Transcript Unit

TEK 8.9
Earth and Space
The student knows that natural
events can impact Earth
systems.
The student is expected to:
8.9 A) Describe the historical development
of evidence that supports plate tectonic
theory.
8.9 B) Relate plate tectonics to the
formation of crustal features.
8.9 C) Interpret topographic maps and
satellite views to identify land and
erosional features and predict how these
features may be reshaped by
weathering.
8.9 Vocabulary
Continental Drift
Pangaea
Plate Tectonics
Mountain Building
Volcano
Erosion
Lithosphere
Seafloor spreading
Divergent plate boundary
Trench
Topography
Weathering
Mid-Ocean Ridge
Topographic map
Asthenosphere
Convergent plate
boundary
Transform boundary
Science Starters…Watch This!
The Himalayas
The Ring of Fire
Tsunami
San Francisco Earthquake
Discussion Questions
These clips are all related to each
other. The clips showed a volcano, an
earthquake, a mountain range and a
tsunami.
• What caused these events to occur?
• How are these things connected?
Discussion Questions
• What do you think is meant by the term
“continental drift” ?
• What do you know about it?
• How does it relate to the clips you saw?
The Theory of Continental Drift
-proposed by Alfred Wegner
1912
-states that all the continents
were once connected in a
single, large land mass
-broke apart 200 million years
ago and drifted slowly to their
current positions
-moving 1-10cm per year
Pangaea
• Large ancient land mass that was
composed of all the continents joined
together.
• Greek meaning “all land”
Pangaea
Evidence of Continental Drift
• Pieces of a Puzzle
• Fossil Record (similar fossils found on
different continents)
• Rock Type and Structure(similar rocks found
on different continents)
• Climate (fossils of plants and animals not
suited for current climate of continent)
Pieces of a Puzzle
Fossil (plant/animal) Record
Rock Type and Structure
Climate
Pangaea
The Theory of Plate Tectonics
-proposed by Harry Hess in
1960’s
-describes and explains the
way that continents separated
into today’s land masses from
Pangaea (one large ancestral
land mass).
Lithosphere
-the outermost layer of the Earth’s surface,
which is rocky and solid.
-includes the crust and the rigid part of the
upper mantle.
-Includes the tectonic plates that move on
semi liquid mantle
**Asthenosphere**
Scientists believe that
convection currents within
the asthenosphere are
responsible for the
movement of the plates that
form the Earth's crust.
Lithospheric Plates
Watch This
Continental Drift
Bill Nye Layers of the Earth
Plate Boundaries
and Land Formations
Divergent Boundary
• “Di-”meaning two
• Boundaries in which plates move apart
• Results in a Rift Valley or Mid Ocean Ridge
Seafloor Spreading
-Theory proposed by
Harry Hess 1960
-States that new
seafloor is formed
when magma is
forced upward toward
the surface at a midocean ridge.
– Divergent
boundaries
Seafloor Spreading
Mid Ocean Ridge
-an underwater volcanic mountain range
-typically has a valley known as a rift running
along its spine
Mid Ocean Ridge
Mid Ocean Ridge
Convergent Boundary
-“con-” meaning together
-Boundaries that come together
-results in mountain building
Convergent Boundary
(subduction)
-the process in which one lithospheric plate
slides under another
-can result in volcanoes and a trench.
Transform Boundary
-Boundaries run transversely to each other.
– Slide past each other
-Creates fault lines
– Origin of earthquakes
Transform Boundary
Hayward Fault Line
Berkely, California
University of California
Memorial Stadium
Interpreting Topographic Maps
Topographic Map
A topographical map is one that shows the
physical features of the land. Besides just
showing landforms such as mountains and
rivers, the map also shows the elevation
changes of the land.
Elevation is shown using contour lines.
Topographic Map
Contour line (contour)
-connects points of the same elevation
(height above sea level).
-closed contours indicate hills.
Contour Lines
Contour interval
-difference in the elevation between any two
contour lines on a topographic map
Contour Interval
Slope
Contour lines
spaced far apart
Shallow slope
Contour lines
spaced close
together
Steep slope
Contour lines
spaced evenly
Constant slope
Index contour
- a contour line that is darker than nearby
lines and has its elevation labeled.
Index Contours
Valleys and Ridges
• Valleys, including rivers, will show as
v-shaped lines pointing in the direction of
higher elevation
Ridges, including hill tops and mountain
ranges, will show as v-shaped lines pointing
in the direction of lower elevation.
Topographic Map Features
Valley
Ridge
Key
--- road
Topographic Map
Should also include
-North Arrow (shows direction)
-Scale (show size)
-Key or legend (showing certain land
features or points)
Topographic Map Features
Key
--- road
What is Topography?
Watch this!
Cross Section
Heading
1/11/13
Science 8-pd
Cross Section
Heading
1/11/13
Science 8-pd
Topographic Lab Map
Requirements
Include and Label
-Color by elevation
ROYGBV R-highest
-Contour Index ( at least 1)
-Contour lines
-steep slope
-shallow slope
-label any rivers/valleys and
draw arrows showing
direction of water flow and
where delta can be found
Must include
-bar scale
-North arrow
-Identify the contour
interval