Topic 8 Lesson 2 Erosion & Deposition

What are the factors that affects the shape and size of sand dunes

direction of the wind, amount of sand, presence of plants

What do you think is the most important agent when a class discuss about mass movement?

gravity

T/F. Only erosion changes the shape of the Earth's surface. Deposition does not alter the shape of the Earth's surface.

False. Both erosion and deposition alter the Earth's surface.

T/F. Erosion takes place during mass movement event, but not deposition.

False. Erosion and deposition both take place during a mass movement event.

T/F Mass movement only happens rapidly.

False. Mass movement can be rapid or slow.

T/F. The timeline in changing in Earth's surface does not vary. It always occur in longer time like thousands to million years. Give one example if possible.

False. The timeline in changing in Earth's surface varies. Some changes can occur in thousand to million years, while some can take only a few moments like rockslide.

T/F. Wind is one of the agents of erosion and deposition. It causes only wearing down of Earth's surface by transporting sediment from one place to another.

False. Wind is an agent of erosion and deposition that wears down and builds up Earth's surface.

T/F. Changes in Earth's surface only happen in a large area. Explain your answer.

False. changes in Earth's surface can happen in both small and/or large area. It depends on the agent of erosion and other factors.

T/F. Only stronger winds has the capacity to move sediments? Explain

False. strong and weak wind both have the capacity to move sediments. The only difference is stronger winds can carry bigger sediments compare to weaker wind

T/F. All sediments picked up by wind eventually falls back to Earth's surface? Why. Explain.

True. All the sediment picked up by wind eventually falls back to Earth's surface. This happens when the wind slows down or encounters an obstacle.

T/F. We can predict how wind deposition can affect the surface in the future

True. The process that changed the Earth's surface billions of years ago, is same process as it does today and future.

Mrs. Quinlan discussed in class that there are factors that causes materials to be transported. What are those agents of erosion?

gravity, water, ice, wind

In areas where there are few plants, which of the following can be a significant agent in shaping the land? Explain. a. water b. land formation c. wind d. gravity

c. wind. Wind can be a significant agent in shaping the land in areas where there are few plants to hold the soil in place.

What small particles/materials do wind picks up?

clay and silt or small, fine particles

What is deflation?

is the erosion by wind where in wind removes the surface materials.

Describe a way in which deposition by gravity slowly changes Earth's surface

landslide forming new land.

Which kinds of mass movement happens quickly

landslide, mudflows, slumps

What are the different types of mass movement?

landslides, mudflows, slump, creep

Strong winds can move what type of particles/sediment?

larger and heavier sediment particles

Explain loess deposits

loess deposits is the fine, wind-deposited sediment. It occurs when wind drops sediment that is finer than sand but coarser than clay far from a source.

What type of weathering is abrasion?

mechanical weathering

What can mass movement be triggered by?

natural disaster - flood, earthquake, hurricane

What does sediment consist of?

pieces of rock or soil, or remains of plants and animals

According to Mrs. Quinlan, there are different types of mass movement. Each one is different from another. What are the types of mass movement and how would you differentiate one from the other.

1. LANDSLIDE - is a RAPID sliding of ROCK AND SOIL down a STEEP slope. It can contain small or large rocks and soil. It is often cause by EARTHQUAKES in the areas where road builders built highways through hills and mountains 2. MUDSLIDE - is a RAPID downhill movement of a mixture of WATER, ROCK AND SOIL. It often occur after HEAVY RAIN in a normally dry area. In a clay-rich soil with a high water content, mud flows occur even on very gentle slope. After heavy rains clay-rich soil suddenly behaves as a liquid and begins to flow. 3. SLUMPS - is a SUDDEN or ONE LARGE slips down of ROCK and SOIL in a slope. It occurs when water soaks the bottom of clay-rich soil. 4. CREEP - is a VERY SLOW DOWNHILL MOVEMENT of ROCK and SOIL. It can also occur in gentle slopes. It is a result of FREEZING and THAWING of water in cracked layers of rock beneath soil. Even though it occurs slowly, Creep tilt vertical objects at unusual angle.

What are the measures or actions that engineers, scientists can do in order to reduce the effects of mass movement? Are all actions can only be done by engineers and scientists? Explain.

Building retaining wall, wire mesh, drainage pipes and increased vegetation. Everyone can help to reduce effects of mass movement by planting.

What is deposition?

Deposition occurs where the agents of erosion deposit or lay down sediment

What causes the most landslides? Which caused the fewest landslides?

Earthquakes. Volcanic eruptions.

Mrs. Quinlan is teaching her class about changing Earth's surface. She asked the class what to they know about erosion. What would you say if Mrs. Quinlan called your name?

Erosion is a process that moves weathered rock from its original location to a new location.

What is more likely to happen if an erosion occurred in one of the biggest mountain?

Erosion wears down mountain in one place, and deposition builds up a new landform in another place

Describe/give an example to describe the process of erosion and deposition.

Ex: ant carrying bit of soil from one place to another which eventually lead to building an ant hill. It is similar to erosion and deposition which involves the picking up, carrying away, and putting down sediment in a different places

What causes mass movement downhill?

Gravity causes mass movement

What is gravity and what is the importance of gravity in mass movement?

Gravity is the force that pulls matter down. Gravity moves rock and other materials downhill.

Mrs. Quinlan gives a classwork to discuss the changing of the Earth's surface. With this classwork, the groups need to explain the process of weathering, erosion, transportation, and deposition. Group A argues that weathering, erosion, transportation, and deposition is a cycle that happens seasonal in a year. Group B argues that it happens continuously but in one whole year only. Group C argues that it is a continuous cycle without a timeline. Lastly, Group D argues that it is a continuous cycle that can last for thousands to millions of years. Who among the groups is correct. Explain your answer

Group C is correct. Weathering, erosion, transportation, and deposition is a continuous cycle that wears and builds up Earth's surface.

What can deflation create in a desert area?

In desert areas, deflation can create an area called desert pavement where smaller sediments are blown away and larger rock fragments are left behind.

Mrs. Quinlan discussed last week regarding the changes in Earth's surface. She mentioned that it is/will not same changes that/will shaped the Earth's surface in the past present, and future. Is this statement correct? Explain

Incorrect. The same changes that shaped Earth's surface int he past still shape it today and will continue to shape in the future.

How does vegetation help with erosion?

It holds the soil in place which stabilize a slope/Earth's surface.

How much does landslides and mudflows affect the States in the US and around the world? How do landslides and mudflow affect the expenses of the government and people's lives

Landslides and mudflows are a problem in all 50 states and around the world. It caused up to billion of dollars and lots of deaths.

What is the importance of loess in farming?

Loess helps form soil rich in nutrients.

What does scientist used to monitor mass movement? Why do they need to create maps for those mass movements?

Scientists use satellites to monitor mass movement and make maps of past mass movements in a regional to better understand their hazard in order to prevent casualties.

________________ is the material that moves by the process of erosion.

Sediment

Julie made a statement during the class that changes in Earth's surface can happen differently. It can be large or small changes and it can happen immediately or longer. Regardless, Julie stated that erosion and deposition is not always a continuous process. What can you say about Julie's statement.

Some of Julie's statement is correct. Changes in Earth's surface can be immediate or slower. It can be small or large changes. But Julie is wrong because the cycle of erosion and deposition is continuous.

What does abrasion mean?

abrasion is the process when particles move against the rock, friction wears the rock when wind, water, and ice carry particles that rub or scrape against exposed rock.

Which statement is correct: a. weathering, erosion, transportation, and deposition is not a continuous cycle that wears down and builds up Earth's surface b. a. weathering, erosion, transportation, and deposition is a continuous cycle that wears down and builds up Earth's surface c. weathering, erosion, transportation, and deposition is not a continuous cycle that wears down Earth's surface d. weathering, erosion, transportation, and deposition is a continuous cycle that builds up Earth's surface

b. a. weathering, erosion, transportation, and deposition is a continuous cycle that wears down and builds up Earth's surface

Give some examples what wind deposition can form?

sand dunes and loess deposits

What is sand dunes? How it is formed?

sand dunes is produced by deposit of windblown sand. It is formed when wind meets and obstacles such as clump of grass.

Explain how wind both builds up and wears down Earth's surface in a desert. Give examples of features that result from these processes

sanddunes obstacle plant

Materials that slightly larger than a silt and clay tend to?

skip or bounce for short distance

What are the factors/agents that act together in a continuous cycle that results in wearing down and building up Earth's surface?

weathering, erosion, transportation, and deposition

What are the factors that affect how high and far the particles/sediment travels?

wind (strong, weak) weight of particles