Reviewer:Science
Lesson 1: Energy within the Earth and the Pacific Rain of Fire
PACIFIC RING OF FIRE-
-looks like horshoe
-450 dormants and Active volcanoes
-there are a lot of volcanoes in the PRF because of the movement,collision, and destruction of lithospheric plates.
FAULT
-no one can stop earthquakes from happening
-a fault is a break in the Earth’s crust along which significant movement has taken place.
Palawan- has no fault line/zone
Philippine Fault Zone – longest fault line in the Philippines(1200 km)
LAYERS OF THE EARTH
CRUST- Outer layer
-the top most and thinnest layer of the earth
MANTLE- the thickest layer of the earth where convection current occurs(
CORE- inner most layer
=outer core – liquid
=inner core -solid
TECTONIC PLATE
-large pieces of rocks that make up the earth’s crust
-asthenosphere- located between the crust and mantle
Tectonic Motion-the movement of tectonic plates
Tectonic cracks
mantle asthenosphere heat plate
earthquake fault
STRESS-
-Is in the Earth’s outer layer pushes the fault’s side together
Types of Stress
Tensional Stress-It occurs when one part of a plate moves away
Compressional Stress- It is caused by two plates moving together or by one plate pushing against another plate that is not
moving
Shear Stress- It is produced when two plates slide past each other
PHILVOCS Philippine institute of Volcanology and Seismology
Parts of a Fault
Fault Line- the trace of the fault that follows the fault plane
Fault Plane-the surface in which motions occurs
Fault Scarp- the portion of the fault plane that is now exposed at the surface
Hanging wall-portion above the wall
Foot wall – surface below the wall
TYPES OF FAULT
Normal Fault- Tensional stress
-longer fault line
-hanging wall moves down to the foot wall
-angle: less than 45 degrees vertical
Reverse – compressional forces that pushes plates towards each other
-hanging wall moves upward relative foot wall
-shortening of fault
-greater than 45 degrees vertical
Strike-slip Fault – the result of sideways movement of blocks of rocks. Blocks move laterally.
- No extension or shortening of fault.
-Nearly vertical, with minimal inclination from the horizontal
OBLIQUES FAULT - has both the normal, reverse, and strike-slip component formed by shear stress, and tensional
or compressional stress
Strike-slip fault in San Andreas Fault
Normal fault on the coast of Somerset, England
Reverse fault in the Grands Causses inBédarieux, France
In the Philippines, strike-slip and thrust (reverse) faults are the most common types of faults.
EARTHQUAKE -The shaking of the Earth’s surface, resulting from the sudden release of energy.
Aftershocks ● are most common immediately after the main quake
SEISMOLOGY-Study of earthquakes
SEISMOLOGIST- Scientist who study earthquakes
Seismic waves – are waves of energy that travel through the Earth’s layer.
Seismograph - Being used to determine the strength of an earthquake
triangulation – the process by which earthquakes are mapped using several seismographs.
Types of seismic waves
I. Body wave II. Surface wave
> can travel through the Earth's inner layers >travel only through solid media.
> They are slower-moving than body waves but
are much larger and therefore more destructive.
➢ p-wave ➢ Rayleigh wave
➢ s-wave ➢ Love wave
> P waves (Primary wave) - First signal to arrive at a seismograph.
- Fastest seismic wave.
- May be transmitted through solid rocks or liquid layers.
> s-waves (secondary wave)- Next to be detected after p-wave.
- Moves in a transverse motion
- May be transmitted in a solid only.
> Rayleigh waves - Rayleigh wave movementis elliptical.
- 4th seismic wave to arrive
> Love waves - Love wave movementis side way
-Most destructive among the seismic waves
Active Fault
✓Faults that recently created a movement of Earth’s crust over the historical period of 10,000 years.
✓It could still potentially create minor or major Earthquakes.
Inactive Fault
✓Faults that historically did not show signs of Earth’s crust movement over the time period of 10,000 years.
PARTS OF AN EARTHQUAKE
Hypocenter/Focus- location where the slippage ormovement took place
Epicenter- point on the ground directly above the hypocenter or focus
Fault Scarp- elevated surface caused by the movement of the fault
MAGNITUDE-Refers to the amount of energy released by an earthquake as the ground shakes
● The more energetic an earthquake is, the higher the value of its magnitude
● The higher the magnitude, the stronger the earthquake.
Richter Scale - scale used to measure the magnitude of an earthquake
INTENSITY -Measure of the amount of energy of an earthquake based on property damage
● Measured on the modified Mercalli Scale
● PHIVOLCS provides a scale similar to modified Mercalli called PHIVOLCS Earthquake Intensity Scale
Tsunami- Huge destructive waves are generated when an earthquake occurs underwater.
-Tsunami is a Japanese word that means “Harbor wave”
-Not all tsunamis are generated by underwater earthquakes.
-Not all fault movement underwater will create a tsunami.
-Most of the time, reverse or thrust faults generate tsunamis
- Requires a vertical push to uplift the water and start a wave
-Usually, it takes an earthquake with Richter magnitude of 7.5 and above to produce a destructive tsunami.
How does a tsunami form?
Two massive tectonic plates in the ocean collide.
Water is displaced by thrusting and vibration of the seafloor.
Megathrust ruptures are created to release accumulated stress.
Seismic waves from earthquake push the water up
25 million meteoroids, An estimated 25 million meteoroids, micrometeoroids, and other space debris enter
Earth's atmosphere each day, which results in an estimated 15,000 tons of that material entering the atmosphere
each year.
The atmosphere refers to the layer of gases that surrounds the Earth.
- Supports life
- Absorbs harmful radiation
- Burns up incoming meteoroids
The gases that make up the atmosphere are present in the following amounts:
21% is oxygen
78% is nitrogen
Meteorology is the branch of Earth Science that deals with the study of the atmosphere and its corresponding
weather patterns.
- People who study the atmosphere are called meteorologists
TROPOSPHERE
✓The layer closest to the surface of the Earth.
✓About 12.5 km from the ground
✓All weather changes and patterns happen in this layer.
✓Formation of clouds
✓99% of water vapor are present here.
STRATOSPHERE
✓2nd layer of the atmosphere.
✓The stratosphere is also home to the ozone layer, which shields the Earth from harmful UV radiation.
✓About 50 km away from the ground
✓ There is less turbulence in this layer, so airplanes fly here instead of the troposphere as it is unstable
MESOSPHERE
✓The mesosphere is the third layer of Earth's atmosphere. It extends approximately from an altitude of about 50
kilometers to 85 kilometers above the Earth's surface.
✓It has no gases that can absorb heat from the sunthat’s why it is the coldest layer
✓Most meteors burn up in this layer due to friction with thin air, creating “shooting stars”
THERMOSPHERE
✓ The thermosphere is the fourth layer of Earth's atmosphere.
✓Ionosphere is found inthis layer.
✓ Ionosphere – consists of electrically charged atoms. These atoms are called ions.
-The aurora in the Northern Hemisphere is called aurora borealis while the aurora in the Southern Hemisphere
is called aurora australis
EXOSPHERE
✓The exosphere is the outermost layer of Earth's atmosphere, located above the thermosphere. It is more than
700 km to 10,000 km from Earth’s surface with no clear boundary
CLOUDS
Clouds are formed from a collection of water droplets or ice crystals that remain suspended in the atmosphere.
This happens when moisture in the air condenses, creating visible water vapor.
Why do clouds appear different?
1. Altitude- Clouds form at different heights in the atmosphere.
High altitude: wispy due to ice crystals Low altitude: denser and thicker
2. Temperature- In troposphere, the higher the altitude, the lower the temperature.
3. Humidity- Rising air forms tall clouds Stable air forms layered clouds
4. Air movement- - Amount of water vapor present in the air.
✓ High Humidity – results in thicker and more developed clouds.
✓ Low Humidity – creates thinner, wispy clouds.
5. Wind speed and direction- How fast is the air moving, and where is the air coming from
✓ Strong wind – stretch clouds into streaks
✓ Gentle wind – allow the cloud to remain fluffy
8 TYPES OF CLOUDS
CIRRUS-
Appearance: Thin, wispy, and feathery
Altitude: high
High Weather Indication: usually signals fair weather but can indicate an approaching storm
Cumulus-
Appearance: Fluffy, cottonlike, and white appearance
Altitude: low
Weather Indication: usually signals fair or good weather
Stratus
Appearance: uniform, grayish, and covers the entire sky like a blanket.
Altitude: Low
Weather Indication: overcast skies, drizzle, or light rain
Nimbostratus
Appearance: Thick, dark, and covers the whole sky
Altitude: Low to mid
Weather Indication: Continuous rain
cumulonimbos
Appearance: towering, anvilshaped, with a dark base
Altitude: Extends from low to high altitudes
Weather Indication: Thunderstorm, heavy rain, and lightning
Altostratus
Appearance: gray or blueish, covers the sky, slightly transparent
Altitude: mid
Weather Indication: precedes rain
Altocumulus
Appearance: white or gray patches of small, rounded clouds
Altitude: Mid
Weather Indication: Fairweather
Stratocumulus
Appearance: low, lumpy clouds, appear in clusters or patches.
Altitude: Low
Weather Indication: Light rain or drizzle possible but mostly dry
