Planetary Geology pdf - NASA

Exercise
One
Suggested Correlation of Topics
The Earth, geography, gradation, impact
cratering, earth science introduction,
tectonism, volcanism
Purpose
The objective of this exercise is to show the frequency
and distribution of events on Earth resulting
from the four major geologic processes. In this
exercise, the student will process and analyze a
geologic data set to produce graphic and written
results. Locating event sites will improve world
geography skills.
Materials
Suggested: magazines and newspapers, glue or
tape, paper, colored pens or pencils, straightedge or
ruler, atlas or world almanac (one atlas per student
group). Substitutions: wall-size world map can substitute
for an atlas.
Background
This exercise illustrates the general frequency
and distribution of volcanic, tectonic, gradational,
and impact cratering events. It is important that students
have an introduction to these processes
through lectures, videos, or slides before working
the assignment. Volcanic and tectonic events (volcanic
eruptions and earthquakes) are typically large
in scale and short in duration. That is, each event
often results in great disruption over a large area,
but last only a short time. However, over long periods
of time, these processes can produce large landforms
such as mountains, plains, ocean basins and
islands. Impact cratering is of short duration and
the frequency of impacts is very low compared to a
Exercise One: Geologic Events on Earth
EG-1998-03-109-HQ Activities in Planetary Geology for the Physical and Earth Sciences
3
2.0 hours each part
(with instructor
modification for grade
level)
Geologic Events
on Earth
Instructor Notes
human lifespan. Early in EarthÕs history, impact cratering
was much more common, but now there are
fewer objects in space to act as impactors. Gradation
occurs at all scales from the erosion of mountain
ranges to the grinding of sand grains in streams.
Gradation on Earth occurs on time scales from seconds
to centuries or more.
Teacher Recommendations
Part One of the exercise requires the student to
collect data in the form of pictures and newspaper
articles. This part can be done in several ways: it can
be assigned as a take-home exercise, the instructor
can collect magazines and newspapers to enable
completing the exercise during a single class period,
students can use a library (make photocopies
instead of cutting up papers), or it can be omitted.
Finding pictures that illustrate landforms created by
all four processes can be frustrating. Many magazine
advertisments with landscapes as the background
will be useful. Make sure only one representation
of an individual event is used; for example,
a major earthquake will get extensive coverage
by the mediaÑbut only one picture of that earthquake's
effects should be used. Encourage the students
to explain the types of landforms they select
and help them classify the formation processes.
Impact cratering occurs so infrequently that it is
unlikely to be represented in magazines; however,
pictures of the Moon show craters and it is up to the
instructor to decide if such pictures can be used. It is
recommended that the exercise be limited to the
Earth. Suggested modifications of Part One for different
grade levels are as follows:
Grades KÐ4: Eliminate procedure B; use
procedure D and questions
1, 2, 5, and 6 for class discussion.
Work in groups, completing the
exercise in class.