Earth’s Interior: Composition, Seismic Waves, and Plate Tectonics
Earth’s Interior
Composition of Earth’s Interior
Direct Methods: Surveys (max. 13km), analysis of meteorites, analysis of lava from volcanoes (crust and mantle materials).
Indirect Methods: Studying Earth’s density (compared to the theoretical density of crustal material), studying seismic waves (behavior of primary and secondary waves).
Why is the outer core liquid and the inner core solid?
Iron Core = 90% + 10% nickel. Core temperature is 5000°C. At these temperatures, these materials are molten;
Read MoreEarth’s Hydrosphere: Composition, Processes, and Contamination
Life on Earth directly depends on water. Civilizations have disappeared, and many ecosystems have been affected by changes in water quantity and quality.
The ocean represents 97.2% of the hydrosphere, while ice in the polar caps accounts for 2.1%. Groundwater and water in lakes and rivers account for 0.6%. The remaining 0.1% is saline (potable) water found in lakes or groundwater.
The Hydrosphere
The hydrosphere is in close contact with the Earth’s lithosphere; therefore, their properties are related.
Read MoreLandform Classification: A Comprehensive Guide to Terrain
1. Landscape and Relief
The appearance of the Earth’s surface, excluding biotic elements, is represented in topographic maps.
1.1. Descriptive Landform Classification
Landforms are classified based on their appearance:
- Mountain: An isolated relief with a significant gap between its base and peak.
- Hill: An isolated relief with slight unevenness.
- Gorge/Throat: A narrow valley with steep walls.
- Plateau: An isolated, flat-topped topography.
- Terrace: A step-like relief.
1.2. Landform Classification by Formation
Read MoreAir Pollution: Dynamics, Effects, and Mitigation
Factors Influencing Pollutant Dispersion
Pollutant dispersion and concentration are influenced by emission characteristics, weather conditions, and geographical/topographical features. The pollutant’s nature, concentration, temperature, and physicochemical properties play a crucial role. When gas emissions exceed the average, weather conditions facilitate dispersion.
Atmospheric Conditions
The atmosphere’s state determines air mass movement and stability, influencing pollution spread. Key factors
Read MoreAutomotive Chassis Components: Springs, Brakes, Bearings, and Lubrication
Springs used in car or train chassis can be categorized into several types:
- Extension Springs: These springs lengthen under tensile stress and return to their original length when the stress is removed. A common example is brake pad springs.
- Torsion Springs: These springs resist twisting forces and return to their original shape when the force is removed. They are often used in watch movements.
- Flat Springs: These springs are made of thin, folded metal plates and are designed to absorb energy during
Chernobyl Nuclear Disaster: A Retrospective
The Chernobyl Disaster
Twenty-three years have passed since the fire and explosion in reactor number 4 at the Chernobyl Nuclear Power Plant. The accident, which occurred at 1:23 a.m., released massive amounts of radioactive material into the atmosphere. This contamination significantly impacted large areas of Belarus, Russia, and Ukraine, severely affecting the local population. The accident was initiated by turbine operators conducting an experiment. The reactor’s state at the time—a higher-than-
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