Earth Science

1. Earth Science Review

2. Pre-Test • The graph below shows the relationship between the distance and velocity of several galaxies.If you observed a new galaxy moving with a velocity of 38,000 km/s, at what distance should it be located? • 60 Mpc • 500 Mpc • 600 Mpc • 28,000 Mpc

3. Pre-Test • The energy source driving Earth’s weather comes from • the Earth’s core through heat conduction. • release of radiant heat energy through volcanic activity. • the Sun through visible light. • the Moon through tides

4. Pre-Test • What is the relationship between the amount of hydrogen, amount of helium, and energy as a low-mass star ages? • Hydrogen increases, helium decreases, and energy is released. • Hydrogen increases, helium increases, and energy is absorbed. • Hydrogen decreases, helium decreases, and energy is absorbed. • Hydrogen decreases, helium increases, and energy is released.

5. Pre-Test • What can we conclude from the observation that nearly all galaxies are moving away from us? • The once smaller universe is expanding in all directions. • The Sun and Earth are located at the center of the universe. • Everything in the universe is moving the same direction. • Massive black holes are drawing galaxies away from Earth.

6. Pre-Test • The Earth’s surface mainly gives off (radiates) which form of energy? • Infrared light • Visible light • Ultraviolet light • The Earth’s surface does not give off energy

7. Pre-Test • The greenhouse effect is: • an undesired atmospheric phenomenon which should be eliminated • directly responsible for the global cooling which resulted in our last ice age • a recent atmospheric event due solely to the actions of humans burning fossil fuels • an increase in atmospheric temperature due to gases that absorb and retain heat radiation

8. Pre-Test • The movement of tectonic plates is inferred by many scientists to be driven by • tidal motions in the hydrosphere. • density differences in the troposphere. • convection currents in the asthenosphere. • solidification in the lithosphere.

9. Pre-Test • The diagram below shows a geologic cross section. Letters A through D represent different rock units. Which sequence correctly shows the age of the lettered rock units, from OLDEST to YOUNGEST? • A → B → C → D • B → A → D → C • C → D → A → B • D → C → B → A

10. Pre-Test • As solar radiation reaches Earth: • only the longest wavelengths of radiation are able to punch through the atmosphere • shorter wavelength radiation reaching the surface is absorbed and changed to infrared • infrared radiation reacts with ozone and becomes short-wavelength ultraviolet radiation • we find having a high albedo decreases the amount of radiation reflected back to space

11. Pre-Test • Based on the accompanying graphic, which Earth surface has the highest albedo? • Forest • Ocean • Sand • Snow

12. Pre-Test • Convection distributes heat energy by: • transporting groups of molecules from one place to another within a substance • transferring energy without the involvement of a physical substance in the transmission • direct, point-to-point contact with static, neighboring molecules • emitting alpha and beta particles from unstable atomic nuclei

13. Pre-Test • Which of the following is the best statement comparing the water of today with the water that was here 100 million years ago? • Water enters and leaves Earth during evaporation and precipitation cycles. • The water present on Earth today is made of the same atoms but the molecules have been recycled through biologic activity. • The atoms that made the water then were destroyed when they were used; the atoms that make up water now were made more recently. • The molecules of water then are the same molecules that exist today.

14. Pre-Test • A sea breeze occurs during __________ as warm air above land rises and cold air over ocean water sinks, causing a convection cell which moves air from the __________. • daytime / land out to the ocean • nighttime / land out to the ocean • nighttime / ocean in towards the land • daytime / ocean in towards the land

15. Pre-Test • Use the diagram to answer the following question. Which type of plate boundary is shown in the diagram? • Divergent • Transform • Convergent • Universal

16. Pre-Test • Based on the diagram, we can see that regions of convecting atmosphere where air is rising are areas of _________ while the regions where air is descending are areas of __________. • conduction / radiation • radiation / conduction • low pressure / high pressure • high pressure / low pressure

17. The Solar System and the Universe

18. I. Red-Shift Spectra • In the early 1920s, an astronomer named Edwin Hubble observed that the light spectra signatures of almost all galaxies were redshifted. • The black lines in the figure below shift toward the violet end of the spectra for objects moving towards us. • The black lines in the figure below shift toward the red end of the spectra for objects moving away from us.

19. Examine the“Spectra of Fast-Moving Galaxies” handout. • The lightest line in the spectrum tells the velocity of the Galaxy. • Figure out how fast each galaxy is moving and write down its velocity in the box by each galaxy. • Use the “Hubble’s Law” worksheet to plot a point for each galaxy’s distance and velocity as determined on the “Spectra of Fast-Moving Galaxies” worksheet. • Do the Red-Shift Activity to investigate how the velocity of a galaxy is related to its distance.

20. Red-Shift ActivityKey • Question1: A negative velocity would mean a Galaxy is moving towards us. What do your velocity answers say about the direction these Galaxies are moving? • Answer: These Galaxies are moving away from the Milky Way. • Question 2: What does your graph say about the relationship between the distance and speed of a Galaxy? • Answer: The graph shows that the further a Galaxy is from us, the faster it is moving.

21. II. Hubble’s Law • The farther the galaxies are from Earth (top closest, bottom farthest), the more the black absorption lines are shift to the red • Galaxies move away from Earth at a rate proportional to their distance from us. • This relationship is now called Hubble’s Law and is an indication that the universe is expanding.

22. Hubble’s Law Activity • Get out your rubber band and data table. • The black dot represents your home galaxy, and the red dots represent two other galaxies • Place your rubber band against a ruler with your black dot at zero. • Your red dots should be at 2cm and 6cm.Record these as your original distances for each galaxy. • Stretch your rubber band until your first red dot reaches the 4 cm mark (make sure the black dot stays at 0 cm.) • Record the final distances of your red dots in your data table. • Calculate the total distance travelled by each galaxy (Final – Original Distance).

23. Hubble’s Law Activity Questions: • How did the distance travelled by Galaxy 2 compare to Galaxy 1? • Galaxy 2 travelled about twice as far as Galaxy 1 • The time you took to stretch the rubber band was the same for both red Galaxies. What does this say about the speed it took each Galaxy to reach its final distance? Remember, speed = distance/time. • Galaxy 2 travelled twice as fast as Galaxy 1

24. III. The Expanding Universe • Hubble’s Law is assumed to apply to all galaxies. • In other words, all galaxies are moving away from every other galaxy. • The farther galaxies are separated, the faster they are moving apart. • With every galaxy moving away from every other, the universe must be expanding.

25. End of Day 1 • Homework: (individual handouts) • The Expanding Universe • Inspect each universe sheet separately. Do you see a “center” to the pattern of dots? • Pick any galaxy on the 1 BYA universe to represent your home galaxy. • Find two other galaxies and measure their distances from your home galaxy and record these as the original distance. Record Data. • NOTE: make measurements to the nearest millimeter (0.1 cm)

26. Day 2 • Place the transparent present-day universe over the BYA universe. • Shift the overlay to make your home galaxy line up. • The differences in dot positions between the paper and the overlay represent how far galaxies have moved in one billion years relative to the “center” galaxy. • What pattern do you see in the direction of motion of the galaxies? • Use the transparency to measure and record the final distances that Galaxy 1 and Galaxy 2 have travelled from your home galaxy. • Calculate the speed of expansion for each galaxy by subtracting their original distances from their final distances. Record Data. • Finish Expanding Universe Homework (5-10 min)

27. Expanding Universe Activity Review • How are galaxies moving in relation to the “center” of the sheets? • They are moving outward. • How does the distance from your home galaxy affect the speed in which other galaxies move away? • The farther they are, the faster they move away.

28. IV. The Big Bang Theory • The expansion of the universe supports the model of our universe’s origin, called the Big Bang. • According to this model, the universe began in a very small, hot, and dense state. At some point, this universe began to expand and rapidly cool. The expansion we observe today is a remnant of that original expansion at the Big Bang. • The age of the universe using Hubble’s Law ranged from 7 to 20 billion years. • More precise measurements using cosmic microwave background radiation place the age of the universe at 13.7 billion years.

29. V. Stars • The primary source of energy in all stars is nuclear fusion. • In the fusion reaction four hydrogen ions (protons) are combined through collisions to create one helium ion (containing two protons and two neutrons). • Energy is emitted in the form of light.

30. Atmospheric Processes

31. I. Earth’s Atmosphere • More than 99% of the Earth’s energy comes from the Sun. • Energy is transferred to the Earth mostly through visible light as solar radiation (insolation). Use your handout to predict what % of the Sun’s radiation goes to each process. Use the following %’s to fill in the blank spots: 51% 20% 19% 6% 4%

32. I. Earth’s Atmosphere Answers 6% 4% 20% Use the following %’s to fill in the blank spots: 51% 20% 19% 6% 4% 19% 51%

33. I. Earth’s Atmosphere • Earth returns energy from the Sun back to space as infrared radiation. • Only 6% of the energy goes directly from the Earth’s surface to space. • About 15% of the Earth’s surface energy is absorbed by water vapor, carbon dioxide and other gases in the atmosphere. • This is called the greenhouse effect.

34. I. Earth’s Atmosphere • Infrared radiation transfer provides energy to the atmosphere. • This energy, which ultimately originated from the Sun, drives all of Earth’s weather and climate.

35. II. The Greenhouse Effect • Increase in the temperature caused by greenhouse gases. • These gases are: water vapor, carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and halocarbons. • Greenhouse effect is not a bad thing. • Without, Earth’s average global temperature would range from around 21C to 33C cooler than it is today • Too cold for the plants and animals living on the planet.

36. II. The Greenhouse Effect • The danger is too great a concentration of greenhouse gases. • Absorb too much of the infrared radiation from Earth’s surface. • Atmosphere acts as a thermal blanket. • Leading to a dangerous increase in global temperatures.

37. II. The Greenhouse Effect • Carbon dioxide is the gas most often thought of during discussions on the greenhouse effect. • Levels of carbon dioxide began increasing with the Industrial Revolution. • Concentrations have been obtained from measurements taken from ice cores and directly from the atmosphere.

38. Demo: Carbon Dioxide Blanket • Put 100 ml of vinegar in a 1000 ml flask. • Add 20 ml of Baking Soda. • Light a candle and hold the opening of the flask nest to the flame. • Pour the invisible gas onto the flame. Questions: • What happens to the flame? • It goes out. • Why do you think this occurs? • Carbon dioxide smothers the flame (like a fire blanket) • How does this activity relate to the Greenhouse Effect? • Carbon dioxide is denser than air and stays close to earth’s surface, trapping infrared radiation.

39. III. Radiation • Radiation is the transfer of energy without the involvement of a physical substance in the transmission. • Solar radiation (called insolation) strikes the earth’s surface at different angles.

40. III. Radiation • The albedo (reflectivity) of Earth’s surface varies. • The higher the albedo, the greater the percentage of insolation reflected • The lower the albedo, the lower the percentage reflected. High Do the poles have a high albedo or low? Does the equator have a high albedo or low? Low Snow reflects, Water absorbs Why are they different?

41. IV. Convection • Convection transmits heat energy by transporting groups of molecules from one place to another within a substance. • A fluid medium must be present in order for convection to occur. • Energy from solar radiation drives the convection found in oceans, lakes and ponds, and convection within the atmosphere.

42. IV. Convection • Winds • As warm air rises, a low pressure center develops. • As cold air descends, high pressure centers are created. • Winds blow from the regions of high pressure towards the regions of low pressure.

43. IV. Convection • Local Convection Patterns • Occurs where land and water meet. • During daytime • The land warms up. • Temperature of water changes little. • The warm, less dense air above land rises. • The cooler, more dense air above the ocean descends and rushes onshore (a sea breeze). Sketch the Sea Breeze diagram on a piece of paper.

44. IV. Convection • At night • Land cools rapidly • Resulting in colder air above the land compared to the temperature of the air above the ocean. • Warmer air above the oceans rise and the colder air above land sinks • Moving the air away from the land and out to the ocean, creating a land breeze. Sketch the Land Breeze diagram on a piece of paper.

45. IV. Convection • Global Convection Patterns • If Earth was smooth and had no interactions between land and ocean masses, two very large convection cells would arise between the polar and equatorial regions. • The spinning earth breaks these cells into smaller cells. • Friction with the spinning earth deflects the surface winds (Coriolis effect) • Thus smaller cells develop in both the northern and southern hemisphere.

46. IV. Convection • Sketch and label the picture of global wind patterns on a sheet of paper

47. End of Day 2 Homework (individual handouts) • Read the Layers of the Atmosphere background information • Use the Data from Table 1 to produce a graph of the average temperatures of the various layers of the atmosphere. • Label the troposphere, tropopause, stratosphere, stratopause, mesosphere, mesopause, thermosphere and ozone layer on your graph. • Answer the activity Questions.

48. Day 3 Homework Review: Graph Answer Key • QUESTIONS: • What is the basis for dividing the atmosphere into four layers? • The variations in temperature changes. • 2. Does the temperature increase or decrease with altitude in the: • troposphere: • stratosphere: • mesosphere: • thermosphere: decrease increase • decrease • increase

49. Day 3 • QUESTIONS: • What is the approximate height and temperature of the: • tropopause: • about 12-18 km • about –60 0C • stratopause: • about 46-54 km • about –2 to 0 0C • mesopause: • about 85-90 km • about –90 0C Homework Review:

50. Day 3 Homework Review: QUESTIONS: • What causes the temperature to increase with height through the stratosphere, and decrease with height through the mesosphere? • The temperature increases in the stratosphere due to ozone layer capturing ultraviolet radiation. The temperature decreases in the mesosphere since there is no ozone and the amount of air is decreasing. • What causes the temperature to decrease with height in the troposphere? • The farther away from the warm earth’s surface we go, the heat dissipates until we hit the ozone layer in the stratosphere.