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

Effects of Ozone Depletion

When the ozone layer is depleted, the ultraviolet radiations of the sun can reach the earth's surface in greater proportion. This results in damage to animal and plant life on the earth. Ultraviolet rays cause skin cancer and cataracts in human beings. The ozone hole is seen in the stratosphere above Antarctica.

Main Sources of Water Pollution

There are two main sources of water pollution: natural and manmade sources. They can be further categorized into various types. Mineral from land that are washed off due to heavy rains, dead animals, animal waste, ash, chemical after forest fires, sulfur compounds after an earthquake, etc. are natural sources of water pollution. City sewage and industrial waste are the manmade... Continue reading "Effects of Ozone Depletion, Water and Noise Pollution" »

Types of Artificial Structures

The main types of structures that have appeared throughout the history of construction are the following:

Massive and Lintelled Structures

These structures were built by stacking rock or other materials, leaving little space between them. For example, to build the pyramids in Egypt, stone or clay blocks were stacked on top of each other. The first human-made structures were carved from rock or larger spaces and increase the size of the openings in the built structure.

Vaulted Structures

The arch was invented later, and vaults enabled builders to cover. Because of their shape, arches and vaults can only resist compression stresses and are self-supporting. They stay in position without mortar or cement. This type of... Continue reading "Types of Architectural Structures" »

The Four Spheres of the Earth

The Earth can be divided into four systems or spheres: geosphere, atmosphere, hydrosphere, and biosphere. They all interact very closely with each other.

Geosphere

Scientists theorize that about 4.5 billion years ago, the Earth was a large ball of molten rock. The molten state was due to three processes that generated heat:

• The continuous impacts of planetesimals during accretion
• The differentiation of materials, due to gravity, into three layers of increasing density: crust, mantle, and core

Atmosphere

During the gravitational differentiation process, large quantities of gas were emitted. Hydrogen and helium escaped into space. Others, such as carbon dioxide and water vapor, were trapped in the crust. A primitive atmosphere... Continue reading "The Four Spheres of the Earth and Earthquake Study" »

Hydroelectric Power Generation

Hydroelectric power generation is an alternative to fossil fuels that produces fewer greenhouse gases. It does not produce high quantities of greenhouse gases.

Global Climate Change Definition

Global climate change is defined as modifications in Earth's climate.

Cap-and-Trade Program

In a cap-and-trade program, industries must buy permits for their emissions.

Carbon-Based Fuels in the Lithosphere

Carbon-based fuels in the lithosphere have been slowly sequestered over many millions of years.

Positive Feedback Mechanism in Climate Change

Warmer temperatures result in the melting of permafrost, which may result in a positive feedback mechanism that would intensify climate change.

US Senate's Stance on Emission Reductions

The... Continue reading "Climate Change and Energy: Impacts and Solutions" »

Energy Sources and Their Environmental Impact

An energy source is any natural or non-natural system from which we can obtain energy in any form. That's because in our everyday life we use huge amounts of energy for factories, transport, and heating. Obtaining, producing, and consuming energy can have several impacts, usually negative, on the environment. This impact varies tremendously depending on which type of energy source we use: renewable or non-renewable.

Non-Renewable Energy Impacts

Non-renewable energy sources include fossil fuels and nuclear energy (fission). The use of these energy sources leads to several problems:

• Release of CO2: This comes from the burning of fossil fuels. The carbon dioxide increases the greenhouse effect and contributes

Geodynamic Model

The lithosphere is the outermost layer of the geosphere, composed of the crust and upper mantle. It is divided into plates with clearly defined boundaries coinciding with major landforms. The mesosphere is the largest part of the geosphere and corresponds to the part of the mantle that does not form part of the lithosphere. The core is the center of the planet, consisting of an outer core and an inner core.

Age of the Seabed

Research projects have established that the seabed is expanding slowly, with new lithosphere formed on either side of the ridge axis. Paleomagnetism and magnetometers have provided evidence for the Earth's magnetic field and the symmetrical distribution of paleomagnetism bands on the seabed.

Theory of Plate

Vocabulary

Pollution

Pollution is any substance added to the environment that negatively impacts the environment or its organisms.

Smog

Smog is a type of air pollution where gases from burning fossil fuels react with sunlight to form a fog.

Particulate Matter

Particulate matter consists of microscopic particles of dust, metal, and unburned fuels produced by industrial processes.

Acid Rain

Acid rain is precipitation with a decreased pH due to atmospheric pollutants. It contains elevated levels of hydrogen ions and is caused by sulfur and nitrogen oxide emissions from factories and power stations.

Greenhouse Effect

The greenhouse effect is the natural warming process where gases like carbon dioxide, methane, and water vapor trap heat in the Earth's atmosphere.... Continue reading "Understanding Pollution and the Water Cycle" »

Relative Dating Methods