SCIENCE 8 - QUARTER 2 - WEEK 1 - EARTHQUAKES AND FAULTS - MELC-BASED

Summary

This video provides an informative overview of earthquakes, focusing on their causes and effects. It explains how faults in the Earth's crust result in earthquakes and illustrates this with hands-on activities demonstrating fault movement. The video also covers different types of faults (normal, reverse, and strike-slip), the role of energy and friction in earthquakes, and the importance of understanding earthquakes to minimize damage. Additionally, it discusses seismology, the study of earthquakes, and highlights agencies like PHIVOLCS that monitor seismic activity in the Philippines.

Takeaways

• 🌋 The Philippines is situated along the Pacific Ring of Fire, a region known for frequent earthquakes and volcanic activities.
• ❌ Earthquakes are associated with faults, contrary to the initial false statement in the script.
• 📊 A fault is a fracture in the Earth's crust where significant movement has occurred, not a static break.
• 🌏 Energy from the Earth's interior exerts force on rocks along faults, causing them to bend and eventually leading to earthquakes.
• 🏞️ Mountains and valleys are formed by different geological processes, not merely by land sinking.
• 🔍 Seismology is the scientific study of earthquakes, and seismologists are the experts in this field.
• 🏛️ In the Philippines, PHIVOLCS (Philippine Institute of Volcanology and Seismology) is the agency responsible for monitoring earthquakes and fault movements.
• 🏡 Earthquakes can cause significant loss of life and property damage, emphasizing the importance of understanding and preparing for them.
• 🧪 Educational activities, such as the cardboard and sand experiment, can simulate fault movements and help visualize how earthquakes occur.
• 🔑 There are three main types of faults: normal, reverse, and strike-slip, each with distinct characteristics and effects on the Earth's surface.

Q & A

What is the Pacific Ring of Fire?

The Pacific Ring of Fire refers to the region around the Pacific Ocean that is commonly hit by earthquakes and volcanic eruptions.

What causes earthquakes to occur along faults?

Earthquakes occur when rocks along a fault suddenly move due to the force exerted by energy from inside the Earth.

What is the difference between a normal fault and a reverse fault?

In a normal fault, rock layers are pulled apart and one section moves downward relative to the other due to gravity. In a reverse fault, rock layers are squeezed together and one section is pushed upward relative to the other.

How does the 'stick and slip' model explain the occurrence of earthquakes?

The 'stick and slip' model explains that rocks along faults are initially stuck together due to friction. When the force from the Earth's interior overcomes this friction, the rocks suddenly slip, causing an earthquake.

What is the role of the Philippine Institute of Volcanology and Seismology (PHIVOLCS) in monitoring earthquakes?

PHIVOLCS is the national agency in the Philippines responsible for monitoring earthquakes and fault movements.

What is the significance of understanding earthquakes for society?

Understanding earthquakes helps society prepare and respond to such devastating events, potentially avoiding or reducing the loss of life and damage to property.

How can the activity with cardboard and sand demonstrate the concept of a fault?

The activity shows that when two sheets of cardboard are pulled apart, a break or crack forms in the sand, simulating how a fault is a break in the Earth's crust with significant movement along the break.

What is the difference between a mountain and a valley in terms of land formation?

A mountain is a large mass of land that rises above the ground, while a valley is a lower part of the land between two higher parts, which might be mountains or hills.

What are the three types of faults mentioned in the script?

The three types of faults mentioned are normal fault, reverse fault, and strike-slip fault.

Why are some countries like Japan, Indonesia, and the Philippines more prone to earthquakes?

These countries are more prone to earthquakes because they are located within the Pacific Ring of Fire, a region known for its seismic and volcanic activity.

Outlines

00:00

🌋 Earthquakes and the Ring of Fire

The video segment discusses the Philippines' location along the Pacific Ring of Fire, an area prone to earthquakes and volcanic eruptions. It explains that earthquakes are associated with faults, which are breaks in the Earth's crust where significant movement occurs. The segment also clarifies misconceptions about earthquakes and faults, emphasizing the role of energy from within the Earth in causing earthquakes. It introduces the importance of understanding earthquakes for safety and the role of seismology and seismologists in studying them. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) is highlighted as the national agency responsible for monitoring earthquakes and fault movements in the country.

05:00

🔍 Understanding Faults Through Activities

This part of the script involves a hands-on activity to demonstrate the concept of faults. It instructs viewers to use materials like cardboard, sand, and a ruler to simulate the formation of a fault. By moving the cardboard sheets, a crack or break in the sand is created, illustrating how faults form. The activity also shows how lines on the sand are displaced, similar to how roads or landscapes can be altered by fault movements. The script explains that faults are breaks in the Earth's crust with significant movement and that there are different types of faults, including normal, reverse, and strike-slip faults. The activity helps viewers visualize how the ground can be pulled apart, forming valleys, or pushed together, forming mountains.

10:03

🏠 Earthquake Simulation with a Rubber Band Model

The video script describes an activity using small boxes, a rubber band, and a paper clip to simulate an earthquake. The setup represents how friction along a fault can cause the ground to stick together until the force overcomes the friction, leading to a sudden movement or earthquake. The activity demonstrates the 'stick and slip' mechanism that occurs along faults, where the ground does not move immediately due to friction but eventually slips, causing an earthquake. The script encourages viewers to build their own models to better understand this process and the role of friction in earthquake generation.

15:04

🌐 The Impact and Study of Earthquakes

This section discusses the broader implications of earthquakes, noting their potential for causing significant damage and loss of life but also their role in helping scientists understand the Earth's inner layers. It emphasizes the importance of understanding earthquake occurrences to prepare for and mitigate their effects. The script includes a self-check quiz for viewers to test their knowledge on topics covered in the video, such as the definition of an earthquake, types of faults, the study of earthquakes (seismology), and the reasons behind the occurrence of earthquakes in certain regions like the Pacific Ring of Fire.

20:08

📝 Review and Conclusion

The final part of the script is a review of the key points covered in the video, including the role of friction in preventing immediate movement along faults and the factors that contribute to the occurrence of earthquakes. It also provides answers to the self-check quiz, reinforcing the learning outcomes. The segment concludes by congratulating viewers for their engagement and encouraging them to continue learning about earthquakes and related geological phenomena.

Keywords

💡Pacific Ring of Fire

The Pacific Ring of Fire is a region around the Pacific Ocean known for its high frequency of earthquakes and volcanic eruptions. It is characterized by a series of tectonic plate boundaries where the Earth's crust is highly active. In the video, the Philippines is mentioned as one of the countries located along this ring, which explains why it experiences frequent seismic activity.

💡Fault

A fault is a fracture or a break in the Earth's crust along which significant movement has taken place. Faults are the primary cause of earthquakes, as they are the zones where tectonic plates move against each other. The video script describes how faults can be visualized through simple activities, such as moving sheets of cardboard, to demonstrate how the ground can shift and cause an earthquake.

💡Seismology

Seismology is the scientific study of earthquakes and the seismic waves they generate. It is a field that aims to understand the causes, effects, and mechanics of earthquakes. In the video, seismology is mentioned as the study that helps scientists predict and monitor earthquakes, which is crucial for public safety and disaster preparedness.

💡Friction

Friction is the resistance that one surface or object encounters when moving over another. In the context of earthquakes, friction along faults can prevent immediate movement, leading to a buildup of stress. The video script uses the 'stick and slip' model to explain how friction can cause the sudden release of energy along a fault, resulting in an earthquake.

💡Earthquake

An earthquake is the sudden shaking and trembling of the ground caused by the release of energy from within the Earth. This energy is released as seismic waves, which travel through the Earth's crust and cause the shaking. The video emphasizes the importance of understanding earthquakes, as they can cause significant damage and loss of life.

💡Seismologist

A seismologist is a scientist who studies seismology, focusing on earthquakes and related phenomena. They analyze seismic data to understand the nature of earthquakes and work on methods to predict and mitigate their effects. The video mentions the Philippine Institute of Volcanology and Seismology (PHIVOLCS) as the national agency responsible for monitoring earthquakes in the Philippines.

💡Fault Types

There are three main types of faults discussed in the video: normal, reverse, and strike-slip. A normal fault occurs when the Earth's crust is pulled apart, causing one side to drop relative to the other. A reverse fault happens when the crust is compressed, pushing one side up over the other. A strike-slip fault is formed when the crust slides horizontally past each other. These fault types are crucial for understanding how different types of earthquakes occur.

💡Stick and Slip

The 'stick and slip' model is a concept used to explain the mechanism behind earthquakes. It describes how rocks along a fault can become stuck due to friction and then suddenly slip, releasing energy and causing an earthquake. The video uses a simple activity with a rubber band and boxes to illustrate this process, showing how the buildup of stress can lead to a sudden release.

💡Energy Release

The energy release from within the Earth is a key factor in the occurrence of earthquakes. This energy, often from the movement of tectonic plates, can cause rocks to bend and eventually break, leading to an earthquake. The video script explains that this energy is what causes the ground to move and shake during an earthquake.

💡Displacement

Displacement refers to the movement of rock along a fault line, where one side moves in relation to the other. This is a key aspect of how earthquakes occur, as the video script describes through the activities and examples provided. Displacement is a direct result of the forces acting along faults and is a critical concept in understanding the mechanics of earthquakes.

💡Tectonic Plates

Tectonic plates are the large slabs of the Earth's crust that float on the semi-fluid asthenosphere. Their movement and interaction are responsible for the formation of faults and the occurrence of earthquakes. The video script mentions that the energy from within the Earth, which is related to the movement of these plates, can cause faults to slip and result in earthquakes.

Highlights

Philippines is located along the Pacific Ring of Fire, a region prone to earthquakes and volcanic eruptions.

Earthquakes are associated with faults, where rocks along a fault move suddenly.

A fault is a break in the earth's crust where significant movement has occurred.

Energy from inside the earth exerts force on rocks along faults, causing them to bend.

Mountains are not formed by land sinking; they are large masses of land that rise above the ground.

Seismology is the study of earthquakes, and seismologists are scientists who study them.

In the Philippines, PHIVOLCS monitors earthquakes and fault movements.

Understanding earthquakes can help reduce loss of life and property damage.

An earthquake is the sudden shaking caused by the release of energy from inside the earth.

Faults can be normal, reverse, or strike-slip, each with different movement characteristics.

The stick-slip model demonstrates how friction can lead to sudden releases of energy causing earthquakes.

Earthquakes can provide insights into the earth's inner layers and help us prepare for such events.

Major earthquakes can be devastating, but they also offer opportunities for scientific understanding.

Friction plays a crucial role in the delay of rock movement along faults.

The roughness of rocks is a factor that keeps them from slipping past each other.

Learning about earthquakes can help in predicting and mitigating their effects.

Countries like Japan, Indonesia, and the Philippines are within the Pacific Ring of Fire due to their location.

Transcripts

[Music]

are you ready

let's get started

number one

philippines is located along the pacific

ring of fire

[Music]

excellent the correct answer is true

the ring of fire refers to the region

around the pacific ocean

that is commonly hit by earthquakes and

volcanic eruptions

some of the countries in the pacific

ring of fire are japan

indonesia and the philippines

number two

earthquakes are not associated with

faults

[Music]

you are right

the statement is false

earthquakes occur when rocks along a

fault suddenly move

number three

a fault is a break in the earth's crust

and along the break no movement has

taken place

[Music]

correct that is false it is true that

the fault is a break in the earth's

crust and along the break significant

movement has taken place

but how do falls produce tweaks we will

learn that later

number four

energy from inside the earth exerts a

force on the rocks

[Music]

that's right

energy from inside the earth exerts a

force on the wraps along faults

this energy from inside the earth makes

the rocks bend

using a model later

we will see how this happens

number

five when a portion of the land sinks

a mountain is formed

[Music]

that's right the statement is false

mountain is a large mass of land that

rises above the ground while the valley

is a lower part of the land between two

higher parts which might be mountains or

heels

did you get the correct answer

then you are doing great

earthquake is used to describe the

sudden shaking and trembling caused by

the sudden release of energy from inside

the earth

try to look at these pictures

what do you see

why do we need to learn earthquakes

strong earthquakes have caused countless

deaths all over the world and no one can

stop quakes from happening

no wonder scientists have been working

very hard to find a way to predict when

an earthquake occurs

[Music]

the study of an earthquake is called

seismology

the scientists who study earthquakes are

called seismologists

in the philippines the national agency

concerned in monitoring the earthquakes

and fault movements is the fivos or the

philippine institute of volcanology and

seismology

there are things that people can do to

avoid or reduce the loss of life and

damage to property the first step is to

have a clear understanding of the

occurrence of the earthquakes

now let us watch this news clip and try

to think carefully about it what would

you feel if you are living in these

areas

an earthquake is one of the most

frightening things that anyone can ever

experience

you grow up believing that the earth is

rock solid and steady

but then the ground suddenly shakes and

you do not know what to believe anymore

earthquakes are associated with faults

when a fault suddenly moves an

earthquake occurs

do you know what a fault is

let us perform this activity a fault is

set up in this activity

we will be needing two sheets of

cardboard

fine sand

ruler

sheets of paper or newspaper

the first thing that we need to do is to

spread the sheet of paper on a table

[Music]

then arrange the two sheets of cardboard

edge to edge

four sand along the boundary of the two

sheets

with a ruler flatten the top of the sand

and make two parallel lines

[Music]

now move the sheets slowly in the

opposite direction

[Music]

now let us try to answer these questions

as you move the sheets what is formed in

the sand

a crack is formed in the sand or we can

also see that a break is formed in the

sand

[Music]

what happens to the lines

[Music]

we can see

that the lines moved

it is shifted or displaced

try to look at this picture carefully

maybe you are thinking that the road was

originally in one piece

but the road is no longer continuous

there is a cut across the road and now

there are two sections

one section has move with respect to the

other

compare what you see in the picture and

what you saw in the activity

is there something in the picture that

looks like what was formed in the

activity

do you see anything similar

based on the activity and the picture

you can probably guess what a fault is

by now

fault is a break or a fracture in the

earth's crust and along the brick

significant movement has taken place

the word break refers to a crack in the

ground

the world crust refers to the outermost

layer of the earth

we live on the surface of the crust

significant movement means the rocks

have been displaced or shifted

considerably

[Music]

this time get the box and cut it in the

middle

[Music]

place one box over the other one

put sand in the nested boxes

shake the box side to side so that the

surface of the sand will become level

[Music]

now we will slowly pull the sides of the

boxes and observe

we can see that the two parallel cracks

formed in the sand

let us continue to pull the box cover

and observe

the sand in the middle of the crack

subsides or move down

forming a depression

this simulates what happens when the

ground is pulled apart by forces within

the earth

[Music]

falls form

a portion of the land sinks and a valley

is formed

[Music]

now let us reassemble the box covers as

before

do not forget to make the surface of the

sand flat

this time let us push the sides of the

box covers

toward each other and observe what

happens

as we can see the opposite happens

instead of the sand sinking the sand

forms a tiny ridge

unfortunately this model does not show a

craft in the sand that would represent a

fault

in the real world a fault is formed when

the ground is squeezed by forces from

inside the earth a portion of the land

is pushed up and mountains are formed

[Music]

there are three types of faults the

normal fault the reverse fault and the

strike's default in the normal fault the

rock layers in the earth's crust are

pulled apart and gravity causes one

section to move downward in relation to

the other

[Music]

[Applause]

while in the reverse fault the rough

layers in the earth's crust are squeezed

together and the force pushes one

section upward about the other

[Music]

then the strike sleeve fall forms when

the rock layers on the opposite sides of

the falls slide past each other

horizontally

[Music]

but how do falls produce quakes now that

you have an idea of how faults look let

us learn how earthquakes occur along

faults

let's do another activity

stick and sleep

this will show us how earthquakes are

related to falls

in this activity two small boxes are

needed the cartons that fruit juice

drinks are packaged in are perfect

scotch tape or masking tape

rubber band and a paper clip

you can also try this at home

let's start

first attach the rubber band to the

paper clip

[Music]

then attach the paper clip to one end of

one box

[Music]

place the boxes side by side

lightly tape the two boxes together then

put a toy house on the box with the

rubber band

remember do not stick the tape on the

boxes too much the tape is meant to come

off

then third hold the box without the

rubber band in place with your other

hand slowly pull on the rubber band the

rubber band should be pulled forward and

horizontally not sideways

upward or

downward it is expected the box will not

move at first because it is steep to the

other box

question

what happens to the rubber band

you are correct the rubber band

stretches

now keep on pulling on the rubber band

[Music]

question

what happens to the box attached to the

rubber

[Music]

band right the box jerks forward

[Music]

what about the house what happens to the

house

you're correct the house falls over

which is fault in this setup

if you think that the fault in the setup

is the boundary between the two boxes

then you are correct

as the box jerks forward this simulates

the sudden movement that occurs along a

fault

in this activity the tape represents

friction in real life

do you still remember what friction is

you are right friction is the resistance

to motion of one object moving relative

to another

if the tape is too sticky it will never

come off no matter how much rubber band

is pulled

but since we tape it on just enough then

the box jerks free from the tape as we

pull the rubber band

imagine the boxes as the ground and the

boundary between them as fault

in real world terms this is what happens

energy from inside the earth exerts a

force on the rocks along faults

but the rocks do not move right away

because of friction

[Music]

the roughness of the rocks keeps them

from slipping past each other

but when the limit is reached the rocks

suddenly sleep and an earthquake occurs

[Music]

some scientists describe this process as

a stick and slip at first the rocks are

stuck together due to friction

later the rocks suddenly slip generating

an earthquake

every time a fault slips the earthquakes

in our activity there was a sudden jerk

but no shaking the boxes did not shake

as in a real earthquake

can you make your false model if so what

materials will you use

can you also demonstrate to us your

fault model

[Music]

although major earthquakes can kill

thousands of people and can cost a lot

of money for damage to repair

earthquakes can also have positive

benefits for humans it helps us to

understand nature

it also allows scientists to study the

earth's inner layer

and understanding earthquakes helps us

to prepare and respond to such

devastating events

if we have a clear understanding of the

occurrence of the earthquakes we can

avoid or reduce the loss of life and

damage to property

let us have a self check

try to answer the following questions

grab a paper and a pen then write down

your answer you may pause the video if

you need more time

[Music]

number one

it is described as the sudden shaking

and trembling caused by the sudden

release of energy from inside the earth

a fault

b friction

c earthquake

d seismology

[Music]

number two

which type of fault is this

a reverse

b normal c strike slip d stick and slip

[Music]

number three

the study of earthquakes

a fault

b earthquake c seismology the friction

[Music]

number four

earthquakes happen along a fault line

which of the following is not true about

faults

a it can be found in the land

b it is where fault cyclone starts

see it is the break in the earth's crust

d

none of the above

[Music]

number five

this is the process refers to the fast

movement between two sides of a fault

wherein the friction is overcome

resulting in a sudden movement or

shaking of the ground

a stick and shake b

stick and bend

c

stick and vibrate

d

stick and slip

[Music]

number six

earthquakes are common occurrence in

japan indonesia and in the philippines

why is this so

a they are located near the equator

b they are considered archipelagic

countries

c they are found within the pacific ring

of fire and d they are surrounded by

seas

[Music]

number seven

what will most likely happen every time

a fall sleeps

a

there will be no movement at all

b the rocks will suddenly sleep and will

generate an earthquake

c the rocks will be stuck together

d there will be movement right away

[Music]

number eight

what philippine agency is concerned

about monitoring fault movement

a philippine institute of volcanology

and seismology or fevox

b philippine atmospheric geophysical and

astronomical services administration or

pagasa c department of labor and

employment or dole

d department of environment and natural

resources or danr

[Music]

number nine

energy from inside the earth makes the

ground move which of the following is

the reason why there is no movement

right away

a friction causes a delay in the

movement of the ground b the rapid

release of energy causes a delay in the

movement of the ground see

there is no movement right away because

of the vibration of the rocks d there is

no movement right away because of the

bending of the rocks

[Music]

number 10

which factor keeps the rocks from

sleeping past each other

a the depth of the rocks

b

the roughness of the rock

c the arrangement of rocks

d the bending of the rocks

[Music]

now let us check your answers

[Music]

congratulations i am sure that you've

learned something new today thank you

for watching

[Music]