Where's The Beach?

At which location will the beach first begin to widen due to sand deposition? (1) A (3) C (2) B (4) E

2-B

How was this beach directly formed? 1) uplifting from an earthquake (2) sinking of land during a landslide (3) deposition of sediments by ocean waves and currents (4) erosion of bedrock by ocean waves and currents

3

When waves from the southeast strike a beach that runs east and west, the direction the longshore current is likely to move toward is the (1) west (3) northwest (2) east (4) southeast

3

Water particles near the surface of a deep water wave (1) move with the wave (2) move against the wave (3) do not move (4) move in a circle

4

What is the most common cause of the approaching waves? (1) underwater earthquakes (2) variations in ocean-water density (3) the gravitational effect of the moon (4) winds at the ocean surface

4

Winds transport sand and other material by (1) water and rolling (2) suspension and bouncing (3) ice and snow (4) ocean currents and water

4

What is a barrier island?

A barrier island is a long offshore deposit of sand situated parallel to the coast.

What is a groin (Earth Science)? How are they designed to protect the beach?

A groin is a shoreline structure that is perpendicular to the beach. It's made with large boulders made with concrete, steel, or wood. This interrupts and traps the longshore flow of sand.

Where does the sand at the beach come from?

Beach sand comes from rivers and streams that carry it directly to the ocean.

What is a seawall and how are they designed to protect beach front property?

Seawalls are structures built of concrete, wood, steel or boulders that run parallel to the beach at the land/water interface. They aare smooth and solid so that the water will reflect and go back into the ocean.

The size of the bulge in the beach at position D will (1) decrease (2) increase (3) remain the same

2

What three aspects of waves will change if the winds change?

Direction, Velocity, and size of Waves.

Explain how humans are negatively impacting beaches?

Humans negatively impact beaches by building these structures such as groins, jettys, breakwaters, and seawalls. These lead to changes in coastal sediment transport pathways resulting in erosion.

Is a sea wall a positive or negative fix and why?

I think it's both positive and negative because it protects the buildings and structures from being flooded and destroyed, but it also may make the beach and surf disappear.

How is a jetty different than a groin in reference to the erosion and deposition of the beach around the jetty?

Jetties are large, man-made piles of boulders or concrete that are built on either side of a coastal inlet. Whereas groins are built to change the effects of beach erosion, jetties are built so that a channel to the ocean will stay open for navigation purposes.

What is a jetty? How are they designed to protect the beach?

Jettys are big piles of boulders that are built on either side of a coastal inlet. They completely interrupt and redirect longshore currents.

What kind of erosion can longshore drift create?

Long, narrow sandbars of sand, called spits.

What are longshore currents? With respect to the beach, which direction do longshore currents travel?

Longshore currents transport sediments along shorelines and cause some of the changes we see in the sediment distribution at the beach.They travel parallel to the shoreline between the breaker zone and the shore.

How is longshore current different than longshore drift?

Longshore drift is the transport of sand from river mouths to beaches that are far from it. Longshore current is the transport of sediment by waves.

3. In your own words, explain why barrier islands are always changing

Longshore drifts are constantly doing different things, and making changes to the land all around them, naturally. These changes include depositing, removing, and redepositing sand. This causes the barrier islands to be subject to change.

What eventually happens to a beach if a breakwater is built?

Over time, sand will accumulate towards a breakwater. Downdrift sand will erode. A breakwater can cause millions of dollars in beach erosion in the decades after it is built.

. In what season is deposition of sand at beaches more prevalent?_______________ and why?

Summer, because these waves deposit sand on shore creating wide, gently sloping beaches.

What are the factors that affect the size of the wave?

The Distance the wind blows it, Strength, and duration of the wind.

Add an arrow to the diagram below to indicate the direction of the longshore current.

The arrow would be parallel to the shore, so horizontal.

What kind of deposition can longshore drift create?

They can create or destroy barrier islands.

What causes the waves to "break"?

When the wave gets in shallow water, the lower part slows down while the upper part continues, and topples over the bottom, this is when it breaks.

In what season is erosion of beaches more prevalent (happens more)? ________________ and why?

Winter, because in winter waves become choppier, more forceful, and more frequent. Winter storms can cause large, powerful waves that crash onto the beach and pull sand offshore.

For a longshore current to form, do the waves need to come in at an angle?

Yes

If there is an easterly wind with a groin running north to south, where will deposition and erosion take place. Make a sketch below.

You have to pay to add a picture but it has water coming from the left, and the groin is potentially blocking it from the structures.