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

Ecology: Understanding Earth's Biosphere

Ecology is the scientific study of the behavior of the biosphere, utilizing various methods to understand the interactions between organisms and their environment.

Studying Aquatic Environments

Key Parameters in Aquatic Environments

• Light Penetration

  Light intensity softens as it enters water. It is typically measured using a Secchi disc to determine water clarity and light penetration depth.

• Water Temperature

  Temperature generally decreases with depth in aquatic environments. Specialized thermometers are used to measure these variations.

• Salinity Levels

  Salinity, the concentration of dissolved salts, is relatively constant within a given mass of saltwater. It is measured using instruments like refractometers

Atmospheric Dynamics: Vertical Movements and Stability

Convection

Vertical movements occurring in the troposphere, called convection, are caused by variations in temperature, humidity, or atmospheric pressure.

• Thermal Convection: These movements are caused by the contrast in air temperature. Air near the surface tends to rise, forming thermals of rising air, while higher up, the air tends to cool and descend.
• Moisture Convection: These are caused by the presence of water vapor in the air. Water vapor can be measured in two ways:

1. Absolute Humidity: The amount of water vapor in a determined volume of air, expressed in g/m³.
2. Relative Humidity: The amount of water vapor in 1m³ of air, expressed as a percentage, in relation to the maximum amount it can

What Are Fossils?

Places with rocks containing marine animal fossils were once under the sea. These organisms lived in the sea; upon dying, their bodies were deposited on the seabed and subsequently buried by sediments. Mountains are not as old as the Earth itself. When the organisms that became these fossils were alive, the rocks that now contain them (and form the mountains) might not have existed as mountains yet.

Explaining Marine Fossil Presence in Mountains

The presence of marine fossils in mountains can be explained by two main processes, both of which have occurred throughout Earth's history:

Changes in Sea Level

• Variation in the volume of water in the oceans: Climate has changed many times throughout Earth's history, affecting global sea

European Relief: Major Morphostructural Units

As a result of geological evolution, Europe possesses several distinct morphostructural units:

1. The Baltic or Fennoscandian Shield

This unit occupies most of Finland and Sweden and the far northwest of Scotland. It is a flat, badly eroded area, which corresponds to a Precambrian erosion surface that has remained stable so far.

2. Platforms, Ancient Massifs, and Sedimentary Basins

These features are primarily related to the devastation caused by erosion following the Primary Orogenies (Caledonian and Hercynian).

Platforms (Sockets)

The **platforms** are flat areas that arise from the erosion of the ridges raised during the two Primary Orogenies: the Caledonian and the Hercynian. These platforms were fractured... Continue reading "European Relief: Geological Formation and Morphostructural Units" »

Humidity

The amount of water vapor present in the atmosphere.

Sotavento (Leeward)

The side sheltered from the wind; the opposite of windward.

Windward

The side facing the wind.

Glacial Valley

Characterized by a U-shaped cross-section or trough, which in geomorphology is seen as the main feature differentiating these types of channels, formed by the movement or sliding of an ice tongue.

Bay

An inlet of the sea into the coast.

Archipelago

A general term for a group or chain of islands.

Coastal Breeze

A gentle movement of air that occurs in coastal locations, blowing from the sea or from land.

Zocalo (Geological Shield)

Plains and plateaus formed in the primary era as a result of the devastation by erosion of mountain ranges encountered during the orogeny of... Continue reading "Essential Geographical and Geological Terms" »

Thermodynamic Factors in Atmospheric Circulation

The thermodynamic factors are responsible for the succession of atmospheric circulation and air masses, which determines the different types of weather. Atmospheric circulation is governed by the jet stream at height and by surface centers of action, air masses, and fronts.

2.1 Circulation in Height: The Jet Stream

In the temperate zone where Spain is located, atmospheric circulation at height is governed by the jet stream. This is a strong, tubular current that runs from west to east. The jet stream separates the low pressure near the pole from the high pressure located toward the tropics. The jet stream is responsible for surface weather.

The current's velocity varies. When it travels fast, it... Continue reading "Atmospheric Circulation: Jet Stream and Surface Pressure Systems" »

Mechanical Dredges

• Bucket Dredge (Stationary): It is a stationary type dredger that does not propel itself, performing operations to fill an auxiliary hopper.
• Articulated Bucket Dredger: Consists of a pontoon housing a jib crane on its deck. A wiring system supports the bucket shell at its extreme, which consists of articulated jaws.
• Rigid Spoon Dredger: It has a front bulldozer blade installed on a spud pontoon. The entire assembly is mounted on a rotating raceway attached to the pontoon.
• Dragline Dredger: Consists of a float (pontoon) housing a tower operated by a cable system with corresponding drum gear, driven by mechanical or hydraulic motors, and equipped with the necessary work accessory at the tip.
• Backhoe Dredger: Consists of a pontoon

Water Diversity: Elements of the River System

Water is an essential element for life, but only 3% is freshwater, with the rest being saline.

The Rivers

Rivers are continuous streams whose flow empties into lakes, other rivers, or seas.

Droughts and Floods

• Droughts: Periods of low flow.
• Floods: Periods of high flow.

Flow Rate

The volume of water in a river is measured in cubic meters per second.

The River Regime

The river regime expresses flow rate. Climate variations and the relief condition the rivers, also influenced by lithology, vegetation density, and human action.

Key Elements Affecting River Systems

1) Flow Rate

Flow is greater at the mouth of the river, where there is little evaporation.

2) Irregularity

This refers to the varying amount of water present... Continue reading "Understanding River Systems: Characteristics and Elements" »

Desertification and Pollution in Our Country

Desertification

Desertification is defined as the process of soil and vegetation loss due to human activity. Soil is one of our country's most important natural resources, so its degradation is a very serious concern. Furthermore, its genesis is very slow and requires a long time.

Land degradation is particularly severe in the Mediterranean area, given its environmental conditions such as aridity, irregular rainfall, and frequent droughts. To these natural factors, human activities must be added, including:

• Inappropriate land use
• Unsuitable cultivation methods

All these cases result in the loss of fertile soil.

The degradation of natural vegetation is a problem in itself and also contributes to soil degradation,... Continue reading "Environmental Challenges: Desertification and Pollution in Spain" »

Global Effects

The Greenhouse Effect

The greenhouse effect is the retention in the atmosphere of a portion of the heat emitted by the Earth's surface after it has warmed due to solar radiation. This process delays the release of thermal energy into outer space.

The concentration of gases in the atmosphere causes average temperatures on our planet to be around 15°C. Without these gases, it would be much colder. The main gas that absorbs terrestrial radiation is CO2, but water vapor also plays an important role.

Computer simulations predict significant changes by the end of the twenty-first century:

• An increase of between 1.5 and 6.5 ºC in average temperature.
• Changes in global rainfall patterns, with a tendency towards drought in some areas and