1. Mapping Earth Do Now: Example: Hills
In your notes, list all the different types of landforms/features of Earth that you can think of.
Example: Hills

2. Topography: The shape of the land. Important Vocabulary
Grand Canyon, Arizona
K2, Pakistan
Napa Valley, California

3. Topographic Maps:
Represent the shape of the land on a flat piece of paper using contour lines

4. Contour Lines represent different elevations on a topographic map.
Each contour line connects values that are of equal elevation making them an isoline. m

5. An isoline: connects points of equal value on a field map.
shows a region with a measurable quantity at every location.

6. Examples of isolines: Isotherms: Isobar: Contour lines:
Lines connecting points of equal temperature
Isobar:
Lines connecting points of equal barometric (air) pressure
Contour lines:
Lines connect points of equal elevation
Anything else you can get a value for. Examples-points of equal: depth, chemical concentration, decibels, damage scale values, ice thickness, snowfall/rainfall totals…

9. Rules for Drawing Isolines:
Isolines connect points of equal value. The line must go through the center of the dot. You MUST use pencil! 5 5 10 10 10 10 15 15

10. Isolines are gentle, curving lines
No sharp corners! No double or messy lines! 5 5
10
10
10
10
15
15

11. Isolines are always closed curves even though the map might only show part of it. Your line must be a closed loop or reach the edge of the map!

12. Isolines NEVER cross- this would mean that one point has two different values. Ex: one spot has two temperatures?
Oh no!
60 °
50 °
40 °
30 ° X
20° Z Y

13. Isolines usually are parallel- ish.

14. Labeling! Isolines are always labeled. 60 50 40 70
Inside the line for contour lines or closed loops

15. Isolines are NEVER labeled between the lines!
50 °
Which line is 50 ° ?

16. What are the Rules That All Contour Lines Must Follow?
Do Now:
Calculate the gradient of the cliff (show work)

17. Rules for Contour Lines
A contour line represents a single equal elevation. (all points on the same contour line have the same elevation) 5 5 10 10 10 10 15 15

18. What is the contour interval of this map?
2. The elevation represented by a contour line is always a simple multiple (5, 10, 50, 100) or contour interval.
0 m
100 m
200 m
300 m
400 m
What is the contour interval of this map?

19. 3. Where one closed contour line surrounds another, the elevation increases. (representing a hill or mountain)
0 m
400 m
Lowest
elevation
Highest
elevation

20. 4. Closed depressions are shown by hachured contour lines
4. Closed depressions are shown by hachured contour lines. The hachures point into the depression. (Hachures = short dashes)

21. 5. A hachured contour line, lying between two different contour lines, is the same elevation as the lower contour line.
Count up
Count down
Contour
Elevation
Repeats

22. 6. Closely spaced contour lines indicate a relatively steep slope.
Gradient
Steep
Gradient

23. 7. Widely spaced contour lines indicate a relatively gentle slope.
Gradient
Gentle
Gradient

24. 8. Contour lines do not cross other contour lines
8. Contour lines do not cross other contour lines. They also never split or divide. A vertical cliff – contour lines seem to touch but never cross
Cliff

25. These lines are off the map
9. Every contour line eventually closes against itself. However, the map area may not be large enough to show this closure. Therefore, the contours will end at the edge of the map.
These lines are off the map

26. 10. Where a contour line crosses a stream or valley, the contour bends to form a “V” that points upstream.

27. Interpreting a Topographic Map

28. Index Contour Line
Heavy lines spaced at a predetermined labeled elevations on a topographic map.
Index Contour

29. Contour Interval
- The vertical distance that separates EVERY contour line on a topographic map.
What is the contour interval of this map?
Benchmark – tells the real elevation at that point

30. Estimating Elevation Label the contour lines based on the map interval
Find the contour line before and after the point you are trying to determine
Your answer should be a point in between those lines
Give a possible elevation for
point “a”
Contour Interval = 10 m 10
. a 20 30
. b
. c
Give a possible elevation for
point “b”

31. What is the highest possible elevation of point “c”?
The highest possible point on a contour map will always be one unit less than the next possible contour line.
Contour Interval = 10 m 10
. a 20 30
. b
. c
Give the HIGHEST possible elevation for
point “c”

32. What about the LOWEST possible point?
The lowest possible point on a contour map will always be one unit more than the lower contour line.
Contour Interval = 10 m 10
. a 20 30
. b
. c
Give the LOWEST possible elevation for
point “c”

33. Where would it be easier to hike?
Why?
B has a gentle slope, or gradient.

34. Gradient Refers to the steepness of the land (slope)
Closer contour lines = steep slopes.
Further contour lines = gradual slopes.
Which side of the hill is the steepest?
WHY? N

35. Contour lines will either
Run off the map or
Close on themselves to create circles

36. Contour lines will NEVER cross and usually do not touch.
(If contour lines touch they represent a very steep gradient, otherwise called a cliff. )

37. Closed contours with hachure marks represent depressions (holes).
Hachure Contours

38. The contour line with the marks, or hachures , has the same elevation as the line before it.
50 Meters

39. River and Streams
When a river or stream crosses a contour line, the contour line bends and points upstream.
upstream
downstream
Upstream is where the river starts, higher elevation.
Downstream is where the river ends, lower elevation.

40. What is the contour interval?
What compass direction is Eagle Mt. located?
What is the elevation at the edge of Wolf Pond?
What is the elevation of point B?
Point C? Point E?

41. What is the distance from B to D? (scrap paper)
Place an “X” on the map where the steepest location would be.
What direction is Deer River flowing? Explain how your know.

42. 8.What is the contour interval of this map?

43. 9. If given the contour interval, can you label the lines?

44. Review What is the contour interval? What is the elevation of point B?
What direction is the creek flowing?

45. Calculating Gradient Gradient (or slope)
The rate of change in values between two points on a field map.
How gentle or steep the land is

46. lines are closer together Gentle slope – lines are farther apart
Steep
Gentle
Steep slope –
lines are closer together
Gentle slope –
lines are farther apart

47. Formula for Calculating Gradient (Formula from the ESRT, pg 1)

48. (First copy the formula from your ESRT)
Gradient examples -
1. A hiker gains 250 meters in altitude by climbing a mountain from the valley. The peak is 5 km from the valley. What is the gradient of the mountain side?
(First copy the formula from your ESRT)

49. Calculate the gradient of the hill :

50. Now try these . . .
3. Two cities are separated by 200 miles. City X has an altitude of 122 meters and City Y has an altitude of 260 meters. Calculate the altitude gradient between the two cites.

51. 4. A map shows two locations A and B. They are 25 kilometers apart
4. A map shows two locations A and B. They are 25 kilometers apart. Location A has an elevation of 535 meters and location B has an elevation of 125 meters. What is the gradient between the two locations?

52. How can a Topographic Profile be Constructed?
There is a mistake on this topographic map. Identify the mistake and explain why it is wrong.

53. View of island from the side. View of island from above.
This would be the topographic PROFILE of the island.
View of island from above.
This would be the topographic MAP of the island.

54. Contour Profile
- The shape you would see if the land were sliced vertically along a line between two points on a topographic map

55. A map, A graph How to draw a topographic profile… First you need
Scrap paper
First you need
A map,
Scrap paper
&
A graph

56. Line your scrap paper up to the correct line on the map.
Step 1 –
Line your scrap paper up to the correct line on the map.

57. Scrap paper
Step 2 –
On your scrap paper, mark off where all the contour lines meet the paper

58. Scrap paper
Step 3 –
Label each tick mark on your scrap paper with the correct elevation from the map 1 2 3 4 5 6 6 6 6 5 4 3 2 1

59. Move your scrap paper to the bottom of the graph
Step 4 –
Move your scrap paper to the bottom of the graph

60. Step 5 –
Go straight up from the first tick mark and place a dot on the graph at the appropriate height.

61. Repeat for each tick mark
Step 6 –
Repeat for each tick mark

62. Connect each dot with a smooth line
Step 7 –
Connect each dot with a smooth line

63. Now you try . . .

64. What is Earth’s Shape and How do we know?
The Earth is NOT a perfect sphere, but it is close!!!!!

65. Equatorial Diameter = 12,757 km
Polar Diameter = 12,714 km
DIFFERENCE OF ONLY 43 km

66. The Earth is ACTUALLY an oblate spheroid
(slightly bulging at the equator)

67. Evidence of Earth’s Shape
Photographs taken from outer space
Sailors noticed that ships slowly disappeared or appeared over the horizon.
Gravity measurements were different depending on where you were on earth.

68. Gravity is the force of attraction between any two objects.
Distance between two objects
Gravitational Force
Mass of objects
Gravitational Force
As mass increases gravity increases
As distance increases gravity decreases

69. Gravity pulls everything to the center of the earth.
Remember . . .
Gravity pulls everything to the center of the earth.

70. The polar radius is only 6,357 km
Because the Earth is an oblate spheroid
There is less distance to the center of the earth from the pole which means there is MORE gravity
(indirect relationship)
The polar radius is only 6,357 km

71. The equatorial radius is 6,371 km
There is more distance between the center of the earth and the equator which means there is LESS gravity
(indirect relationship)
The equatorial radius is 6,371 km

72. To the human eye the Earth appears ROUND.
**The best representation of a true scale model of the Earth is a Ping-Pong Ball.**
To the human eye the Earth appears ROUND.

73. Where are you?
Imagine a single dot on a ping pong ball. How would you describe its location?

74. Latitude and Longitude
The Global Grid
Scientists use two special Earth measurements to describe location.
Latitude and Longitude
** Every location on the earth has its own latitude and longitude **

75. *Important Vocabulary*
Latitude
*Important Vocabulary*
Imaginary lines which run horizontal
Measures distances north and south of the Equator
Range from 0o to 90o

76. *Important Vocabulary*
Longitude
*Important Vocabulary*
Imaginary lines which run vertically through the poles
Measures distances east and west of the Prime Meridian
Ranges from 0o to 180o
* Prime Meridian (0o) and the International Date Line (180o) are the same line *

77. NOW TRY THESE . . . What is the latitude and longitude of . . .
Point A – __________________________
Point B – __________________________
Point C – __________________________
Point D – __________________________
Point E – __________________________

78. Estimate the location of city

79. Estimate the location of each point

80. B = 30OS, 60OW
D = 60ON, 90OE
E = 0, 90OE
C = 30OS, 30OE
A = 60ON, 120OW
F = 30OS, 135OE

81. Calculating Precise Locations
Lines of latitude and longitude are measured in degrees.
To be more precise you can break a degree into minutes and seconds
One degree is divided into 60 minutes (60’)
One minute is divided into 60 seconds (60”)
For example – 63O11’34” N

82. Using degrees and minutes,
Give the latitude and longitude of Mt. Marcy
Give the latitude and longitude of Plattsburgh
Place an X at 44o30’ N and 73o30’ W
** Round to the nearest 15’ **

83. The material in this PPT was adapted from Teresa Lee at Rockville Center Schools