a

The Earth's Lithosphere

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good day my students and viewers i am mr

gianpaolo adverbar

your science learning partner let us

make our science classes be filled with

saya in this session

we will talk about the earth's

lithosphere

today you should be able to

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first describe the earth's lithosphere

and different shaped oceanic crust

and continental crust second

infer that the earth's lit sphere is

divided into plates

and identify the major lithospheric

plates

third determine the scientific basis

for dividing the little sparring plates

let us have a review in the previous

years you have learned many geological

concepts

i want you to arrange the sets of

jumbled letters

to form words that you have learned

before

a picture will be given to you as a hint

for each set

you will hear this sound

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and after each sound you will be given

the correct answer

are you ready to play

first set

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correct the first concept is earthquake

earthquake is the sudden shake of the

ground

next set

you're right the word is pangaea

pangaea is the super continent that is

believed to have existed

200 million years ago

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next

correct the concept is continental drip

theory this theory

states that the continents are once

joined together

as one supercontinent

next set

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you're right the next concept is seispic

waves

seismic waves are waves that provide a

geologist

information about the internal structure

of the earth

and last set

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correct the next concept is volcano

volcano is a landform where molten

materials from

inner earth are released

you are all excellent give yourself a

big virtual applause

you all did well and now let us begin

with our discussion

are you familiar with this picture

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correct that is the planet earth our

planet

is composed of many layers one of the

distinct layers of our planet

is the little sphere

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lithosphere is the rigid rocky outer

layer of the earth

consisting of the crust and solid

outermost layer of the upper mantle

it extends to a depth of about 60 miles

or 100 kilometers

however this outer covering of the earth

is not as solid as you think

it has cracks that are both observed in

continents

and ocean floors and these cracks

create the two important features

of the earth's lithosphere and these are

plate boundaries

and tectonic plates

due to these cracks the little sphere is

broken into smaller sections called

tectonic plates

whereas the edges that separates them

with one another are called plate

boundaries

for you to understand better let us take

a look at the picture of the hard-boiled

egg

let's imagine that the earth

is just like this egg the shell of the

egg

resembles the earth's little sphere

the sections of the shells the past ones

as the tectonic leaves and the lines of

the cracks from that egg

as the plain boundaries

for concept number one what is little

spear

the little spear is the rigid rocky

outer layer of the earth

consisting the crust and upper mantel

the little sphere is divided into

smaller sections

called tectonic plates and lined with

rocks

as plate boundaries

the little sphere's outermost layer is

the grass

and we have two types of brass

first the continental grass

second the oceanic crust

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the key that distinguishes the two is

based on their location

let us take a look at this picture

continental crush is the exposed land

masses of the earth

whereas the oceanic grass lies in the

bodies of

water or oceans

here is the table that compares the two

types of crust

continental crust is relatively older

than oceanic crust

then continental crust is thicker than

oceanic crust

the density of the continental crust is

less than

oceanic crust and finally

the continental crust is made up of

granite

or granitic in nature whereas

oceanic crust is made up of basalt

or basaltic in nature

for concept number two what are the two

types of crust

correct the two types of crust are the

continental crust

and oceanic crust

this time let's continue our lesson by

performing

a simple activity let us all explore

the different major plates found in the

planet earth

i want you to study carefully the map

that i'm going to show on the screen

illustrating the major plates

found in our planet

i will give you 10 seconds to study the

map

carefully and timer starts now

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do you observe the sizes of the tectonic

blades

in the illustration

have you observed that some plates are

large

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and some plates are small

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large plates are mostly named after

continents

these plates are known as primary plates

can you name the seven largest plates

or primary plates in our map

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first we have the african plate

second we have the antarctic plate

third we have the eurasian plate

fourth we have the north american plate

fifth we have the south american plate

sixth we have the engine plate

and seventh we have the pacific plate

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then small placer known as secondary

plates

in our map how many are those

yes we have eight and these are the

following

arabian plate caribbean plate

nazca plate scoria flat

juan de foca plate caucus plate

philippine sea plate and australian

plate for concept number three

what are the two types of plate large

plates

are known as primary plates

small plates are known as secondary

plates

remember the number seven and eight

we have seven primary plates and

eight secondary plates

let us take a look at this video

overlaying three important maps

the three maps that are included in this

video is first the map

of the epicenters of earthquakes second

the map of different volcanoes in the

world

and third the map depicting the

different

mountain ranges present in the planet

earth

please observe carefully

what have you observed from the video

correct the placement of the earthquakes

epicenters volcanoes

and mountain ranges lies on the similar

boundaries

this serves as the evidence of the

scientists that the earth is truly

divided

into plates for concept number four

what are the scientific basis for

dividing lithospheric plates

the geologic processes and features such

as the current sets of earthquakes

volcanoes and mountain ranges are the

evidences

used by scientists to divide the earth

into lithospheric plates that

ends our discussion let us now recall

the

four important things you must remember

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first the little spear is the rigid

rocky outer layer of the earth

consisting the crust

and upper mantle the little sphere is

divided

into smaller sections called tectonic

plates

and lined with cracks as plate

boundaries

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second the two types of grass are the

continental crust

and oceanic crust

third major plates on earth can be

large primary plates or small secondary

plates

there are seven primary plates and eight

secondary plates on earth

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fourth the geologic processes and

features

such as the occurrence of earthquakes

volcanoes

and mountain ranges are the evidences

used by scientists to divide the

lithospheric plates

now that we know these important

concepts let us

apply what we have learned in our daily

lives

we are aware that every day different

parts of our country experiences

earthquakes and sometimes sudden

volcanic eruptions

may also occur just like what happened

in ta'al volcano

last january 2020 so

now what is the reason behind this

based on what we have learned from

today's lesson

please comment your answers to my

questions

in the comment box of this video

or simply post your answers in our

facebook science group chats

before we end this session i want you to

check

your understanding today

we will be having a multiple choice quiz

i want you to choose the letter of the

correct answer

for each question i will be giving you

5 seconds to answer each

you will hear this sound

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before i reveal the correct answer

are you prepared now let us start

first question what makes up the little

spear

letter a upper mantel

b continental crust

c crust and upper mantle

letter d oceanic and continental crust

the correct answer is letter c grass

and upper mantle

second question which of the following

refers to the divided portion of the

earth's lithosphere

a asthenosphere

b crust c

mantle d tectonic plates

the correct answer is letter d tectonic

plates

third question which of the following

statements about continental crust

is true a it is

denser than oceanic plate

b it is thinner than oceanic plate

letter c it is relatively older than

oceanic plate d

it has the same composition as the

oceanic lithosphere

the correct answer is letter c it is

relatively older than oceanic plate

part question which of the following is

not a secondary lithospheric plate

a antarctic plate

b indian plate

c nazca plate

the scotia plate

the correct answer is letter a antarctic

plate

which of the following were used by

scientists

as a basis for dividing lithospheric

plates

the choices are a

one two and three only

b one three and four

only c

one two and four only

d two three and four

only

the correct answer is letter b

one three and four only

which includes mountain ranges seismic

activity

and volcanism

what is your score in this piece

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congratulations i hope that you have

learned something new today

this is your learning buddy saying

goodbye for now

and i hope to see you in our next

session full of

saya

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you