1. Model: A representation of a real object or event. Ex: Map Globe Graphs A. Models are useful because they allow an easier way to study objects or

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2 1. Model: A representation of a real object or event. Ex: Map Globe Graphs A. Models are useful because they allow an easier way to study objects or events. 2. The shape of the Earth A. The earth is round. B. Evidence: 1) A ship sailing away a) Observation: A ship gradually disappears below the horizon. b) Inference: The earth s surface is curved.

3 2) Lunar Eclipse The shape of the earth s shadow is seen on the moon s surface as the moon enters and exits the eclipse. View from Outer space SUN

4 Earth s Shadow Earth s shadow is curved!!!

5 3) Altitude of Polaris (The North Star) a) Polaris appears at different altitudes at different places at the same time. To Polaris (very, very far away) Reason: The Earth is round!! 90 o North Pole 60 o 20 o

6 90o 90o 90o

7 3. How Round Is The Earth?? A. The earth is not perfectly round (but very close). B. The shape of the earth is called an oblate spheroid. a) slightly bulged at the equator. b) slightly flattened at the poles. *********(Not Enough to See However!!!!)********

8 P.D.= Polar Diameter P.D. E.D.= Equatorial Diameter Earth E.D. > P.D. E.D.

9 C. Diameter / Circumference Measurements Diameter Circumference Polar Equatorial 12,714 km 12,756 km 40,008 km 40,076 km

10 4. How Smooth is the Earth??? A. Surface features such as mountains are very minor irregularities on a planetary scale. Ex: This line is too thick to show the true ocean depth. EARTH This point is too big to show the true height of the tallest mountains.

11 5. The Outer Spheres of the Earth A. Lithosphere 1) The solid outer shell of the earth. (Rocks) B. Hydrosphere 1) All of the water (H 2 O) on the earth s surface. C. Atmosphere 1) The shell of gasses (air) that surrounds the earth.

12 6. Locating Positions on the Earth A. Coordinate system 1) A system of intersecting lines on a surface used to pinpoint locations. Ex: latitude and longitude 7. Latitude A. The angular distance north or south of the equator. B. Lines of latitude are called parallels. C. Latitude starts at 0 o. D. The most latitude can be is 90 o.

13 North Pole 60 o N 30 o N North Latitude 0 o 30 o S 60 o S South Latitude Equator South Pole

14 Therefore, where the dashed line intersects the surface of the earth is the 45 o latitude line. What is this angle? 45 o What is the South Pole s Angle??? 90 o

15 E. In the northern hemisphere, latitude is found by measuring the altitude of Polaris (North Star). 1) Astrolabe: the instrument that measures the altitude of stars. To Polaris

16 Ex: Location X Altitude of Polaris = 34 o 34 o Latitude of X = Polaris Location X 34 o Angle is determined by reading where string crosses the protractor.

17 8. Longitude A. The angular distance east or west of the Prime Meridian (0 o Longitude). B. Longitude lines are called meridians. They all meet at the poles.

18 North Pole 90 o W 60 o W 30 o W 90 o E 60 o E 30 o E South Pole West Longitude East Longitude

19 C. The Prime Meridian passes through Greenwhich, England. D. Every 15 degrees of longitude is = 1 hour of time. Reason: Earth rotates (spins) 360 o in 24 hours. A circle has 360 o therefore: E. To Calculate Longitude: 360 o 24 hours = 15 o / hour 1) Find the number of hours between local time (your time) and the time on the Prime Meridian (Greenwich Time). 2) Multiply x 15 o / hour 3) a) If local time is earlier than Greenwhich time, your longitude is west. b) If local time is later than Greenwhich time, your longitude is east. Reason: Earth rotates from west to east.

20 F. Everyone on the same meridian of longitude has the same solar time. G. Ex: Local time: 4:00 am But what Greenwhich time: 1:00 am direction is it?? Your longitude: 45 o West Time Difference = 3 hours Time difference x 15 o = 45 o Ex: Your longitude: 90 o W Local time: 3:00 pm Greenwhich time: 9 pm But is it later or earlier in Greenwhich?? Time Difference x 15 o = 90 o W Time Difference = 90o 15 o = 6 hours Try this one on your own Ex: Local time: 10:00 am Friday Greenwhich time: 1:00 pm Friday Your longitude: 45 o W

21 And this one. Ex: Your longitude: 30 o E Local time: 5:00 pm Greenwhich time: 3:00 pm 9. One degree of latitude = 68 miles (110 km) A. Slightly less at the poles and slightly more at the equator due to the earth s imperfect shape. 10. One degree of longitude = at equator = 70 miles at the poles = 0 miles Reason: Longitude lines meet at the poles.

22 11. To pinpoint more specific locations>>>degrees are subdivided into minutes and seconds. A. One degree = 60 minutes B. One minute = 60 seconds Ex: Latitude of location X: 43 o N Ex: What are the coordinates of Ithaca, NY? 42 o 29 N, 76 o 30 W 12. FIELDS A. Any region of space in which a quantity can be measured at any point. Ex: Temperature field magnetic field Gravitational field elevation field

23 12. Fields can be shown on a map. 1) Lines called isolines are drawn connecting points of equal value. Ex: Isotherms: lines of equal temperature. Isobars: lines of equal pressure Contour lines: lines of equal elevation. C. Field values change with time 1) Some change fast Ex: temperature air pressure. 2) Some change slowly Ex: elevation

24 D. Drawing Field Maps 1) Several field values (numbers) are plotted on a map. 2) Isolines are drawn connecting points of equal value.

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26 E. Reading Isolines Maps 1) Distance on maps is shown by using a scale. Ex: ) Every point on the same isoline has the same field value. 13. Gradient A. A measure of the rate of change across a field. (slope of field). B. General Rule: The closer the isolines, the greater the gradient (or steeper the slope) High or steep gradient Low or gentle gradient

27 C. Calculating Gradient Change in field value Gradient = Distance (RT front page) Ex: Calculate the gradient between points A and B on the map below: meters A B 0 km 50 km 100 km Gradient = Change in field value Distance 80m 50km Distance between A and B = 50 km Change in field value between A and B = 180m-100m = 80m Plug the numbers into the above equation = 1.6 m/km

28 14. Topographic Maps A. Maps that show the elevation field of an area. B. Topographic maps show the shape of the land by using contour lines which are lines of equal elevation (isolines). C. Contour Interval: The number of feet between lines (contours) To figure out the contour interval, count the lines that are between the numbered lines. 5 lines = 100 feet therefore: goes into 100, 20 times so the contour interval = 20 feet 400

29 D. Hills: Shown on a map by circular lines. E. Depressions (holes): Shown on a map with circular lines with hachures.

30 F. When contour lines cross a river, they bend upstream. Therefore, the river flows opposite of the way the contour lines bend.

31 15. On a topographic map, latitude and longitude are in the corners of the map. 43 o o o o 15 N 43 o o o o 15 Latitude covered: 43 o o 00 = 15 minutes Longitude covered: 73 o o 15 = 15 minutes Direction is indicated by which way the numbers increase. N S E W

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33 ?? What is the contour interval of this map????

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36 16. Map Profile: The side view of a section of a topographic map. Procedure: ) Draw a line x-y 2) Figure out contour interval 20 feet 3) Lay a strip of paper on the line and mark elevation on it. 4) Mark any features (swamp, streams hilltops etc..) on paper 5) Decide the max and min numbers needed for profile 6) Place strip of paper on bottom of graph. 7) Mark off the correct elevations and connect the dots x x x

37 17. USGS Topographic Maps A. Areas covered are called quadrangles (Quads). B. These come in 3 sizes according to Latitude and Longitude. 1) 7.5 minute 2) 15 minute 3) 30 minute C. Numerical Scale: Tells how many map units are covered by each ground unit. Ex: 1:24,000 (7.5 quad) This means that for every one map unit there are actually 24,000 ground units.

38 1:62,500 (15 quad) Ex: 1cm on map = 62,500 cm in real life. OR 1 inch on map = 62,500 inches in real life. 1:250,000 (30 quad)

39 18. Scientific Notation: A. Using powers of 10 to express very large or very small numbers. Ex: 1) 3.8 x 10 4 = 38,000 2) 28.9 x 10 8 = 2,890,000,000 3) 67 x 10-6 = ) 5,300,000 = 5.3 x ) 400,000 = 4.0 x ) = 6.5 x 10-4