This is the Hyperion Sewage Treatment Plant.
39. What “stuff” gets processed at a sewer treatment plant?
How do you send material to the sewage treatment plant? _________________________
40. How do we process sewage at a sewage treatment plant?
The plant pumps wastewater 6 miles out into the ocean.
41. Do you think that the wastewater has a significant impact on the water quality
on the local beaches during normal operating conditions? Why or why not?
42. On rainy days in the winter a lot of extra water flows into the sewer system.
What is the plant forced to do? ______________________________________________
Lab 14D-9
43. What are storm drains?
What are they suppose to do? _______________________________________________
44. What are carried into the ocean by storm-drain water
and “bloom” in the ocean?
________________________
Hint: If they become too abundant, local authorities will “close” the beach.
Untreated sewage and other wastes (yard waste like dead grass and leaves, pet and
wild animal fecal matter, fertilizers from lawns, etc.) can “fertilize” the ocean,
allowing ocean microorganisms to reproduce in massive numbers (a “bloom”).
45. Give 2 examples of how this overabundance of ocean life can harm humans and wildlife.
(1) _____________________________________________________________________
(2) _____________________________________________________________________
46. In your opinion, which is more likely to lead to
a beach closure when it rains, water from the
sewage treatment plant or water from storm drains?
________________________
Why? Explain your reasoning.
47. What kinds of trash did you find on the beach during your walk to the groin?
•
_________________________
●
_________________________
•
_________________________
●
_________________________
48. How can this trash harm animals?
49. What percentage of the trash is plastic?
____________
How long will the plastic last? How long will it take for it to breakdown? ____________
Lab 14D-10
50. Where has a lot of plastic pollution collected?
________________________
In general, most pollutants are not concentrated in this location, because they do not float
right at the surface, so they are not directly pushed by winds and surface currents.
Taking into consideration all kinds of pollution,
where is most ocean pollution concentrated,
near the coast or in the middle of the ocean?
51. Where is there more life in the ocean,
near the coast or in the middle of the ocean?
________________________
________________________
Why is there more life in this place?
Stamp
Name:
Section:
Lab 14D-11
Sandy Shores ASA (14D) Review: Hints & Advice
Activity #1: Sediments
Do not forgot to discuss what the black minerals are and what is special about them.
LST does NOT carry sediments down the coast;
LST IS sediments moving down the coast. So what causes LST?
As part of your answer, you must discuss the evidence that supports the hypothesis that you think
is correct, not just the evidence that undermines the other hypotheses. Specifically, you must
discuss the size of the sediments.
Activity #3: Rip Currents
Activity #4: Tides
You must give a detailed description when discussing the evidence that sea level goes up and
down each day. For example, you must discuss WHERE the evidence is relative to the shoreline
in the pictures, and how the land farther from the shoreline is different; simply stating that you
saw “seaweed on the beach” or “wet sand” is not satisfactory.
Activity #5: Waves
Winds – especially the winds of storms – create waves.
So the answer should not be “winds AND storms” but “winds of storms.”
Activity #6: Longshore Transport and Hard Stabilization
You must explain why sand piles up on the north side.
Simply stating that it does so does not answer the question which was asked.
You must explain why sand is removed from the south side. Explaining that sand cannot reach
the south side does not explain why less and less sand is present on the south side.
Activity #7: Life on a Sandy Beach
You must explain how these things benefit kelp. Simply stating “the California Current” or
“upwelling” is not satisfactory, nor is the statement “cold water”: Why do kelp like or need cold
water? What is the water unusually cold along the coast of California? If you mentioned a rocky
bottom, you need to discuss how or why they need to hold themselves in place along the coast.
NOTE: California does NOT have a lot more runoff than other coasts (we have a dry climate,
right?).
Lab 14D-12
Activity #8: Pollution
Make sure that you give a detailed explanation of why there is more life near the coast or in the
middle of the ocean. At this point in the semester, students should be able to give an answer that
is several sentences long (at least a long paragraph or two shorter paragraphs).