Joy Branlund: How Humans' Dependence on Earth's Mineral Resources meets a community college's general-education goals, at Southwestern Illinois College

In this course, students will learn how and why Earth is the way it is, and why humans should care. A systems-based approach to Earth Science will be utilized which incorporates components of geology (such as the rock cycle and plate tectonics), meteorology (including winds and weather), the hydrosphere (water in the geosphere, atmosphere, and oceans), astronomy (the Sun and Earth's place in space), and climatology. Students in ES101 will use the tools of science to find patterns in nature, which is useful when considering how humans interact with and are affected by our natural world. Students will analyze climate change, our need and use of natural resources (possibly including water, mineral, and energy resources), and causes and impacts of natural hazards (possibly including flooding, earthquakes, volcanoes, and severe storms).

Course Goals:

Apply knowledge of science and scientific methods.

Science is both a process and a product. Science attempts to explain the natural world using theories, which are based on (and judged according to) experience (observation and fact). Discoveries in modern science usually result from the work of many scientists, and science has several checks and balances, such as peer-review, to confirm and validate results. The results, no matter how robust, are considered tentative, as science often changes (although always progressing) in light of new observations.

Measure properties of matter; manipulate measurements and convert measurement units.

Measurements are integral in describing matter. Material properties, such as temperature, volume, mass and density, are integral in understanding several Earth phenomena. Students should be able to measure these properties. In addition, students should be familiar with the metric system and be able to make basic conversions of measurement units. An understanding of other concepts, such as gravity (force) and pressure, also explain different Earth processes and properties.

Adeptly use and interpret maps, including contour maps.

Earth processes are often place specific, which explains why maps are a prevalent way of displaying data in Earth sciences. Students should be able to locate places on Earth and understand coordinate systems (latitude and longitude) used to do so. Students must navigate a map, using direction, scale, and legends appropriately. Students must read absolute values displayed in contour maps, as well as interpret gradients. Finally, students should be able to use maps to understand/interpret Earth phenomena, such as plate boundaries and weather.

Use Earth science knowledge to explain natural hazards.

Several natural processes occurring in the geosphere, hydrosphere, and atmosphere become natural hazards when they affect people. These processes happen all the time but vary in severity. Science can explain where and why these natural hazards happen but not necessarily when. Although scientific knowledge may not be able to prevent natural hazards, it can be used to mitigate damage and loss of life.

Apply knowledge of Earth's interior and the plate tectonic theory to explain observations of Earth's surface and geologic phenomenon.

Energy within Earth drives the plate tectonic cycle. Convection of the solid mantle moves rigid lithospheric plates around Earth's surface. The interaction of plates causes earthquakes, volcanoes, and mountain building. We expect these things (earthquakes, volcanoes, and mountains) only at plate boundaries, which explains why they happen mostly in certain places. Types of geologic phenomenon can be explained based on relative motion of plates and the types of crust (oceanic or continental) at each plate boundary. Plate tectonics is a great example of a scientific theory, and therefore explains several observations made in geology.

Infer past processes from the mineral composition and texture of rocks, and explain how one rock can change to another using the rock cycle.

Earth materials (rocks) transform one to another through a series of processes, and these materials and processes define the rock cycle. The rock cycle is a conceptual model, placing all rocks into one of three groups. Like all conceptual models, the rock cycle is not perfect. But the model simplifies nature in order to enable understanding. The processes of the rock cycle have been working continually through geologic time, but not in all places at all times, as plate tectonics drives some parts of the rock cycle. Almost all rocks are made of minerals, which are crystalline, homogeneous, mostly inorganic and natural solids. The appearance of a rock (texture and composition) depends on the processes that worked to create that rock. As such, geologists can deduce past processes based on a rock's appearance. Both minerals and rocks can be mined as natural resources. Natural resources have limited quantities and often occur in specific places. Extraction of the resources comes with societal benefits (economic, material) as well as consequences (pollution, limits on quantity).

Use relative and absolute dating as well as other observations to deduce the billions-of-years-old age of Earth.

Plate tectonics acts on a very slow time scale, as do several processes involved in the rock cycle. These processes have taken a very long time to shape the Earth into what we now see, with cliffs of layered sedimentary rocks, wide oceans, deep canyons, huge mountains, etc. In fact, Earth is 4.6 billion years old. While radiometric dating techniques tell us Earth's absolute age, concepts of relative time help geologists determine when rocks formed, and confirms that Earth must be billions of years old.

Describe reservoirs and exchanges of water throughout the hydrosphere.

The hydrosphere (including the cryosphere) contain all water on Earth. Water is important in the rock and plate tectonic cycles and for human existence (as a natural resource); water helps shape Earth's surface and fills Earth's oceans, and water can be a natural hazard (flooding and tsunamis). Water exists in certain places (reservoirs) but also moves through those reservoirs as described by the hydrologic cycle. Water moves through some reservoirs faster than others, which explains why some reservoirs store water while others are conduits for water. Water exists in all three states on Earth's surface, and as water moves through the hydrologic cycle it also changes state, absorbing or releasing latent heat. Therefore, the cycle moves not only water but also energy.

Apply knowledge of Earth's place and motion in space to explain the distribution and fluctuation of solar energy, and implications of these energy variations.

Processes on Earth's surface and atmosphere are driven by energy from the Sun. Earth is one of four terrestrial planets orbiting the Sun, the only star in our solar system. There are also Jovian planets, dwarf planets, comets, and asteroids orbiting the Sun. Only stars create energy by nuclear fusion, which explains the Sun's luminosity. The Moon revolves around Earth as Earth revolves around the Sun, and reflection of sunlight combined with the shift in relative positions creates the Moon's phases. Earth rotates once a day on a tilted axis, and the tilt relative to the Sun changes as Earth revolves. This causes the length of daylight (except at the Equator) and the sun angle (the angle of incident sunlight) to change throughout the year, creating our seasons. Sun angle also varies with latitude, explaining why higher latitudes are typically cooler than lower latitudes.

Using knowledge of atmospheric chemistry and electromagnetic radiation, explain vertical stratification of the atmosphere, infer air stability, and describe patterns of air and ocean circulation.

The atmosphere is a mixture of gases, including water vapor, the concentration of which defines humidity. The atmosphere varies vertically, with pressure increasing toward the surface and layers defined according to temperature. The temperature differences can be explained by considering how different wavelengths of electromagnetic radiation, both emitted by Sun and Earth, react with atmospheric gases and Earth's surface. Vertical temperature profiles impact weather as they determine the stability of air. There are also spatial differences in temperature and pressure, caused by variations in sun angle. Because surface air moves from high to low pressure, the differences in pressure and temperature cause circulation in the atmosphere, which in turn causes circulation of ocean water. These processes affect Earth's climate.

Describe and explain the weather accompanying different air masses, pressure systems, and fronts.

Local weather depends on air masses, which take on characteristics of their source regions. Fronts are the edges of air masses, and their passage therefore causes changes in weather (temperature, wind direction, humidity, and precipitation). These changes in weather depend on the type of front. Fronts often extend from mid-latitude cyclones, which greatly impact the weather of our region. Mid-latitude cyclones remind us that there are patterns in nature; weather in different sectors of a mid-latitude cyclone is consistent, and weather can be predicted using this knowledge. The mid-latitude cyclone is a low-pressure system, and all low-pressure systems have characteristic cloudy and stormy weather. In contrast, high-pressure systems (anticyclones) have clear skies.

Link processes and components from the atmosphere, geosphere, hydrosphere, and biosphere in a variety of positive and negative feedbacks in order to explain global climate change.

Global climate is Earth's average weather, most easily quantified as temperature, which has been quite variable over geologic, and even historic, time. Humans have altered the atmosphere's chemistry, especially by burning fossil fuels. Humans have also altered Earth's reflectivity, or albedo. These changes have altered Earth's climate, causing global temperature to warm over the last 100-plus years. The temperature changes and effects of these changes are observable. (Global warming is a hypothesis, but there are many observations that support that hypothesis.) Predicting future temperatures is tricky given the large number of positive and negative feedbacks that work (on different timescales) to regulate Earth's temperature.