Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion EXIT CHAPTER 4.1 Earth’s Formation 4.2 Earth’s Rotation 4.3 Earth’s Revolution CHAPTER OUTLINE

4 4.1 Earth’s Formation Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.1 Earth’s Formation VOCABULARY Earth formed about 4.6 billion years ago from a whirling cloud of dust and gas. It developed layers as it cooled and dense material sank to its center. inner core outer core mantle The four layers are the inner core, outer core, mantle, and crust. crust lithosphere asthenosphere Inner Core • solid • 6371 km from surface • approx. 6000K magnetic field Outer Core • liquid • 5150 km from surface • 3700–5500K (increases with depth SECTION OUTLINE

4 4.1 Earth’s Formation Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.1 Earth’s Formation VOCABULARY Earth formed about 4.6 billion years ago from a whirling cloud of dust and gas. It developed layers as it cooled and dense material sank to its center. inner core outer core mantle The four layers are the inner core, outer core, mantle, and crust. crust lithosphere asthenosphere Mantle • solid with liquid properties • 2890 km from surface • 1500–3200K (increases with depth magnetic field Crust • solid • 0–65 km from surface • <1000K (increases 10–30K/km with depth SECTION OUTLINE

4 4.1 Earth’s Formation Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.1 Earth’s Formation VOCABULARY The four layers are the inner core, outer core, mantle, and crust. The crust and top of the mantle are further classified by their properties into the lithosphere and the asthenosphere. inner core outer core mantle crust lithosphere Crust Lithosphere asthenosphere Mantle magnetic field Asthenosphere SECTION OUTLINE

4 4.1 Earth’s Formation Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.1 Earth’s Formation VOCABULARY Meteorite impacts, the weight of overlying material, and the decay of radioactive isotopes caused Earth to heat up soon after its formation. Since then, Earth has been losing heat. inner core outer core mantle crust lithosphere Earth has a characteristic magnetic field. asthenosphere magnetic field SECTION OUTLINE

4 Earth’s Structure and Motion inner core CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY inner core outer core inner core mantle The solid innermost layer of Earth, composed of iron and nickel under extremely high pressure and temperature. crust lithosphere asthenosphere magnetic field SECTION OUTLINE

4 Earth’s Structure and Motion outer core CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY inner core outer core outer core mantle The layer of Earth’s interior located between the inner core and mantle, composed of iron and nickel in a liquid state. crust lithosphere asthenosphere magnetic field SECTION OUTLINE

4 Earth’s Structure and Motion mantle CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY inner core outer core mantle mantle The thickest of Earth’s layers, located between the outer core and Earth’s crust, composed mostly of compounds rich in iron, silicon, and magnesium. crust lithosphere asthenosphere magnetic field SECTION OUTLINE

4 Earth’s Structure and Motion crust CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY inner core outer core crust mantle The very thin outer layer of Earth above the mantle, composed of a rigid layer of lighter rocks that can extend 65 kilometers at its deepest point. crust lithosphere asthenosphere magnetic field SECTION OUTLINE

4 Earth’s Structure and Motion lithosphere CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY inner core outer core lithosphere mantle The outer shell of the Earth consisting of the crust and uppermost portion of the mantle. crust lithosphere asthenosphere magnetic field SECTION OUTLINE

4 Earth’s Structure and Motion asthenosphere CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY inner core outer core asthenosphere mantle The partially melted layer of the mantle that underlies the lithosphere. crust lithosphere asthenosphere magnetic field SECTION OUTLINE

4 Earth’s Structure and Motion magnetic field CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY inner core outer core magnetic field mantle An area in which the motion of charged particles creates a magnetic force, such as the field of magnetic force generated by the movement of fluid in Earth’s outer core. crust lithosphere asthenosphere magnetic field SECTION OUTLINE

4 4.2 Earth’s Rotation Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.2 Earth’s Rotation VOCABULARY Earth makes one complete 360° turn on its axis about every 24 hours, rotating at a rate of 15° per hour. Its axis of rotation is tilted 23.5° with respect to Earth’s orbital plane. rotation standard time zones time meridian prime meridian 23.5° International Date Line Orbital plane Axis of rotation Effects of this rotation include the Coriolis effect, Foucault pendulum behavior, day and night, and sunrise and sunset. SECTION OUTLINE

4 4.2 Earth’s Rotation Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.2 Earth’s Rotation VOCABULARY Earth is divided into 24 worldwide standard time zones that begin at the prime meridian. rotation standard time zones time meridian The prime meridian SUNLIGHT A time meridian A standard time zone is 15° wide. prime meridian International Date Line SECTION OUTLINE

4 Earth’s Structure and Motion rotation CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY rotation standard time zones rotation time meridian The turning of a body, such as Earth, on its axis. prime meridian International Date Line SECTION OUTLINE

4 Earth’s Structure and Motion standard time zones CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY rotation standard time zones standard time zones time meridian Areas roughly defined by twenty-four 15° sections of longitude, each centered on a time meridian that establishes the hour of the day. prime meridian International Date Line SECTION OUTLINE

4 Earth’s Structure and Motion time meridian CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY rotation standard time zones time meridian time meridian A line of longitude exactly divisible by 15° on which each standard time zone is roughly centered. prime meridian International Date Line SECTION OUTLINE

4 Earth’s Structure and Motion prime meridian CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY rotation standard time zones prime meridian time meridian The imaginary line dividing Earth’s surface into Eastern and Western Hemispheres, established as 0° at Greenwich, England; the starting point for standard time zones. prime meridian International Date Line SECTION OUTLINE

International Date Line CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY rotation standard time zones International Date Line time meridian The imaginary line placed at roughly 180° longitude where the new calendar day begins, moving east to west. prime meridian International Date Line SECTION OUTLINE

4 4.3 Earth’s Revolution Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.3 Earth’s Revolution VOCABULARY Earth revolves around the sun in an elliptical orbit with the sun as one focus. Evidence for Earth’s revolution includes seasonal constellation changes and parallax, the apparent shift in a star’s position. revolution parallax summer solstice June 21–22 March 21–22 Dec. 21–22 Sept. 21–22 winter solstice Earth makes one revolution around the sun every 365.24 days. vernal equinox autumnal equinox SECTION OUTLINE

4 4.3 Earth’s Revolution Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.3 Earth’s Revolution VOCABULARY Combined with Earth’s tilt, revolution causes seasonal changes. The summer and winter solstices are the longest and shortest days of the year in the Northern Hemisphere, respectively. revolution parallax summer solstice winter solstice vernal equinox autumnal equinox Sun’s rays SECTION OUTLINE

4 4.3 Earth’s Revolution Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME 4.3 Earth’s Revolution VOCABULARY Combined with Earth’s tilt, revolution causes seasonal changes. The summer and winter solstices are the longest and shortest days of the year in the Northern Hemisphere, respectively. revolution parallax summer solstice winter solstice On the vernal and autumnal equinoxes, day and night are of equal lengths. vernal equinox autumnal equinox Sun’s rays SECTION OUTLINE

4 Earth’s Structure and Motion revolution CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY revolution parallax revolution summer solstice The movement of one body around another, such as the Earth in its orbit around the sun. winter solstice vernal equinox autumnal equinox SECTION OUTLINE

4 Earth’s Structure and Motion parallax CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY revolution parallax parallax summer solstice The apparent shift in one object’s position relative to another caused by a change in the location of the observer. winter solstice vernal equinox autumnal equinox SECTION OUTLINE

4 Earth’s Structure and Motion summer solstice CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY revolution parallax summer solstice summer solstice The first day of summer in the Northern Hemisphere, which occurs on or about June 21 each year when the noon sun appears to reach its most northern point in the sky. winter solstice vernal equinox autumnal equinox SECTION OUTLINE

4 Earth’s Structure and Motion winter solstice CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY revolution parallax winter solstice summer solstice The first day of winter in the Northern Hemisphere, occurs on or about December 21 each year when the noon sun appears to reach its most southern point in the sky. winter solstice vernal equinox autumnal equinox SECTION OUTLINE

4 Earth’s Structure and Motion vernal equinox CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY revolution parallax vernal equinox summer solstice Start of spring in the Northern Hemisphere, occurring on or about March 21 each year when the noon sun is directly over the equator; one of two days each year when day and night are of equal length in both hemispheres. winter solstice vernal equinox autumnal equinox SECTION OUTLINE

4 Earth’s Structure and Motion autumnal equinox CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY revolution parallax autumnal equinox summer solstice Start of fall in the Northern Hemisphere, occurring on or about September 22 each year when the noon sun is directly over the equator; one of the two days each year when day and night are of equal length in both hemispheres. winter solstice vernal equinox autumnal equinox SECTION OUTLINE

4 Earth’s Structure and Motion I. Earth’s Formation CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY I. Earth’s Formation inner core A. Origin of the Solar System outer core B. Earth’s Size and Shape mantle C. Earth’s Interior crust D. Earth’s Heat lithosphere E. Earth’s Magnetic Field asthenosphere magnetic field KEY IDEA SUMMARY

4 Earth’s Structure and Motion II. Earth’s Rotation CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY II. Earth’s Rotation rotation A. Evidence for Rotation standard time zones B. Axis of Rotation time meridian C. Effects of Rotation prime meridian 1. Measuring Time International Date Line 2. Standard Time Zones 3. International Date Line KEY IDEA SUMMARY

III. Earth’s Revolution CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME VOCABULARY III. Earth’s Revolution revolution A. Evidence for Revolution parallax B. Path and Rate of Revolution summer solstice C. Effect of Revolution and Tilt winter solstice D. The Laws of Thermodynamics vernal equinox E. The Effects of Earth’s Surface autumnal equinox F. Human Activity and the Cycles KEY IDEA SUMMARY

4 Earth’s Structure and Motion CHAPTER 4 Earth’s Structure and Motion CHAPTER HOME This is the end of the chapter presentation of lecture notes. Click the CHAPTER HOME button or exit the presentation.