Lecture#1c the Earth

8/6/2019 Lecture#1c the Earth

1/25

1

Physical Geology

QAB1013

Lecture #1THE EARTH

Jasmi Ab Talib

Geoscience & Petroleum Engineering Department


2/25

2

Learning Outcomes

At the end of this lecture, students should

be able to

Explain the formation of the solar systemand the composition of the Earth.


3/25

3

GeologyGeology What is it?What is it? Geology is the study of the

Earth. It includes not only thesurface process which haveshaped the earth's surface, but

also includes the study of theocean floors, and the Earthsinterior.

It is not only the study of the

Earth as we see it today, butthe history of the Earth as it hasevolved to its present condition.


4/25

4

GeologyGeology What is it?What is it?

GEOLOGY

The solid earth sciences are that investigate the

physical and chemical characteristics and processes ofthe earth and astrobodies; the origin, distribution,development, and utilization of earth materials and theland as a whole, and the interaction between the solidearth and the hydrosphere and atmosphere.

The study of the rocks and similar substances thatmake up the earths surface, especially in order tounderstand its structure, origin etc.


5/25

5

GeologyGeology What is it?What is it?

GEOMORPHOLOGY

The science which studies the nature andhistory of landforms and processes;

weathering, erosion and deposition which

created them.


6/25

6

EARTH SCIENTISTSEARTH SCIENTISTS

Investigate, forecast and mitigate naturalhazards (earthquakes, volcanic eruptions,weather hazards, sea-level changes, floods,

landslides, environmental degradation) Find and design strategies for extracting

resources from the Earth (water, petroleum,natural gas, metal ores, industrial minerals)

Do basic research on Earth system processesand the Earths history


7/25

7

THE SCIENTIFIC METHODTHE SCIENTIFIC METHOD Observations are made about some phenomenon Hypothesesare untested explanations of those

observations. Most scientists form multipleworking hypotheses.Hypotheses are tested, usually by making predictions

based on them and then making new observations aboutthe predicted outcome

Hypotheses that withstand numerous tests becometheories. Hypotheses that do not withstand study areabandoned.

A theory is an explanation of a phenomenon thathas been tested rigorously, and that holds trueafter competing hypotheses have been eliminated.


8/25

PAB 1023 Petroleum Geoscience 8

The nebular

hypothesis

1) Initial accretion of theplanet Earth: Big Bang

Theory (14 billion years

ago)

The solar nebula (4.6

billion years ago) (gas)

contracted, cooled andcondensed into dust sized

particles that accreted

(stuck together as the

result of collisions) into

protoplanets (asteroid

sized bodies) and thenlarger planets. Solar

Nebula: 99.6% (Sun); 0.4%

(Earth + 7 planets +

asteroids)


9/25

9

Could you imagine, how small is our Earth


10/25

10

The EARTH Earth is the 3rd planet from the Sun at a

distance of about 150 mil. km.

It takes 365.256 days for the Earth to travel

around the Sun and 23.9345 hours for the

Earth rotate a complete revolution.

It has a diameter of12,756 km (7,973

miles), only a few hundred km larger than

that of Venus.

Our atmosphere is composed of78%,

nitrogen, 21% oxygen & 1% other.

Earth is the only planet in the solar systemknown to harbor life.

Our planet's rapid spin and molten nickel-

iron core give rise to an extensive magnetic

field, which, along with the atmosphere,

shields us from nearly all of the harmful

radiation coming from the Sun and otherstars.

Earth's atmosphere protects us from

meteors (100-1000 tons daily), most of

which burn up before they can strike the

Earth surface.


11/25

11

EARTH DIMENSION

Radius (Av.) 6,371 km

Density 5.517 g/cm3

Weight 5.98 x 1024kg

Continental area (29.02%) 148x106 km2

Oceanic area (70.98%) 362x106 km2

Average continent high 823 m

Average ocean depth 3,800 m

Mt. Everest 8,848 m

Mariana Trench 11,033 m Mean surface temperature 15oC

Atmospheric composition N2 (78%); O2 (21);Others (1%)


12/25

12

Cross section through the earth. Expanded section shows the

relationship between the two types of crust; the lithosphere and

the asthenosphere, and the mantle. The crust ranges from 5 to 50kilometers thick.

Solid iron

Liquid iron


13/25

13

3) Earths interior

melted. Dense molten

iron moved inward, and

lighter elements moved

toward the surface. The

core, mantle and crust

form.

Melting and differentiation of the Earth or evolution

2) Following accretion the Earthwas homogeneous (?)


14/25

14

4) Origin of the Atmosphere & Hydrosphere

Gases escapefrom Earths

molten interior

through volcanic

activity. We observe this

happening in the

present.


15/25


Crust (5-70km):Most abundant

elements are silicon(Si) and oxygen (O)

Mantle (2900 km):Most abundant

elements are

magnesium (Mg),

oxygen (O) and silicon

(Si)

Core:Composed mainly of

iron (Fe), with some

nickel (Ni), lighter

elements

Inner core is solid,

outer core is liquid

Solid Earth


16/25

16

Look at the outer

layers of the solid

Earth:

Upper mantle &

crust = lithosphere


17/25

17

Three mechanical layers of the crust and mantle:

Lithosphere (crust and upper mantle, about 100 km thick) isstrong and brittle

Asthenosphere (mantle, 100-660 km) is plastic and deformable

it contains a small amount of molten rock or magma.

Mesosphere (>660 km) is strong, but not brittle


18/25

18

EARTHS INTERIOR

http://www.solarviews.com/eng/earthint.htm

Seismic discontinuities aidin distinguishing divisionsof the Earth layers into: inner core,

outer core, D (Gutenberg) lower mantle, transition region, upper mantle, Mohorovicic, and

crust (oceanic &continental).

Lateral discontinuitiesalso have beendistinguished and mappedthrough seismic

tomography.


19/25


In profile section, the Earth consists of 7 layers

Allah is He Who created seven heavens, and of the earth the like of them; the

decree continues to descend among them, that you may know that Allah has power

over all things and that Allah indeed encompasses all things in (His) knowledge. .

At-Thalaq, (65:12)

EARTHS INTERIOR


20/25

20

Earths lithospheric plates


21/25

21

CONTINENTAL DRIFT

Rate of plate movement varies, from 5 to 10cm/year.


22/25



23/25



24/25

24

CONCLUSION

The formation of the universe focusing to

our Solar System are originated from the

Big-Bang Theory.

The main components of the Earth are

lithosphere, asthenosphere, mesosphere,

outer core and inner core.


25/25

25

NextLecture:

The motion of lithospheric plates and

plate tectonics

Lecture#1c the Earth

Documents

Transcript of Lecture#1c the Earth