Essential Concepts: Energy, Earth Science, and Digital Systems
Understanding Fossil Fuels
Fossil fuels are combustion materials formed from ancient plants and other living organisms that existed on Earth. These include various types of coal, oil, and natural gas, which are processed into different products.
Nuclear Power: Fission and Fusion
Nuclear power is generated by either breaking atomic nuclei (nuclear fission reactions) or combining atomic nuclei (nuclear fusion reactions).
- Fission: The process of breaking a large atomic nucleus into smaller nuclei.
- Fusion: The process of combining small atomic nuclei to yield a larger nucleus.
The energy produced as heat from these reactions is then converted into electricity.
Key Environmental and Geological Terms
In-Stream Water Use
This refers to water use that occurs within the stream or river itself, without diversion. Examples include hydroelectric power generation, navigation, water quality improvement, aquaculture, and recreation.
Biodiversity
Biodiversity is the term referring to the wide variety of life on Earth. It encompasses the variety of ecosystems and the genetic differences within each species.
Global Climate Change
Global climate change refers to significant, long-term changes in Earth’s global climate. Such changes occur across different timescales and affect various climate parameters, including temperature, precipitation, and cloudiness. These changes can be attributed to both natural causes and human activities.
Epicenter
The epicenter is the point on the Earth’s surface directly above the origin (hypocenter) of an earthquake. It is where the earthquake’s intensity is typically greatest, often resulting in extensive damage.
Types of Seismic Waves
Seismic waves are energy waves caused by earthquakes or explosions. They are categorized into two main types: body waves (P and S waves) and surface waves (R and L waves).
- Body Waves:
- P-Waves (Primary Waves): These are the first waves to be recorded on a seismograph. They propagate in a longitudinal direction (compressional waves), meaning particles vibrate parallel to the direction of wave propagation.
- S-Waves (Secondary Waves): These waves arrive after P-waves and are slower. They vibrate in a direction perpendicular to the direction of wave propagation (shear waves).
- Surface Waves:
- R-Waves (Rayleigh Waves): These waves move in an ascending and descending motion on the Earth’s surface, similar to ocean waves.
- L-Waves (Love Waves): These waves exhibit an S-like horizontal motion, similar to a snake’s movement, but confined to the surface.
Mediterranean Heavy Rainfall Events
These are characterized by heavy rainfall occurring in the late summer or early autumn in the Mediterranean area. They are primarily caused by high sea temperatures and warm, moist air masses at the surface. When a mass of cold air arrives in the upper layers of the atmosphere, it creates an atmospheric inversion. The warm, moist air rises rapidly, and the cold air descends, leading to intense condensation and torrential rainfall.
Earthquake Risk Assessment: Hazard, Exposure, and Vulnerability
Understanding earthquake risk involves three key components:
- Hazard: The probability that a particular area will experience an earthquake of a certain intensity.
- Exposure: The number of people, assets, and infrastructure located within an area prone to a specific risk.
- Vulnerability: The degree to which exposed elements are susceptible to damage or loss from a particular hazard. It represents the actual value of exposure that could be affected by a risk.
Global Positioning System (GPS)
The Global Positioning System (GPS) is a satellite-based navigation system that provides location, velocity, and time synchronization. It has widespread applications in positioning, navigation, and monitoring. The integration of GPS into mobile phones has significantly increased its accessibility and everyday use. Notably, until 2000, the U.S. Department of Defense intentionally introduced a degree of error (known as Selective Availability) into GPS signals to prevent adversaries from obtaining highly precise location data for sensitive sites like military bases.
Digital Technology Fundamentals
The Binary System
The binary system is a numerical system that uses only two symbols, typically 0 and 1. In digital technology, it encodes analog signals into a numerical sequence for easier storage, processing, and manipulation.
Advantages of Digital Imaging
Compared to conventional photography, digital imaging offers several significant advantages:
- No Film Required: Hundreds of photos can be stored on a single memory card, eliminating the need for film reels.
- Lower Cost Per Photo: The cost associated with taking individual pictures is significantly reduced.
- Instant Access & Printing: Photos do not require chemical development; they can be viewed instantly and printed directly.
- Easy Transmission: Digital images are easily transmitted and shared over the internet without degradation.