Soil Science: Understanding Earth’s Foundation
Soil: The Foundation of Life
It allows us to grow food and the materials we use to make everything from the shirt you have on to the medicine you took this morning.
Soil is made up of small pieces of rock that have broken down over thousands of years.
Soil is also partly made up of the remains of plants and animals, and is home to many organisms, from earthworms to ants.
In this Unit, you will learn how soil forms, what it contains, and how to protect it.
The Lithosphere
Soil is found on the uppermost
Read MoreAir Quality and Pollution
Composition of the Atmosphere
Nitrogen: 78%
Oxygen: 21%
Argon: 1%
Carbon Dioxide: 0.04% (important because it’s involved in the greenhouse effect. Plants need it, and it is produced by us.)
Structure of the Atmosphere
Exosphere: 1000 km
Thermosphere (Ionosphere): 200 km
– Temperature increases because X-rays are absorbed.
Mesosphere: 70 km
– Temperature decreases, gases are less dense.
Stratosphere: 15 km
– Temperature increases as we move up.
– Ozone Layer: 35 km
– UV rays are absorbed here (main reason
Read MoreIntroduction to Geology and Atmospheric Sciences
Geology
The Earth’s crust occupies 0.6% of the planet’s volume and 0.4% of its total mass. It is remarkably thin compared to the Earth’s radius. The oceanic crust averages about 7 km thick, while the continental crust increases to 35-40 km. Beneath the crust lie the mantle, outer core (both fluid), and the solid inner core at the planet’s center. These layers likely represent different chemical compositions and are classified based on their physical behavior.
The lithosphere, Earth’s rigid outer layer,
Read MoreIntroduction to Ecosystems and the Anthropocene
Ecosystem: A Dynamic Complex
An ecosystem is a dynamic complex of plant, animal, and microorganism communities and their non-living environment interacting as a functional unit. It is also the network of interactions among the living and non-living elements of the system.
Research on these interaction networks showed the need to consider ecosystems as a whole when studying nature. The science behind these studies is called ecology.
Ecology is not:
- A political option
- An ethical approach to nature
- A social
Water and Air Pollution: Sources, Impacts, and Mitigation
Water Pollution
BOD and Eutrophication
BOD (Biological Oxygen Demand): BOD indicates the level of organic pollution in water. Eutrophication occurs when inland waters are contaminated with excessive organic substances. These pollutants, often from discharges, lead to a high concentration of organic nutrients. As these nutrients degrade into inorganic substances, they consume significant oxygen, negatively impacting aquatic life, ecosystems, and water quality.
Wastewater Treatment
Debugging: Two primary
Read MoreAtmospheric Dynamics and Climate Classification
DYNAMIC AIR
The temperature difference between the poles and the Equator, along with Earth’s rotation, drives atmospheric circulation. This circulation involves horizontal air movement parallel to the surface and vertical movement that can reach the top of the troposphere.
LATITUDINAL DISTRIBUTION OF SOLAR ENERGY
The amount of solar energy a location receives depends on:
- The Angle of the Sun: Energy received is greater at smaller, more direct angles.
- Exposure Time: Earth’s axial tilt affects the hours