Notes, summaries, assignments, exams, and problems for Geology

Tectonic Dispositions

• Horizontal or Aclinal Relief: Self-sedimented areas with horizontal strata, alternating hard and soft layers. Water systems erode softer layers, creating residual relief.
• Monoclinal Relief: Gently sloping sedimentary areas with alternating hard and soft materials. Erosion forms steep slopes and isolated hills.
• Faulted or Germanic Structure: Results from pressure exceeding rock deformation capacity, leading to fractures, uplifted blocks, and sunken areas.
• Folded Relief: Formed by folding of sedimentary rocks due to compression. Anticlines are prone to erosion, while synclines retain more compact materials.

Appalachian Relief

Folded relief leveled by erosion, forming a base.

Jurassic Relief

Found in young mountain ranges with alternating... Continue reading "Understanding Landforms: Tectonics and Stress Factors" »

Fossil Fuels: A Deep Dive

Most of the energy used worldwide today comes from fossil fuels. They are used in transportation, to generate electricity, to heat rooms, and for cooking.

Fossil fuels include oil, coal, and natural gas, formed millions of years ago from the organic remains of dead plants and animals. Over millennia, the remains of organisms were deposited at the bottom of seas, lakes, and other water bodies, covered by layers of sediment. Chemical reactions of decomposition and the pressure exerted by the weight of these layers transformed these organic remains into gas, oil, or coal.

The Non-Renewable Nature of Fossil Fuels

Fossil fuels are nonrenewable resources; we cannot replace what we consume. They will eventually run out, and it... Continue reading "Fossil Fuels: Formation, Uses, and Future Availability" »

Wind Energy

Benefits of Wind Energy

• It is a clean, free, and inexhaustible resource.

Drawbacks of Wind Energy

• Manufacturing requires large and expensive machinery.
• Production is discontinuous, leading to challenges with energy storage and transportation.
• Wind can carry abrasive particles that may damage turbine blades.

Geothermal Energy

Geothermal energy is the heat stored in the Earth's interior, originating from volcanism and the radioactivity of rocks.

Operating Methods

It operates by using liquid or gaseous water that flows naturally to the surface or by harnessing the increasing temperature observed at depth within the Earth.

Types of Geothermal Energy

Geothermal energy is categorized as either high-temperature or low-temperature.

High-Temperature

Carbon Cycle

The main reservoir of carbon is the atmosphere, but water also contains small amounts of CO2. Atmospheric CO2 is fixed by producers through photosynthesis. Consumers and decomposers incorporate carbon through food. Carbon can escape the cycle and remain separated from living beings, such as when fossil fuels are formed.

Nitrogen Cycle

The atmosphere is composed of 78% nitrogen, but this gas is inaccessible to most living things except bacteria. Consumers and decomposers incorporate nitrogen through food. Atmospheric nitrogen can be transformed into nitrates, which can leave the cycle when transported by water to sediment, where they form sedimentary rocks.

Homeostasis in Ecosystems

Homeostasis is the set of self-regulatory mechanisms... Continue reading "Carbon, Nitrogen Cycles & Ecosystem Dynamics Explained" »

Atmospheric Pollution

The combustion of hydrocarbons, largely due to industrial processes or transportation, generates smoke, suspended particulates, and gaseous pollutants. The most common are carbon monoxide, carbon dioxide, sulfur oxides, nitrogen oxides, and hydrogen sulfide.

Industrial facilities and power plants usually emit a greater volume of contaminants. In the developed world, the danger of some issues has forced the relocation of industries to industrial belts outside of densely populated urban areas. However, emissions are still causing serious environmental problems.

Acid Rain and Smog

Emissions of sulfur and nitrogen react in the atmosphere when in contact with oxygen, water vapor, and light, producing mainly sulfuric acid and nitric... Continue reading "Atmospheric Pollution and Environmental Degradation: Causes and Effects" »

Physical Properties of Oil

Color: Varies from yellow to reddish-brown. The color darkens with increasing specific gravity, which increases with the percentage of asphalt.

Odor: Varies depending on the amount of light hydrocarbons and impurities. Examples include a pleasant smell of petrol to an unpleasant odor similar to combustion.

Specific Weight: Oil is lighter than water. Its weight is influenced by factors such as the percentage of asphalt.

Viscosity: Depending on the specific gravity and chemical composition, oil can be either very fluid or viscous.

Solubility: Insoluble in water; due to its lighter weight, it remains on the surface. It is soluble in benzene, ether, chloroform, and other organic solvents.

Chemical Properties of Oil

Crude oil... Continue reading "Understanding Oil: Physical, Chemical Properties and Types" »

Understanding Cavitation in Fluid Dynamics

Cavitation, sometimes referred to as suction vacuum, is a hydrodynamic effect that occurs when water or another liquid fluid passes at high speed over a sharp edge, producing a fluid decompression due to the conservation of the Bernoulli constant (Bernoulli's Principle). It can reach the vapor pressure of the liquid so that its constituent molecules immediately change to a vapor state, forming bubbles or, more correctly, cavities. The formed bubbles travel to areas of higher pressure and implode (the vapor suddenly returns to a liquid state, abruptly collapsing the bubbles), producing a trail of gas and potentially damaging the metal surface where this phenomenon occurs.

Discharge Cavitation Explained

Discharge... Continue reading "Cavitation and Water Hammer Phenomena in Fluid Systems" »

Urban Drainage Master Plans

A master plan involves a set of studies for the planning of urban drainage in a city (study area) over a period of time, considering its interaction with external contributing basins and receiving streams. These plans are designed to maintain hydraulic order.

Drainage System Components

A drainage system typically includes:

• The main collector and its discharge works to a main channel or another collector.
• Branches and tributaries.
• Inspection and cleaning chambers.
• Sinks (inlets) that capture runoff from roads, e.g., Zanjón de la Aguada.

Collectors can be in open channels or underground.

Key Hydraulic Structures

Dams and Reservoirs

A reservoir is a body of work consisting of a dam that closes a natural channel. An embankment... Continue reading "Urban Drainage & Water Systems: Key Infrastructure" »

Earthquake Causes, Effects, and Prevention

Causes of Earthquakes

• Regional-Global Scale: Lithospheric subduction zones (cause of large earthquakes).
• Local Causes:
  • Volcanic eruptions
  • Escape of materials related to large surface currents
  • Fractures
  • Fluid extraction: groundwater, petroleum
  • Excavation collapse: mining, filling of reservoirs

Effects of Earthquakes

• Shaking of soil and buildings (the majority of deaths are caused by the collapse of buildings).
• Ground displacements taking place across fault lines.
• Landslides (a violent earthquake can trigger thousands of them).
• Tsunamis or tidal waves (traveling at high speed).
• Explosions: nuclear tests, exploration for mineral and oil deposits, mining operations.

Increased Seismic Risk Factors

• Human overpopulation

Characteristics of Earth as a Planet

Source: Earth was formed approximately 4.6 billion years ago by the agglomeration of matter subject to gravitational attraction.

Mass: Approximately 5,976 trillion tons (estimated from the formula of universal gravitation and gravitational acceleration).

Gravity: This force influences the arrangement of materials according to their density (less dense at the top, more dense at the bottom). On Earth, air, water, and rocks are arranged in this way.

Greenhouse Effect

Visible solar radiation penetrates the atmosphere and warms the Earth's surface. The Earth radiates heat as infrared radiation into the atmosphere; some of it escapes into space, and some is sent back to the surface. Increasing greenhouse gases in the... Continue reading "Earth's Characteristics and Atmospheric Layers" »