Key Concepts of EarthComm
Why Use An Earth System Approach?
Bringing It Together In EarthComm
EarthComm differs from many existing Earth science curricula in
important ways. Four key concepts drove the development of the
instructional design: relevance, community, systems, and inquiry.
The explanations below will help you understand the role of each
concept in EarthComm, how each interacts with the others, and
how the EarthComm approach differs from other approaches to Earth
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Earth science is all about context and relevance. Earth scientists
seek to understand the where, when, and how of a process or event
and to use that understanding to make wise decisions. Earth science
has exceptionally broad scope. After all, everything on Earth
and in space is affected by and related to Earth science.
This broad scope challenges teachers and curriculum developers
to make the Earth science curriculum manageable for students.
For example, volcanoes interact with the atmosphere and living
things in important ways, yet these interactions become obscured
by teaching weather as one topic, volcanism as another topic,
and living things in a completely different course (life science).
The Earth systems science focus of EarthComm enables teachers
to help students form a chain of connections from nearly any Earth
science phenomenon to many other ideas, and eventually back to
the students' immediate world. EarthComm uses such chains of connections
to highlight the relevance of Earth science to the learner.
The traditional solution to teaching Earth science is to subdivide
it into discrete subjects (geology, meteorology, oceanography,
space science, etc.) and topics (rock cycle, volcanoes, ocean
currents, moon phases, seasons, etc.) Unfortunately, disconnecting
the topics from each other and from any specific place and time
undermines the holistic character of Earth science. Traditional
curricula present Earth science as a set of generic ideas that
can be applied in various circumstances. Presenting topics without
reference to place and time often strips Earth science of both
context and personal relevance. Volcanoes become generic objects
divided into broad types, and examples given to illustrate general
principles often ignore the specific setting, effects, and history
of a particular volcano. This is inconsistent with the National
Earth Science Teachers Association (NESTA) position paper, The
Importance of Earth Science Education. The NESTA paper argues
that Earth science is important because students "need only
step outdoors to observe and find relevance in concepts learned
in the Earth Science classroom" and "students who study
Earth Science are better prepared to discuss issues and make informed,
responsible decisions." Similarly, the National Science Education
Standards call for a change in emphasis from learning science
content areas "for their own sake" to learning in ways
that makes science relevant in personal and social perspectives.
The concept of relevance permeates the EarthComm curriculum.
It is made explicit as each chapter is introduced, and it is maintained
through the attention given to the Chapter Challenge. Any EarthComm
chapter can be used to demonstrate this effectively. For example,
in "Volcanoes and Your Community," the first thing the
students read in the chapter is the question, "Can a volcano
that erupts on the other side of the world affect your community?"
The answer, of course, is that it can. In completing the investigations
within the chapter, students determine the kinds of effects that
they might experience. This focuses their attention on the relevance
that apparently distant Earth processes have upon their immediate
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EarthComm addresses Earth science instruction by focusing on communities.
EarthComm is designed to relate directly to the student's neighborhood,
town, state, region, and so on-the student's community taken at
a variety of levels. The idea of a community is first and foremost
a biological concept, and its use in EarthComm demonstrates the
emphasis on crossing traditional disciplinary boundaries. A community
is, in essence, a group of varied living things interacting in
some ways. (In one perspective, biologists might speak of living
things being organized from cells, to tissues, to organs, to organ
systems, to organisms, to populations, and to communities.) In
human terms, we think of communities as involving some form of
deliberate social organization, such as cities and counties, making
it a political and cultural concept, too. The result is that we
can think of varied communities such as neighborhoods, towns,
states, countries, and so on. Earth science phenomena affect communities
in many and varied ways. The social relevance of Earth science
and the role Earth science plays in the design and function of
communities becomes clear through the explicit attention EarthComm
gives this concept.
The idea of community overlaps with the geographic concept of
regions, because living things (biotic factors) are affected by
and affect non-living things (abiotic factors), making the physical
setting important. Ideas such as climate and topography become
important in understanding communities, which brings this into
the Earth sciences. A mountain may have a community of living
things on it, which are affected by both the topography and climate
of the region. At the same time, that community is part of a larger
community, the mountain range, which overlaps with the community
encompassed by the watershed, and so on. The same would be true
in a grassland, desert, or ocean. This demonstrates that it is
possible to conceive the organization of a community at several
levels, such that the idea of what constitutes a community crosses
and extends political boundaries and physical barriers.
Nebraska Surface Cover and Counties
This image demonstrates that communities
can be thought of in many ways, which may overlap with
each other. The various surface coverage types are biological
communities. These overlap with the counties (political
communities), which are also shown on the map.
Communities can themselves be considered systems and subsystems.
Both systems and communities can be taken as units of analysis,
with boundaries that are decided by the purposes of those analyses.
Finally, the overlap between the community concept and the concept
of a region is appropriate and necessary because of the interactions
between and among biotic (living) and abiotic (non-living).
Community in EarthComm is apparent in many activities that make
use of resource materials, such as maps, to describe how Earth
processes affect the students' community. For example, in the
first activity in "Volcanoes and Your Community", students
use a map of volcanoes to begin to get a sense of where volcanoes
are found relative to their community. The notion of various levels
of "community" is important. Do the students answer
this question in terms of their city or town, their county, or
their state? Students' responses will depend on both the prevalence
of volcanoes and the level of "community" being considered.
The question can be raised, too, as to whether political boundaries
are the most important ways to consider community in this case.
It might be more important to think in terms of a geographic region
and how volcanoes affect that region.
Another example of the community concept in EarthComm is the
first activity in "Water Resources And Your Community."
Here the extent of the community is defined by the information
available, which will most often be given by county. Conceiving
of the community as a county has both benefits and limitations.
There are enough data put together to allow meaningful analyses.
Yet, the effect of a drought on different municipalities (which
may or may not be listed separately) may be lost as data are aggregated.
Any particular definition of "community" will have similar
benefits and limitations.
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EarthComm uses a systems metaphor to develop Earth science understandings
- the Earth system is like a living system. In this systems metaphor,
the idea that "everything is connected to everything else"
becomes a central framework for developing the curriculum. This
metaphor differs from a mechanistic metaphor. In a mechanistic
metaphor, nature is seen as a machine, in that large-scale phenomena
can be understood through analysis of smaller parts. So, for example,
students might study a volcano by looking at the lava, the cone,
the magma chamber, and so on, and then bringing that information
together. The classic example of mechanistic thinking is to see
a phenomenon as a clock. If one understands the parts of a clock,
and how they interact, then one can understand the functioning
of the whole machine. A systems approach is more holistic, considering
interactions between subsystems. Separating the subsystems-studying
them in isolation-gives an inaccurate picture of the whole because
the actions of one subsystem actually change the other subsystems
as the activity occurs. While subsystems can be defined, their
ongoing interactions with other subsystems must be constantly
considered. This is the kind of thinking that EarthComm promotes.
Toward that end, Earth science phenomena are considered to be
operating within five major subsystems or "spheres"
that interact with and affect each other. The "Earth Systems"
diagram, which appears inside each Student and Teacher Edition
of EarthComm, represents this way of thinking.
To fully appreciate the systems metaphor, several ideas have
to be understood. Systems have parts and properties that make
them identifiable. Systems also have inputs and outputs of energy
and matter, leading to interactions among those parts, the results
of which are governed by the properties of the system. This means
that systems have feedback networks in which changes in one part
of the system bring about, directly or indirectly, changes in
other parts. The boundaries of a system are, therefore, never
entirely fixed. We may talk about a particular system, such as
a desert ecosystem, for example. But that system may be part of
a larger system, and may be made up of smaller, overlapping systems.
Another way to say this is that every system is made up of other
systems-subsystems-and is itself a part of, or a subsystem of,
a larger more comprehensive system.
Rain forests, which have become familiar to many people through
recent media attention, can be used to provide a suitable example
of an Earth system. In a tropical rain forest, rain is the input,
and water vapor rising from the forest is the output. On average
this feedback loop keeps the rainfall at about the same level
year after year. In the case where a rain forest is burned, there
is a response to that change. This results in a modification of
the feedback loop that results in less water vapor being returned
to the air above the forest, which, in turn, results in fewer
clouds because of less water vapor, which, in turn, means a reduction
Activity two (How Does Your Community Maintain its Water Supply?)
in the Water Resources And Your Community chapter illustrates
the components of a system. In this activity students set up an
apparatus in which hoses allow water to flow from a coffee can
to a soda bottle (filled with sand) and from the bottle into a
pan. The conditions of one part of the system, such as the level
of water in the coffee can, affect the flow rate (output) that
goes to another part of the system (input), which has other conditions
(sand and soil) that affect the flow rate to the pan. Additional
examples are given below and in the "Additional Workshop
Activities" section of this manual.
Identifying Components of A System: Watershed Examples
The properties as well as the inputs and outputs to a system are
easy to identify in some cases, such as with a rain forest. However,
the individual parts of Earth systems are numerous and the connections
are sometimes unclear because we often have incomplete knowledge
of what constitutes a properly functioning natural system. Surface
water systems related to rivers and streams can be used to illustrate
the systems approach to natural environments, with the caveat
that the feedback between many of the parts and processes involved
are not completely understood.
Lancaster County, NE and Associated Watersheds
Characteristic parts and properties
of the system:
Determining the parts and properties of a system depends
upon the extent to which we can define the boundaries
of the system. Once the boundaries are established, we
can begin to collect information about the system. In
the context of a surface water system, some of the key
parts and properties for which data and information would
need to be collected are river flow (discharge), precipitation,
evaporation, overland runoff, transpiration, and groundwater
Boundaries of the system:
One of the most challenging aspects of using a systems
approach is determining the boundaries of the systems.
In the image titled "Lancaster County, NE and Associated
Watersheds," the city of Lincoln, NE resides in Lancaster
County. Its political boundaries overlap parts of four
distinct river basins (identified by numbers), that represent
natural Earth system boundaries related to water. Although
these four river basins can be identified as distinct
hydrologic systems, they are also subsystems of the much
larger Missouri River basin system (the dark area on "Nebraska
Watersheds in the Missouri River Basin & Counties").
It should be apparent that establishing boundaries is
strongly dependent upon what you are interested in. If
you are interested in stream flow in Lincoln, you will
need to know something about the behavior of the hydrologic
basin number 10200203 (Salt Creek). In contrast, an interest
in the water system for Lancaster County requires that
you know the system dynamics for all four river basins.
Nebraska Watersheds in the Missouri River
Basin and Counties
Input and Output:
The property of a river or stream that reflects the change
in inputs and outputs is the river flow. Examples of natural
input include precipitation, overland runoff, and ground
water inflow. Rivers and streams can also lose water (output)
by evaporation and by the loss of surface water to ground
Feedback: An example of feedback
for a surface water system is when the surface water levels
rise, the ground water levels adjacent to the stream rise.
As the stream levels decline with decreasing input, the
ground water stored adjacent to the stream may return
as input back into the stream.
Examples from Nebraska above illustrate systems
in specific locations. Instructions for developing a similar image
for any area in the United States can be found in the "Resources"
section of this manual.
Of the key concepts used in the design of EarthComm,
the systems concept is often least familiar to teachers. Reading
the essay "Why Use An Earth Systems Approach?" will
help you to stress the importance of the concept to workshop participants.
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USE AN EARTH SYSTEMS SCIENCE APPROACH?
In the summer of 1969, when the Apollo astronauts looked back
at the Earth from the Moon, the image of the Earth changed for
all who shared this new vantage point. Seeing the Earth as an
object in space illustrated in a dramatic way the interconnectedness
of the planet's many elements, bringing into perspective the unity
and diversity of our planet. Over the past three decades since
the Apollo missions there have been tremendous advances in our
understanding of the planet Earth. Changes in our understanding
has led Earth scientists to reevaluate the relationships between
the various parts of the Earth - the land, oceans, atmosphere,
and life - which were once considered individually. This change
in perspective has required reinterpreting the relationships between
the various scientific disciplines and their modes of scientific
investigation. These changes are documented in the Bretherton
Report, which was developed by a committee of scientists representing
various government agencies with mandates for Earth science research
(Bretherton, 1988). Through subsequent discussions between scientists
and educators, a new focus and philosophy for Earth science education
has emerged, Earth System Science (Mayer et al.,1992).
Earth system science is an important tool for not only understanding
the complexities, ambiguities, and uncertainties of the processes
that control and shape the planet, but also for understanding
the relationship between humans and the Earth. Using a systems
approach to science education recognizes that the natural and
designed world is complex; large, complicated, and contains parts
that cannot be understood entirely in isolation from each other.
Many types of systems are familiar to us: the solar system, our
system of government, the school system, a car's ignition system,
and the human body system. These systems all contain parts that
are interconnected and function as a whole. Thinking and analyzing
any these systems requires that we know how the parts are related.
We also need to know the input into the system that makes it go,
and the output that may result. The complexity of a system means
that at some level in every system its behavior is predictable,
while at other levels it is not (and may never be). Students can
develop an understanding of the regularities in systems and gain
an appreciation for the role of chance events. Through this understanding
they can develop an understanding of basic laws, theories and
models that explain the world.
As pointed out in a recent summary by Ireton et al. (1996), the
famous geneticist T. Dobzhansky once said, "nothing in biology
makes sense except in the light of evolution." The evolutionary
paradigm has had an extraordinary impact on organizing the thoughts
and ideas related to the understanding of biological processes.
In a similar fashion most aspects of the Earth are explainable
in the context of the Earth systems, operating at various time
scales and over widely variable scales of space.
Another important attribute of Earth System Science is that it
provides a scientific framework for local, national, and international
cooperation because environmental and resource issues transcend
political boundaries. Water availability, climate variability,
and mineral resource development are global natural resources
issues that link Earth resources to their users. Only through
an understanding of resource renewal and consumption rates, and
an assessment of cultural values, can necessary balances be developed
to deal with shortages and protect the system from damaging exploitation
(Ireton et al., 1996). A systems view of the Earth provides an
explanatory power that enhances our ability to understand our
planet and to improve our capacity to use its resources appropriately
to ensure our survivability on Earth.
Bretherton, F.P., 1988. Earth System Science: A closer view,
NASA, Washington, D.C.
Ireton, M.F.W., C.A. Manduca, and D.W. Mogk, 1996. Shaping the
future of undergraduate Earth science education: Innovation and
change using as Earth System Approach. Report of A workshop convened
by the American Geophysical Union in cooperation with the Keck
Geology Consortium and with support from the National Science
Mayer, V., Armstrong, R.E., Barrow, L.H., Brown, S.M., Crowder,
J.N.,Fortner, R.W., Graham, M., Hoyt, W.H., Humphris, S.E., Jax,
D.W., Shay, E.L., and Shropshire, K.L. (1992). The role of planet
Earth in the newcurriculum. Journal of Geological Education, 40
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EarthComm is designed to encourage authentic inquiry. Authentic
inquiry features questions for which the answers are not already
entirely known by the students, teachers, or publishers before
the learning begins. EarthComm establishes the centrality of inquiry
through the "Chapter Challenge". The challenge motivates
students to ask how the Earth science ideas that are being learned
relate to the specific communities they are considering.
Inquiry is central to advancing personal and collective scientific
knowledge. EarthComm supports this inquiry approach with a variety
of activities in each chapter. Some are open-ended, some place
the students in the position of interpreting data, some help to
illustrate phenomena so that students can assess the impact the
phenomena might have on their communities-but all support the
emphasis on inquiry-based learning.
In considering how to teach using inquiry, it helps to understand
that scientific inquiry is not a specific set of steps that can
be used to grind out new knowledge. The process of scientific
inquiry is often presented as a single "scientific method"
to students, looking something like the diagram below:
This diagram can only serve as a model of the practice of science,
and will always leave out many possibilities. For example, unexpected
results can lead to new problems as well as contribute ideas about
problems under study. Aspects of scientific practice, like the
importance of communicating with other scientists, are often left
off of such diagrams, too. In that there are many such diagrams
of "The Scientific Method" that may be familiar to teachers,
it is not worthwhile to spend time discussing the particular differences
between one depiction and another. The general ideas about these
representations remain the same. While models of scientific inquiry
are worthwhile, they have to be understood for the limitations
as well as their benefits. As noted in Science for All Americans
Scientific inquiry is not easily described apart from the
context of particular investigations. There simply is no fixed
set of steps that scientists always follow, no one path that
leads them unerringly to scientific knowledge. (P.4)
Scientific inquiry is a multifaceted activity that involves many
skills and a healthy dose of creativity. Observation, question
posing, and other skills are important to scientists, but do not
occur in any pre-determined order in an investigation. The reasoning
used to gather information and develop and test a hypothesis is
more important than any particular procedure, and reasoning is
also where creativity often takes a central role.
Science educators may disagree about the exact set of skills
used in inquiry, how the process of inquiry is broken into steps,
and what constitutes an "experiment" rather than an
"activity". The list given below for Science A Process
Approach (an NSF-funded curriculum project developed in the 1960's)
is one of many such lists. The list provided in the National Standards
(NRC, 1996) is part of the matrix of standards addressed in EarthComm
(see "Science as Inquiry" in the matrix on the next
Inquiry in science education is related to "hands on science".
Science educators recognize how students benefit from "hands-on
science" (activities that involve students in directly manipulating
non-text materials). These activities allow students to see scientific
principles in action, which helps students to gain experience
with processes that may be difficult to comprehend solely through
reading. Hands-on activities also motivate students. Students
enjoy working with various supplies used in hands-on activities
and seeing the results, which often surprise them.
The structure of hands-on activities often mimics an inductive
investigation. Some activities are authentically inquiry-based;
others, however, lose the essential character of inquiry-asking
questions and finding ways to answer them based on evidence. This
happens when students or the teacher already know the outcome
of an activity. Thus, although hands-on activities offer many
benefits in science education, they do not always equate with
Outcomes of inquiry that go beyond simply experiencing the results
of an activity are those that enable students to see a scientific
idea in action. The list of inquiry-based outcomes shown below
includes ideas about how students relate to science and how they
use information. The list makes it easy to imagine the kinds of
activities that students need to be doing to be taking part in
authentic inquiry. EarthComm highlights these outcomes by focusing
student activity and learning on creating a product, usually informational
or persuasive, which uses the information that students gather
in the activities and applies it to their communities.
There are several barriers to teaching through authentic inquiry.
These barriers can be divided into instructional and administrative
issues. Administrative issues like rigid time schedules that don't
allow for necessary revisions of investigations must be dealt
with on a local level. Instructional issues include a lack of
information regarding how the phenomena relate to specific contexts,
inaccessible primary source material, and insecurities regarding
the direction in which students might take open-ended investigations.
EarthComm has addressed each of these barriers. Consistent with
the National Standards, EarthComm promotes inquiry in science
instruction. Students actively investigate systems, natural phenomena,
and how the phenomena affect their community. The EarthComm lessons
are organized to encourage students to develop their own explanations
and reasoned arguments based on evidence.
While many science educators understand the nature of inquiry,
this aspect of EarthComm may offer the most practical difficulty
for educators. It is tempting to say that the difficulty results
from logistical problems like obtaining, storing, and maintaining
equipment. Although those are important concerns, many effective
ways of addressing them have been developed and successfully implemented.
Nor can it be said that inquiry-based instruction might present
problems because it is so new. Many teachers have entered the
profession since the time the emphasis on inquiry first began.
In fact, even though the concepts of systems and community are
relatively new to Earth science education, they may be easier
to implement than inquiry. Past efforts in inquiry-based instruction
can detract from the intent current efforts.
While hands-on inquiry is part of many activities in EarthComm,
it stands out as ideas are applied to the students' community.
Following each activity, a section called "Preparing for
the Chapter Challenge" encourages students to consider the
local implications of what they have learned. Because the implications
differ for each location where EarthComm is taught, there can
be no entirely pre-existing answers, which adds to the authenticity
of the inquiry.
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IT TOGETHER IN EARTHCOMM
In EarthComm, the focus on relevance-of working with ideas as
they relate to communities at various levels-raises the importance
of inquiry-based instruction. Direct instruction, teaching by
telling students information, can work against this focus on relevance
and inquiry. It is unlikely that students will recognize the relevance
of Earth science concepts if presented as already fully developed,
already organized, and with their meaning already carefully determined
and described. Simply exposing students to ideas does nothing
to actively facilitate the students' understanding of how those
ideas relate to their personal lives, or the everyday and long-term
workings of their communities. EarthComm makes community relevance
the focus of instruction by making it the focus of the inquiry
that the students undertake in each chapter. The "Chapter
Challenge" calls on the students to engage with the topics,
to investigate how those topics affect their lives and communities,
and to express their conclusions to others through some concrete
product. In this way the concepts of relevance, community, systems,
and inquiry-based teaching support each other, and provide focused
and motivating opportunities for learning.
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AGI's professional development programs for teachers are supported
by generous contributions from corporate contributors of the American Geosciences Institute Foundation, the American
Association of Petroleum Geologists Foundation, and ChevronTexaco.