GEOG 2350 Earth Science

Earth Science

• Definition of Earth Science: Earth science is the study of the Earth’s processes, components, and history, combining aspects of geology, meteorology, oceanography, and astronomy to understand the planet's physical and biological systems.

• Four Categories of Earth Science:

  1. Geology: The study of Earth’s solid material and processes, including rocks and minerals.
  2. Meteorology: The study of the atmosphere and weather patterns.
  3. Oceanography: The study of oceans, including marine ecosystems and oceanic processes.
  4. Astronomy: The study of celestial bodies and the universe.

• Four Major Spheres on Planet Earth:

  1. Atmosphere: The layer of gases surrounding Earth.
  2. Hydrosphere: All the water on Earth, including oceans, rivers, and groundwater.
  3. Lithosphere: The solid outer layer of Earth, consisting of rocks and soil.
  4. Biosphere: The regions of Earth where life exists, encompassing various ecosystems.

• Environmental Science: Environmental science is the interdisciplinary study that examines the interactions between the physical, chemical, and biological components of the environment, taking into account human impacts and sustainability.

• Biosphere: The biosphere is the global sum of all ecosystems. It is the zone of life on Earth, a closed system that integrates all living organisms and their physical environments.

Scientific Method

• Definition of the Scientific Method: The scientific method is a systematic process used for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge.

• Difference Between Science and Pseudoscience:

  • Science is based on empirical evidence, follows systematic methods, and is subject to peer review.
  • Pseudoscience lacks rigorous testing, does not adhere to the scientific method, and often relies on anecdotal evidence or untestable claims.

• Steps of the Scientific Method:

  1. Observation: Identifying a phenomenon or question.
  2. Research: Gathering information and resources.
  3. Hypothesis: Formulating a testable statement or prediction.
  4. Experiment: Conducting a test to validate or invalidate the hypothesis.
  5. Analysis: Interpreting data and results.
  6. Conclusion: Drawing conclusions based on the analysis.
  7. Publication: Sharing findings with the scientific community.

• Goal of an Experiment: The goal of an experiment is to test the validity of a hypothesis by observing and measuring variables in a controlled setting.

• Last Step Before Publication in the Scientific Method: The last step before publication involves peer review, where other experts evaluate the research for validity and significance.

Minerals

• Definition of a Mineral: A mineral is a naturally occurring, inorganic solid with a specific chemical composition and a crystalline structure.

• Main Characteristics of Minerals:

  1. Naturally Occurring: Formed by natural geological processes.
  2. Inorganic: Not made from living organisms.
  3. Solid: Has a fixed volume and shape.
  4. Definite Chemical Composition: A specific chemical formula.
  5. Crystalline Structure: Atoms are arranged in a specific, repeating pattern.

• Four Physical Properties of Minerals:

  1. Hardness: Resistance to scratching, measured using the Mohs hardness scale.
  2. Luster: The way light reflects off a mineral’s surface, categorized as metallic or non-metallic.
  3. Cleavage: The tendency of a mineral to break along flat planes of weakness.
  4. Fracture: The way a mineral breaks in an irregular manner, not along planes.

• Reliability of Color as a Characteristic: Color is not a reliable characteristic for identifying minerals because different minerals can share the same color, and impurities can alter the color of a mineral significantly.

Rocks and Rock Cycle

• Difference Between Magma and Lava:

  • Magma is molten rock located beneath the Earth’s surface.
  • Lava is molten rock that has erupted onto the Earth’s surface.

• Rock Cycle Components: The rock cycle describes the continuous transformations of rock types, including processes such as melting, cooling, compacting and cementing, weathering and erosion, and heat and pressure.

• Purpose of Hydraulic Fracking: Hydraulic fracking is a method used to extract oil and natural gas from deep underground by injecting fluid at high pressure to fracture the rock formations.

Weathering

• Definitions:

  • Weathering: The breaking down of rocks and minerals through physical, chemical, or biological processes.
  • Mass Wasting: The movement of rock and soil down a slope due to gravity.
  • Erosion: The transport of weathered material from one location to another via wind, water, or ice.

• Difference Between Mechanical and Chemical Weathering:

  • Mechanical Weathering: Physical processes that break rocks into smaller pieces without changing their chemical composition.
  • Chemical Weathering: The alteration of the chemical structure of minerals due to reactions with water, air, or other chemicals.

• Four Important Processes in Mechanical Weathering:

  1. Frost action: Expansion of ice in cracks causing rocks to break.
  2. Thermal expansion: Repeated heating and cooling causing rock layers to flake off.
  3. Biological activity: Roots of plants breaking rocks apart as they grow.
  4. Abrasion: Friction from wind or water wearing down rock surfaces.

• Factors Influencing the Rate of Weathering:

  1. Climate: Temperature and moisture affect weathering rates.
  2. Rock type: Softer rocks weather more quickly than harder rocks.
  3. Topography: Steeper slopes can enhance erosion, influencing weathering.
  4. Vegetation: Plants can protect soil but may also contribute to mechanical weathering.

• Components of Soil: The main components of soil include mineral particles, organic matter (humus), water, and air.

Soil Texture Analysis

• Soil Texture Table Completion:

  Soil	% Clay	% Sand	% Silt	Texture Name
  A	5	5	???	??
  B	5	10	???	??
  C	75	15	10	??
  D	20	40	???	??

• Suitability of Soil Textures for Agriculture:

  • Soils with good agricultural viability typically exhibit a balance of sand, silt, and clay, allowing for proper drainage and nutrient retention. Loamy soil is often considered ideal for farming due to its balanced texture and fertility. Justification would require analyzing the proportions of the components from the table, particularly focusing on Soil C, which has a high clay content that may retain moisture and nutrients well.