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

A natural hazard is the probability that a small or large population in an area suffers damage or a catastrophe as a result of natural processes.

Factors:

• Hazard Probability: Probability of occurrence in a geographical area at a determined time. Depends on geographical areas of distributions of certain natural phenomena.
• Geographic Area Affected: Recurrence interval or return period.
• Degree of Danger: Characteristics of the phenomenon and intensity of interference.
• Vulnerability: Total human and material assets exposed to risk factors, such as population density and the economic value of assets exposed.
• Harm: The percentage of human life or property exposed that can be affected by a natural phenomenon.

Factors Influencing Harm:

• Existence of prevention

Stars: Celestial Powerhouses

Stars are celestial bodies formed from large amounts of hydrogen and helium atoms. Internal nuclear reactions cause the emission of a large amount of energy. Stars reach very high temperatures and produce fusion reactions that release energy. A fusion reaction involves two hydrogen atoms and one helium atom.

Types of Stars

• Blue-white
• Yellow
• Orange
• Red

Stars are formed from nebulae. They broadcast particles via the Doppler effect. Light and sound propagate as waves. If the issuing body moves, the waves arrive at the receptor more compressed or more elongated as they move away or closer.

Galaxies: Islands of Stars

Galaxies are huge groups of stars, gas, and dust. They have different shapes and sizes, and the number of stars... Continue reading "Stars, Galaxies, and Celestial Objects: A Deep Dive" »

Earth's Continents and Oceans

The continents are large landmasses on Earth's surface. The main continents are:

• Asia
• North America
• South America
• Europe
• Oceania
• Africa
• Antarctica

Oceans are large bodies of salt water. The major oceans are:

• Pacific Ocean
• Indian Ocean
• Atlantic Ocean
• Arctic Ocean

Major Landforms

The land surface is neither smooth nor uniform. Various landforms shape the terrain.

Mountains

High elevations of terrain. If a grouping is of little extension, it constitutes a range, and if it is of great extension, a cordillera.

Plains

Large tracts of land that are flat or slightly wavy.

Plateaus

Large areas of land with a flat upper surface, often elevated.

Valleys

Sunken areas of land, often elongated, surrounded by highlands.

River Systems and Features

Flow

Watershed / River System

A watershed, also known as a river basin or drainage basin, is the territory drained by a main river and its tributaries. It is bounded by watersheds (divides). A basin is considered symmetrical if the structure and number of its tributaries are similar in both areas. In Spain, the largest basin is that of the Douro River.

Fluvial Regime

A fluvial regime refers to the variation of river flow throughout the year. It depends on rainfall distribution and the importance of snowmelt. Accordingly, we can speak of pluvial, nival, or mixed fluvial regimes.

Rambla

A rambla is a watercourse, generally dry, which theoretically carries a river current. Ramblas appear in rivers that have a torrential regime, meaning they have no flow... Continue reading "Understanding Hydrological Features and River Terminology" »

Ecological Footprint and its Impact

The impact of a species or population on the environment depends on the number of individuals it is composed of and the environmental impact of each individual. The ecological footprint is an indicator that measures the soil surface in hectares needed to produce resources consumed by a citizen or a population, as well as to absorb and detoxify the waste generated. These areas are located where they are needed.

The average ecological footprint is calculated by dividing the existing productive land on Earth by 6 billion. The average consumption per inhabitant per year is 2.8 hectares. Three consequences we can extract are:

• Slow population growth
• Cannot be extended to all
• Reducing consumption

Renewable Energy Sources

Solar

Oil: Composition

Oil molecules are primarily composed of carbon and hydrogen. Major hydrocarbon deposits are natural. These oil and gas fuels are mixtures of various types of oil.

Formation and Location of Hydrocarbon Deposits

Oil and natural gas form from the decomposed remains of marine organisms accumulated in seafloor sediments. Three conditions are needed:

• Source Rock: A fine-grained sedimentary rock where organic matter decomposes.
• Reservoir Rock: A porous rock where oil accumulates after migration.
• Trap: An impermeable rock that prevents oil from escaping to the surface.

The source rock requires rapid burial of marine organisms to prevent decomposition. Conversion starts at temperatures between 40°C and 60°C when sediments are buried 1-2... Continue reading "Hydrocarbon Deposits: Formation, Exploitation, and Environmental Impact" »

Optimal Tilt and Orientation of a Solar Collector in Cadiz

This document discusses the optimal tilt and orientation for a flat plate solar collector located in the province of Cadiz, Spain. The orientation will be towards the equator, which, in the Northern Hemisphere, means facing south.

The ideal tilt angle of a solar collector varies with latitude. For Cadiz, located at approximately 36º latitude, the base tilt is 36º. However, the inclination can be adjusted by ±15º depending on the specific application, usage, and architectural integration criteria. A steeper tilt favors solar incidence during the winter months, while a shallower tilt promotes solar incidence during spring and summer.

Essential Components of a Flat Plate Solar Collector

A... Continue reading "Solar Thermal Collectors: Design, Tilt, and Manufacturers" »

Item 4: Introduction to Earth's Dynamics

The movement of the Earth's crust (lithosphere) is continuous, but until just a century ago, it was not understood. Erosion, earthquakes, landslides, and volcanoes were observed, but it was thought that the Earth was eternally unchanging. There are many theories that attempt to explain the dynamics of the land, which are discussed below.

The Theory of Continental Drift

The idea that the continents had moved in the past was revived when the first maps of the East Coast of South America were created, and it was observed that it matched the West African coast. Later, the following information was discovered:

• Prehistoric, identical continents are now widely separated.
• The same types of rocks from the same period

1) Topography

The set of principles and procedures to represent a land surface, including natural and artificial shapes and details.

a) Planimetry

Focuses on the projection of the field on a horizontal plane.

b) Altimetry

Measures level differences in points of the terrain.

Planimetry and Altimetry: Together, they allow for the creation of a topographical map, showing both position and elevation of land points.

2) Forms and Definitions of Land

a) Geoid

The gravitational equipotential surface closest to the average sea level.

b) Ellipsoid

A mathematical model of the Earth formed by rotating an ellipse about its minor axis.

c) Geographical Features

• CENID: An imaginary point at the intersection of all planes perpendicular to the ground.
• Nadir: The point diametrically

Water Resources: A Vital and Limited Resource

Water is a dominant factor for the development of life. It is a limited resource, since the available quantity is conditioned by its unequal distribution in space and time. Nearly two billion people live in countries facing water stress. The problems presented with respect to water as a resource are the increase in consumption and scarcity. Agricultural practices, industrial and urban activities, as well as the increase of population and improvement in the quality of life in society, increase water requirements.

Solutions for Sustainable Water Use

• Improving efficiency in water use
• Sharing available water in solidarity
• Introducing new technologies in industries
• Implementing water policies based on efficiency,