Coastal Processes and Landforms Name__________________
5 points (missing three questions is -1)
Coastal landforms occur as waves, currents, and tides interact with the rocks and sediments of the lithosphere. Through time, wave refraction tends to smooth or straighten a rugged, irregular coastline. Typical landforms on this type of coastline include wave-cut platforms, sea cliffs, sea caves, sea stacks, sea arches, and marine terraces. Along other coastlines, such as more gently sloping submergent coastlines, longshore current action redistributes sediment in the form of sand deposits. Typical landforms on this type of coastline include spits, bay barriers or baymouth bars, tombolos, barrier islands, and estuaries. Since most of the world’s population lives along a coast, the natural changes of erosion and deposition can be increased by human alteration of the landscape through the use of constructed features such as a breakwater, jetty, or groin.
Section 1: West Coast
Stereopair Book
p. 11 Point Lobos California
Assume the right side of the stereopair is north.
Find a headland, sea stack, and marine terrace on the stereopair; give the geographic place name (proper name) for each from the topo map.
Find a wave crest. What was the wind direction that generated these waves?
Topo Map Book
p 20 Pt. Reyes, California
Assume that north is to the top of the page.
What is the longshore current direction at Limantour Spit?
If this current continues to transport sand, what will Limantour Spit become?
Based on the longshore current, what will eventually happen to Estero de Limantour and Drakes Estero, without human intervention?
.usgs.g o v/
You will need the cardboard stereoglasses.
Go to Point Reyes National Park and select thumbnail images. Select the Chimney Rock and Chimney Rock Overlook photos.
What feature did this used to be?
If wave erosion continues, what will eventually happen?
p 21 San Luis Rey, CA
Assume that north is to the top of the page.
How did Buena Vista Lagoon form?
What is the wide, level landform at around the 50 ft contour line, where the homes and the Atchison, Topeka, and the Santa Fe Railroad tracks are located?
What did it used to be?
Give two possible reasons for this landform no longer being at sea level.
p 77 Oregon
What is the purpose of the jetties at the Coquille River?
Section 2: East Coast
Topo Map Book
p 45 Mount Desert, Maine
What type of coastal landform is Moose Island in the southwestern part of the map?
What type of coastal landform does the stippled (dotted) pattern connecting Moose Island to the mainland represent?
How did it form?
p 84 Kingston, Rhode Island and photographs at the front table
What is the elongated feature in the lower left of the map that nearly separates Trustom Pond from the open ocean?
What direction is the longshore current going?
Your beach cottage is located at the “h” on Browning Beach. Your neighbor at the “c” on Browning Beach has built a groin that extends 100 ft from the beach into the ocean. Draw this setting and explain how this will affect your neighbor’s beach and your beach.
Section 3: Visiting Barbra
Point Dume, California topo map and web site photo
California Coastline (iforniacoastline.org) is an organization concerned with coastal erosion. This Malibu mansion is the home of singer, actress, director, and producer Barbra Streisand. After attending a Malibu Neighborhood Association meeting, Barbra has learned about coastal erosion and she is worried!
She hires you to be her personal coastal geographer. After reviewing the aerial photography and the topographic map, your main concern is the action of waves. Waves most often approach the coastline from the southeast. The * on the topo map points to Barbra’s home.
To give you an idea of wave action in this area, in addition to this photo, B is the location on Zuma Beach County Park where I broke my tailbone.
What coastal landform is her house built on?
Why is the beach below her house so flat?
As wave refraction continues to act on Point Dume, what coastal landform will it become?
If a rise in sea level continues, what will begin to happen to the sea cliff at the edge of Barbra’s backyard?
Consider the construction of a breakwater to alleviate wave erosion. Make a map view sketch of Barbra’s scene.
Now add in the proposed breakwater to the sketch above so that it will reduce erosion on Barbra’s beach.
How will the breakwater work to reduce wave erosion on Barbra’s beach?