Earth Systems CRT Review

Observation, fact, inference

• observation: using your senses to obtain information about the world around you

• Fact: something that has happened and in known to be true (you can see or measure it)

• Inference: a conclusion based on a series of facts, a kind of “prediction" you did not see or measure it…yet)(“I smell McDonald’s”)

Hypothesis and theory

• Hypothesis: an idea or explanation based on observations that can be tested (“I think it smells like McDonald’s)

• Theory: an explanation based on observation, experimentation, and reasoning…it has been “tested”

Standard I: Students will understand the scientific evidence that supports theories that explain how the universe and solar system developed.

Objective 1: Describe the big bang theory and evidence supporting it.

Objective 2: Relate the structure and composition of the solar system to the processes that exist in the universe.

Life in the Universe• As far as we know, Earth is the only planet with life.• Why? Earth has the right temperature, atmosphere,

and water to sustain life.• Next closest planet? Mars-It does have an

atmosphere but not just like Earth’s), it has somewhat moderate temperatures (but too cold at times), it has polar ice caps (but not water or liquid water)

• We are searching Mars for evidence of water for possible past life (although a fossil would be great)

Formation of Universe(Big Bang Theory Common Today)

• Models and theories have changed over time as new evidence (observations) was obtained.

• Hubble- Red Shift (in light spectrum) supports a Big Bang by showing that all stars are moving away from each other

• Expanding Universe- red shift supports the motion of stars and galaxies away from each other and a central point where the big bang happened

• Doppler effect: an apparent shift in the frequency of a wave due to the motion of an object

• Big Bang- all of the matter and energy present today was compressed into a small space. -when hydrogen and helium formed- The rest of matter HEAVY ELEMENTS) formed in stars or supernova explosions by combining lighter elements

Doppler effect

Life Cycles of Stars

• Stars are born (nebular theory)• They all start like our sun converting hydrogen

into helium by high temperature and nuclear fusion

H-R DiagramHertzsprung-Russell

H-R DiagramHertzsprung-Russell

H-R DiagramHertzsprung-Russell

Life Cycle of Stars by MASS

Nebula-gas and dust Protostars

Star like our sun

Massive star

Red giant

Red supergiant

Planetary nebula

White dwarf then black dwarf?

supernova Neutron star and/or black hole

Standard II: Students will understand that the features of Earth’s evolving environment affect living systems, and that life on Earth is unique in the solar system.

Objective 1: Describe the unique physical features of Earth’s environment that make life on Earth possible.

Objective 2: Analyze how ecosystems differ from each other due to abiotic and biotic factors.

Objective 3: Examine Earth’s diversity of life as it changes over time.

Diversity of Life

• Biodiversity means many different kinds of life forms

Diversity of LifeLots of biodiversity Less biodiversity

Why is there sometimes more or less biomass?(Biomass is the total mass of living material)

WHY? WHY?

Energy Flow

Sun-source of energy

Producers-plants-turn sunlight into food for consumers

Consumers- eat produces to get their energy

Decomposers- break down deadOrganisms to release CO2 and Nitrogen back into the environment

Energy Flow

Standard III: Students will understand that gravity, density, and convection move Earth’s plates and this movement causes the plates to impact other Earth systems.

Objective 1: Explain the evidence that supports the theory of plate tectonics.

Objective 2: Describe the process within Earth that result in plate motion and relate it to changes in other Earth systems.

Continental drift

• Alfred Wegener proposed it 100 years ago• He had strong evidence of fossils, glacial

deposits, rocks, climate• He could not explain the forces that moved

the plates

Continental drift

Continental drift

Earthquakes and volcanoes

• Most occur along plate boundaries

Plate tectonics

• Earth is divided into sections that move about on convection currents in the upper mantle

Plate tectonics: 3 boundary typesConvergent, divergent, transform

Plate tectonics: 3 boundary typesConvergent, divergent, transform

Which type?

transform

Plate tectonics: 3 boundary typesConvergent, divergent, transform

Which type?

divergent

Ex.: seafloor spreading

Plate tectonics: 3 boundary typesConvergent, divergent, transform

Which type?

convergent

Hawaiian Volcanoes: Hot Spot

Dinosaur extinction theory

• An asteroid or large meteor hit Earth about 65 million years ago

Dinosaur extinction theory

• An asteroid or large meteor hit Earth about 65 million years ago

Meteor crater in Arizona; meteorite was thousands of time smaller

Standard IV: Students will understand that water cycles through and between reservoirs in the hydrosphere and affects the other spheres of the Earth system.

Objective 1: Explain the water cycle in terms of its reservoirs, the movement between reservoirs, and the energy to move water. Evaluate the importance of fresh water to the biosphere.

Objective 2: Analyze the physical and biological dynamics of the oceans.

Tides

• Caused by gravity

Tides• Caused by gravity

Water cycleThe sun is the source of energy

The water cycle

Standard V: Students will understand that Earth’s atmosphere interacts with and is altered by the lithosphere, hydrosphere, and biosphere.

Objective 1: Describe how matter in the atmosphere cycles through other Earth systems.

Objective 2: Trace ways in which the atmosphere has been altered by living systems and has itself strongly affected living systems over the course of Earth’s history.

Carbon Dioxide

• Greenhouse effect: warming of Earth due to greenhouse gases (carbon dioxide, water vapor, methane) trapped in the atmosphere

• Greenhouse effect is increasing and has been for about the past 120 years

Carbon Dioxide

• Fossils fuels- gas, coal, oil• Fossil fuels are a major source of carbon

dioxide

Carbon cycle

Carbon cycle

Animals

PEOPLE

Carbon dioxide levels and temperature increases

Carbon dioxide levels and temperature increases

What would you conclude?Carbon dioxide change over time

Temperature change over time

Is there a link between carbon dioxide and temperature??

Ozone

• A special oxygen molecule that absorbs ultraviolet light, protecting us from the sun.

Standard VI: Students will understand the source and distribution of energy on Earth and its effects on Earth systems.

Objective 1: Describe the transformation of solar energy into heat and chemical energy on Earth and eventually the radiation of energy to space.

Objective 2: Relate energy sources and transformations to the effects on Earth systems.

Weather and climate

• Weather- the condition of the atmosphere right now (wind, temperature, precipitation, etc.)

• Climate- the average weather over a long period of time.

Coriolis effect

Due to Earth’s rotation wind and ocean currents in the Northern Hemisphere appear to curve to the right

Coriolis effect

Due to Earth’s rotation wind and ocean currents in the Northern Hemisphere appear to curve to the right