Earth FieldsFields: Regions of space where there are measurable quantities of a given property at every point.I solines: connect points of equal value.

-Diff erent types of isolines: I sotherms: connect points of equal temperature

I sobars: connect points of equal air pressureContour lines: connect points of equal elevationRules for I solines:

-Lines can’t end in the middle of the map and must extend to the edge of the map or f orm a continuous loop

-Each line must connect an equal value and must be in sequence

-Lines cannot cross each other

Isolines: contour lines on an elevation mapIsotherms: contour lines on a temperature mapIsobars: contour lines on an air pressure map

CONTOUR LINES- LINES THAT CONNECT POINTS

OF EQUAL ELEVATION

CONTOUR I NTERVAL

THE DI FFERECE I N ELEVATI ON BETWEEN TWO CONTOUR LI NES

WHAT I S THE CONTOUR I NTERVAL OF THI S MAP?

RIVER AND STREAM FLOW

THE “V” BEND POINTS UPSTREAM.

THE STREAM FLOWS OUT OF THE WIDE END OF THE “V” BEND.

WHAT DIRECTION IS THE STREAM FLOWING?North

South

West East

GRADIENT: The rate of change in field values between two points in a field.

Gradient= Change in field value Distance

Quick (steep) change in elevation: closer lines

Slow (gradual) change in elevation: wider lines

ESRT formula

SAMPLE GRADIENT PROBLEM: -Calculate the average slope of a mountain trail from the 980-meter contour line to the 480-meter contour. The distance between these two elevation lines measures 4 Kilometers.

Gradient= change in field value distance

difference in elevation (m)distance between the points (km)

1) 980m – 480m =

4km

500m =

4km125m/km

Close lines

Wide lines

Profile:A cross-sectional view that shows the changes in elevation of the land from a side view.

What is the topography of this profile?

(the shape of this profile is a valley)

How do you create a

topographic profile?:Line the edge of a blank sheet

of paper along the profile line A to A’. Where each contour line touches the paper , make a tick

mark and label it with the appropriate elevation. Then

transfer the tick marks onto the bottom of the grid paper as

shown, then plot each elevation directly above on the grid as shown. Connect each dot to

show the profile of line A – A’.

LATITUDELATITUDE – measured NORTH or SOUTH of the Equator (horizontal imaginary lines)

LONGITUDE – measured EAST or WEST of the Prime Meridian (vertical imaginary lines)

Earth