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

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" »

Hydrological Effects

The construction of a dam is usually responsible for profound changes in the hydrology of the stream, both regarding the system of flow and sediment transport.

Changes in Flow Regime

The construction of a dam substantially alters the flow regime upstream since it changes a particular stretch of river with flowing water into an artificial lake. As a result, the formation of the reservoir causes changes in the water table around the lake, these being more or less significant changes, according to the variation of the water level in the reservoir over time. This can cause problems with slope stability periodically immersed in the foundations of buildings near the reservoir, the water supply wells in agricultural areas in the... Continue reading "Hydrological Effects of Dam Construction" »

Study of Earth's Interior

Indirect Methods for Studying the Deep Earth

• Seismic Method: This involves analyzing the echoes of sound waves produced by a small surface explosion. These waves bounce off different layers within the Earth.
• Gravimetric Method: This method detects small variations in the gravitational field caused by the distribution of rock mass deep within the Earth. Light rocks create a negative gravity anomaly, while dense rocks create a positive one.
• Measurements of Isotopes: This allows scientists to determine the exact temperature of the water in which an organism lived.
• Radiometric Dating: This is used to determine the age of a rock sample.
• Study of Meteorites: Meteorites provide valuable insights into the composition of the early

Vaporization: Evaporation and Boiling

To produce vaporization, liquid particles must reach sufficient kinetic energy to overcome the forces holding them together. This allows them to separate and move independently. Vaporization can occur in two ways: evaporation and boiling.

Evaporation occurs at all temperatures but only on the surface of the liquid. It happens more rapidly when temperature increases or pressure decreases. Not all liquids evaporate at the same rate; those that evaporate quickly are called volatile.

Boiling occurs throughout the volume of the liquid but only at a specific temperature called the boiling point. The boiling point is characteristic of each pure substance but depends on pressure (it increases as pressure increases)... Continue reading "Understanding Phase Transitions" »

Understanding Earthquake Magnitude and Intensity

The moment magnitude is determined from an estimate of the area that breaks along a fault plane during the earthquake, the amount of movement or slippage at failure, and the stiffness of the rocks near the focus of the quake.

The intensity of an earthquake is often indicated by the Modified Mercalli Scale, which is a qualitative measure. The intensity of an earthquake is usually displayed on a map.

Seismic Waves Explained

When a fault is generated, the rocks break suddenly and violently, releasing energy in the form of seismic waves.

P Waves

The P waves, also called compressional or primary waves, are the most rapid of the two main types. They can travel through a solid, liquid, or gas. P waves travel... Continue reading "Earthquake Magnitude, Seismic Waves, and Zones" »