Notes, summaries, assignments, exams, and exercises for Geology for Secondary education

Why in soft clays should be done undrained cond? Clays soils present a very low permeability, so water pres disipation takes a lot of time, so failure will be reached in undrain conditions. It contracts when shear stresses are apllyed. Undrain resist is much smaller than draine, and can be aprox: Cu=0,25+sicma'v and for triax cu=q/2 b)How the second consol coef can be estimated?Settlement can be reduced  by preloading the soil with a load equal or higher to the one it will withstand after construc. 2) Which parameters or fundamental control the seismic ... Shear modulus G and damping (la de compu rara), which are turned relationed with porosity, relatv densi y wave speed 's'. Shear modu is the ratio of shear stres and deformation . Damping...

Composition of the Atmosphere

• Nitrogen: 78%
• Oxygen: 21%
• Other: 1% (carbon dioxide, ozone)

Due to the pull of gravity, the atmosphere’s density decreases with altitude. Weather is directly related to air pressure, and the pressure of an air column on a body decreases as altitude increases.

Layers of the Atmosphere

Troposphere

Temperature: Decreases. This is the lowest, thinnest, and densest layer, containing 80% of the atmosphere's mass. Weather occurs here. The tropopause acts as a barrier between cold and hot air, and this is where airplanes fly.

Stratosphere

Temperature: Increases. Contains 19% of the air. Temperature rises because gas particles absorb solar radiation. It houses the ozone layer, which shields humans from ultraviolet radiation. Weather...

Understanding Water Pollution

Water pollution is any chemical, physical, or biological change in water quality that has a damaging effect on anything living that consumes that water. When humans drink contaminated water, they often have health problems. Water contamination can also make it unsuitable for its intended use.

Common Types of Water Pollutants

There are several kinds of water pollutants. The first of these are disease-causing agents. These include bacteria, viruses, protozoa, and parasitic worms that are incorporated from sewage systems and raw sewage.

Oxygen-Consuming Agents

A second category of water pollutants are oxygen-consuming agents; these are residues that can be decomposed by oxygen-consuming bacteria. When the bacterial populations...

Energy Resources

Nonrenewable Energy

Nonrenewable energy is a source of energy that exists in limited quantities and, once used, cannot be replaced except over millions of years.

Examples:

• Coal (fossil fuel)
• Oil (fossil fuel)
• Natural gas (fossil fuel)
• Uranium (rock)

Renewable Energy

Renewable energy is a source of energy that can be replaced in a relatively short period of time.

Examples:

• Hydroelectric
• Solar
• Geothermal
• Wind
• Biomass
• Nuclear fusion (potentially in the future)

Most renewable energy originates from the sun.

Fossil Fuels

Oil, natural gas, and coal are known as fossil fuels because they were formed underground from the remains of once-living organisms. Fossil fuels are relatively inexpensive and are usually readily available, but their use creates...

Natural Disasters

• Avalanche

• Drought

  Drought is the unusual dryness of the soil caused by levels of precipitation.

• Earthquake

  An earthquake is the result of a sudden release of energy.

• Famine

• Flood

  A flood is an overflow of water that covers the earth.

• Hurricane

• Landslide

• Tornado

  A tornado is a column of violent rotating air.

• Tsunami

  A tsunami consists of huge waves caused by an underwater earthquake or a volcanic eruption.

• Volcano

  Volcanoes can cause widespread destruction and consequent disaster in various ways.

• Wildfire

Weather

• Blizzard

• Cloudy

• Damp

• Dry

• Foggy

• Hailstones

• Heatwave

• Icy

• Rainy

• Snowy

• Stormy

• Sunny

• Thunder and Lightning

• Warm

• Wet

• Windy

Understanding Major Pollution Types and Mitigation Strategies

Air Pollution: Effects and Solutions

Effects of Air Pollution

• Acidification: Chemical reactions involving air pollutants create acidic compounds that harm vegetation and buildings.
• Eutrophication: Rain carries and deposits nitrogen from pollutants onto rivers and soils.
• Ground-level Ozone: Chemical reactions involving air pollutants create ozone, a poisonous gas.
• Particulate Matter: Air pollutants in this form are highly detrimental to human health.

Preventing Air Pollution

Government and Community Level Prevention

• Using renewable green energy sources (e.g., wind, solar).
• Enforcing regulations that compel companies to control the pollution they cause.
• Promoting the use of energy-efficient vehicles.

Deforestation

The technique used to clear forests today is often called slash and burn. It is the rapid destruction of woodland, leading to:

• Reduced soil fertility
• Flooding and landslips
• Disrupted nutrient recycling
• Climatic changes
• Species extinction

The Causes of Oxygen Depletion

Most aquatic organisms respire aerobically and require oxygen from their environment. The two pollutants that most often reduce oxygen in water are:

• Fertilisers: Nitrates and phosphates added to soil by farmers.
• Sewage: Contains an excellent source of organic food for bacteria and phosphates from detergents.

Eutrophication

If a pond or river receives too many nutrients, it is called eutrophication. The solution to this problem is straightforward: do not allow excess nutrients...

Coastal Landforms: Erosion and Deposition

Headlands and Bays

Cliffs and Wave-Cut Platforms

Dynamic Earth

The Earth's Crust

The Earth's crust is a layer of solid minerals covering the surface of the planet. There are two main types:

• The continental crust has an average thickness of 35-40 km. Its mineral composition is varied, with an outer layer of granitic character and deeper layers of basaltic character. Geologically, continents do not end at the sea but extend for hundreds of kilometers under the oceans in the so-called continental shelf.
• The oceanic crust has a much smaller thickness and a homogeneous basaltic composition. The rocks that compose it are younger and have a higher density than the continental crust. The oceanic crust covers approximately 60% of the Earth's surface.

Early Theories and Geological Enigmas

Initially, the...

Impact on Workers and Occupational Safety

Industrial activities can cause two types of injuries:

• Occupational Diseases: These often appear due to the aggressions to which the worker is exposed while performing work; for example, due to prolonged exposure to certain substances.
• Workplace Accidents: These may result from contingencies. Most cases are preventable and often occur because safety measures have not been complied with.

Environmental Impact and Limits to Growth

The environmental impact is the alteration that occurs in the environment when a project is carried out, such as the construction of a road or the manufacturing of a product. The land is finite; the growth of any physical object, including the human population and its products, cannot...