PHYSICAL GEOGRAPHY. By Brett Lucas

Transcription

1 PHYSICAL GEOGRAPHY By Brett Lucas

2 INTRODUCTION

3 Introduction to Earth Geography as a Field of Learning Geography is from two Greek words, Geo Earth, and Graphien to write. Elements/Branches of Geography Physical & Human or Cultural (see next slide). This class is concerned with Physical Geography.

4 Elements of Geography

5 Introduction to Earth Environmental Spheres (next slide) The Solar System Size and Shape of Earth The Geographic Grid Earth Movements Annual March of the Seasons Telling Time

6 Environmental Spheres Lithosphere Litho, Greek for stone Atmosphere atmo, Greek for air Hydrosphere hydro, Greek for water Biosphere bio, Greek for life L Interacting spheres A B H

7 The Solar System Figure 1-6: Elliptical orbits Pluto is NO longer one of the planets in our solar system as of 2006

8 Size and Shape of Earth 3 rd Rock from the Sun (93 million miles) Size Diameter approx. 8,000 miles (12,800 km) at the equator 5 th largest in diameter

9 Size and Shape of Earth Earth s highest pt: 29,000 ft above sea level. Lowest point: 36,000 ft below sea level More bulgy at the equator: a difference of 0.3%. As a result, it s not a true/perfect sphere (circle), but an Oblate Spheroid, slightly flat on top and bottom.

10 Size and Shape of Earth

11 Size and Shape of Earth

12 Angle of Tilt See imaginary rotation axis. Interesting fact about Earth: The Earth tilts towards the east, at an angle of 23.5 degrees. This is called the inclination of the rotation axis.

13 The Geographic Grid The Combination of Latitude and Longitude Lines

14 Summary (Geographic Grid) Longitude (also called Meridians) Measures distance east and west around the globe, beginning at the Prime Meridian Important longitude lines: Prime Meridian & International Date Line degrees East or West Latitude (also called Parallels) Location on the Earth s surface between the equator and the north or south pole Important latitude line: Equator 0-90 degrees North or South

15 The Geographic Grid The Equator (next slide) the line thru the earth s middle Latitude (run north and south of Equator) Longitude E/W of the Prime/Greenwich Meridian They are used to establish location, for navigation and for telling time. The circle is 360 degrees around; therefore since there are 24 MAJOR longitude lines, each line is 15 degrees, same as ONE HOUR. So 360 degrees = 24 hours.

16 The Equator More interesting facts about Earth: Earth ALWAYS points to Polaris, the North Star Earth moves/ rotates from West to East.

17 Great and Small Circles A great circle is the largest circle than can be drawn on a sphere and they bisect the Earth into 2 equal halves e.g. The Equator The Prime Meridian The Sun s Circle of Illumination (see Blue Beauty NASA slides) Small circles are any other circles that can be drawn.

18 Latitude: Parallels There are 7 important parallels. Measures from 0º to 90º N and S of the equator. Also, the Tropics or tropical areas are hotter, due to the bulge.

19 Longitude: Meridians 0 degrees Longitude passes thru Greenwich, England. And it s then measured East and West Measures from 0º to 180º E & W of the Prime/Greenwich Meridian Established in 1884 at the International Meridian Conference in Washington, D.C. Also used for determining World Time (every 15 degrees is an hr)

20 Regions on Earth Regions on Earth (Latitude bands) Low latitude» 0º 30º N and S (close to Equator) Mid latitude» 30º 60º N and S High latitude» 60º 90º N and S (close to poles) Equatorial» within a few degrees of the equator Tropical» within the tropics between 23.5º N and 23.5º S Subtropical» 25º 30º N and S Polar» within a few degrees of the North and South Pole

21 Earth Movements Rotation on Axis (Daily) One complete rotation is 24 hrs Rotation Direction (West to East), see next slide Rotation Speed, see table and pg Revolution Around Sun (Annual) 365 days, 5hrs, 48 minutes and 46 seconds, simplified to or 365 ¼ days Leap Year

22 Rotation Direction West to East

23 Rotation Speed Note: Always constant speed, only DISTANCE at each location varies!

24 Annual March of Seasons Solstices Summer & Winter; unequal daylight (see next slides) Equinoxes 12 equal hours of daylight; start of Spring and Fall (anywhere between the 20 th and the 23 rd ) Also, see Table 1-7 (pg 22)

25 Solstices

26 Solstices

27 Equinoxes

28 Changes in Daylight

29 Time Zones Accurate calendars have been kept by great civilizations for 1000s of years the Egyptians, Mayas, Aztecs, Chinese, Indians, etc. Pg 23 (Babylon 2,000 B.C.) A.M. & P.M. are Latin words (pg 23). Meri (highest) is the root word for Meritorious. 3 units of natural time the year, month and day. Everything else is man-made (hour, minute, second, etc)

30 Time Zones Standard Time starts at the Greenwich Meridian (GMT) or Zulu. Now called UTC (Universal Time Coordinated). All areas to the east of the Prime Meridian are ahead in time, and all areas to the west are behind in time. Some countries have one time zone, while others have several. Russia has 9. International Date Line (further slides)

31 World Time Zones

32 U.S./Canada Time Zones

33 International Date Line Starts at 180 degrees; this is also where a NEW DAY (new DATE) begins i.e. 12 Midnight. It is the OPPOSITE of the Prime Meridian (zero degrees longitude) in Greenwich i.e. 12 Noon There is a difference of 12 hours between the Prime Meridian (zero degrees) and the International Date Line (180 degrees longitude)