Earth’s Energy Dynamics and Geological Processes
Types of Energy That Cause Changes
- Internal energy is contained inside the Earth from the time of its formation and triggers *endogenous* geological processes.
- Solar energy influences the atmospheric dynamics and hydrosphere.
Distribution of Solar Energy
- In polar regions, the sun is low on the horizon, just heating the air, and temperatures are low.
- Equatorial regions receive more direct solar energy.
Dynamics of the Atmosphere and Wind
The wind is generated when air moves from areas of higher atmospheric pressure to areas of lower pressure.
- Cold air masses have higher air pressure.
- Warm air masses have lower atmospheric pressure.
- The Earth’s rotation is responsible for air masses being diverted and describing a curved path.
Dynamics of the Hydrosphere
- Formation of clouds: Air contains water vapor that comes from the evaporation of natural water and plant transpiration. When air rises, it cools, and the water vapor condenses.
- Rainfall: When cooled, clouds may produce precipitation. This cooling occurs when they are pushed by wind and ascend. Water can run on the Earth’s surface, accumulate in natural deposits, or infiltrate the ground.
Isobars are lines connecting points of equal atmospheric pressure. They indicate the intensity of the wind and its origin.
- Anticyclones are areas on a map where the pressure is higher.
- Squalls are areas of low atmospheric pressure.
Weathering
Weathering is the process of alteration or decomposition of rocks by the combined action of the atmosphere, water, and living things.
Physical or Mechanical Weathering
Physical or mechanical weathering is the disintegration of rocks on the Earth’s surface into loose grains or fragments that retain the chemical composition of the original rock. Processes include:
- Gelifraction: The breaking of rocks that occurs when water freezes in cracks and expands.
- Thermal cracking: The breakage of rocks due to expansion and contraction as a result of sudden temperature changes.
- Weathering due to the activity of living beings.
- Canchal: Chunks of rock that break off and accumulate at the bottom of a slope.
Chemical Weathering
Chemical weathering is the chemical transformation experienced by rocks. Processes include:
- Oxidation: Caused by the combined action of oxygen and moisture from the air.
- Dissolution: Occurs in rocks containing water-soluble minerals.
- Carbonation: Limestone is dissolved by the combined action of water and CO2 in the air.
- Activity of living beings.
Geologic Processes and Relief
- Construction: Endogenous processes that give rise to relief.
- Destruction or modeling: Exogenous processes that destroy relief.
Agents of Geomorphological Phenomena
These phenomena shape the relief by erosion and transportation. They are:
- Action of surface waters: Runoff and streams.
- Water infiltration: Enters the soil and causes groundwater.
- Ice glaciers: Model the relief of the polar regions.
- Action of the wind.
- Action of waves, tides, and sea surface currents.
Construction of Relief
The internal energy of the Earth generates forces that push rocks towards the surface in areas deep within the Earth’s crust.
Destruction of Relief
This produces a set of processes:
- Weathering and soil formation
- Erosion
- Transportation
- Sedimentation