Weathering and Erosion Basics

Summary

This educational video explores the concepts of weathering and erosion, distinguishing between the two processes with a practical demonstration using a graham cracker and a rolling pin. It delves into the agents of weathering and erosion, such as wind, water, gravity, and ice, and explains four types of mechanical weathering: frost wedging, abrasion, exfoliation, and organic action. The video promises a follow-up on chemical weathering and encourages students to take notes for an upcoming quiz.

Takeaways

• 📚 The video discusses the difference between weathering and erosion, highlighting that weathering is the process of breaking down materials into smaller pieces, while erosion involves the movement of these materials.
• 🔨 Mechanical or physical weathering is demonstrated using a graham cracker and a rolling pin, showing how materials can be broken into smaller pieces through physical force.
• 🧪 Chemical weathering is introduced with a baking soda and vinegar experiment, illustrating how a chemical reaction can change the substance permanently, unlike physical weathering.
• 🌬 Agents of weathering and erosion include wind, water, gravity, and ice, each causing breakdown and movement of materials in different ways.
• ❄️ Frost wedging or ice wedging is a type of mechanical weathering where water in fractures of rocks expands upon freezing, causing the rock to break apart.
• 🏔 Abrasion is identified as the process where earth materials collide, often caused by glaciers, rivers, gravity, or wind, leading to the wearing down of rocks.
• 🦵 Exfoliation is a type of mechanical weathering where rocks peel away in layers due to the release of pressure, often after the overlying softer rock has been eroded away.
• 🌳 Organic action is another form of mechanical weathering, where living organisms like trees, animals, or insects physically break up rocks.
• 📝 The video script emphasizes the importance of taking good notes for an upcoming quiz on the mechanical agents of weathering.
• 📚 The next video will cover chemical weathering and erosion, expanding on the concepts introduced in the current video.
• 💬 The instructor encourages students to ask questions via Edmodo or email, indicating an open line of communication for further clarification.

Q & A

What is the main difference between weathering and erosion?

Weathering is the process of breaking down rocks and minerals into smaller pieces without necessarily moving them, while erosion is the process of transporting these broken-down materials from one place to another by agents like wind, water, or ice.

What are the two main types of weathering mentioned in the script?

The two main types of weathering mentioned are mechanical (or physical) weathering and chemical weathering.

Can you explain the concept of mechanical weathering using the example given in the script?

Mechanical weathering is demonstrated by smashing a graham cracker into smaller pieces using a rolling pin. This represents the process of physical breakdown of earth materials into smaller pieces.

What is an example of chemical weathering provided in the script?

An example of chemical weathering is the reaction between baking soda and vinegar, which causes the baking soda to chemically change and produce bubbles, indicating a permanent transformation.

What are the agents of weathering and erosion as mentioned in the script?

The agents of weathering and erosion include wind, water, gravity, and ice (such as glaciers).

What is the process called when water freezes in rock fractures and causes the rock to break apart?

This process is called frost wedging or ice wedging, where the expansion of water upon freezing causes the rock fractures to enlarge and the rock to break up.

How does abrasion contribute to both weathering and erosion?

Abrasion occurs when earth materials, such as rocks, collide with each other. This can happen due to the movement of glaciers, running water in rivers, or even gravity causing rocks to roll down a hill, leading to the breakdown and transportation of materials.

What is exfoliation in the context of mechanical weathering?

Exfoliation is a type of mechanical weathering where layers of rock peel away due to the release of pressure, often occurring when a magma chamber is exposed and expands after the overlying rock has been worn away.

What is organic action in relation to weathering?

Organic action refers to the physical breakdown of rocks by living organisms, such as tree roots growing between rocks, animals walking over them, or even insects like ants digging tunnels.

Why is it important to take good notes on the types of mechanical weathering discussed in the script?

Taking good notes on the types of mechanical weathering is important because it helps in understanding the different processes that break down rocks and minerals, and these concepts will be tested in an upcoming quiz.

Outlines

00:00

🌪️ Weathering vs. Erosion: Fundamental Concepts

This paragraph introduces the video's focus on weathering and erosion, explaining the distinction between the two geological processes. Weathering is described as the process of breaking down earth materials into smaller pieces, illustrated by physically crushing a graham cracker. Erosion, on the other hand, is the movement of these materials, exemplified by wind or water transport. The paragraph also touches on chemical weathering, using a baking soda and vinegar reaction to demonstrate a chemical change that cannot be reversed. The agents of weathering and erosion are mentioned, including wind, water, gravity, and ice, setting the stage for a deeper dive into the types of mechanical weathering in subsequent content.

05:02

🏔️ Mechanical Weathering: Processes and Examples

This paragraph delves into the specifics of mechanical or physical weathering, detailing four primary types: frost wedging/ice wedging, abrasion, exfoliation, and organic action. Frost wedging is explained as the expansion of water when it freezes, causing rocks to crack. Abrasion is described as the collision of earth materials, such as rocks, which can be caused by glaciers, rivers, gravity, or wind. Exfoliation is depicted as the peeling away of rock layers due to the release of pressure in geological formations. Organic action refers to the physical breakdown of rocks by living organisms, like tree roots or burrowing animals. The paragraph provides examples to illustrate each type, emphasizing the relevance of these processes in various environments, not just in mountainous or glacial regions.

Keywords

💡Weathering

Weathering is the process where rocks and minerals are broken down into smaller pieces by natural forces. In the video, it is differentiated from erosion by explaining that weathering involves the breakdown without the displacement of material. An example given is mechanical or physical weathering, where a grand cracker is smashed into smaller pieces using a rolling pin, illustrating how rocks can be broken down by forces like wind or ice.

💡Erosion

Erosion is the process of moving weathered rock and soil from one place to another by natural agents such as wind, water, or ice. The video script uses the analogy of moving the crushed grand cracker crumbs to explain how erosion works. It's distinguished from weathering by the movement of material, not just its breakdown.

💡Mechanical Weathering

Mechanical weathering, also referred to as physical weathering in the script, involves the breakdown of rocks into smaller pieces without changing their chemical composition. The video demonstrates this with the grand cracker example, where the cracker is physically smashed. It's a key concept in understanding how rocks are broken down by natural forces like temperature changes, water, or abrasion.

💡Chemical Weathering

Chemical weathering is the process where the chemical composition of rocks is altered by reactions with substances like water or acids. The video script introduces this concept by showing a chemical reaction between baking soda and vinegar, which causes the baking soda to change chemically and cannot be reversed, illustrating how rocks can be chemically altered over time.

💡Agents of Weathering and Erosion

The agents of weathering and erosion are the forces that cause these processes to occur. The script mentions wind, water, gravity, and ice as the primary agents. For instance, wind can move rocks and cause abrasion, while water can cause both weathering through chemical reactions and erosion by moving sediment.

💡Frost Wedging

Frost wedging, also known as ice wedging, is a type of mechanical weathering where water that has seeped into cracks in rocks freezes, expands, and causes the rock to break apart. The video script describes this process using the example of water in rock fractures that expands upon freezing, leading to the rock breaking up.

💡Abrasion

Abrasion is the process by which rocks and sediments are worn down through friction and collision with other rocks or sediments. The video script explains that glaciers can cause abrasion as they move downhill, carrying rocks that grind against the mountain's rocks. Additionally, running water and wind can also cause abrasion by moving earth materials that collide with each other.

💡Exfoliation

Exfoliation is a type of mechanical weathering where rocks peel away in layers due to the release of pressure. The video script uses the analogy of a skin peeling away to describe how rocks can exfoliate when the pressure from overlying rock is removed, such as when a magma chamber expands outward after the softer rock above it has eroded away.

💡Organic Action

Organic action refers to the role of living organisms in breaking down rocks. In the video, examples include tree roots growing between rocks, animals walking over rocks, or even ants digging tunnels. This concept is important as it shows how biological processes can contribute to the physical breakdown of rock material.

💡Glaciers

Glaciers are massive bodies of ice that move slowly across land and are significant agents of both weathering and erosion. The script mentions glaciers as a cause of frost wedging and abrasion, highlighting their role in shaping landscapes through the movement of large amounts of rock and sediment.

Highlights

Introduction to the topic of weathering and erosion, discussing the differences between the two processes.

Demonstration of mechanical or physical weathering using a graham cracker and a rolling pin to illustrate the concept.

Explanation of erosion as the movement of broken materials, differentiated from weathering which involves breaking down.

Introduction to chemical weathering with a baking soda and vinegar experiment to show a chemical reaction.

Differentiation between physical and chemical weathering based on whether the substance's chemical composition changes.

Listing of the agents of weathering and erosion, including wind, water, gravity, and ice.

Discussion of the specific type of mechanical weathering called frost wedging or ice wedging, using water freezing in rock fractures as an example.

Illustration of how ice wedging contributes to the formation of pointed and jagged mountain peaks and potholes in roads.

Explanation of abrasion as the collision of earth materials, with examples of how glaciers, water, and gravity can cause this type of weathering.

Introduction to exfoliation as a type of mechanical weathering caused by the release of pressure and expansion of rock layers.

Description of organic action as a form of mechanical weathering caused by living organisms that physically break up rocks.

Emphasis on the importance of taking good notes for an upcoming quiz on the mechanical agents of weathering.

Announcement of a follow-up video that will cover chemical weathering and erosion.

Invitation for students to ask questions via Edmodo or email, encouraging interaction and clarification of concepts.

Highlighting the practical application of the concepts discussed in class and the importance of understanding the agents of weathering and erosion.

Reinforcement of the distinction between physical and chemical weathering processes and their outcomes.

Transcripts

you

alright guys this video is going to get

into weathering and erosion we'll talk

about the difference between weathering

and erosion we'll talk about what the

agents are of weathering and erosion and

what that means is what causes them to

happen and we'll also get into the types

of mechanical or physical weather and

mechanical and physical mean the same

thing in the next video we'll get into

chemical weathering and erosion make

sure you take good notes on this one or

the quiz on in class also a couple of

activities that we're going to do follow

up with this video as well I'll check

your notes in class for a stamp let me

know if you have any questions alright

guys so what is the difference between

weathering and erosion

let's go ahead and take a look at this

graham-cracker here and let's take this

rolling pin and let's smash it up so as

I do this I'm taking the big Grand

cracker and I'm breaking it up into

smaller pieces little tiny crumbs that

what weathering is now this type of

weathering is specifically what's called

mechanical weathering or physical

weathering it's taking earth material

and it's smashing it up into little

pieces now what's the difference between

this and erosion erosion is when you

take it and you move it somehow either

by wind like that or maybe water will

wash it away or maybe a glacier will

wash it away really the big difference

is that weathering is when something

gets smashed like this and erosion is

when something moves it now weathering

doesn't need to be just be a physical

process here I have another substance

this is baking soda I'm going to add a

little bit of vinegar here and you're

going to notice

hopefully that it bubbles this is a

chemical reaction this chemical reaction

is chemical weathering I'm chemically

changing the substance the baking soda

is changing forever it chemically cannot

be changed back to what it was when it

first started so what's a big difference

one is a chemical one's a physical

process where at the end it's chemically

the same and the other is a chemical

process where at the end its chemically

different and it can't be undone alright

so what are the agents of weathering and

erosion and what I mean by agents is

what are the things that

caused it to happen first thing is the

wind the wind not necessarily the wind

itself but when the winds blow rocks

across a desert environment then rocks

can smash and rocks and they break up

then there's the water now water can

cause weathering and erosion in a number

of different ways but primarily caused

something called abrasion we'll get into

that in just a little bit but water

carrying rocks and those rocks then

smashing into one another there's also

gravity rocks just rolling down a hill

and then there's ice and again there's a

couple different ways that ice can cause

weathering and erosion to happen so to

understand these better let's get into

some more specific details and talk

about the types of mechanical or

physical weathering okay so the first

type of mechanical weathering that we're

going to talk about is I sweating or

frost wedging they both mean the same

thing here we have a rock that has some

fractures in it filled with water and if

we lower the temperature of that water

and we freeze it that water is going to

cool down turn into ice and when it does

water expands when it freezes and it's

going to make those fractures much

larger and it will be it will break up

those rocks let's go ahead and see that

again here's the water we freeze it it

expands notice that the fractions and

rock it bigger and then it breaks up the

rocks this is called frost wedging or

ice watching same thing ice white dreams

going to be really important when we

start to talk about glaciers take a look

at this picture here notice how pointed

and how jagged that mountain looks that

all formed because of erosion due to ice

wedging and if you take a look at the

bottom picture here there's this big

pothole in the middle of the road this

pothole formed because of ice washing so

just because we don't live in the

mountains near glaciers doesn't mean

we're not affected by ice why dang

alright so next we have abrasion which

simply means the collision of earth

material remember earth material can be

rocks minerals anything like that and if

we can begin up here in the mountains

and we can go ahead and take a look at a

glacier glaciers can certainly cause

abrasion house also because glaciers

hold in a lot of rocks and as those

glaciers move downhill because of

gravity the rocks within the glacier

grind up against the rocks of the

mountains

and it causes those rocks to smash up so

glaciers can absolutely cause abrasion

the let's say the glacier melts or some

rain comes down and we get a little

river that forms down the side of the

mountain and that running water that

running water can cause rocks to slam

into one another why because as that

water cascades down the mountain it's

going to carry earth material with it

and as that earth material gets carried

in the water the rocks within it will

smash up against one another then we

also simply have gravity we have a

hillside here and gravity can run rocks

on down the side of the mountain which

can cause them to smash up into one

another so gravity is also a cause of

abrasion and we also have wind if

there's wind blown across the land here

that can cause rocks to smash into one

another and then as rocks fall into the

ocean we have water again that can cause

these rocks to smash up so one of the

big things that cause abrasion to happen

we have wind water gravity and ice like

in glaciers okay our third type of

mechanical weathering is called

exfoliation you may have heard of

exfoliation before like the peeling away

of layers of skin or dead skin so

exfoliation happens because of a release

of pressure and here's what I mean by

that over here we have this big igneous

formation underneath the ground maybe a

batholith or a laccolith or something we

learned about that back with volcanoes

and then something washes away all these

softer rocks up on top and exposes that

hardened magma chamber

well this heart of mammoth chambers been

compressed over a very long period of

time and eventually once enough of that

softer Rock is worn away and the

pressure from the overlying Rock is gone

that hardened magma chamber is going to

expand outward and cause these rocks to

peel away in layers and that's what

causes exfoliation and lastly we have

organic action what that means is

anything living that can break up rocks

here we have a tree that's growing

between rocks but it's not necessarily

just a tree it could be an animal that's

walking over the rocks that breaks them

up it could be

an ant digging a tunnel it could be a

snake burrowing through the ground

basically anything living that can break

up rocks physically and we call that

organic action alright so in this video

we discussed the differences between

weathering and erosion we talked about

the causes of weathering and erosion or

the agents of weathering and erosion and

we got into the four types of mechanical

or physical weathering but we got a

video coming that's going to discuss

chemical weathering but make sure you

took really good notes on the mechanical

agents of weathering your never quiz on

it pretty soon and we're also going to

apply it in lecture I'm going to check

your notes for a stamp please feel free

to send me a message on Edmodo with any

questions or you can send me an email