Chapter 1 Introduction to Earth Science

1. Chapter 1Introduction to Earth Science Earth Science

2. What is Earth Science? 1.1 • What forces produced the mountains shown on page 1? • Why does our daily weather change? • Is our climate changing? • How old is Earth? • How is Earth related to other planets in the solar system? • What causes ocean tides? • What was the Ice Age like? • Will there be another?

3. Overview of Earth Science 1.1 • Deals with Earth and its neighbors in space • Geology “study of Earth” • 2 broad areas • Physical – examination of materials that make up Earth & explain possible process that shape our planet • Earthquakes, mountains, volcanoes, erosion, rocks, minerals • Historical – understand Earth’s long history • est. time line

4. Overview of Earth Science Continued… 1.1 • Oceanography – study coastal process, seafloor topography, marine life, and composition and movement of seawater • incorporates: chemistry, physics, geology, & bio • Meteorology - study of the atmosphere, weather, and climate • Astronomy – study of the universe • all objects in space, including earth

5. Formation of Earth 1.1 • 1 of 9 (or 8) planets • Solar system = orderly • Formed during same span as other planets and from the same material as the sun • Nebular Hypothesis – bodies of solar system evolved from enormous rotating could, the solar nebula • made mostly of H & He

6. http://daphne.palomar.edu/lyon/Animations/NebHypo.swf

7. Nebular Hypothesis 1.1 • Look at Picture on Page 4 • What do all the stages of this hypothesis have in common? • What was the first stage in the development of our solar system? • While Earth formed, denser materials sank to Earth’s core while less dense materials escaped to the atmosphere

9. Layers Form on Earth 1.1 • Earth Formed • Radioactive element breakdown (decay) • Heat released (from all the colliding particles) • Melting of the interior • Denser element (iron and nickel) sink to center • Lighter/rocky float outward • Still believe to occur • Atmosphere forms from gases escaping

10. A View of Earth 1.2 • Earth’s Major Spheres • 3 major PHYSICAL Environment • Hydrosphere – water portion • Evaporates  falls back as precipitation  runs back to rivers/oceans/etc • Oceans = 97% of water on Earth • 3% = groundwater, streams, lakes, and glaciers • Important b/c the sustain life and help create land forms

11. Atmosphere • Gaseous envelop • 100 km above earth • 90% just within 16 km of earth • Provides air we breath • protects • Geosphere • Not uniform • Core – heavy dense inner core • Mantle • Crust – lighter – not uniform • Thinnest beneath the ocean • Thickest beneath continents • Lithosphere – uppermost mantle • Asthenosphere – below lithosphere - molten rock

13. 4th major sphere • Biosphere – all of life on earth • Ocean floor and upward for several km into the atmosphere

14. Plate Tectonics 1.2 • Grand Canyon, the Rocky Mountains, and the Appalachian Mountains did not exist a billion years ago • Destructive forces – weathering, erosion (wear away land) • Constructive Forces – mountain building and volcanism (raising the land) • Revolution – learning more about Earth • Idea that continents moved the face of the Earth = PLATE TECTONICTS • Earth broken at lithosphere into plates • Motion caused from uneven heating of earth’s surface = earthquakes, volcanic activity, rocks into mountains

16. Representing Earth’s Surface 1.3 • Global Grid • Latitude (fatitude) – distance N or S of the equator (0o latitude) – lines run E and W • Longitude – Distance E or W of the prime meridian (0o longitude) – lines run N and S • Earth is 360 degrees around • Equator divides Earth in 2 hemispheres • Northern and southern • Prime Meridian divides earth in 2 hemispheres • Eastern and western

17. Globes 1.3 • Shapes, sizes of islands, continents, and bodies of water • Found by exploring • Best represented thru a globe • Earth is round

18. Maps and Mapping 1.3 • Flat representation of Earth’s surface • Can not be accurately represented • Too small, big, out of place • The Mercator Projection • Gerardus Mercator made map in 1569 to help sailors navigate • Lines of longitude are parallel (compare to globe) • Makes grid rectangular • Bonus: showed directions accurately • Negative: sizes and distances distorted (esp around poles)

19. The Mercator Projection

20. Different Projection Maps for Different Purposes 1.3 • Best project determined by use • Robinson Projection – widely used • Bonus: show most distances, sizes, and shapes accurately • Negative: distortions around the edges • Conic Projection – wrap a cone of paper around a globe at line of latitude, trace • Almost no distortion at line of latitude • High distortion away from latitude line • Accuracy great over small area (used for maps) • Gnonomic Projection • Place piece of paper on globe so it touches since point • Distance and direction distorted • Useful to sailors to show shortest distance between 2 oints

22. Topographic Maps 1.3 • Represent Earth’s 3-D surface in 2-D • Show elevation by contour lines • Also can show water, roads, gov and public buildings, political boundaries, and places names • Contour Lines – every position along a single contour line is the same elevation • Every 5th line is bolded = index contour • Closer together line = steep slope • Farther apart lines = gentle slope • Never touch or intersect • Depression = circular contours that have hachure marks – small lines on circle that point to the center

23. Scale of Topographic Maps 1.3 • Determine distances on the map and relate them to the real world • Certain distance on the map is drawn to equal a certain distance on the surface • 1:24,000 = ratio • Has no units • 1 unit on map is equal to 24,000 units on the ground

24. Geologic Maps 1.3 • Shows type and age of the rocks exposed • Each rock formation assigned a color and sometimes a pattern

25. Advance Technology 1.3 • Gives us the ability to more precisely analyze Earth’s physical properties • Use satellites and computers • Remote sensing – process of collecting data about Earth from a distance

26. Technology and Earth Science 1.3 • Weather Satellites – monitor temp, humidity, & clouds • Navigation Satellite – assists ships and submarines • Landsat Satellite – Data on Earth’s landmasses, coastal boundaries, and coral reefs  complete 14 orbits per day • GPS - Combines satellite with computer technology providing latitude, longitude, and altitude • Very Long Baseline Interferometry – measures the geosphere – study tectonic plates

27. Earth System Science 1.4 • Look at earth as a system made up of numerous interacting parts • Tries to study all branches of science • What is a System? • Any size group of interacting parts that form a complex whole. • Closed System – no matter enters or leaves the system; energy moves freely • Open System – both energy and matter flow into and out of the system • Most natural systems

28. Earth as a System 1.4 • Earth powered by energy from 2 sources • Sun – drives external processes (weather, climate, ocean circulation, erosion processes) • Earth’s interior – from radioactive element and from time Earth formed • power internal process = volcanoes, earthquakes, and mountains • Change in one system affects the other • Volcano erupts  lava flow block nearby valley  influence drainage system  ash influences solar energy = drop in temp. • Our actions produce changes in all parts of Earth’s system

29. People and the Environment 1.4 • Environment – everything that surround and influences an organism • Biological or social • Nonliving = physical environment = air, water, soil, rock, temp, humidity, sunlight • Environmental Science – focus on relationships between people and the natural environment

30. Resources 1.4 • Water and soil, metallic and nonmetallic minerals, and energy • Foundation of modern civilization • RENEWABLE resource – can be replenished in a short period of time • Plants and animal food, natural fibers, lumber, paper, water, wind, and the sun • NONRENEWABLE – process to create sources takes millions of years • Iron, aluminum, copper, oil, natural gas, coal

31. Population 1.4 • Growing rapidly • Population increases, demand for resources increases • Yet, energy resources do not increase • Leads to many questions • How long will the remaining supplies of basic resources last? • How long can we sustain the rising standard of living in today's industrialized countries? • How much environmental deterioration are we willing to accept to obtain basic resources? • Can alternatives be found?

32. Environmental Problems 1.4 • Air pollution • Acid rain • Ozone depletion • Global warming • Loss of fertile soils to erosion • Toxic waste • Depletion of water resources • Natural hazards: earthquakes, landslides, floods, hurricanes, drought • Knowledge about Earth and how it works is necessary to our survival and well being

33. What is Scientific Inquiry? 1.5 • Science based on 2 assumptions: • Natural world behaves in a consistent, predictable manner • Careful, systematic study can explain the natural world’s behavior • Basics steps to the scientific method • Collect data thru observation and measurement • (Question) • Hypothesis (1 or more working hypothesis) • Test and Analyze • Conclusion = acceptance, modification, or rejection of hypothesis

34. Scientific Inquiry 1.5 • Theory • Made after hypothesis has been tested extensively and competing hypothesis eliminated • well tested and widely accepted by scientific community • EXPLAINS observable facts