Downloaded 47 times
More Related Content
Ch01
- 1. Chapter 1: Introductionto Earth McKnight’s Physical Geography: A Landscape Appreciation, Tenth Edition, Hess
- 2. Introduction to Earth •Geography as a Field of Learning • Science and Geography • The Environmental Spheres • The Solar System • The Size and Shape of Earth • The Geographic Grid • Earth-Sun Relations • The Annual March of the Seasons • Telling Time 2© 2011 Pearson Education, Inc.
- 3. Geography as aField of Learning • Definition • Sciences which branch from geography • Physical versus cultural • “Why what is where and so what?” 3© 2011 Pearson Education, Inc.
- 4. Science and Geography •The Scientific Method – Observe phenomena – Formulate a hypothesis – Design an experiment – Predict the outcome of the experiment – Conduct the experiment – Draw conclusions • Scientific “proof” 4© 2011 Pearson Education, Inc.
- 5. Science and Geography •Measurement Systems – Need measurement systems to quantify scientific processes – SI versus English units – Conversions 5© 2011 Pearson Education, Inc.
- 6. The Environmental Spheres •Four primary spheres 1. atmosphere—“air” 2. lithosphere—“stone” 3. hydrosphere—“water” 4. biosphere—“life” 6 2 3 1 4 Interactions between the spheres © 2011 Pearson Education, Inc.
- 7. The Solar System •Formation of the Solar System – Formed 4.5 to 5 billion years ago – 8 planets revolve around the Sun – 4 terrestrial planets – 4 gas giants – Earth is the third planet 7 Figure 1-4 © 2011 Pearson Education, Inc.
- 8. The Solar System 8 Figure1-5 © 2011 Pearson Education, Inc.
- 9. The Size andShape of the Earth • Earth’s Physical Characteristics – Equatorial diameter ~ 12,756 km – Polar diameter ~ 12,714 km – Circumference of 40,000 km – Maximum relief 9© 2011 Pearson Education, Inc. Figure 1-6
- 10. The Geographic Grid •Location on Earth – Need an accurate location on Earth to describe geographic features – Use Earth’s rotation axis to base location on the surface – North Pole and South Pole – Plane of the Equator—halfway between poles and perpendicular to Earth’s surface – graticule 10 Figure 1-9 © 2011 Pearson Education, Inc.
- 11. The Geographic Grid •Great Circles – Circles which bisect a sphere and pass through the sphere’s center – Identify the shortest distance between two points on a sphere—great circle distance – Circle of illumination – Small circles 11 Figure 1-10 © 2011 Pearson Education, Inc.
- 12. The Geographic Grid •Latitudes – Parallels – angle north or south of the equator – 7 important latitudes: – Tropic of Cancer and Capricorn (23.5° N and S) – Equator (0°) – Poles (90° N and S) – Arctic and Antarctic Circles (66.5° N and S) – Latitude zones 12 Figure 1-12 © 2011 Pearson Education, Inc.
- 13. The Geographic Grid •Longitudes – Meridians – Prime Meridian (0° longitude) located at Greenwich, England – angle east or west of the Prime Meridian – Converge at the poles 13 Figure 1-16 © 2011 Pearson Education, Inc.
- 14. Earth-Sun Relations • Rotationof the Earth – 24 hours for one rotation – Circular motion at all latitudes but the poles – Rotation is counterclockwise relative to the North Pole – Converge at the poles – Diurnal transition from light to darkness – Tidal effects from the Moon and Sun 14© 2011 Pearson Education, Inc.
- 15. Earth-Sun Relations • Earth’sRevolution around Sun – One revolution takes 365 ¼ days – Elliptical orbit – Aphelion (152,171,500 km) – Perihelion (147,166,480 km) – Average distance (149,597,892 km) – Earth at perihelion during Northern Hemisphere winter; aphelion during Northern Hemisphere summer 15 Figure 1-19 © 2011 Pearson Education, Inc.
- 16. Earth-Sun Relations • OrbitalProperties – Plane of the Earth’s orbit is the plane of the ecliptic – Earth’s axis tilted at 23.5° – Plane of ecliptic is not parallel to equatorial plane • Polarity of the Earth’s axis – Parallelism – North Pole always points toward Polaris (“North Star”) 16 Figure 1-20 © 2011 Pearson Education, Inc.
- 17. The Annual Marchof the Seasons 17 • Three important conditions – Declination of the Sun – Solar altitude – Length of day • Two solstices – June solstice – December solstice • Two equinoxes – March equinox – September equinox Figure 1-22 © 2011 Pearson Education, Inc.
- 18. The Annual Marchof the Seasons 18 • June solstice – Occurs on approximately June 22 each year – Sun is directly overhead at 23.5° N latitude – Antarctic Circle in 24 hours of darkness – Marks start of summer in Northern Hemisphere; winter in Southern Hemisphere Figure 1-22 © 2011 Pearson Education, Inc.
- 19. The Annual Marchof the Seasons 19 • December solstice – Occurs on approximately December 22 each year – Sun is directly overhead at 23.5° S latitude – Arctic Circle in 24 hours of darkness – Marks start of winter in Northern Hemisphere; summer in Southern Hemisphere Figure 1-22 © 2011 Pearson Education, Inc.
- 20. The Annual Marchof the Seasons 20 • Equinoxes – Occur on approximately March 21 and September 21 each year – Day length is 12 hours worldwide (“equinox”) – Sun is directly overhead at the equator Figure 1-22 © 2011 Pearson Education, Inc.
- 21. The Annual Marchof the Seasons 21 • Day length – Always 12 hours at the equator – In the Northern Hemisphere, day length increases after March equinox – Maximum day length during June solstice in Northern Hemisphere – Opposite for Southern Hemisphere © 2011 Pearson Education, Inc.
- 22. The Annual Marchof the Seasons 22 • Significance of seasonal patterns – Spread of solar rays over small and large areas – Tropical latitudes consistently warmer – Polar latitudes consistently cooler – Large seasonal variations in temperature in midlatitudes © 2011 Pearson Education, Inc.
- 23. Telling Time 23 • Threephysical measures of time – Tropical year – Lunar month – Solar day • Solar noon – Sun casts the shortest shadow • Ante-meridian (AM—“before noon”) • Post-meridian (PM—“after noon”) Figure 1-23 © 2011 Pearson Education, Inc.
- 24. Telling Time 24 • Currenttime system – 24 time zones – Greenwich Mean Time (GMT) is standard – Controlling Meridian for each time zone – Several countries have multiple time zones in their borders – Time zone boundaries subject to local political and economic boundaries of different nations – 180° meridian chosen as the International Date Line © 2011 Pearson Education, Inc.
- 25. Telling Time 25 Figure 1-24 •Time zones of the world © 2011 Pearson Education, Inc.
- 26. Telling Time 26 • Timezones of the United States Figure 1-25 © 2011 Pearson Education, Inc.
- 27. Telling Time 27 • Daylight-savingtime – Move clocks ahead by an hour during the summer months – Originally done by Germans during WWII; now practiced by many nations – Conserves lighting energy by providing an extra hour of daylight © 2011 Pearson Education, Inc.
- 28. Summary 28 • Geography isthe study of the distribution of physical and cultural attributes of Earth • Many sciences have branched off of geography • The scientific method is important when doing scientific studies • Earth has four primary spheres: the atmosphere, the lithosphere, the hydrosphere, and the atmosphere • The solar system formed 5 billion years ago and consists of 8 planets © 2011 Pearson Education, Inc.
- 29. Summary 29 • Earth isan imperfect sphere • A latitude and longitude grid help identify locations on Earth’s surface • Earth rotates on its axis in 24 hours • Earth revolves around the Sun in 365 ¼ days • Tilt of Earth’s axis causes seasons • Equinoxes and solstices help identify when a seasonal transition occurs © 2011 Pearson Education, Inc.
- 30. Summary 30 • Time zoneswere established to have a uniform global time system • Daylight-saving time was devised to conserve energy by adding an hour of daylight © 2011 Pearson Education, Inc.