Chapter 1 Introduction to Earth Science



Chapter 1A Introduction to Earth Science

What is Earth Science?

1. Branches of Earth Science

a. Geology-study of the earth’s

surface & interior

b. Astronomy-study of the universe

c. Meteorology-study of the earth’s

atmosphere

d. Oceanography-study of the

oceans

2. Careers in Earth Science

a. Geologists-study origin, history, and structure of the Earth and the processes that shape its surface

b. Astronomers-study objects and happenings beyond their physical reach using the laws of physics and mathematics

c. Oceanographers-study problems dealing with the Earths oceans

d. Seismologists- study earthquakes and Earth’s interior

e. Meteorologists- study physical characteristics, processes and movement of the atmosphere

f. Surveyors- measure and map Earth’s surface

g. Archaeologists- excavate, preserve, study and classify objects and structures from past cultures

B. How did the universe form?

ACTIVITY: Read- Earth as a System Earth’s Place in the Universe text p. 6 and take notes below

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C. Systems of Earth

1. Where Earth Science begins: The Solar System

a. Hypothesis-an informed guess that tries to explain how or why an event occurs

-a good hypothesis explains known facts

b. Earth is a System made of 4 spheres:

1. hydrosphere- 97% oceans

2. atmosphere- envelope of gas- 90% within 16 km

3. geosphere-lithosphere (rigid crust and upper mantle), asthenosphere (partially molten) and dense lower mantle, inner and outer core

4. biosphere- all life that interacts with the other 3 spheres

c. System- any size group of interacting parts that form a complex whole

d. The Earth system is powered by energy sources: the sun and radioactive material in the inner core

1. environment- everything that surrounds and influences an organism; all the resources, influences and conditions at Earth’s surface

2. Earth is considered the “Goldilocks Zone” (habitable zone) resulting in certain factors:

• Mild temperatures/climate

• Soil development

• Organism diversity

• Water- we are the water planet

• Well developed atmosphere- O3 protection

• Solar protection- Van Allen belts protect us from solar flares (produce protective magnetic field

e. Environmental Science is the systemic study of the environment; it draws from many other fields

f. Resources- sources of material and energy used by humans to sustain life

i. renewable resource- can be replaced in nature at a rate close to its rate of use

ii. nonrenewable resource- one that exists in a fixed amount or is used up faster than it can be produced

ACTIVITY: Categorize these resources as either (R) renewable or (NR) Nonrenewable

___1. oxygen

___2. trees

___3. food grown in soil

___4. uranium

___5. gold, silver, iron

___6. sand

___7. coal

___8. oil

___9. natural gas

___10. solar energy

g. Humans are part of the Earth System- human action produces changes in all of the other spheres

Threats to the environment- pollution, acid rain, ozone depletion, global warming, depletion of the rain forest

h. Populations affect sustainability; as population increases, the need for resources increases (observe J curve on p. 21)

2. How did the Earth form? (Nebular (Protoplanet) Hypothesis)

i. 5 bya, cloud of gas and dust (solar nebula) rotated and eventually shrank under the pull of its own gravity or by a passing star exploding. Composition was mostly hydrogen and helium and a small percentage of heavier elements.

j. material gathered in center and the compressed materials got very hot forming the sun

k. Cooling of the nebula caused rocky and metallic materials to form tiny solid particles; Repeated collisions of these particles formed asteroid sized bodies that eventually formed the 4 inner planets, lighter materials (H, He, H2O, CO2, methane and ammonia) and rock and metals formed farther away forming the 4 outer planets

3. How did the Oceans form?

a. When Earth formed, it had neither oceans nor atmosphere

b. Earth became hotter (compression, radioactive materials, meteorites) and iron melted and sank (core)

c. As iron melted, it also melted other materials around it, releasing water and gases trapped in those materials

d. These gases and water escaped through a volcanic eruption

4. How did the Atmosphere form?

a. Atmosphere is made of 78% Nitrogen, 21% Oxygen, 1% other

b. Original atmosphere came from volcanoes which contain no oxygen (water, CO2, sulfur gases)

c. Oxygen came from breakup of water molecules by sunlight in the upper atmosphere

d. Photosynthesis-take in CO2 and make O2

5. How is the Earth structured?- radioactive elements and colliding particles produced heating of the interior. Denser iron and nickel went to the center, lighter material remained near surface

a. Inner core-SOLID iron and nickel

b. Outer core-LIQUID iron and nickel

c. Mantle-rocks w/iron, magnesium, silicon

d. Crust-continental and oceanic

e. Layers formed as very hot temperatures melted iron and nickel forming streams of liquid; melted lighter rocks as it flowed forced them up towards the surface

6. How did the continents form?- (2 hypotheses)

a. light rock (from above #5) forced up formed one large continent

b. volcanic eruptions over millions of years

c. Earth is a “dynamic” planet- ever changing

1. constructive forces- mountain building and volcanism

2. destructive forces- weathering and erosion wear away the surface of the earth

3. Plate Tectonics theory- spring board from Continental Drift hypothesis by Alfred Wegener which provided evidence of lithospheric plate movement

ACTIVITY: Read and analyze map p. 9 of text: What is the relationship between mountain chains and plate boundaries?

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D. How is Science conducted?

ACTIVITY: Watch Bozeman Science vod-cast on the Scientific Method

Assumptions in Science:

the natural world behaves in a consistent and predictable manner

• through systematic study, we can understand and explain the natural world and use this knowledge to make predictions

• Science habits of Mind: curiosity, honesty, openness to new ideas, skepticism

• Science skills and methods:

Basic process skills- text p. 728-729

a. observing- using one or more of the 5 senses (qualitative) or tools to measure (quantitative) and record

b. inferring- interpreting an observation or statement based on prior knowledge

c. predicting- inference about a future event based on evidence, experience or knowledge; a way to test ideas

d. measuring- comparing an object or process to a standard

e. calculating- process of using mathematical operations to manipulate numbers or symbols

f. classifying- grouping items according to some organizing idea or system

g. using models-

h. using statistics, graphs and charts-

Experimental Skills text p. 730-731

a. Posing questions- after observing, noticing and questioning, make an inference

b. Formulating hypotheses- predictions that can be tested

c. Designing experiments- control group vs. experimental group

d. Controlling variables- identify variables (independent, dependent, and controlled/constants)

e. Forming operational definitions-describe what to do

f. Analyzing data- observations and measurements

g. Drawing conclusions- confirm or refute

h. Communicating results-repeat or publish

i. Evaluating and revising- further research

Safety Skills Text p. 732-733

General Rules and First Aid

Follow the dress code- goggles, apron, gloves, and hair

Heating and fire safety-burn protection, hair, flammable materials

Electrical safety- water, sockets, damaged cords, wires

Glassware safety- careful use, proper disposal

Chemical safety protection, dress, safety, mixing care

Sharp instrument safety- use, first aid and disposal

End of experiment rules- disposal, clean up, wash hands, check for controls turned off

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