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

Dear editor,

i'm writting about my concern relating to Deforestation in my area. In my opinion , i think it's dangerous.

Firstlly,  they Belive that cutting the trees will grow immediately,  but it isn't. Secondly, when they cut the Trees the animals are homeless and many species became extinct. Thirdly , can Cause changes in climate. Having fewer forest means emit more amount of Greenhouse gases. Plants and animals balances out the amount of oxygen And carbon dioxide in the air. Plants take in carbon dioxide and release oxygen While, on the other hand, animals take in oxygen and release carbon dioxide. Deforestation can unbalance the cycle by killing trees and other plants. 

if more people write about suggestions , we will have a better service.... Continue reading "Air law" »

The Composition and Classification of Rocks

Rock is any natural, inorganic material made up of one or more minerals. Rock forms the solid part of the Earth's crust.

Rocks formed of only one type of mineral are called mono-mineralic rocks, but rocks are usually formed of more than one mineral.

Exceptions to the Definition

There are two notable exceptions often referred to as 'rocks':

• Oil: Considered a liquid 'rock'.
• Coal: Formed from the remains of plants (organic material).

The Three Main Types of Rocks

Rocks are classified into three primary types based on their formation process:

1. Igneous Rocks: Rocks formed when magma cools and solidifies. (Magma is molten rock.)
2. Sedimentary Rocks: Rocks formed by the accumulation and cementation of fragments of other

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.

Types of Plate Boundaries

1) Constructive or Divergent Boundaries

Two plates move apart from each other. New magma rises to the surface, cools, and forms basalt, creating volcanoes and rift valleys.

2) Destructive or Convergent Boundaries

Two plates move towards each other. Typically, an oceanic plate sinks below the other in a subduction zone. Sediments between the plates fold, forming mountain ranges. Friction melts rocks, causing volcanoes and earthquakes.

3) Conservative Boundaries

Two plates slide against each other, often at different speeds. Stress buildup leads to sudden movements and friction, resulting in earthquakes.

Negative Impacts on People

Earthquakes

Earthquake shockwaves damage buildings, bridges, and roads, causing injuries and fatalities.... Continue reading "Understanding Plate Boundaries and Their Impact" »

Composition of Earth's Atmosphere

• Nitrogen (78%)
• Oxygen (20%)
• Argon (1%)

Greenhouse Gases

Examples: H2O, CO2, CH4, NO2, O3

Importance: Without greenhouse gases, Earth's temperature would be -22 to -36 degrees Celsius.

Greenhouse Effect

Solar energy absorbed by Earth and re-radiated as heat by greenhouse gases.

1. Natural Greenhouse Effect
2. Human-Induced Greenhouse Effect (Global Warming)

Global Warming / Climate Change

Caused by burning fossil fuels, deforestation, and human activities that increase carbon dioxide levels, leading to Earth's warming.

Ozone, Hole in Ozone, UV Rays, CFCs

Ozone

Located mostly in the lower stratosphere, it acts as a shield against harmful UV radiation from the sun.

Hole in the Ozone Layer

Causes: Primarily caused by human-made chemicals... Continue reading "Understanding Earth's Atmosphere and Climate Change" »

Coastal Erosion

Factors Influencing Wave Size and Energy

The size and energy of a wave are influenced by:

• How long the wind has been blowing
• The strength of the wind
• The fetch (the distance the wind blows over the surface of the water)

Rate of Coastline Erosion

The rate of coastline erosion is influenced by:

• Type of rock (e.g., chalk and limestone form steep cliffs)
• Strength of waves
• Speed of waves

Destructive Waves

Destructive waves are created in storm conditions. They are characterized by:

• Being created from big, strong waves when the wind is powerful and has been blowing for a long time
• Occurring when wave energy is high and the wave has traveled over a long fetch
• Eroding the coast
• Having a stronger backwash than swash
• Having a short wavelength and being

Volcanoes

Scenario: Consider a geographic location for a volcano. What type of plate setting is it located in? What kind of volcano is it (composite, dome, or shield)? What kind of lava does it produce (rhyolite, andesite, or basalt)? Is the lava predominantly silicate, feldspar, or ferromagnesian? Why? Is the lava felsic, mafic, or a combination in origin? Why? Describe the characteristics of a volcanic eruption.

Plate Tectonics:

• Divergent (mid-ocean ridges = volcanoes)
• Rift zones = volcanoes
• Subduction zones = volcanoes
• Hot spots = volcanoes

Lava

Composition:

• Result of the geologic setting, which determines available source material.
• Extent of melting, which determines what becomes the source material.
• A mix of SiO4, Al, Fe, Mg.

• Rich in SiO4: more felsic

Climate Feedbacks and Their Impact on Climate Change

Feedbacks within the climate system amplify climate changes initially caused by external factors. This can be visualized as:

• Initial climate forcing → Initial climate response → Response amplified

Example: An increase in heat energy sent to Earth by the Sun causes high-latitude snow and ice to retreat. This allows more sunlight to be absorbed by the Earth's surface, leading to further climatic warming (amplifying the changes underway). Another example is delayed bedrock rebound.

Negative Feedback Mechanisms in Climate Change

Initial climate changes can also lead to a reduced response:

• Initial climate forcing → Initial climate response → Response reduced

Example: Chemical weathering acts... Continue reading "Climate Change: Feedbacks, Processes, and History" »

Key Definitions in Hydrology and River Systems

River Features and Drainage Systems

River Channel: The bed and sides of a river form the river channel.

Drainage Basin: The area of land drained by a river.

Confluence: The point where a river and a tributary meet.

Tributary: A smaller river which joins a larger river.

Source: The starting point of a river.

Mouth: The end point of a river, where it enters the sea or a lake.

Watershed: A ridge of highland which determines to which drainage basin the water flows.

The Hydrological Cycle (Water Cycle Processes)

Hydrological Cycle: The continuous movement of water on, above, and below the surface of the Earth (the water cycle).

Evaporation: The change in state from a liquid (such as water) to a gas (such as water... Continue reading "Essential Hydrology and River System Terminology" »