Earth's Dimensions II

Mapping Fields Fields – Any region of _________ or the ____________ that has some measurable value of a given quantity at every point. Examples: ??? space environment

Temperature

Sea level

Magnetic anomalies

Gravity

These field values can be mapped so that they can be easily read.

Isolines – Lines that connect points of _____________ field values on a map. equal

Types of Isolines ____________ - connect points of equal temperature. ____________ - connect points of equal air pressure. ____________ - connect points of equal elevation. ____________ - connect points of equal water depth. isotherms isobars contours isobaths

Types of Isolines Every point on an isoline has exactly the same value. Isolines can never cross one another. Isolines always close to form an irregular circle, but sometimes part of an isoline extends beyond the mapped area, so that you cannot see the entire circle formed. Each consecutive isoline increases by the same amount (contour interval). Adjacent lines typically increase or decrease in value, however under special circumstances adjacent lines may have the same value.

Draw isolines with an interval of 5oC. Starting at 60oC Where is the heat source in the above map? What are the names of the isolines in the above map?

What is the highest elevation on this map? What are the names of the isolines in the above map?

Gradients – The rate of change from place to place within a field map. Calculations The gradient can be calculated in two ways: Gradients can be estimated by observing the closeness of the isolines. The closer together the isolines, the greater the gradient. Gradients can be calculated using the following formula (pg. 1 of your E.S.R.T.)

24oC - 20oC Gradient = 6km Gradient = .67oC/km

Topographic Maps Display _____________ (expressed using contour lines) rivers, buildings and roads. Elevations are based off of ___________________ (m.s.l.) being set at 0. A. Contour lines Connect points ______________ elevations Equal elevation Mean sea level of equal

The shape of the contour lines reflects the shape of the land.

________ lines inform you of elevation and are usually bold Index

1. Contour Intervals The _____________ in elevation between one contour line and another (often expressed, if not it must be calculated) difference

__________ is the term used to express the difference in elevation between the highest and lowest points of area being mapped 2. Determining Slopes of Areas When isolines are close together, the area is __________ Relief steep

3. Rules for determining the Direction of River Flow Examine the changes in Elevation- water flows from regions of ________ elevation to ________ elevation high low

Contour lines form “V’s” when they encounter a river Contour lines form “V’s” when they encounter a river. The “V” always points upstream. (Law of the the V’s) With few exceptions, all rivers eventually flow into the _________ ocean

4. Finding Maximum and Minimum Elevations The maximum elevation on the map is one unit less than the next highest contour line drawn on the map.

760 740 760 780 780 760 760 740 720 700 700 720 740 760 780

740 760 780 780 760 760 760 740 720 700 700 720 740 760 780