EARTH AND LIFE SCIENCE REVIEWER
© angelica garcia
EARTH SCIENCE
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I.
II.
III.
IV.
all the sciences that collectively seek to understand Earth and its neighbors in space
ASTRONOMY
- the study of the universe
- very useful in probing the origins of our own environment
METEOROLOGY
- study of the atmosphere and the processes that produce weather and climate
GEOLOGY
- Study of the earth
- Study of solid earth, the rocks of which it is composed and the processes by which they change.
A. Physical
 Examines the materials composing earth and the processes that operate beneath and
upon its surface.
B. Historical
 Aim to understand the origin of Earth and development of the planet through its 4.5billion-year history
OCEANOGRAPHY
- the study of the composition and movements of seawater, coastal processes, seafloor
topography and marine life
THE UNIVERSE
Theories on the Creation of the Universe
1. BIBLICAL CREATION
- came from the bible
- States that the entire cosmos was created in 6 days by a Supreme Being.
2. BIG BANG THEORY (1920)
- Alexander Friedman and George Lamaitre
- Universe started with a huge explosion 13.7 Billion years ago.
- Explains what happened at the very beginning
- “The Universe started with a cataclysm that created space and time and all the matter and
energy that has ever existed in the universe”
- Caused by random fluctuation in an empty void. Then there was a great explosion and
expansion.
 Evidences:
- The red shift of galaxies supports the big bang and the expanding universe theories.
- Scientists discovered a type of energy called cosmic background radiation (CMB). Scientists
think that this radiation was produced during the big bang.
- Abundance of light elements: helium, hydrogen, and lithium beryllium confirms occurrence of
the big bang nucleosynthesis.
 Red Shift aka Doppler Shift
- Red shift, or a Doppler shift toward the red end of the spectrum, occurs because the light waves
are “stretched,” which shows that Earth and the source are moving away from each other.
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Hubble’s Law
- Hubble’s law is a law that states that the galaxies are retreating from the Milky Way at a speed
that is proportional to their distance.
- Analogy for an expanding universe: as the dough rises, raisins (galaxies) originally farthest apart
travel greater distances than those located closer together. Thus, in an expanding universe (as
with the raisins) more space is created between two objects that are farther apart than
between two objects that are closer together.
Fate of the Universe
- Scenario 1: the outward flight of the galaxies will slow and eventually stop
- Scenario 2: the universe will continue to expand
3. Steady State Theory (1948)
- Bendi, Gold, and Hoyle
- “The Universe has no beginning and end.”
- Density of matter is constant over time
- The universe remained the same all throughout time
- Proposed that the universe is unchanging in time and uniform in space
4. Inflation Theory
- Alan Guth, Andrei Linde, Paul Steinhart, and Andy Albrecht
- Extension of the Big Bang Theory
- Proposed a period of exponential expansion of the universe.
- It could appear flat even though it has been curved at the start
- Offers solution to unresolved problems of the big bang theory.
a. FLATNESS
 Big bang states there should be curvature
 Things will appear flat even though it is curved
b. MONOPOLE
 Big bang predicts production of magnetic poles
 Monopoles dropped exponentially to undetectable level during rapid expansion
c. HORIZON
 Big bang states that space in opposite direction are so far apart they could never have
contact with each other
 Exponential expansion in early universe presupposes that the distant regions were much
closer to each other prior to inflation
5. STRING THEORY
- Suggests that subatomic particles do not exist. Instead, tiny piece of vibrating string is too small
to be observed in today’s instrument replaced the subatomic particles
- Before the Big Bang
- Form the combination of Einstein’s theory of relativity and Quantum Mechanics
- Strings may be open or closed (measures roughly around 1.6 x 10 -35 mm)
- Replaced by a fundamental block that can either be closed or open.
- The vibration may represent the different particle types. (Electron and Photon)
6. M-THEORY
- Unification of Strings
- Universe is a result of the contact of two hyper-dimensional branes.
- Considers 11 space-time dimensions:
a. We are familiar with the x, y, z and time
b. The other 7 space-time dimensions are so tiny and curled up that they are undetectable.
THE SOLAR SYSTEM
Notable Personalities
1. Eratosthenes – used the sun to measure the size of the Earth
2. Claudius Ptolemy – Set up a model of the solar system in which the sun, the stars, and others revolve
around the Earth; Geocentric – “Earth Centered”
3. Nicolaus Copernicus – proposed a model of the solar system that involved the earth revolving around
the sun; Heliocentric – “Sun Centered”
4. Johannes Kepler – determined that the planets travelled around the sun not in circles but in ellipses.
5. Galileo Galilei – creation of optical telescope; discovered the 4 moons of Jupiter as well as the ring of
Saturn
6. Edward Haley – proposed the appearance of comets; comets that appeared in 1456, 1531, 1607, and
1682 were all the same and would return in 1758
Astronomy
Theories on the formation of the Solar System
1. Descartes’ Vortex Theory
- The space was entirely filled with matter in various states, whirling about the sun.
Theory of colliding particles which hypothesized the collisions supplies the force that pushed the
planets towards the Sun.
- He explained the orbits of the planets are the primary whirlpool motion and the satellites the
secondary whirlpool motion.
2. Buffon’s Collision Theory
- Planets were formed by the collision of the sun with a giant comet.
- Resulting debris condensed and formed into planets that rotate in the same direction as they
revolved around the sun.
- Failed to explain the strange positioning of planets around the Sun.
3. Kant-Laplace Nebular Theory
- Suggested that a great cloud of gas and dust, called nebula, began to collapse because of
gravitational pull.
- As the cloud contracted, it spun more rapidly. Spinning cloud flattens into a pancake-shaped
object with a bulge at the center. As the nebula collapses further, local regions contracted on
their own due to gravity.
- Major Flaw: Assumed that the total angular momentum of the system was in the sun, which is not
the case. Only 0.5% of the angular momentum was contained in the Sun’s spin. The rest was in
the planetary orbit
- Hydrogen and other gases swirled around and condensed into our sun and its planets.
- Most widely accepted theory that explains the formation and evolution of solar system.
- It suggests that the Solar System formed from nebulous material. The theory was developed
by Immanuel Kant and published in his Universal Natural History and Theory of the Heaven.
Originally applied to our own Solar System, this process of planetary system formation is now
thought to be at work throughout the universe.
4. Jean Jeffrey and James Hopwoods’ Tidal Theory
- Proposed that the planets were formed from the substance that was torn out of the sun.
- As a speeding massive star passed near the sun, it pulled off material due to gravitational
attraction. These torn-off materials condensed to form the planets.
5. Solar-Nebular Theory
- Describes the formation of our solar system from condensation of interstellar gas and dust cloud.
Due to gravity, it began to condense the solar nebula, with the center becoming a protostar. As
the cloud continued to shrink, rotational speed increased and became a rapidly rotating disk.
The contraction converted gravitational energy into heat energy and caused the center to
glow. When the temperature is sufficient enough, a nuclear reaction began at the core of the
protostar and became the SUN.
- The remaining gas and dust cloud form diskshaped bodies (due to rotation) called SOLAR
NEBULAE. Formation of the planets involved:
a. Accretion of grain-sized particles to form cm-sized particles which later grew to several km in
distance
b. Formation of more massive objects from coalescing planetisimals  PROTOPLANETS 
PLANETS
6. Condensation Theory
- The solar system formed a large spinning cloud of gas and dust, called the solar nebula.
- Once gravity pulled it to a diameter of less than 100au, the solar nebula had become a wide
rotating disc
7. Fission Theory
- One day, our sun burst open, and planets, and moons shot out at high speeds and went to their
respective places, then stopped, and started orbiting the sun, as the moons began orbiting the
planets.
8. Capture Theory
- Planets and moons were flying around, and some were captured by our sun and began circling.
9. Accretion Theory
- A pile of space dust and rock chunks pushed together into our planet, and another pile pushed
itself into our moon. Then the moon got close enough and began circling the earth.
10. Planetary Collision Theory
- Our world collided with a small planet, and the explosion threw off rocks which became the
moon and then it began orbiting us.
11. Stellar Collision Theory
- Our planets, moons, and stars spun off from the collision between stars
12. Gas Cloud Theory
- Gas clouds were captured by our sun but instead of being drawn to it, they began whirling and
pushing themselves into the planets and moons.
Our Solar System
1. The sun
2. Four terrestrial inner planets. (MVEM)
- Mercury
- Venus
- Earth
- Mars
3. Four gas giant outer planets. (JSUN)
- Jupiter
- Saturn
- Uranus
- Pluto
4. An asteroid belt composed of small rocky bodies and comets.
What is a Solar System?
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The sun, its planets, and all the objects moving around them collectively
Entirely dependent on the Sun and the only one which is self-luminous
Rest of the planets reflect the light received from the sun
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Star of the Solar System
Scientific name is “Sol”
Heaviest among the Solar System
Ball of hot, burning gases
Sun
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Nearest star to the Earth
Light from the Sun takes approximately 8
minutes to reach the Earth.
Classification of Planets by Composition
1. Terrestrial Planets (Earth-like planets or Inner Planets)
- Composed mostly of dense, rocky, and metallic materials
- Mercury, Venus, Earth, Mars
- Formed within the frost line where rocks and metals condense, and hydrogen compounds
remain as gas.
2. Jovian Planets (Jupiter-like planets or Outer Planets)
- Composed mostly of Hydrogen and Helium
- Jupiter, Saturn, Uranus, Neptune
- These planets are formed outside the frost line where light elements condense into ice.
Classification of Planets by Position Relative to the Sun
1. Inner Planets
- Mercury, Venus, Earth, Mars
2. Outer Planets
- Jupiter, Saturn, Uranus, Neptune
Classification of Planets by Position Relative to the Earth
1. Inferior Planets
- Mercury, Venus
2. Superior Planets
- Mars, Jupiter, Saturn, Uranus, Neptune
What is a Dwarf Planet?
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Celestial body that has the following characteristics:
a. Is in orbit around the sun
b. Has sufficient mass for its self-gravity to overcome rigid body forces
c. Has not cleared the neighborhood around it
d. Is not a satellite
Haumea, Pluto, Makemake, Eris
Kepler-452B
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Earth’s Cousin or Earth 2.0
An exoplanet orbiting the sun-like star Kepler-452 about 1,400 light years from earth in the constellation
Cygnus
a. Has a probable mass 5X of Earth and surface gravity twice of Earth
b. Takes 385 Earth days to orbit its star
c. Has an equilibrium temperature of 265 K
d. Its host star Kepler-452 (G-type) is about the same mass of the Earth’s sun and has a surface
temperature of 5757 K (Earth’s sun = 5778 K)
Planets
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Come from Greek which means wandering star
Heavenly bodies which revolve around the sun in elliptical orbits
Between inner and outer planets, there is a ring of small bodies, which are made or rock and metal,
these are called asteroids. They also keep moving around the Sun. This ring is also called Asteroid Belt.
1. Mercury (Swift Planet)
- Named after Messenger of the Roman gods
- Closest planet to the Sun
- The Inner Planet
- Large variations in day (400ºC) and night (-180ºC) time temperatures
- Smallest and its orbit is not the most fully circular
- Does not have any satellite
- No water or atmosphere
- Can be seen with naked eyes
- Orbits the sun once in every 88 Earth days
- No seasons on its surface
2. Venus (The Veiled Planet; Morning Star and Evening Star)
- Surrounded by thick cloud: The Veiled Planet
- Brightest and Hottest Planet
- Named after Roman goddess of love and beauty
- Orbits the sun once in every 225 Earth Days
- Reaches its maximum brightness shortly before sunrise or shortly after sunset so it’s also known as
the Morning Star or Evening Star
- Also “sister” or “twin” planet to Earth because of its similar size and mass to Earth
3. Earth (The Blue Planet)
- Orbits the sun once in every 365 Earth Days
- Rotates about its own axis, thus creating a day and night. It takes 24 hours to do that.
- Revolves around sun due to its tilt; seasons are created
- Due to gravity, the layer of gases remain attached to it (which is known as atmosphere), it
prevents too much heat or UV rays from the sun
- Moon is the only satellite of Earth
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Moon (Earth’s Only Satellite)
- Diameter of only 1/4th of Earth
- Looks bigger to us as it is closer to us
- Has no atmosphere
- 127ºC in day and -173ºC in night
-
Only celestial body other than Earth on which humans have set foot. (Neil Armstrong [American
Mission Apollo] on July 21, 1969)
4. Mars (The Red Planet)
- Named after Roman god of war
- Red Planet: Iron oxide is prevalent on its surface that gives the planet its reddish appearance
- Home to Olympus Mons
5. Jupiter (The Giant Planet)
- Named after ruler of Roman gods
- Largest planet in the Solar System
- Has a great red spot, it is a rotating storm inside the planet
6. Saturn (The Jewel Planet; Ringed Planet)
- Sixth planet from the sun
- Second largest planet
- Named after roman god, Saturn
- Classified as gas giant planet
7. Uranus (Ice Giant)
- Named after Roman god of the sky
- A planet on its side
- Only planet which rotates on its axis from east to west
8. Neptune (Big Blue Planet)
- Most distant gas planet
- Named after Roman god of the sea
- Most windy planet
Properties of the Solar System
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The orbits of all planets are almost in the same plane.
- Solar system is flat.
The planetary orbits are nearly circular.
The orbits of the planets are nearly in the same plane as the rotation of the sun.
The calculated distances (Bode’s law) and the observed distances of the planets from the sun are
almost the same (except of Neptune & Pluto)
The satellite systems of Jupiter and Saturn are nearly identical in their arrangements with the solar
system.
The satellites and planets contain almost all the rotational motion of the solar system.
The solar system contains asteroids and comets.
Asteroids
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A celestial body bigger than 10m orbiting the Sun, mainly between Mars and Jupiter.
Comets
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A smaller celestial body mainly composed of ice and dust. If a comet approaches the Sun it can
generate a tail of gas and/or dust.
Meteoroids
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Similar to an Asteroid, but significantly smaller. Mostly debris of comets, sometimes debris of asteroids.
Meteors
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A bright tail of light caused by a meteoroid during its atmospheric flight, also called a shooting star or
falling star.
 Types of meteors:
a. Fireball
- Another term for very bright meteor, generally brighter than magnitude -4, which is about the
same magnitude of the planet Venus in the morning or evening sky, sometimes even brighter.
b. Bolide
- A fireball that explodes during its atmospheric flight, often with visible fragmentation.
- Refers to a fireball approximately as bright as the full moon, and it is generally considered a
synonym of a fireball.
Described as a fireball reaching the apparent magnitude of -14 or brighter – more than twice as
bright as the full moon.
Meteorites
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The part of a meteoroid or asteroid that survives the passage through our atmosphere and reaches the
Earth’s surface.
Asteroids
Comets
Meteoroids
Meteors
Meteorites
NOTE:
The brightness of a star is referred to as magnitude. There are two kinds of magnitude:
a. The brightness of the star observed from the Earth is referred to as the Apparent Magnitude.
b. If the star is at 10 parsecs (32.6 light years) distance from the Earth, then it would be
referred to as Absolute Magnitude.
GEOLOGIC TIME SCALE
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Divides up the history of the earth based on lifeforms that have existed during specific time since the
creation of the planet.
Model of the history of the Earth showing the major events that occurred along the way
88% of Earth’s History (Precambrian – very little evidence of life); Other 12% (Phanerozoic – sudden
development of life in the oceans, hard parts developed which increased the fossil record)
1. Eons
- Longest units of time
- Precambrian: Earliest Span of time
- Phanerozoic: Everything since
2. Era
- Precambrian, Paleozoic, Mesozoic, Cenozoic
- Precambrian:
 Fossils are rare
 Simple organisms with soft bodies
 Volcanic Activity heat and pressure “erased” the
fossil evidence
 Stromatolites blue-green algae were common
- Paleozoic: (Age of the Invertebrates)
 Hard Parts developed
 Marine animals thrived
 Pangaea formed
 Extinction: 90% of marine animals became extinct
- Mesozoic: (Age of the Reptiles)
 Dinosaurs developed
 Pangaea began to break up
 Extinction of Dinosaurs (Dinosaurs lived on earth for
150 million years; Humans lived on Earth for 100 – 200
thousand years // the debris from the meteor impact
caused global climate changes)
 Trilobites
 Brachiopods are marine animals that upon first
glance, look like clams
 Impact Theory: No dinosaurs found after the cretaceous – tertiary
- Cenozoic: (Age of Mammals)
 Mammals became dominant
 Humans evolved
 Continents moved to their current positions
 Alps Himalayas formed
 Small rodents, early horse, and bats
 Ice cap formed
 Land bridges formed Ice Age
 Early Ancestors to human fossils found
3. Period
- Paleozoic: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian
- Mesozoic: Triassic, Jurassic, Cretaceous
- Cenozoic: Paleogene, Neogene, Quaternary
4. Epoch
- Paleogene: Paleocene, Eocene, Oligocene
- Neogene: Miocene, Pliocene
- Quaternary: Pleistocene, Holocene
Principles behind Geologic Time
 Proposed by Nicholas Steno (1638 – 1687), a Danish Physician
1. Superposition
- In an undisturbed sedimentary rock, each bed is older than the one above it and younger than
the one below it.
- The layer on the bottom was the oldest and the youngest was on top.
2. Horizontality
- Layers of sediment are generally deposited in a horizontal position
- Rocks that are folded or tilted must have been moved into that position AFTER their formation
3. Original Lateral Continuity
- Original deposited layers of rock extend laterally in all directions until either thinning out or being
cut off by a different rock layer.
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James Hutton (1726 – 1797)
- Scottish Physician
- “The present is the key to the past”
- Theory of Uniformitarianism
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Theory of Uniformitarianism
- Advocated by Charles Lyell
- What happens today is what happened in the past
- Supports very old age of Earth
- Earth is believed to be 4.6 billion years old
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Neocatastrophism
- Blends uniformitarianism and catastrophism
- Earth developed and changed at a very slow rate like today but had some catastrophic events
that caused some sudden changes.
Geologic Dating
1. Absolute
- Determines how many years old something is
- Know DATES
- Uses Radiometric
 Radioactive Decay (half-life): occurs when the nuclei of unstable atoms break down,
changing the original atoms into atoms of another element.
 Half-life is the amount of time it takes for half the atoms of a substance to decay into
another element.
 Different substances have different half-life’s
 Ex: Uranium 238 and Carbon 14 (Carbon 14 – date biological remains since Carbon is
incorporated into the cells of living organisms and begins to decay when the organism
dies; Uranium 238 – used to date rocks [larger half-life])
 Half-lives of radioisotopes vary depending upon the isotope
2. Relative
- Used to determine if one thing is younger or older than another
- Know ORDER OF EVENTS BUT NOT DATES
- Superposition, Index Fossils, Correlation of Rock layers
- Comparing of rock units to decipher their age relative to one another
a. Principle of Horizontal Originality
b. Principle of Superposition
c. Principle of Crosscutting Relationships – any feature (fault or intrusion) that cuts across rocks is
younger than the youngest rock that is cut.
d. Principle of Inclusion – states that objects enclosed in rock must be older than the time of
rock formation.
Fossils
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Remains of Ancient Plants and Animals, Evidence of Life
Commonly Preserved (Hard Parts)
a. Bones
b. Shells
c. Hard Parts of Insects
d. Woody Material
Rarely Preserved (Easily Decayed Parts)
a. Internal Organs
b. Skin
c. Hair
d. Feathers
Types of Fossils
1. Mold
- When sediments bury an organism and the sediment hardens into rocks.
- The organisms decay slowly inside the rocks leaving a cavity in the shape of the organism.
2. Cast
- The cavity or mold can be filled with mud.
- When the mud hardens, it takes on the shape of the organism.
3. Petrified
- Permineralized fossil
- Forms when minerals soak into buried remains
- The materials replace the remains, changing them to rock
4. Carbonized
- Forms when organisms or parts like leaves, stems, flowers, fish, are pressed between layers of soft
mud or clay that hardens, squeezing almost all the decaying organism away and leaving the
carbon imprint on the rock.
5. Trace
- When mud or sand harden into rock where a foot just trail or burrow was left behind
EARTH: STRUCTURE AND SUBSYSTEMS
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Layers of the Earth:
1. Inner Core
- Discovered by Inge Lehmann in 1936
Radius of 1250 km
- Solid Fe-Ni alloy
- Magnetic
- approximately 6000ºC
- 3.6 million atm
2. Outer Core
- Discovered by Richard Dixon Oldham (earth’s core as a whole) in 1906.
- 2300 km thick
- Lehmann discontinuity - Boundary between the inner and outer core.
- Liquid Fe and Ni
- Magnetic
- 4000-5000ºC
3. Mantle
- average thickness is ~2900 km.
84% of the earth’s volume.
- Gutenberg discontinuity - Boundary between the outer core and the mantle.
- Predominantly made of Silicate rock
- Subdivided into the upper and lower mantle
a. Lower Mantle (Mesosphere)
 Plasticity (easily shaped and modelled)
 ranging from approx. 650 km to 2900 km below the surface.
 Approx. 2250 km thick
 Rich in silicon and magnesium
 Approximately 3000-5000ºC
b. Upper Mantle
 320-250 km in diameter
 Divided into two parts:
b.1 Asthenosphere - highly viscous and relatively weak. Responsible for plate tectonic
movement. Has some degree of plasticity.
b.2 Lithosphere - outermost shell, which is defined by its rigidity. It is partly composed of
the crust. Solid and brittle.
4. Crust
- Outermost layer of the earth
- Mohorovičić (Moho) discontinuity – Boundary between the mantle and the crust
Subdivided into two types
a. Continental crust
 30-50 km thick
 composed of less dense rocks like granite
b. Oceanic crust
 5-10 km thick
 primarily composed by dense rocks like, basalt and diabase
 younger than continental crusts
Subsystems:
1. Geosphere/Lithosphere
- Refers to the solid Earth
- Composed of naturally-occurring minerals, rocks, and organic material. Collectively called
Regolith
Made up of Rocks
 Rocks
- Naturally occurring solid cluster of one or more minerals
The three major types of rocks:
a. Igneous
 Formed through the cooling and solidification of lava and or magma
 Two types:
a.1 Intrusive - Solidifies within the crust
a.2 Extrusive - Rocks that solidifies at thesurface of the Earth
b. Sedimentary
 Formed by the deposition of the weathered remains of other rock at the Earth’s surface
 Deposition - a process in which sediments accumulate and added to the land mass
 Lithification - unconsolidated materials solidify into rocks.
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c.
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Three Types:
b.1 Chemical - Formed by precipitation of materials from water
b.2 Biological/organic - form from the accumulation of plant and animal debris
b.3 Clastic - formed from the debris due to mechanical weathering of rocks
Metamorphic
 Formed through the transformation, either by heat or pressure, of existing rocks.
 The original rock (protolith) can be igneous, sedimentary, and can also be metamorphic.
 Two major types:
c.1 Foliated – metamorphic rocks that exhibited layering. It occurs during recrystallization
c.2 Non-foliated – rocks that has no foliation
Geomorphic Processes
- Natural processes that result in the change and or modification of the landforms on the Earth’s
surface.
- Two Processes:
A. Exogenic Process
 External Process
 Transform Rocks to sediments through weathering
 Also called Weathering
 Types of Weathering:
a. Physical Weathering – Physical, Block disintegration, exfoliation, frost weathering
b. Chemical Weathering – Oxidation, Carbonation, Hydration
c. Biotic Weathering – Plants, Animals, Humans
 After Weathering?
a. Mass Wasting – Downslope movement of a mass of rocks, soil, and other sediments;
Commonly caused by water
b. Soil Erosion –The removal of soil at a greater rate than its replacement; More gradual
than the mass wasting
B. Endogenic Process
 Internal Process
 Reshaping the Earth’s landforms
 Transform the Earth from within the crust
 Two types:
a. Volcanism
 Volcano – An eruption of molten rock, called magma on the surface of the Earth
 Magma from the mantle rises through the crust and, ultimately, unto the surface.
 Lava is the primary material expelled from a volcano, in addition to rocks, ash,
and dust.
b. Tectonic Forces
 The Lithosphere can be broken up into smaller parts called Tectonic plates. These
plates are subjected to stress and, eventually, deformation. (Deformation is any
change in the shape and size of a rock as a response to stress.)
 Folding Deformation: Occurs when the plates are subjected to compressional
stress on both sides, causing them to fold.
 Faulting Deformation: Fracture or displacement of the plates along a fault plane.
Three Types:
1. Normal
2. Reverse
3. Transform
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Plate Movement
- The movement of the plates is the result of convection currents. (Convection currents are
currents that carry heat from the lower mantle and the core to the lithosphere.)
- Seafloor Spreading: A process in which tectonic plates split apart from each other due to mantle
convection; The slow churning of the Earth’s mantle
1. Convergent – towards; forms trenches, mountains, and volcanic arcs
2. Divergent – away; creates seafloor spreading, oceanic ridges, and continental drifting
3. Transform – slide past each other; creates earthquakes
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Geologic Hazards
1. Earthquakes – A sudden perceptible shaking of the Earth due to the sudden release of energy in the
Earth’s crust or volcanic eruption.
The Philippines is largely susceptible to earthquakes due to its location, which is within the
pacific ring of fire. (PRoF – Major area in the pacific ocean where 90% of the earthquake
occurs.)
The Philippines Institute of volcanology and Seismology (PHIVOCS) overlooks the seismic and
volcanic activities in the Philippines.
2. Landslides – Also known as landslips; A form of mass wasting in which a great amount of soil, rocks,
and or sediments move downslope; Common cause of landslides: Earthquake, Volcano Eruption,
Water (raining)
3. Tsunamis – An event caused by earthquakes, volcanic eruption and or other seismic activities that
affect bodies of water, thus, also known as seismic sea wave; Generated by a large displacement
of water; The Philippines is susceptible to tsunami due to its location.
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Other Subsystems:
2. Atmosphere
- layer of gases, such as nitrogen and oxygen, that
surrounds the planet.
- Came from the greek word “atmos” (vapour) and
“sphaira" (sphere).
- Four layers:
a. Troposphere
 The lowest part of the
 Boundary layer: lowest part
Atmosphere;
of the troposphere.
 The layer that we live in
 Tropopause:
boundary
 Contains all of the weather
between troposphere and
 Colder as the distance from
stratosphere.
sea level increase (due to
 Poles: 7-10 km
decreased pressure).
 Equator: 17-18 km
 Contains 75% of all the air in
the atmosphere
b. Stratosphere
 Area between the tropopause to about 50 km above sea level.
 It contains most of the ozone (O3) in the atmosphere.
 The temperature increase with height due to the absorption of Ultraviolet (UV) light by
the ozone.
 Stratopause: boundary between stratosphere and mesosphere.
Ozone is inorganic molecule that is essential in maintaining life on earth.
Ozone hole: located on the poles (particularly the south pole);Created due to the
introduction of free radical catalysts, such as CFC (Chlorofluorocarbon) in the
atmosphere.
c. Mesosphere
 Area above the stratopause to ~100 km above sea level.( ~85 km in higher latitudes)
 Temperature decrease with height due to: decreased solar heating, less greenhouse
gases, Coldest part of the earth, Temperature reaching as low as -100ºC
 Mesopause: boundary between mesosphere and Thermosphere.
 Least explored (cannot be reached by balloons and lower than the altitude of space
stations)
 Meteors burn in this layer.
d. Thermosphere
 Area above the mesopause to the ~500-1000 km. (Varies due to location, time of day,
solar influx, season)
 Temperature increases with height due to: Absorption of solar radiation
 Thermopause: boundary between thermosphere and exosphere.
 Satellites orbit in the thermosphere. (Such as the space shuttles and the International
Space Station.)
 Where the Aurora occur (Charged particles from space collide with atoms and
molecules in the thermosphere)
e. Exosphere
 The regions beyond the thermosphere (above ~500-1000km)
 Outermost layer of the atmosphere
 Composed mainly on hydrogen. (Helium, Carbon dioxide, atomic oxygen, etc. is found
on its base)
 Molecules are bound by gravity yet rarely interact with each other. (behave in a
“ballistic trajectory.”)


3. Hydrosphere
- Combined water found in and on earth
- Ground water, Lakes, Oceans, Streams, Ice caps, Air
~1400 million km3
- Average Salinity of Earth’s ocean is 35 grams of salt per kilogram of sea water (3.5%)

Hydrometeorological Phenomenons
a. Monsoons – Seasonal changes in atmospheric circulation and precipitation
Two Types:
1. Southwest monsoon (Habagat) – experienced in the Philippines on May to October
2. Northeast monsoon (Amihan) – experienced in the Philippines on November to February
b. Tropical Cyclones – Rapidly rotating storm system characterized by a low pressure centre, strong
winds, and spiral arrangement of thunderstorms
Philippine Atmospheric, Geophysical, and Astronomical Services (PAG-ASA) monitors the
atmospheric occurrences in the Philippine area