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

Divergent Plate Boundaries

Mid-Ocean Ridges

Mid-ocean ridges are high elevations located in the middle of all oceans, with a total length of about 65,000 km. Some peaks of the ridges protrude above sea level, forming volcanic islands. The central part of the ridge consists of a system of fractures that form a large groove called the rift valley. The ridges are crossed by numerous transform faults.

The Genesis of an Ocean

The formation of a ridge (dorsal), and therefore a new ocean, under a continent begins when a hot spot appears. Hot magma from the mantle rises, slightly lifting the lithosphere and forming a dome. The rigid lithosphere then breaks, forming a system of three cracks called a triple point. These cracks, called rifts, continue to... Continue reading "Plate Tectonic Boundaries: Formation and Destruction of Oceanic Crust" »

Tsunami: Understanding Ocean's Powerful Waves

A Tsunami (from Japanese tsu meaning "port" or "harbor" and nami meaning "wave," literally "harbor wave") is a series of high-energy waves that occur when a large body of water is displaced vertically by a significant phenomenon.

Causes and Characteristics

It is estimated that 90% of tsunamis are caused by earthquakes, in which case they are more accurately termed tectonic tsunamis. The energy of a tsunami depends on its height (wave amplitude) and speed. The total energy discharged on a coastal area also depends on the number of peaks in the wave train (for example, the 2004 Indian Ocean tsunami had up to 7 peaks).

Impact and Displacement

These waves displace a much greater quantity of water than surface... Continue reading "Global Phenomena: Tsunami and Agricultural Transformation" »

Residue Definitions

Residue (Generic): Any product in solid, liquid, or gas form from an extraction, processing, or use process that is worthless to the owner, who decides to discard it.

Residue (Legal): Any substance or object belonging to any of the categories listed in the annex to this law, which the holder discards or intends or is required to discard. This consideration also applies to items listed in the European Waste Catalogue (EWC), approved by Community institutions.

Urban and Municipal Waste

Urban and Municipal Waste: Waste generated in private homes, commercial establishments, offices, and service industries, and those that do not have hazardous classifications, which by their nature and composition can be likened to waste produced... Continue reading "Essential Waste Management Terms & Definitions" »

Distribution Line Failures and Maintenance

Breaking load: Load that causes failure of any part of the support.

Effort: This is the maximum mechanical stress applied to a support. This mechanical stress, multiplied by the factor of safety, must be supported by the support.

Nominal effort (E): Horizontal stress available at a distance h from the top of the head, in the principal direction.

Secondary effort (S): Horizontal stress found at height h, considered equal in magnitude to the nominal effort. En (torque) = Et: the available horizontal stress at the end of a crossarm placed at a distance h from the top of the head, and at a distance d from the center of support; it tends to rotate the support about its vertical axis.

Secondary effort (S): Horizontal... Continue reading "Distribution Line Failures, Loads and Maintenance Procedures" »

The Landscape and Earth's Relief

Relief is the aspect of the Earth's surface regardless of biotic elements.

Descriptive Classification of Landforms

• Mountain: Isolated relief with a large elevation difference between its base and top.
• Cerro (Hill): Isolated relief with a gentle gradient.
• Gorge or Throat: A narrow valley bottom featuring steep walls on its sides.
• Plateau: Isolated topography with a flat top.

Interpretative Classification of Relief Forms

• Mountains: Formed by the folding of material or volcanic activity. An alignment of ridges or mountains is called an orogen.
• Witness Hill (Cerro Testigo): Isolated relief whose summit is at the height that the surrounding area once reached in the past.
• Terraces: A fragmented and tiered zone, consisting of

Factors Determining Erosion Effectiveness

The energy of a geological agent: A great river with steep and erosive capacity has more than one of lower flow and calmer course. A large glacier erodes more than a smaller one.

The strength of rocks: Some rocks such as clay, limestone, and sandstone are easily eroded, while granite and gneiss are hard rocks where erosion progresses slowly.

Related Geological Agents

Wild Water

• Water with no fixed course, from rains.

Rivers

• Permanent water courses.

Torrents

• Located in mountains, always with water.

Glaciers

• Rivers of ice in polar regions or high mountains.

Landform Examples

• Wild-water gully
• River valley in V
• Valley glacier-torrents
• Sea cliff
• Glacier valley

River Characteristics

Upper Course

• Runs through high mountain areas.

Climate and Vegetation in Spain

General Characteristics

• Annual Average Temperatures: Temperatures increase from north to south. They are lower in the peninsular interior, where a greater temperature range is also observed compared to the coast.
• Rainfall: Precipitation has a strong seasonal variation, except in the northern peninsula. It decreases from north to south, from west to east, and from the coast inland.

Types of Climate

Oceanic Climate

This climate is characterized by mild temperatures and abundant rainfall throughout the year.

Mediterranean Climate

Its main characteristic is a marked dry season in summer. There are several varieties:

• Coastal Mediterranean Climate

  Features mild temperatures and moderate rainfall.

• Inland Mediterranean Climate

  Presents

Understanding the Ecological Footprint

The ecological footprint is an indicator that measures the soil surface in hectares needed to produce the resources consumed by a citizen, population, etc., and also needed to absorb and detoxify the waste generated. Its purpose is to assess the impact on the planet.

Energy and Development

Population growth and economic development have required the consumption of large amounts of energy. Fossil fuels have been the most used.

The Drawbacks of Fossil Fuels

One drawback is that fossil fuels produce carbon dioxide, carbon monoxide, hydrocarbons, etc. These substances are pollutants.

The Rise of Renewable Energy Sources

For these reasons, and more, we have started to exploit renewable energy sources as they are cleaner.... Continue reading "Ecological Footprint, Renewable Energy, and Soil Conservation" »

Fundamentals of Plate Bending

Bending a sheet involves shaping it, in part or in whole, into a cylindrical or conical form. The bending process can be classified as either open or closed. The bending of sheets is achieved by a bending force caused by pressure applied manually, by machine, or through impact shocks.

The Neutral Fiber Concept in Bending

To understand the development of a bent piece, consider a sheet 10 mm thick and 628 mm long, with edges perfectly perpendicular to the faces. When forming a cylinder of revolution with this plate, we observe the following:

• A) The thickness does not change during the bending process.
• B) The two extreme edges match perfectly.

If a sheet is bent and its length is compared to the original, we see that the... Continue reading "Plate Bending Techniques and Roll Machine Mechanics" »

New Discoveries Shaping Our Understanding of the Cosmos

New discoveries.

The Immensity of the Universe

The Sun is a star in the Milky Way. Our galaxy is only one among the billions that make up the universe.

The Discovery of Deep Time

It was once believed that Earth was only about 6,000 years old.

Biological Evolution

It was once believed that each species had been created as we know it. Darwin's Origin of Species showed that species change over time.

New structure for the solar system.

Defining a Planet

A planet is a body orbiting a star, with a large mass and a spherical shape, that has cleared the area around its orbit. Its mass should be enough for its shape to be almost spherical, and it must have cleared its orbit.

That should explain a theory about... Continue reading "Unveiling the Universe: Discoveries, Solar System & Theories" »