Continental Drift Theory
What is Continental Drift Theory?
It was an explanation of continents slowly moving and changing their positions relative to one another.
What is Plate Tectonic Theory?
States the Earth’s crust is broken into sections called plates which are pushed by convection currents in the Earth’s mantle.
What are the two different types of plates?
Oceanic and Continental
What do topographic maps show?
Elevation
What is Weathering?
Process by which exposed rock and other surfaces are broken down
Who proposed Continental Drift Theory?
Alfred Wegner
How does Plate Tectonic Theory relate to Continental Drift Theory?
Plate Tectonics Theory finally explained “HOW” continents moved. This was the missing piece to the Continental Drift Theory.
How do Oceanic crust and Continental crust differ from each other?
Oceanic Crust: thinner and more dense
Continental Crust: thicker and less dense
What are Contour Intervals?
The difference in elevation between any two contour lines on a topographic map.
What is Erosion?
Process by which weathered material is moved by wind, water, or ice
What is the name of the supercontinent?
Pangaea
Who proposed Plate Tectonic Theory? (hint: not Alfred Wegener)
Harry Hess
Name the Plate Boundary:
Plates that collide together
Results in volcanoes and mountain chains, and underwater trench
Convergent
What are Contour Lines?
Map symbol that show shape and/or change in elevation on a topographic map
What is Deposition?
Process by which weathered and eroded material is deposited by wind, water, or ice
Why was the Continental Drift theory rejected?
There was no evidence for "HOW" the continents were moving.
What is Sea-Floor Spreading? AND how is it related to plate tectonics?
Sometime after World War II, the U.S. Navy started on a project to study and learn about sea-floor spreading (which occurs when the seafloor spreads apart along both sides of a mid-ocean ridge as new oceanic crust is added).
Name the plate boundary:
Plates that divide apart
Results in ridges and canyons, and seafloor spreading
Divergent
How can you tell whether the slope is steep or gradual on a topographic map?
Widely spaced = gradual
Closely spaced = steep
What are FOUR of the eight examples of erosional features?
Canyons
Deltas
Mountains
Rivers
Islands
Valleys
Coastlines
Sand Dunes
What are TWO of the four pieces of evidence that Wegener used to prove his theory?
Fossil evidence
Continental fit
Glacial evidence
Landforms and rock layers
What are TWO of the four pieces of evidence that further support Plate Tectonic Theory?
Magnetic Striping and Reversal
Correlation of Fossil Data
Seismic Zones and Plate Boundaries
Earthquakes and Volcanic Activity
Location of Mountain Ridges
Name the plate boundary:
Plates that slide past one another
Results in earthquakes
Transform
What symbol(s) indicate there is a river, and how can you tell which way it's flowing?
Contour lines crossing a valley or stream are V or U shaped
The closed end of the V or U points uphill
The open end of the V or U points downhill and indicates the water flow
What are THREE of the six factors that may affect how land and erosional features are reshaped?
Presence or absence of plants that hold soil in place
Presence or absence of flowing water
Presence or absence of waves
Direction of ocean currents
Shape of the land or erosional feature causing specific paths of resistance or flow
Change of water flow causing deposition where streams meet large bodies of water