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

Earthquakes and Volcanoes

Earthquakes

An earthquake is a violent trembling of the Earth's crust, lasting a short time and varying in intensity. It occurs when materials abruptly fracture within the lithosphere. The point of origin is called the hypocenter. From the hypocenter, freed energy transmits as seismic waves in all directions. The most affected surface point is the epicenter. Energy transmits in superficial seismic waves.

Volcanoes

Volcanoes expel extremely hot materials. A volcano is an opening in the Earth's crust through which melted rocky materials from inside the Earth are expelled. This material is called magma within the crust and lava once expelled.

Continental Drift and Plate Tectonics

Continental Drift

Alfred Wegener proposed the... Continue reading "Earth's Dynamic Processes: Earthquakes, Volcanoes, and Plate Tectonics" »

Earth's Geological Features

Continental Landforms

Mountain Ranges: Formation & Tectonics

Mountain ranges form through a slow process, taking about 100 million years, which is impossible to appreciate during a human lifetime.

The interaction of two tectonic plates is key to understanding mountain ranges. Areas where two plates *collide* are subjected to immense pressure, compressing sediments deposited on the ocean floor and causing them to fold, thus forming mountains. This explains why *volcanic and seismic movements* are frequent in mountainous regions.

Ocean Floor Topography

Key Seafloor Features

• Mid-Ocean Ridges: These are large underwater *elevations* located in the central part of the oceans. They have an average height of 2,000 meters and

Understanding Tides: Definition and Causes

Tides are periodic and alternative movements of the rise and fall of the sea and large lakes.

They are produced by the gravitational attraction of the Moon and Sun on Earth, which causes changes in the ocean's level.

The Earth-Moon system revolves around a common center of gravity, causing every point on Earth to experience a centrifugal force opposite to the Moon's direction.

Types of Tides

Spring Tides

Spring Tides occur when the Sun, Moon, and Earth are aligned. In this configuration, the gravitational forces of the Moon and Sun combine, producing higher high tides and lower low tides than average.

• Conjunction (New Moon): The Moon is between Earth and the Sun.
• Opposition (Full Moon): Earth is between the

Weather and Climate

Weather

Weather is the state of the atmosphere at a specific time and place. It's characterized by its variability and is determined through direct observations. Meteorology is the science that studies weather.

Climate

Climate represents the average state of the atmosphere in a particular location. This average is determined by the typical patterns of weather that occur throughout the year. Climate exhibits more stable characteristics over time and is statistically determined by calculating average values over a period of at least thirty years to ensure reliability.

Atmospheric Pressure

Barometer: Measures the weight of air above a unit area, typically in millibars (mb) or hectopascals (hPa).
Isobars: Lines on weather maps connecting... Continue reading "Weather and Climate: A Comprehensive Overview" »

Water Treatment Methods

Physical Filtration

Desbastement: Pass water through filters and/or grids of different porosity to remove large particles.

Activated Carbon Filter: Pass water through activated carbon, which has small pores, to remove salts, odors, and strange tastes through electroaffinity.

Decanting/Sedimentation: Let water sit in large containers so suspended solids settle to the bottom. Collect the surface water free of solids. Sometimes used after flocculation.

Ultraviolet Radiation: Use UV light to eliminate microorganisms.

Reverse Osmosis: Subject water to high pressure to force it through membranes, removing dissolved salts.

Chemical Treatment

Coagulation-Flocculation: Add a substance to the water to chemically bind finely divided, suspended... Continue reading "Water Treatment and Air Pollution" »

The Alcántara Bridge: A Roman Engineering Marvel

The Alcántara Bridge is a magnificent Roman arch bridge constructed between 104 and 106 AD. It majestically spans the Tagus River in the town of Alcántara, Cáceres. This impressive structure consists of six arches of unequal height, resting on five pillars that rise from different elevations above the hewn slate rock. At the center-top of the bridge stands a memorial shrine with a triumphal arch, reaching a height of 10 meters, famously known as the Arch of Trajan. The bridge itself is meticulously crafted from rusticated granite blocks, each measuring between 45 and 50 cm. Furthermore, at the foot of the bridge, there is a Roman temple dedicated to its constructor, Lácer, which was Christianized... Continue reading "Spain's Enduring Roman Architectural Heritage" »

Understanding Malolactic Fermentation

Malolactic Fermentation (MLF) is a slow process where malic acid converts to lactic acid, softening the wine's acidity. Dry wines can have initial malic acid levels ranging from 1.2 g/L up to 5 g/L. After fermentation, the wine is left to rest, undergoing racking to clarify and stabilize it. This process aids in the wine's classification.

Young Wines: These wines are stabilized (e.g., through tartaric acid stabilization to prevent crystal formation), filtered, and then bottled.

Carbonic Maceration Explained

Carbonic Maceration is a technique primarily used for young, fruity red wines. Whole grape clusters are placed in sealed tanks and covered with carbon dioxide. Fermentation occurs intracellularly within... Continue reading "Winemaking Essentials: Processes, Aging, and Wine Styles" »

The Transformation of Soil

Soil is a nonrenewable resource that is essential not only for survival but for the life of people. Major threats affecting the soil are erosion, loss of organic matter, contamination, salinization, compaction, loss of biodiversity, landslides, and inundations, which may become irreversible. The transformation of the ground, compared to other resources, has been uneven across the planet. It has become 10 times faster than in the past.

Mineral Resources as a Source of Energy

These resources, such as coal, oil, and natural gas, have a renewal time that is useless for our purposes, so reserves will eventually be depleted. Many resources have formed from the incomplete decomposition of organic matter within the earth. The... Continue reading "Soil, Energy, and Biodiversity: Resources and Conservation" »

The Kyoto Protocol

The Kyoto Protocol is an international agreement that aims to reduce emissions of six greenhouse gases that cause global warming: carbon dioxide, methane, nitrous oxide, and three fluorinated industrial gases: hydrofluorocarbons, sulfur hexafluoride, and perfluorocarbons. The goal was to reduce emissions by approximately 5% between 2008 and 2012, compared to 1990 emissions. For example, if the contamination of these gases in 1990 reached 100%, by the end of 2012, it should have been at least 95%. It is important to note that this does not mean that each country must reduce its emissions of gases covered by 5% or more. Instead, this is a global percentage, and each country is bound by its own Kyoto emission rates.

The instrument... Continue reading "Kyoto Protocol: Reducing Greenhouse Gas Emissions" »

Gadidae Family

Fish with a compressed body, three dorsal fins, and a chin barbel on the lower jaw.

• Cod
• Haddock
• Whiting
• Saithe

Merluccidae Family

Fish with an elongated and slightly compressed fusiform body, two dorsal fins, and no chin barbel on the lower jaw.

• Maruja
• Hake
• Forkbeards

Cod

A demersal fish found in the cold waters of the North Atlantic, between 50 and 75 degrees N. They inhabit depths beyond the continental shelf, up to 500 or 600 meters. Cod undertake significant migrations between feeding and spawning grounds. Depending on their habitat in colder or less cold waters, sexual development and maturity will be more rapid or delayed.

Cod Spawning Grounds

• Iceland
• Newfoundland
• Labrador
• Lofoten Islands
• North Sea
• West Greenland
• Faroe Islands

Spawning occurs... Continue reading "Marine Fish Species: Biology, Habitats, and Migratory Patterns" »