1. Ms. Susinno FIELD MAPPING AND ISOLINES

2. A field map shows a region with a measurable quantity at every location.

3. ISOLINES An isoline is a line connecting points of equal value.

4. EXAMPLES OF ISOLINES : Isotherms: points of equal temperature Isobar: points of equal barometric (air) pressure Contour: 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…

5. EXAMPLES OF ISOBARS :

6. EXAMPLES OF ISOTHERMS

7. EXAMPLES OF CONTOUR LINES on topographic maps

8. EXAMPLES OF ISOBATHS

9. EXAMPLES OF ISOPACH MAP MEASURING GLACIER THICKNESS

10. RULES FOR DRAWING ISOLINES: Isolines connect points of equal value. The line must go through the center of the dot. You MUST use pencil! 15 5 5 10

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

12. 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!

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

14. Isolines usually are parallel ish. (They have a parallel trend.)

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

16. LABELING! Isolines are always labeled! Or at the end of the line where they reach the edge of the field or map Either way is acceptable

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

18. GRADIENT Gradient shows how quickly the value changes from one point to another. Another world for gradient is SLOPE

19. A steep (high) gradient changes quickly and the isolines are close together. A gentle (low) gradient changes slowly and the lines are far apart. Steep area Gentle area

23. AUG. ‘05

28. THE END!