Notes, abstracts, papers, exams and problems of Geology

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,

Plate Tectonics and Earth's Structure

Plate Boundaries

Mid-ocean ridges are constructive plate boundaries where lithospheric plates separate, leading to ocean growth.

Oceanic trenches are destructive plate boundaries where the oceanic lithospheric plate subducts beneath another plate.

Earth's Crust

Continental crust extends 30 to 70 km deep beneath continents.

Oceanic crust extends 5 to 10 km deep beneath oceans.

Three major ocean ridges exist in the Pacific, Atlantic, and Antarctic Oceans.

Volcanoes

Magma

Magma, molten rock found deep within the Earth's crust, can withstand temperatures of 1000 to 1200 °C.

Magma composition consists of silicate rock, gases, and water vapor.

Magma viscosity is determined by the amount of silica (SiO2); higher silica content... Continue reading "Exploring Earth's Dynamic Processes: Crust, Volcanoes, and Earthquakes" »

Sustainable Development

According to the Brundtland report, where this term first appeared, sustainable development is "development that meets the needs of the present without compromising the ability of future generations to meet their own needs." This requires a respectful attitude towards all people, all living beings, and all ecosystems.

This involves:

1. Consuming resources below their regeneration capacity.
2. Disposing of waste in quantities that nature can absorb.
3. Utilizing renewable energy sources.
4. Ensuring development reaches the entire population.

Sustainable development has three components: economic growth, environmental conservation, and social equity. It's important not to confuse the concepts of growth and development. Economic growth refers... Continue reading "Sustainable Development, Atmosphere, and Pollution" »

Parthenon: An Architectural Marvel

I observe the front, main elevation, facade, or side elevations of a structure. The primary material used in this construction is marble. A significant portion of the outer space is visible, along with a part of the building's interior. The structure rests upon a base (crepidoma) with steps (crepis) extending along its entire perimeter.

Structural Elements

The load-bearing elements include walls and columns. Where visible, the wall presents meticulously matched stones, indicating a regular ashlar construction. The columns do not directly rest on the stylobate. The shaft features sharp edges or ridges, separated by grooves. The capital comprises an abacus, echinus, and collarino.

Supporting elements include the... Continue reading "Parthenon & Maison Carrée: Ancient Greek Temples" »

1 .- Visión binocular 2 .- Color Perception 3 .- Trunk erect climbing, walking or sitting. 4 .- orbits surrounded by bone 5 .- Thumbs opposed to other fingers. 6 .- Presence of flat nails rather than claws, hands and feet. 7 .- Shoulder joint well developed 8 .- The elbow joint allows rotation of the forearm. The forearm rotation movements are known as pronation and supination.
Monkeys: Cercopitecoideos: Macaques, baboons, Chucks
Hominoids: chimpanzees, orangutans, gorillas, gibbons, Male hominoids - Hylobatidae (Gibbons) - Hominidae (orangutans (ponginos) Gorilla (gorilla), chimpanzees (Pan), Man (homo))
Foramen magnum in the center of the skull, thus allowing a march erguida.-Increased skull size and more rounded. - Absence of supraorbital... Continue reading "Primate Evolution and Human Ancestry: Key Adaptations and Milestones" »

The Rock Cycle

The Rock Cycle: Igneous rocks are formed by the cooling and crystallization of magma. When exposed to weathering agents on the Earth's surface, they decompose. Weathering products are transported and deposited as sediment. During and after deposition, the lithification process occurs, in which sediments become sedimentary rocks. When buried deep underground, under high temperatures and penetrated by chemically active gases and solutions, these rocks are transformed into metamorphic rocks. Metamorphism does not melt the rock, but the minerals change shape and often in nature. If the rock melts, it creates magma. This magma, upon cooling, produces igneous rocks, and a new cycle begins. The cycle can be interrupted and follow paths... Continue reading "Rock Cycle, Minerals, Monsoons, Air Fronts, and Metamorphism" »

Understanding Environmental Impact

Appeal refers to anything that humanity uses to meet their basic needs and desires. These resources can be categorized based on their origin:

• Natural resources: such as water and air.
• Human resources: resulting from our activities.

Based on availability, resources can be:

• Renewable: capable of regeneration (e.g., solar, wind).
• Non-renewable: finite and not easily replenished (e.g., oil, minerals).

Several factors impact resource availability and environmental health:

• Demographic explosion: High population growth leads to increased demand and utilization of resources, resulting in overfishing and ecosystem changes.
• Uncontrolled development: Prioritizes the production of goods without considering environmental degradation.

Nitrogen Oxides (NOx): Environmental and Health Impacts

There are eight distinct nitrogen oxides (NOx), but only three are commonly found in the atmosphere:

• Nitrous oxide (N₂O): Emitted naturally, non-toxic, and not considered an air pollutant.
• Nitrogen monoxide (NO): A toxic, colorless, and odorless gas primarily from natural sources, with a smaller contribution from anthropogenic sources.
• Nitrogen dioxide (NO₂): A toxic, reddish-brown gas with a strong, suffocating odor, almost entirely of anthropogenic origin.

Effects of Nitrogen Oxides

The danger of nitrogen oxide contamination to plants and animals is more potential than actual, given current atmospheric levels. Of these oxides, NO₂ is the most toxic to humans, affecting the respiratory system... Continue reading "Nitrogen and Sulfur Oxides: Impacts on Environment and Health" »