Earth Science T1

Plato’s belief in the world of ideas

Our existence depends on higher beings.

Aristotle’s belief that reality is found on earth rather then in the world of ideas.

• “To say of what is that it is not, and of what is not that it is, is falsehood, while to say of what is that it is, and of what is not that it is not, is truth. “ – Aristotle at Metaphysics

What is Earth Science?

All sciences in correlation to the understanding of earth and its neighbors in space.

What is Geology?

The study of ‘Earth’, it's layers and the processes happening on and within them.

What is Oceanography?

The study of the oceans
-     75% of the Earth’s surface is covered in water

• Of that 75% of the water, 97% is made of oceans (saline; undrinkable water)

• Without oceans, we cannot live. We won’t have the atmosphere and aquatic life needed for oxygen production.

What is Meteorology?

The study of the atmosphere and the processes that produce weather. 

What is Astronomy?

The study of the universe and the Earths role in it.

Natural Hazards. 

• Earthquakes, floods, landslides, tsunamis, volcanic eruptions, etc.

• If a volcano is active/inactive

Earth science is what?

an environmental science. 

What are peoples influences on the earth’s natural processes

We burn lots of fossil fuels → More greenhouse gasses → Climate change

what is the Geologic Time Scale

Divides history of Earth into different units

what is Geologic time

The Span of time since Earth’s formation.

How old is the Earth

Earth is 4.6 billion years old

How were the earths layers formed?

As Earth formed, the decay of radioactive elements and heat from high-velocity impacts caused the temperature to increase
-   - Iron and nickel began to melt and sink towards the center

• Lighter rocky components (such as Silica or Oxygen)  floated outward, towards the surface

Hydrosphere.

It is 97.44% saline and 2.56% fresh water

Saline Water

It is 97.44% of earths water
It is undrinkable
96.5% is the ocean and 0.94% is Saline Groundwater and lakes

Freshwater

It is 2.56% of the earths water.
Drinkable
1.76%/ 69% of it is in glaciers
0.77% is Ground water?
the rest can be found in streams and lakes. 

Atmosphere

It is 100 kilometers thick
it is a tenuous blanket ot air
one half lies below 5.6km(3.5) miles

Biosphere

Includes all life
Concentrated near the surface in a zone that extends from the ocean floor upward for several kilometers into the atmosphere

Key component: Organic Carbon

• Contains C-H bonds

Geosphere

Solid Earth

Extends from the surface to the center of the planet

Largest of the Earth’s four spheres

Earths Crust

Earth’s thin, rocky outer skin

it has 2 parts the Continental & Oceanic crust

Continental Crust

 it is Less dense and has many rock types

It is Granitic; ex: Silicone, Potassium, Sodium, Aluminum 

Oceanic Crust

It is Dense and mainly comprised of basaltic rock

Weather

Constantly changing over a short period of time.

Climate

Generalized, composite of weather over a long period of time.

Elements of weather & climate

• Temperature

• Humidity

• Cloudliness

• Precipitation

• Air pressure

• Winds speed and direction

Composition of the atmosphere

• Air is a mixture of discrete gases

• Nitrogen 78%

• Oxygen 21%

• Carbon Dioxide 0.0397%

  • Absorbs heat energy from Earth

• Argon & Other Gases

Variable components of air

Water vapor, Aerosols, Ozone, and Pressure Changes

Water Vapor

• Up to 4% of air’s volume

  • More than 4% → Condensation → Clouds

  • Hot air → Humidity

• Forms clouds & precipitation

• Absorbs heat energy from Earth

Aerosols

• Tiny solid and liquid particles

  • Carbon black: incomplete combustion of organic materials

  • Burning of fossil fuels

    • Release of NOX, SOX

    • Bad for our health

• Water vapors can condense on solids

• Reflects sunlight

• Help color sunrise and sunset

Ozone

• Stratosphere 

• Distribution not uniform

• Concentrated between 10km to 50km above the surface

• Absorbs harmful UV radiation

  • The hotter, the higher in the spectrum in radiation

• Human activity is depleting ozone by adding chlorofluorocarbons (CFCs)

  • Breaks ozone bond

Pressure Changes

• Pressure: Weight of the air above

• There’s less air above due to gravity and density & it feels lighter the higher the altitude

• Average sea level pressure

  • Slightly more than 1000 millibars (mb)

  • About 14.7 pounds per square inch

  • 1.2kg per 1m³ of air (sea level)

    • We can’t feel it because the pressure’s evenly distributed

• Pressure decreases w/ altitude

  • Half of the atmosphere is below 3.5 miles or 5.6km

  • 90% of the atmosphere is below 10 miles or 16km

What makes up the structure of the atmosphere

Troposphere, Stratosphere, Mesosphere ,Thermosphere

Troposphere

Bottom layer; thickest varies – average height is 12 km

• temp. decreases w/ altitude → environmental lapse rate

• 6.5°C per kilometer (average)

• 3.5°F per 1000 feet (average

• Outer boundary is named the tropopause

• Ozone is somewhat present but not useful; considered air pollutant; considered a carcinogen

Stratosphere

12km to 50km above sea level

• Greenhouse gasses (abundantly CO2) change the temperature; negative environmental lapse rate

• Presence of Ozone

• Outer boundary is called stratopause

Mesosphere

50km to 80km above sea level

• Positive environmental lapse rate

• Outer boundary is named mesopause

• Burning of meteoroids happen here due to air friction; disintegration of meteoroids

Thermosphere

No well-defined upper limit

• Presence of aurora

• Fraction of atmosphere’s mass

• Gasses move at high speeds

Next layer: exosphere (not part of atmosphere; outer space)

The Earths Motions (bobokanlngifdimotonakuha)

Rotation and Revolution

The Duration of one of the earths Rotations (istg)

24 HOURS

The Duration of the Earths revolution around the Sun

365 days

How does a Solstice occur

Earth’s axis is 23.5° tilted as it orbits around the sun → results in solstices

Summer Solstice

• (June 21–22): Time of daytime is longer than night time

  • North Pole is 24/7 morning

Winter Solsitce

• (June 21–22): Time of daytime is longer than night time

  • North Pole is 24/7 morning

what is an Equinox

the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of approximately equal length

Autumn Equinox

• (Sept. 22-23): Sun’s vertical rays are located at the equator; time is equal

Spring/Vernal Equinox

• (Mar. 21-22): Sun’s vertical rays are located at the equator; time is equal