MyWorld™ Project Template
A World of My Own
Steven Branting, Independent School District #1
Project Description
The Earth has undergone many transformational stages in the so-called Supercontinent Cycle – beginning with
Vaalbara. By the time they begin their study of earth science, most students have heard of Pangaea, the last supercontinent that formed about 300 million years ago.
This lesson explores an adaptation of the reverse of the Supercontinent Cycle – the Wilson Cycle. Formulated by J.
T. Wilson (1908-1993), this cycle describes the periodic opening and closing of ocean basins as the Supercontinent
Cycle progressed.
Background Information
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Sea depths decrease as continents move closer to one another.
Seafloor depth is controlled by the age of the seafloor.
Supercontinents were surrounded by a lot of old seafloor, and sea levels were low.
Dispersed continents (as is the condition today) are surrounded by a lot of young seafloor, and sea levels
are high.
Q.E.D. The older the sea floor the more likely it was to be above sea level.
Subjects
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continental drift
ocean basins
seafloor age
supercontinent
Selected Relevant National Curriculum Standards
Science Content Standard D (Earth and Space Science): Lithospheric plates on the scales of continents and
oceans constantly move at rates of centimeters per year in response to movements in the mantle.
Geography Standard 1: How to use maps and other geographic representations, tools, and technologies to acquire, process, and report information.
Geography Standard 7: The physical processes that shape the patterns of Earth's surface.
GIS Skills/Concept List
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Analyze
Select
Uniform color
Projection
Orthographic
Re-center
Edit (See tutorial for this function.)
New layer
Culminating Outcomes
As a result of this MyWorld™ lesson, the students will be able to:
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create a new configuration of dry land
create extensions of existing geographical features commensurate with the new dry land
formulate hypotheses based on geographical data
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MyWorld™ Project Template
A World of My Own
Steven Branting, Independent School District #1
Suggested Grade Level and Length of Activity
Grade levels: 9
Length of lesson: 1 – 2 class periods (depending on tutorial needs)
Suggested Courses for Use
Earth Science
Learning Objectives
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To isolate geographical regions by single variables
To use creative idea-finding to portray a hypothetical ancient Earth
Student Activity
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Introduce the concept of the Wilson Cycle and how sea floor depth is related to age.
Direct the students in MyWorld™ to the SEA-FLOOR AGE data set and have them add the layer.
Direct the students to ANALYZE and review the SELECT function and how to use the BY VALUE tool.
SELECT sea-floor ages ≥ 250 million years (my) and make the selection a new layer.
In order to visualize the new layer as continents, change the fill color to UNIFORM. The students may
now HIDE the original sea-floor layer (or delete it).
Direct the students to add the LINES OF LATITUDE & LONGITUDE layer.
They may now add layers of their choice. Appropriate layers are RIVERS, LAKES, SURFACE
CURRENTS, GLOBAL WIND PATTERN and WORLD GLACIERS.
Review or instruct the students in the use of the EDIT function to add points, lines and polygons. The
students can then extend rivers, add/delete glaciers, add/delete currents. et. al.
Activity Extensions
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The default PROJECTION will be MILLER CYLINDRICAL. Direct the students to change this to ORTHOGRAPHIC, which is a spherical projection.
Using the RE-CENTER PROJECTION tool (see below), the students may rotate
the planet. The default position places the axis of the Earth at a right angle to the
plane of the Solar System. The lines of latitude are a guide to reset the axis. Using
the Equator as the guide, clicking at a point approximately 23.5oN will set the map to
summer in the Northern Hemisphere, with the student seeing the planet from the
perspective of the Sun. Longitude may be changed using meridians.
Re-center Projection tool
original image
Students may wish to position the Earth in a
unique alignment with reference to the Sun,
thereby opening the activity to multiple
questions about the rotational effects on
ocean currents and prevailing winds.
Bibliography
realigned to 23.5o
The Wilson Cycle. Online at csmres.jmu.edu/geollab/fichter/Wilson/Wilson.html
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