Download SGES 1302 INTRODUCTION TO EARTH SYSTEM

SGES 1302
INTRODUCTION
TO EARTH SYSTEM
LECTURE 1:
Introduction to Course
The Universe
Course Info
Course Code :
Course Title :
Credit Hours :
SGES 1302
Introduction to Earth System
2
Learning
Outcomes :
At the end of this course it is expected that students would:
1.
understand the relationship between planet earth and the other planets of
the solar system and the galaxy
2.
relate the earth structure in relation to the theory of plate tectonics
3.
understand the geologic time and earth history
4.
understand the interactions between hydrologic system and other earth
spheres
5.
recognize minerals and rocks
Synopsis of
Course Contents
:
Earth is a unique planet in the solar system. The question why and how earth can
support life can be answered by looking into the secrets of the formation of earth
and the functions of the various components of earth system. This course will
introduce the understanding of the earth systems, which include the relationship
between planet earth and other planets of the solar system and the galaxy, the
earth structure in relation to the theory of plate tectonics, the geologic time and
earth history, the interaction between hydrologic system and other earth spheres,
mineral and rock, the earth seismicity, the environment and the earth resources.
Assessment :
Continuous Assessment : 40%
Final Examination : 60%
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SGES 1302
INTRODUCTION TO EARTH SYSTEM
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DR. NG THAM FATT
Room GB214, Tel:79674153, email:[email protected]
TESTS : (1=5 Oct); (2=24 Oct); (3=30 Nov); (4=21 Dec); Total 40%
FINAL EXAM (60%): Pre-requisite – 80% attendance
REFERENCES:
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Butz, S.D. (2004): Science of Earth Systems. Delmar Learning, New York, 655 p.
Hamblin, N.K. (1992): Earth Dynamic System (6th Ed). MacMillan Publshing Co., New York,
647 p
Skinner, B.J., Proter, S.C. and Botkin, D.B (1999): The Blue Planet – An introduction to Earth
System
White, I.D., Mottershead, D.N., and Harrison, S.J. (1994): Environment System: An
Introductory Text (2nd Ed), Chapman and Hall, London, 495 p.
Tarbuck, E.J. and Lutgens, F.K. (2006): Earth Science (11th Ed). Pearson Prentice Hall, New
Jersey, 726 p.
Hamblin, W.K. (1991): Introduction to Physical Geology. Macmillian Publ. Co., New York, 378
p.
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Course Content
SGES1302 INTRODUCTION TO EARTH SYSTEM
1
Earth and its relation with other planets of
the solar system and the galaxy ‘Milky
Way’
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Introduction to minerals
2
Introduction the earth’s internal structures
and the theory of plate tectonics
9
Magma and igneous mineral
characteristics and identification igneous
rocks
3
Introduction to rock structure, fold, fault,
and joint.
10
Sedimentary rock formation and
classification in relation to sedimentary
environment
4
The concept of relative geologic time
scale and standard geologic column
11
Metamorphism and the concept of
metamorphic facies and the identification
and classification of metamorphic rocks
5
Isotope and the concept of radioactivity in
geology
12
Earth’s seismicity and relation to
earthquake
6
Radiomatric measurements in relation to
absolute geologic time
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The type of natural resources: energy &
mineral resources
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Introduction to the earth hydrologic
system
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Revision / discussion
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EARTH, SOLAR SYSTEM AND THE UNIVERSE
Our Solar System
The Milky Way
(Sun, planets, moons
& other smaller
orbiting bodies)
(billions of stars)
The Universe
(billions of galaxies)
EARTH
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Origin of the Universe
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When we look up at the sky on a clear night, we are sharing a view
that has been seen by our ancestors and countless people for
thousands of year.
This creates a unique connection between all people who are living
and have lived on Earth
Over time our with advancement of technology, understanding of our
Universe has improved
The Big Bang
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The Big Bang
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The Big Bang is a cosmological model in
which the universe has been expanding for
around 13.7 billion years, starting from a
tremendously dense and hot state.
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The Big Bang release all known energy in the
Universe, which began to spread from a
central point. As energy spreads wider, it
cooled to form clumps of matter, in the
form of elements such as H and He.
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Energy and matter continue to spread apart
and the universe grew larger, clumps of dust
and gas (molecular cloud) began to form. The
clouds collapse to form the millions of stars.
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The Universe
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The Universe is defined as the summation of all particles and energy that
exist and the space-time in which all events occur. This include all the stars,
galaxies, and our solar system.
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Based on observations of the portion of the universe that is observable,
physicists attempt to describe the whole of space-time, including all matter
and energy and events which occur, as a single system corresponding to a
mathematical model.
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To an observational cosmologists, the Universe most frequently refers to the
finite part of space-time which is directly observable by making observations
using telescopes and other detectors and using the methods of theoretical
and empirical physics for studying the basic components of the Universe
and their interactions.
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A majority of cosmologists believe that the observable universe is an
extremely tiny part of the "whole" (theoretical) Universe and that it is
impossible to observe the whole Universe (infinite).
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The Universe - Composition
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The currently observable universe appears to have a geometrically flat space-time
containing the equivalent mass-energy density of 9.9 × 10-30 g/cc.
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This mass-energy appears to consist of 73% dark energy, 23% cold dark matter and
4% atoms. The exact nature of dark energy and cold dark matter remain a mystery.
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Thus the density of atoms is on the order of a single hydrogen nucleus (or atom) for
every four cubic meters of volume.
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Prior to the formation of the first stars, the chemical composition of the Universe
consisted primarily of hydrogen (75% of total mass), with a lesser amount of helium-4
(4He) (24%) and trace amounts of the isotopes deuterium (2H), helium-3 (3He) and
lithium (7Li).
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Subsequently the interstellar medium within galaxies has been steadily enriched by
heavier elements. These are introduced as a result of supernova explosions, stellar
winds and the expulsion of the outer envelope of evolved stars.
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The temperature of the background radiation has steadily decreased as the universe
expands, and now primarily consists of microwave energy equivalent to a
temperature of 2.725 K.
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The Universe - Shape
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Currently, most cosmologists believe that the observable universe is
very nearly spatially flat, with local wrinkles where massive objects
distort spacetime, just as the surface of a lake is.
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The universe has no spatial boundary according to the standard Big
Bang model, but nevertheless may be spatially finite (compact). This
can be understood using a two-dimensional analogy: the surface of
a sphere has no edge, but nonetheless has a finite area.
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If the universe were compact and without boundary, it would be
possible after traveling a sufficient distance to arrive back where one
began. Hence, the light from stars and galaxies could pass through
the observable universe more than once.
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The Milky Way
Galaxy & the Milky Way
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Galaxies
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A galaxy is a grouping of millions or billions of
individual stars, each of which sprang from the
gaint molecular clouds or stellar nebulae.
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Galaxies appears as a faint clouds of light when
viewed through the telescope but their amazing
forms are revealed by powerful telescopes.
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There are 3 main types of galaxies: spiral,
elliptical and irregular.
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Spiral galaxy appears like a pin wheel surrounded
by spiral arms. The nucleus appears like a large
bulge of light (halo) which conststs of millions of
stars. The spiral arms are composed of stars that
rotate around the halo.
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Elliptical galaxy has a nucleus and halo but no
spiral arms. They are the most common type of
galaxy.
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Irregular galaxy has no well defined shape.
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The Milky Way
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The Milky Way is a barred spiral galaxy within the Virgo Supercluster.
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The main disk of the Milky Way Galaxy is about 80,000 to 100,000 lightyears in diameter, and outside the Galactic center, about 1,000 light-years in
thickness. (1 light years = 9.5x1012 km)
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The galaxy is estimated to contain 200 billion stars but this number might
reach 400 billion if small-mass stars predominate. All the stars we see at
night are located within the Milky Way.
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As a guide to the relative physical scale of the Milky Way, if the galaxy were
reduced to 65 km in diameter, the solar system would be a mere 1 mm in
width.
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The Milky Way
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The term "milky" originates from the hazy band of white light appearing
across the celestial sphere visible from Earth, which comprises stars and
other material lying within the galactic plane. The galaxy appears brightest
in the direction of Sagittarius, towards the galactic center.
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The fact that the Milky Way divides the night sky into two roughly equal
hemispheres indicates that the solar system lies close to the galactic plane.
The Milky Way's visual absolute magnitude is −20.9
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Milky Way's mass is thought to be about 5.8×1011 solar masses.
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It is extremely difficult to define the age of the Milky Way, but the age of the
oldest stars in the Galaxy is currently estimated to be about 13.6 billion
years, which is nearly as old as the Universe itself.
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Many astronomer believe that there is a black hole at the center of the Milky
Way.
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The Milky Way
color
arm(s)
cyan
3kpc and Perseus Arm
sky-blue
Norma and Cygnus Arm (Along with
a newly discovered extension)
green
Crux and Scutum Arm
pink
Carina and Sagittarius Arm
There are at least two smaller arms or spurs,
including:
orange
Orion Arm (which contains the solar
system and the Sun)
The distance from the Sun to the
galactic center is estimated at
26,000 ± 1400 light-years
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Life Cycle of Stars
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A star is a large, hot, glowing ball of gas that is powered by nuclear
fusion. They begin as a stellar nebulla, a large cloud of dust and
gas.
Gravitation attraction of the atoms within the stellar nebulla cause it
to begin to collapse. As it collapse, it heats up and its density and
pressure increase, forming a proto star.
Eventually it heats up to extreme temperatures, and the pressure
within is high enough to start a fusion reaction (H atom fuse to form
He, and releases energy). This is the main sequence stage of a star
where the star begin to shine.
Eventually the star use up all its H, causes it to begin to expand and
cool down (red gaint stage) and eventually burns itself out (white
dwaft) and then cools (neutron star).
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Next Lecture: Solar System
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