Plate Tectonics and Topographic maps

How do the plates move? Convection currents, in the plastic like layer of the mantle of the earth, constantly churn in a circular motion, the hot magma rises, cools, then falls back down to the core. This movement causes tectonic plates to meet at plate boundaries.

Plate Boundaries Convergent- tectonic plates collide or combine Divergent- tectonic plates move apart from each other Transform/Transverse- tectonic plates slide/grind past each other

Continental – Oceanic Dense oceanic plate subducts under less dense continental plate, which creates a subduction zone. This can create ocean trenches, and very violent subduction volcanoes such as Mt. St. Helens. Ring of fire- Pacific Plate Convergent Boundaries Continental-Continental Fold mountains, mountain ranges. EX: The Himalayas Oceanic- Oceanic Creates deep trenches Sometimes volcanoes can be formed

Divergent boundaries Continental- Continental Forms Rift Valleys, sometimes magma can fill in the rift The Great African Rift Oceanic- Oceanic Forms mid ocean ridges Older crust is found further away from the ridge, while younger crust is found just near the ridge. Mid-Atlantic Ridge

Transform boundaries Strike Slip Faults Fault lines The San Andreas Fault line- North American Plate and the Pacific Plate

Ring of fire Caused along most of the boundaries formed by the pacific plate and various other plates Many volcanoes form here, hence the name ring of fire Earthquakes and mountains form here as well.

Topographic maps Topographic maps are used to show 3D geographical features on a 2D map. This includes elevations, inclines, declines, rivers, and valleys.

Contour lines Contour lines are used to show elevation of a geographical area according to how close together or far apart they are drawn. Close together lines are steeper areas of land, while further apart contour lines indicate flatter land areas.

Relief Low Relief- land area that is more flat than steep, such as grassland or plains. High Relief- land area that is more steep than flat, such as mountainous areas, or vast inclines.

1.What moves Earth’s Tectonic Plates? A. convulsion currents B. concentric currents C. convection currents D. magic

2. What layer of Earth is under the crust and upper mantle? A. lithosphere B. mesosphere C. asthenosphere D. troposphere

3. New crust is being made at the Mid-Atlantic Ridge. What happens on the other side of the plates? A. The total amount of crust is always increasing B. Mountains just keep getting bigger. C. The total amount of crust is always decreasing. D. Crust is destroyed at subduction zones.

4. The Ring of Fire is named that because it has so many: A. earthquakes and tornadoes B. mountains and valleys C. volcanoes and earthquakes D. volcanoes and hurricanes

5. What type of boundary is the San Andreas fault? A. divergent B. convergent C. transform D. transparent

6.If the contour lines in an area on a topographic map are close together, what does this indicate? A. the land is steep B. the land has a low slope C. the contour interval is high D. the contour interval is low

7. Topographic maps of which areas generally have larger contour intervals on topographic maps? A. areas with high relief B. areas with more water features C. areas with more human-made features D. near the summit of a mountain

8. Which of the following is least likely to be on the legend of a topographic map? A. scale B. water features C. animal feeding areas D. human-made features

9. What is one thing satellite images are used for monitoring? A. weather balloons B. global patterns of volcanic ash C. birds D. Animals habitats

10. Folded mountains are created by what force? A. convection B. compression C. tension D. friction

Key 1.C 2.C 3.D 4.C 5.C 6.A 7.A 8.C 9.B 10.B