Lab 01: Earth Systems and Earth’s Four Spheres
Making observations of the landscape is an essential component of Geography. This lab will connect you with the geography of the place in which you live. It is an important skill to describe the natural and anthropogenic features of the landscape, and to consider ways in which a change in one aspect may affect all others. It is only as we seek to understand the interconnectedness of Earth spheres and systems that we will find appropriate solutions to our global environmental issues.
After completion of this lab, you will be able to:
- Orient a map to the landscape;
- Draw a simple sketch map;
- Name and identify natural and built features of the local area;
- Observe and record characteristics of the local atmosphere, lithosphere, hydrosphere, and biosphere;
- Describe the anthropogenic impacts on natural systems;
- Examine examples of positive and negative feedback systems at work; and
- Describe potential changes to natural systems.
To complete this lab, students need background information on geographic approaches and themes, drawing sketch maps, Earth spheres, and systems theory. These topics are typically covered in Chapter One of first-year geography textbooks. Use the textbook’s index to find these topics, then read about them.
Geographic Approaches and Themes
Textbooks may vary on the exact terms used to describe geographic approaches and themes. Central to the study of physical geography is the approach of a spatial analysis, and the concept that there is a natural world that is impacted by human activities. Humans are in turn influenced by natural systems. Monitoring, striving to understand, and mitigating environmental change is a key aspect of physical geography
Our natural environment can be broken down into four spheres. Keep in mind, however, that these sub-divisions are artificial and that in reality there is constant and considerable interaction and overlap between all spheres.
The hydrosphere consists of water in all its forms (solid, liquid, and gas; fresh and salty), as it appears at or near the Earth’s surface. It includes oceans, rivers, lakes, springs, glaciers and ice caps, shallow groundwater, and atmospheric water vapor.
The atmosphere is a mixture of gasses, forming an envelope around the Earth, and held in place by gravity. Up to an altitude of about 80km the composition is nearly constant at 21% oxygen, 78% nitrogen, and traces of argon, xenon and krypton. In addition, there are variable quantities of carbon dioxide, methane, and water. We are most interested in the troposphere, the lower 18km where weather and climate are determined.
The lithosphere is the upper mantle and the Earth’s crust that create landscape features such as mountains and valleys.
The biosphere includes all living things and their physical environment. It extends from several kilometers below the sea floor to about 8km above the surface and requires the presence of water as well as an energy source of some kind. The range for individual species within the biosphere can change as local conditions within the other spheres change. (Christopherson, R.W. & Byrne ML).
Systems Theory and Feedback Loops
A system is any ordered, interrelated set of things and their attributes, linked by flows of energy and matter. A system is in some way distinct from its surrounding environment; for example a watershed is an identifiable system. Systems are described as open if they are receiving inputs and providing outputs of matter and energy. A system is described as closed if it receives inputs and outputs of energy but not matter. Very few systems are truly closed
If a system is steady, it will fluctuate around conditions which are considered normal for that system. For example, with seasonal variability in a stream, discharge may be high during snow melt, but the water levels will drop once that snow has disappeared, and temperatures rise. This correction or return to normal conditions is referred to as a negative feedback loop. If a system moves out of its steady state, or out of equilibrium and a system continues in that direct then the system is said to be in a positive feedback loop. Many global changes that are occurring as a result of climate change, such as the melting of polar icecaps are in positive feedback loops. Eventually the system will find a new equilibrium.
In this introductory geography lab you will become familiar with the local geography and begin to think like a geographer. You may print the lab exercise and complete it on paper in the field, but the final submission should be typed.
Start by opening Google Maps on your phone or computer. Zoom into the area you will viewing in the field. If you are on a desktop computer you will need to print the map, otherwise refer to the map on your phone or tablet while in the field. It will be helpful to watch the following two minute video:
Bring a clipboard, some blank pieces of paper, a pencil, and a digital or printed copy of the lab exercises. Ahead of your departure read through the Lab Exercises and follow your instructor and institution’s recommendations for safe field procedures. Head out into the field to a safe and easily accessible viewpoint (a hillside, bridge, tall building – your instructor can suggest locations) where you can make and record observations of the landscape.
This lab consists of four exercises and you should be able to complete the lab within two hours. You will need to allow for travel time (walking, biking, public transit, driving etc.) to your field site. The field sketch should take approximately half an hour to complete. The rest of the lab will take the remaining time.
Once you have arrived at your field location you will need to orient your map to your location. Open the map on your phone or tablet or pull out the paper copy of the map.
- First, find your location on the map. If you are on Google Maps this is easily done by pressing the small arrow. Zoom in or out to view the map at a scale that reflects what you can see in the landscape.
- Find features on the map that are evident in the surrounding terrain.
- Turn your map (phone) so that the features in front of your view match the features on your map.
- Assuming north is at the top of your map, determine where north is relative to the direction you are facing.
You may be new to this area of British Columbia or you may have lived here your entire life; regardless, you can build your geographic literacy by being able to name and describe the natural and built features of the surrounding landscape.
You do not need to be an artist to complete a field sketch. The best maps are simple with clearly define lines. Find a suitable viewpoint and spend a few moments observing the landscape (see Figure 1.1). Decide on an area that is appropriate to capture in your sketch. It may be a valley bottom with a river running through it or you could narrow in on a smaller area such as your neighbourhood. The sketch will be from above, a bird’s eye view or map view.
The following are important elements to consider as you draw your map. Refer to Figure 1.3 for a sample sketch map.
- Clearly define the boundaries or edges of your map. Mountains, watersheds, shorelines, roads and railways tend to define our vision and are commonly used as edges. The scale of a sketch is determined by the objects in view and the amount of detail required to be shown. Determine how much area you want to draw. From the viewpoint, represented by Figure 1.2 the area in the rectangle was selected for the sketch map.
- Identify pathways or routes which dissect your selected area such as roads, trails, rivers, streams, power lines. We generally experience our surroundings as we move along these routes. Show direction of travel of rivers with an arrow.
- Identify any significant junction points where important pathways come together. The confluence (meeting) of two streams, the intersection of two roads.
- Identify polygons or districts. These are small areas with a common feature, such as urban areas, single family housing, parks, open fields, changes in vegetation type (from leaf bearing/deciduous to needle bearing/coniferous) etc.
- Identify any significant landmarks that are distinctive because of their height, shape, or historical significance. An example might be a well-known mountain peak, a waterfall, a statue, a mall. (Lynch,1960)
- On your map you must also include a title/location, date, your name, a legend (symbols which indicate vegetation type, mountains, urban areas), north arrow, and approximate scale.
- Scan or photograph your field sketch and submit it.
- Take a selfie photograph at the field site holding your student card or other photo ID and submit it.
- Using the map, local knowledge, and if needed, a computer search; identify local characteristics of the hydrosphere, atmosphere, lithosphere and biosphere in the table below (in Worksheets). Your answers may pertain to the area in general and need not be restricted to the area represented by your field map.
|Sphere||Identify 2-4 features in the landscape for each sphere and describe (e.g. size, location, significance)||Anthropogenic Impacts (describe ways in which the sphere has been altered by humans – be specific)|
|Hydrosphere – Name oceans, streams, lakes, wetlands, bogs and provide of description of relative size and significance in the landscape.)|
|Atmosphere – Describe characteristics of local weather and climate (consider seasons, temperature range, climatic changes)|
|Lithosphere – Name geomorphological features (mountains, valleys, plateaus, terraces, floodplains)||
|Biosphere – Describe vegetation types (coniferous*,deciduous**, grasslands, shrubs, mosses) spatial extent and distribution (dense, sparse, regular, irregular), aspect (direction slope faces)|
*Coniferous tree is a needle leaf tree that bears cones
**Deciduous tree is a leaf bearing tree that sheds its leaves seasonally
We are living through an era of rapid environmental change. Consider ways in which a change in one sphere may affect all others (point form is acceptable).
- Specific to the landscape you are observing, describe how a catastrophic (very large) wildfire might impact each sphere. Consider both the immediate impacts and long-term impacts (4-7 impacts). Identify a specific change created by the fire and discuss whether it is a positive or negative feedback loop.
- Depending on whether hydrological dams exist in your area, consider how either putting in a dam or removing dams (if they already exist) might impact local spheres and alter the entire watershed system. (4-7 impacts)
- Describe how a pandemic lockdown has impacted human activities and how it may have altered Earth’s spheres in your area or on a global scale. (2 examples of how it has altered)
- Now that you have completed a field sketch, describe how this process differs from simply printing a map or taking a photograph. (1-2 sentences)
- What information could be conveyed on a field sketch that is not available on photographs, remotely sensed images or a map?
- Describe “the sense of place” this area has for you; this will be different for each student depending on your life experiences. For example, are you connected to this landscape? Are you concerned or optimistic about how the landscape is changing? Try to be honest here, do not write what you think your instructor is looking for. (3-5 sentences)
Blank Sketch Map
Christopherson, R.W. & Byrne ML. 2016. Geosystems, An Introduction to Physical Geography, Canadian 4th Edition, Toronto: Prentice-Hall Inc.
Lynch, Kevin. 1960. The Image of the City. MIT Press.
- Figure 1.1 Viewpoint © Allison Lutz
- Figure 1.2 Looking South Over Castlegar Valley From Brilliant Terraces © Allison Lutz
- Figure 1.3 Sketch map of rectangle area from Figure 1.2 © Allison Lutz