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

Young Heartwood

Young heartwood is a defect that occurs in wood from trees that have had a strong initial growth rate in diameter. This rapid growth results from favorable ecological conditions or growing up in a forest of low mass density (low density of trees per hectare or defective). This rapid growth results in wood that differs from normal wood of a particular species, with the following characteristics:

• In the late wood, there is a lower proportion of cells with thick walls.
• The apparent specific gravity is lower.
• The fibers are shorter.
• Tangential and radial contractions are lower, while the longitudinal contraction is higher, this being 10 times more intense than in normal wood.
• Sawn pieces that contain young heartwood tend to warp during

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.

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" »

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" »

Understanding and Classifying Risks

Risk: It may be called risk to any action, process, or event which might cause injury, disease, economic loss, or environmental damage. With the exception of wars, natural disasters such as hurricanes, floods, and earthquakes are those which reach a greater magnitude.

Classification of Risks

Cultural Technology Risk

Originating as a result of human error in productive activities (oil spills, radioactive leaks, industrial pollution,...) or lifestyles and socio-political activities (drugs, alcoholism, eating habits, smoking, war, dangerous sports,...).

Natural Hazards

Caused by natural causes (profound alteration of the environment as a result of natural processes). They can be:

Organic Hazards

Due to the action of... Continue reading "Understanding and Classifying Different Types of Risks" »

Health Systems in Developing Nations: Challenges

• Increase spending on health for the whole population, both rich and poor.
• Achieve health coverage for the largest number of people possible. The state should provide health services for pregnancy, disease control, family planning, etc.
• Allocate resources efficiently, taking the initiative towards the prevention and study of diseases specific to these countries.

Determinants of Health

Our health depends on several factors, some unchangeable (hereditary) and others modifiable (lifestyle). Even with the advance of science, unchanging genes could stop being so soon. The elements involved in our health are the environment, personal lifestyle, biological factors, and the health system.

Environment

Global... Continue reading "Health Systems in Developing Nations: Challenges & Determinants" »

Landscape: Interaction of Geographical Agents

Natural and Human Elements

The landscape results from the interaction of various geographical agents. These include:

• Natural elements: Originating from the lithosphere, atmosphere, hydrosphere, and biosphere (e.g., relief, climate, vegetation, soil, water). The action of these agents creates natural landscapes, although such landscapes are now limited and reduced in extent.
• Human elements: Derived from anthropic factors such as settlement patterns, land use, communication networks, etc. Human actions give rise to humanized or cultural landscapes, which represent the majority today.

The landscape must be considered in a multidisciplinary, complex, and dynamic way.

Integrated Landscape Concept

The current... Continue reading "Landscape Dynamics and Spanish Heritage Protection History" »

Risk Assessment and Mitigation

Risk assessment and mitigation are based on studying the extent of damage caused by similar events in the past and related factors. It takes into account three factors:

Hazard (P)

Hazard is the probability of a phenomenon whose severity makes it potentially harmful in a particular place within a specific time interval. It is assessed from three perspectives:

• Severity: Assesses the magnitude of the event and is classified into different categories or degrees of danger (from zero to catastrophic) or within the maximum risk or medium risk.
• Time of return: Frequency or how often the event repeats.
• Geographic distribution: Areas hit by a historically specific phenomenon.

Vulnerability (V)

Vulnerability is the degree of effectiveness... Continue reading "Risk Assessment, Planning, and Mitigation Strategies" »

Hydrological System

Hydrological phenomena are extremely complex and cannot be known completely. However, we can represent them in a simplified form using the concept of a system, which is a set of interacting parts as a whole. The hydrological cycle is a system with components like precipitation, evaporation, and runoff. These components can be grouped into subsystems, allowing us to analyze them separately and combine the results based on their interactions.

Hydrological Model

The objective of hydrological systems analysis is to study the system's operation and predict its output. A hydrological model approximates the real system. Its inputs and outputs are measurable hydrologic variables, and its structure is a set of equations or transfer... Continue reading "Understanding Hydrological Systems and Watersheds" »