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

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

... Continue reading "Earthquake and Volcanic Hazards: Causes, Effects, and Prevention" »

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" »

Tidal Power

Tidal energy is produced by the movement of water masses caused by rising and falling tides and the waves that originate on the sea surface due to wind action.

Benefits:

• It is a clean energy source.
• No waste.
• Almost inexhaustible.

Disadvantages:

• They can only be in sea areas.
• May be affected by weather disasters.
• Depends on the tidal ranges.
• Facilities are large and expensive.

Hydraulic Power

Hydropower is produced by the water retained in dams and reservoirs at high altitudes (which has gravitational potential energy). If at one point dropped to a lower level, this energy is converted into kinetic energy and then into electricity in a hydroelectric power station.

Advantages:

• It is a source of clean energy.
• No waste.
• Easy to store.
• The water stored

... Continue reading "Clean Energy: Sustainable Power from Natural Resources" »

Historical Ideas on Earth's Age

• 1650: Archbishop James Ussher

  Anglican Archbishop James Ussher published a study that fixed the creation of the Earth in 4004 BC, precisely at 9 pm on October 23.

• Until the 18th Century

  The accepted age of the Earth was less than 6,000 years. This is known as short chronology or biblical chronology because it was based on a literal interpretation of the Bible.

The Answer Lies in the Rocks

Everything began to change in the 19th century when it was discovered that the past was preserved in the rocks. From this point, scientists attempted to "decipher" the geological code.

Reconstructing the Geological Past

Geologists seek answers to three fundamental questions:

1. What happened?

   Identifying the major events that have affected

... Continue reading "Unraveling Earth's Age: Geological History and Dating Methods" »

Fundamental Concepts in Ecology and Biogeography

Ecosystem Structure and Energy Flow

Tidal Amplitude

The difference between the levels of high tide and low tide. This measurement varies based on depth, the volume of the water basin, and coastal morphology.

Gross Primary Production (GPP)

The total amount of energy fixed by autotrophic organisms (or organic matter produced) per unit of time.

Net Primary Production (NPP)

The quantity of energy or organic matter stored per unit of time, representing the remaining biomass after respiration.

Secondary Production

The amount of energy (or organic matter) fixed or assimilated by animals and other heterotrophic organisms.

Gross Secondary Production (GSP)

The total amount of energy absorbed by an animal per... Continue reading "Key Concepts in Ecology, Biogeography, and Population Dynamics" »

Eutrophication: A Threat to Lakes

Rivers, due to their erosive power, carry salts, organic matter, and suspended solids. To this, human action adds waste from domestic and industrial activities (solids and metals mining), agriculture, and livestock (nitrates, phosphates, pesticides, etc.). The self-purification capacity of rivers cannot always handle this load, which triggers pollution processes. The effects of this pollution include:

• Restriction on the use of water
• Alteration in wildlife and/or aquatic flora
• Unpleasant appearance and odor

Rivers are better equipped to handle pollution dynamics, allowing them to dilute pollutants. In contrast, lakes tend to accumulate waste. One of the main problems affecting lakes is the process of eutrophication.... Continue reading "Eutrophication in Lakes: Causes and Solutions" »