Thursday 11-13-14

1. Update SN (Journal Check Next Week!)

2. Grade Rock Cycle Lab & Types of Rocks WS3. Topographic Map Notes4. Lake Lackawanna WS

Topographic MapsBy the end of class be able to Interpret a

topographic map

– Identify where the slope is steep or gentle

– The elevation of locations on the map

– Where hilltops, valleys, & rivers are

– Draw a profile of a topographic map

Topographic Maps

• Two dimensional model of the Earth’s surface (represents 3-D world)

Shows surface features of the earth including;• natural features like rivers, lakes and mountains

• manmade features like cities, roads, and bridges.

Contour Lines - represent elevations (height in relationship to sea level.)

Contour Map

“Real World”

Topographic Maps• A Contour Line –

- connects points of EQUAL elevation.- show elevation - and shape of the land

Relief – difference between highest and lowest contour lines on map

• What is the relief of this map?30 mHighest = 30 m

-Lowest = 0 m

Topographic Maps

• Contour Interval –difference in elevation between each line.

MUST be equal value between any 2 lines.

600-500 =

# of lines between =

100/5 = Contour interval = 20 feet

520

540560

580

100

5

Topographic Maps

• Index Contour – Usually every 5th line is printed darker and has an elevation printed on it.

Rules for Contours

1. Contour lines never cross

Rules for Contours2. Contours form closed loops (even if not

shown of the map.) • The innermost circle is the top of the hill.

Rules for Contours3. Contours bend upstream (uphill) when

crossing a stream, forming a “V” or “U” in the map

Rules for Contours

4. The maximum possible elevation for a hill is “1” less than what the next contour “should” be.

The highest possible elevation of the hill is just below the value of the next line that is not shown

5060

70

80

90

239

399

179

A

C

B

Closely Spaced Contours

5. Steeper Slope (Gradient) – contour lines are closer together.

Wide Spaced Contours

6. Gradual/Gentle Slope (Gradient) – contour lines are farther apart.

A

B

Depressions

• Contour lines which show a depression, crater, or sinkhole on a map.

• Shown by dashed lines (hachure marks) on the inside of a contour line

• The elevation of the first depression contour is the same as the lowest regular contour near it.

Rules for ContoursThe lowest possible elevation for a depression is “1” more than what the next contour “should” be.

The lowest possible elevation of a depression is just above the value of the next line that is not shown

50

90 90

80

7060

51

100100

50

Benchmarks

• a location whose exact elevation is known and is noted on a brass or aluminum plate.

• bench marks are shown on maps by an X with the letters BM written next to them.

Gradient

• The slope between any two points on a hill

• Gradient = Change in Elevation

Horizontal Distance

Rise (Y)Run (X)

Gradient

200

Contour Interval = 20 ft

0 2 4 6 8 10

miles

220280

280 ft – 220 ft

60 ft5 mi

= 12 ft/mi

Change in elevation =

= 60 ft

Distance travelled = 5 mi

Change in Elevation

Horizontal Distance

1. Contour interval = 2. Relief =

3. Which hill has a depression at the top of it?

4. The highest mountain is

Color the steepest area red and the gentlest slope green

10m 40

Oak hill

Ash hill

To Do

• Lake Lackawanna WS

• Fill out Planner for the week– Journal Check THURSDAY (or turn it in today for

extra credit!)• Check Trout Brook• Finish Notes• Topographic Map Lab• Start Review (front page only)

Monday 11-18-13

To Do:

• Extra Credit for Journals?• Topographic Map Lab• First page of Review