7Contours (isolines)connect measurements in a field of equal value
8REMEMBER: make “loops” or “take it off” and label!
9The air-pressure field map represents a high-pressure system over the central United States. Isobars show the air pressure in millibars (mb).Areas of equal pressure may be found at locationsA and C (3) C and D(2) B and E (4) D and E
10What is a possible elevation, in meters, of point X? (1) 55 (3) 68(2) 57 (4) 70
11The map shows sea-level air pressure in millibars for a portion of the eastern coast of North America.The air pressure recorded at point D was most likely1014 mb (3) 1010 mb(2) 1012 mb (4) 1006 mb
12TOPOGRAPHY – contours of land DistanceLegend(w/ directional)ContourIntervalSea levelSlope(or Gradient)Rivers(& theirdirection)
13What is the elevation of point A on the topographic map? The small map identifies the New York State region shown in the topographic map.What is the elevation of point A on the topographic map?(1) 1,700 ft(2) 1,600 ft(3) 1,650 ft(4) 1,550 ft
14When is it a hill and when is it a hole in the ground? 202030204010HATCHER LINES mean decreasing
15What is the value of Point A if the contour interval is 25 m? How about Point C?60 m (51 – 74 m)
16What is the CONTOUR INTERVAL of this map? The topographic map of an island below measures elevations in meters and has a scale of 1cm = 2 km(1) 40 m(2) 10 m(3) 0 m(4) 20 m
17What is the elevation of Point B? The topographic map of an island below measures elevations in meters and has a scale of 1cm = 2 km(1) 40 m(2) 10 m(3) 0 m(4) 20 m
18A What is the elevation of Point D? (1) 40 m (2) 10 m (3) 0 m (4) 20 m The topographic map of an island below measures elevations in meters and has a scale of 1cm = 2 km(1) 40 m(2) 10 m(3) 0 m(4) 20 mWhich point on this map MAY HAVE an elevation of 73 m?A
19Elevations are in meters. What is the elevation of points:ABC70m20m30mDE10m-10m (between 0m & -20m!)
21Lines are closer together so it is steeper! The topographic map below shows two hills labeled A and B. The tributary streams labeled X and Y have the same volume of water.Lines are closer together so it is steeper!Which statement is best supported by the map?(1) Hill A is higher than hill B.(2) Stream X flows faster than stream Y.(3) Hill B is higher than hill A.(4) Stream Y flows faster than stream X.
26The topographic map below shows a lake and two rivers. In which direction does each of the rivers flow?(1) The Sapphire River and the Garnet River both flow east.(2) The Sapphire River and the Garnet River both flow west.(3) The Sapphire River flows east and the Garnet River flows west.(4) The Sapphire River flows west and the Garnet River flows east.
27In which general direction is the stream flowing? The topographic map below shows part of a stream.In which general direction is the stream flowing?(1) northeast(2) northwest(3) southeast(4) southwest
36Gradient = change in field value/distance = 20 ft/0.5 mi = 40 ft/mi GRADIENT- The change in any value from one location to another (“over a distance”).0 ft10 ft20 ft20 foot elevation change.5 mile distanceGradient = change in field value/distance = 20 ft/0.5 mi = 40 ft/mi
37Gradients are calculated for many things, like: The gradient (or slope) of a hill.The temperature gradient between two states.The snowfall gradient between two cities.Same day in Minneapolis and Miami
38Rate = change in value/time = 20 ft/10 min = 2 ft/min RATE is the change in any value as time passes.10 min time change0 min5 min10 min0 ft10 ft20 ft20 foot elevation changeRate = change in value/time = 20 ft/10 min = 2 ft/min
39Gradient = 0.056 mb/ Km Gradient = Change in field value/ distance The map at left shows pressure measured in mb. The distance between the points is 500 Km. CALCULATE the pressure gradient.Gradient = Change in field value/ distanceGradient = 1004 mb – 976 mb/ 500 Km = 28 mb/ 500 KmGradient = mb/ Km
40Air moves like water.Big gradient = FastSmall gradient = SlowThe STEEPER the AIR hill, the faster the wind moves from HIGH to Low pressure!