EARTH SCIENCE

Chapter 1: Introduction to Earth Science

Chapter 1: Introduction to Earth Science

• I. What is Earth Science– (Note Objectives A-C On Page 3)– Topic 1 Branches of Earth Science

-Geology: surface and interior of earth-Astronomy: universe-Meteorology: weather-Oceanography: oceans-Hydrology: water budgets and water systems

-Others: paleontology, volcanology

Chapter 1: Introduction to Earth Science

• Topic 2 Activities of Today’s Geologists-Origins of the earth-History of the earth-Structures of the earth-Processes shaping the surface-Searching for sources of oil, Uranium, geothermal

energy

Chapter 1: Introduction to Earth Science

• Topic 3 What Astronomers Do-Study of things beyond our reach-Development of investigating tools

Chapter 1: Introduction to Earth Science

• Topic 4 What Meteorologists Do-weather forecasters-study air pollution-study long term climate changes

Chapter 1: Introduction to Earth Science

• Topic 5 What Oceanographers Do-measure ocean depths-look for ocean mineral deposits-study ocean currents-glacial movements-touch on marine biology-underwater earthquakes

Chapter 1: Introduction to Earth Science

• II. The Origin of the Earth (and Solar System for that matter)– (Note Objectives A-C On Page 7)– Topic 6 Where Earth Science Begins: The

Solar System• A. Hypothesis – A good guess explaining known

facts

Chapter 1: Introduction to Earth Science

• Topic 6 B. Six facts of the solar system1. All planets revolve around the sun in the same

direction.2. Nearly circular orbits (Actually ellipses)3. Most are in the same plane4. Sun turns on axis (rotation) in same direction of

planets.5. Most planets rotate in same direction as sun.6. Seven planets have moons and these rotate in

same direction as rotating planets and sun.

Chapter 1: Introduction to Earth Science

• Topic 7 The Protoplanet Hypothesis– 1944 von Weizsacker and 1950 Kuiper

A. Six steps1. 5 billion years ago, gas and dust cloud

1 billion km in diameter existed.2. It shrank, why?, and started to rotate

quicker.3. Got hot and ignited fusion reaction.4. % of material blown off in a disc.5. Masses clung together within the disk

(Protoplanets)6. Uncollected materials exist as comets,

meteoroids, and asteroids.

Chapter 1: Introduction to Earth Science

• Topic 8 Origin of Oceans (3 Steps)1. Earth grew hotter, due to compression,

radioactive materials, and meteor showers.2. Fe (iron) melted and sank, water and gasses were

released.3. Upon cooling, water condensed into oceans.

Chapter 1: Introduction to Earth Science

• Topic 9 Origin of Atmosphere (2 Steps)1. Original atmosphere was from volcanoes.

Mostly: water, carbon dioxide, and sulfurdioxide

2. First oxygen from breakdown of water at hightemperatures, but most from photosynthesismuch later over billions of years. Nitrogencame from Hydrogen cyanide.

Chapter 1: Introduction to Earth Science

• Topic 10 Structure of Solid Earth– A. Model – used to help us picture what we

can’t see.

Chapter 1: Introduction to Earth Science

• Topic 10 B. The 4 parts of the earth– 1. Inner core

• 1200 km in diameter • Made of solid Fe and Ni

– 2. Outer core• 2250 km thick• Made of liquid Fe and Ni

– 3. Mantle• 2400 km thick• Fe, Mg, Si

– 4. Crust• 10-65 km thick• No drilling has penetrated it

Chapter 1: Introduction to Earth Science

• Topic 11 How the Continents Formed (Not really sure)– A. Two Possibilities?

1. Immense single continent formed from forcedout rock.

2. From great lava flows over 100’s of millions of years.

Remember: Today’s continents are different from those long ago.