TOPIC 1 OBJECTIVES
DIMENSIONS OF THE EARTH
1. Define altitude as used in locating stars, sun, moon, etc.
Altitude is an angle formed by a line that goes from the horizon to an observer, and by a line that goes from the observer to an object above the horizon.
2. Using the Big Dipper, determine the location of the North Star.
The North Star can be found by following a line created by the last two stars in the Big Dipper's dipper. Follow the line towards the open end of the dipper.
3. Determine and write the latitude on Earth, given the altitude of Polaris.
An observer's latitude is equal to the altitude of Polaris.
4. Given cross sectional diagrams of the Earth, identify the one that represents the actual appearance of the Earth's shape.
Pick the diagram that is closest to being absolutely round and smooth.
5. Using the Earth's polar and equatorial diameters, describe how this represents the Earth as being slightly oblate.
The Earth is not quite a perfect sphere. Its Polar diameter is slightly smaller than it's equatorial diameter.
6. List three kinds of evidence that can be used to determine the shape of the Earth.
1) We have been in space and seen the Earth.
2) When objects disappear on the horizon, the bottom of the object disappears first, then the middle and finally the top.
3) During a lunar eclipses the Earth casts a curved shadow on the Moon
7. Given the Earth Science Reference Tables (ESRT) identify any listed physical value or dimension of the Earth.
The chart is on page 16 of the ESRT.
8. Calculate the number of miles or kilometers in a degree of latitude.
To find the answer, divide the circumference of the Earth by 360o. If the circumference is not given use the radius of the Earth information on page 16 of the ESRT and the circumference formula also on page 16.
9. Determine the circumference of the Earth, using the difference in altitude of a star from two different positions, taken at the same time, on a North-South line.
They need to use the Eratosthenes' formula on page 16 of the ESRT.
10. Describe the parts of the Earth:
a. lithosphere: The lithosphere is the solid outside layer of the Earth. It contains the crust and a thin layer of the mantle.
b. atmosphere: The atmosphere is layer of gas surrounding the Earth.
c. hydrosphere: The hydrosphere is liquid water found on or just below the surface of the Earth.
11. Compare the relative densities of the lithosphere, atmosphere, and hydrosphere.
From most dense too least dense they are: Lithosphere, hydrosphere, and atmosphere.
12. a. Given graphs of distance vs. ocean depth identify the graph which best shows the ocean floor relief in true scale.
Done to true scale the line representing the bottom of the ocean should be on top of the horizontal axis.
b. Given diagrams showing the Earth and its atmosphere, identify the diagram most nearly in true scale.
The line representing the atmosphere should be right on top the line representing the Earth.
13. Create a model that best shows the relief of the Earth's surface in true scale.
Students should pick objects which are perfectly round and smooth. Objects like marbles, and pool balls are good examples.
14. On a map or globe, identify lines of latitude and lines of longitude.
Lines of latitude run east to west on a map, while the lines of longitude run north to south.
15. Given latitude and longitude values (degrees, minutes, seconds), identify that location on a map.
Students can use the map on page 3 of the ESRT to practice using latitude and longitude coordinates.
16. Define isoline.
An isoline is a line which connect points of equal value.
17. Construct an isoline map, given measured values.
The students have had many practice maps to work on. There are 3 basic rules to follow:
1) Isolines never cross.
2) Isolines either form a circle or go to the edge of the map.
3) You must follow the stated interval.
18. Given a topographic map, be able to interpret and read the map.
The students have several worksheet practicing reading topographic maps.
19. Given a field map with isolines, match the correct profile with the change in isoline values.
The students have done several labs and worksheets creating profiles.
20. Calculate the gradient on a topographic map, given the difference in elevation between two places.
The formula is on page 16 of the ESRT.
