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

Measuring Exoplanet Properties

The characteristics of extrasolar planets (exoplanets) are determined using various sophisticated techniques:

• Period and Distance: Measured by Doppler, astrometric, or transit methods.
• Eccentricity: Measured by Doppler or astrometric methods.
• Mass: Measured by Doppler or astrometric methods.
• Size: Measured primarily via the transit method.
• Density: Calculated using size (transit) plus mass (Doppler/astrometric) data.
• Atmospheric Composition and Temperature: Determined by transit or direct detection.

Limitations of Doppler Measurements

We cannot measure an exact mass for a planet without knowing the tilt of its orbit, because the Doppler shift tells us only the velocity toward or away from us. Therefore, Doppler data typically... Continue reading "Exoplanet Detection Methods and the Nebular Theory Challenge" »

Consonants. In phonetic materials, the noun "consonant" has the following meanings: a consonant sound; a letter representing a consonant sound in writing. Consonants are speech sounds produced by creating an obstruction (completely or partially) in the mouth for the air flow from the lungs, or the mouth passage is so narrow that the air is expelled with audible friction. There are 20 consonant letters in the English alphabet. They represent 24 consonant sounds.

Consonants are generally classified according to three basic dimensions:

1. The state of the glottis. This refers to whether or not the vocal cords vibrate in the production of the sound. If the vocal cords vibrate, the resulting sound will be voiced; if they don’t vibrate, the sound will

Natural Stone

River Rocks

Smooth and round. Used for decoration and pavements, especially in areas where children play.

Crushed Rocks

Irregular edges provide more friction. Used for paths or roads.

Types of Stone

Limestone

Porous, off-white sedimentary rock. Usually white and may contain animal fossils. Used for sculptures, buildings, and breakwaters.

Marble

Hard, dense metamorphic rock naturally formed from limestone. Cool to the touch and known for its resistance to compression and weather conditions. Available in a variety of colors and has a shiny finish when polished. Used for sculptures, decorations, columns, floors, and kitchen countertops.

Granite

Igneous rock composed of quartz, feldspar, and mica. Formed by the crystallization of volcanic magma... Continue reading "Rocks, Stones, and Ceramics: A Comprehensive Look at Construction Materials" »

Introduction to Geology Fundamentals

The Development of Geological Thought

The understanding of Earth's history evolved through competing theories:

• Mid-1600s – James Ussher: Catastrophism
  • Proposed that Earth’s landscapes were shaped primarily by sudden, short-lived catastrophes.
• 1795 – James Hutton: Uniformitarianism
  • States that the physical, chemical, and biological laws that operate today have operated throughout the geologic past.
  • Famous maxim: “The present is the key to the past.”

Energy Sources of the Earth System

The Earth system is powered by two main sources:

External Processes (Solar Energy)

The Sun drives external processes occurring in the:

• Atmosphere
• Hydrosphere
• At Earth’s surface

Internal Processes (Earth's Interior Heat)

The Earth... Continue reading "Fundamentals of Physical Geology: Structure, Systems, and Rock Cycle" »

Hello, I’m Aner, and I am going to do a review about hydro energy power. This renewable energy comes from hydropower (or water power), which is the power using the energy of moving water (falling water or fast-running water).

Hydroelectric energy can be defined as a form of hydropower where the motion of running water (kinetic energy) is converted into electricity. Hydroelectric energy is potential energy that is converted to kinetic energy through the forces of gravitation, which again comes from solar energy, driving the water cycle around. Thus, it is the result of heat energy from the sun and the gravitational forces from the earth. The water cycle is driven directly by solar energy. When the sun heats the water in the ocean, some of the... Continue reading "Harnessing Hydropower: Benefits and Applications of Hydro Energy" »

Hadean Eon: 4500-4000 Million Years Ago

Geology:

• Intense volcanic activity
• Intense meteorite activity
• Moon formation
• First solid crust
• Formation of mantle and core

Climate:

• Atmosphere formation
• Hydrosphere formation

Archean Eon: 4000-2500 Million Years Ago

Geology:

• First microcontinents (plate tectonics)

Biosphere:

• First prokaryotic cells (bacteria and archaea)

Proterozoic Eon: 2500-541 Million Years Ago

Geology:

• First supercontinent (Rodinia)
• Active tectonic activity

Climate:

• Extreme climates (interior of Rodinia)
• Major glaciation at the end - "Snowball Earth"

Biosphere:

• First eukaryotic cells
• First cyanobacteria - photosynthesis - O2 production
• First multicellular organisms

Phanerozoic Eon: 541 Million Years Ago - Present

Paleozoic Era (541-252 Million Years Ago)

• Cambrian

Sedimentary Rocks

Sedimentary rocks are produced from the weathering of preexisting rocks or biological matter.

• Detrital: Rocks produced from rock fragments.
• Chemical: Rocks produced by the precipitation of dissolved ions in water.
• Organic: Rocks produced by the accumulation of biological debris.

Sediments: Loose, solid particles originating from the weathering and erosion of preexisting rocks.

Deposition: The settling and coming to rest of transported materials and the accumulation of chemical or organic sediments, typically in water.

Lithification: The general term for processes converting loose sediments into sedimentary rock.

• Breccia: Coarse-grained clastic sedimentary rocks.
• Sandstone: Medium-grained clastic sedimentary rock.
• Shale: Fine-grained

Climate Change

Climate Change is the global variation in the Earth's climate. These changes can be caused by processes internal to the Earth, external forces or human activities. However, the influence that our activities have on the planet is called global warming. Because of this, the temperature has increased two degrees in the last thirty years and it will go on increasing in the future if we don't do anything. On the one hand, thousands of people have some responsibility for this change, but on the other hand there are other reasons, as for example: The greenhouse effect, To burn fossil's combustibles, The felling and burning of trees, The pollution that is caused by cars and factories. Some of these activities are giving off so much carbon... Continue reading "The Impact of Climate Change and How to Address It" »

Ozone Depletion

Problem

Ozone hole

The ozone layer

Causes

Chemicals

• Destructive agents: Freon and similar gases used in fridges, air conditioners, aerosols, etc.

Effects

• Skin cancer
• Death of ocean plankton
• Death of crustaceans
• Reduced harvest
• Increased smog
• Destruction of the ozone layer: More ultraviolet rays with an increase in skin cancer

Solutions

Substitution/replacement of these products.

Greenhouse Effect

Problem

Greenhouse effect

Causes

• Chemicals, gases
• Deforestation
• Burning of fossil fuels (coal, oil, peat)

Effects

• Melting of the polar ice caps
• Increase in the world sea level
• Floods
• Changes in the world climate
• Changes in world agriculture
• Droughts (long periods of very dry weather)
• Raising of average temperatures
• Increase in the Earth's global temperature

Solutions

• Reforestation
• Energy

Chapter 7: Volcanoes & Chapter 10: Restless Ocean

Volcanic Eruptions

Eruptions can be explosive (gases escape from melt) or quiescent ("Hawaiian" very fluid basaltic lavas).

Volcano Types

Volcano types include shield volcanoes (accumulation of fluid basaltic lavas, exhibit shape of broad domed structure) and composite volcanoes (large, nearly symmetrical, persistent eruption of viscous lava, conical shape).

Viscosity: Determined by temperature, composition, and amount of dissolved gases – how resistant to flow.

Pyroclastics: Pulverized rock, lava, and glass fragments ejected from vent.

Chapter 9: Oceans

Ocean Features

Continental Shelf: The gently sloping submerged portion of the continental margin that extends from the shoreline to the continental... Continue reading "Volcanoes, Oceans, and Seawater Composition: Key Concepts" »