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A solar flare, also known as a corona, is a long filament of solar material, erupting out from the sun into space. The Sun is Earth's major source of energy, yet the planet only receives a small portion of its energy and the Sun is just an ordinary star. Many stars produce much more energy than the Sun. The energy sour... | {
"Header 1": "GEOG 101",
"Header 2": "STAR ENERGY: NUCLEAR FUSION",
"token_count": 405,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Think about how the color of a piece of metal changes with temperature. A coil of an electric stove will start out black but with added heat will start to glow a dull red. With more heat, the coil turns a brighter red, then orange. At extremely high temperatures the coil will turn yellowwhite, or even blue-white (it's ... | {
"Header 1": "GEOG 101",
"Header 2": "STAR CLASSIFICATION",
"token_count": 1242,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Astronomy is one of the oldest sciences, and early civilizations performed methodical observations of the night sky, and astronomical artifacts have been found from much earlier periods. However, the invention of the telescope was required before astronomy was able to develop into a modern science.
The Big Bang Theor... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 2 SUMMARY",
"token_count": 262,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
In its broadest sense, geology is the study of Earth, it's interior and its exterior surface, the rocks and other materials that are around us, the processes that have resulted in the formation of those materials, the water that flows over the surface, and lies underground, the changes that have taken place over the va... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT IS GEOLOGY?",
"token_count": 817,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
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The Geologic Time Scale and the basic outline of Earth history were worked out long before we had any scientific means of assigning numerical units of age like years to events of Earth history. Working out Earth history depended on realizing some key principles of relative time. Nicholas Steno introduced a basic unders... | {
"Header 1": "GEOG 101",
"Header 2": "GEOLOGICAL TIME",
"token_count": 2048,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Geological Dating is a technique used in Geology to date a certain type of rock that contains radiometric elements and those radiometric elements decay at a constant rate. This unit will discuss several different types of dating, both relative and absolute.
*Figure 3.7 Geological Time S... | {
"Header 1": "GEOG 101",
"Header 2": "GEOLOGIC DATING",
"token_count": 1929,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
All the events of earth history can be placed in sequence using the principles of relative time called the five Principles of Stratigraphy. The Geologic Time Scale was completely worked out in the 19th Century using these principles and used as a calendar for telling the story of the earth.
Hutton's Uniformity Princi... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 3 SUMMARY",
"token_count": 281,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Cartography is the study, practice, and interpretation of maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.
The fundamental problems of traditional cartography are to:
- ➢ Set the map's agenda a... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT IS CARTOGRAPHY?",
"token_count": 2004,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Because the Earth is round, +180° (or 180° E) and -180° (or 180° W) are the same grid line, termed the International Date Line. Opposite the International Date Line is the prime meridian, the line of longitude defined as 0°. The north-south scale, called latitude, ranges from +90° (or 90° N) at the North Pole to -90° (... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT IS CARTOGRAPHY?",
"token_count": 681,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The term "map projection" refers to both the process and product of transforming spatial coordinates on a three-dimensional sphere to a two-dimensional plane. In terms of actual mechanics, most projections use mathematical functions that take as inputs locations on the sphere and translate them into locations on a two-... | {
"Header 1": "GEOG 101",
"Header 2": "PROJECTION MECHANICS",
"token_count": 2042,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
[Image](https://geo.libretexts.org/Bookshelves/Geography_(Physical)/Book%3A_Mapping%2C_Society%2C_and_Technology_(Manson)/03%3A_Scale_and_Projections#footnote-398-12) is used under [a CC BY-SA 3.0.](https://creativecommons.org/licenses/by-sa/3.0/us/)*
Compromise projections preserve not one property but instead seek ... | {
"Header 1": "GEOG 101",
"Header 2": "PROJECTION MECHANICS",
"token_count": 380,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The combination of a topographic map and this system can be used to locate features within a few acres and is a primary means of subdividing tracts of land for sale. The organization of the township-section system is based on the definition of baselines and principal meridians. The position of a baseline and meridian w... | {
"Header 1": "GEOG 101",
"Header 2": "PUBLIC LAND SURVEY",
"token_count": 277,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Students explored the concepts of scale, resolution, and projection. All maps also use a projection that can be formed from a developable surface and can preserve one or two properties at most.
In cartography, a map projection is a way to flatten a globe's surface into a plane to make a map. This requires a systemati... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 4 SUMMARY",
"token_count": 278,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The solar system is made up of the Sun, the planets that orbit the Sun, their satellites, dwarf planets, and many, many small objects, like asteroids and comets. All of these objects move, and we can see these movements. We notice the Sun rises in the eastern sky in the morning and sets in the western sky in the evenin... | {
"Header 1": "GEOG 101",
"Header 2": "THE SUN AND THE EARTH SYSTEM",
"token_count": 1507,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
It is a common misconception that summer is warm, and winter is cold because the Sun is closer to Earth in the summer and farther away from it during the winter. Remember that seasons are caused by the 23.5° tilt of Earth's axis of rotation and Earth's yearly revolution around the Sun. This results in one part of the E... | {
"Header 1": "GEOG 101",
"Header 2": "EARTH'S SEASONS",
"token_count": 1608,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
As the Earth rotates on its axis and revolves around the Sun, several different effects are produced.
The summer solstice is the longest day of the year, and the winter solstice is the shortest. The equinox is the time when the day and night are the same numbers of hours.
The reasons for the seasons are beyond the ... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 5 SUMMARY",
"token_count": 227,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Earth's atmosphere is a thin blanket of gases and tiny particles called air. We are most aware of air when it moves and creates wind. All living things need some of the gases in the air for life support. Without an atmosphere, Earth would likely be just another lifeless rock. Earth's atmosphere, along with the abundant... | {
"Header 1": "GEOG 101",
"Header 2": "THE SIGNIFICANCE OF THE ATMOSPHERE",
"token_count": 333,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Nitrogen and oxygen together make up 99% of the planet's atmosphere. The rest of the gases are minor components but are sometimes very important. Humidity is the amount of water vapor in the air. Humidity varies from place to place and season to season. This fact is obvious if you compare a summer day in Atlanta, Georg... | {
"Header 1": "GEOG 101",
"Header 2": "ATMOSPHERIC GASSES",
"token_count": 835,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The atmosphere is layered, corresponding with how the atmosphere's temperature changes with altitude. By understanding the way temperature changes with altitude, we can learn a lot about how the atmosphere works. While weather takes place in the lower atmosphere, interesting things, such as the beautiful aurora, happen... | {
"Header 1": "GEOG 101",
"Header 2": "LAYERS OF THE ATMOSPHERE",
"token_count": 1548,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Energy travels through space or material. This is obvious when you stand near a fire and feel its warmth or when you pick up the handle of a metal pot even though the handle is not sitting directly on the hot stove. Invisible energy waves can travel through air, glass, and even the vacuum of outer space. These waves ha... | {
"Header 1": "GEOG 101",
"Header 2": "ATMOSPHERIC HEAT, ENERGY & MOTION",
"token_count": 2017,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
[Image](https://commons.wikimedia.org/wiki/File:Katabatic-winds-antarctica.png) is used under a [Attribution-Share Alike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/deed.en) license.*
#### **Chinook Winds**
Chinook winds develop when air is forced up over a mountain range. This takes place, fo... | {
"Header 1": "GEOG 101",
"Header 2": "ATMOSPHERIC HEAT, ENERGY & MOTION",
"token_count": 729,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Because more solar energy hits the equator, the air warms and forms a low-pressure zone. At the top of the troposphere, half moves toward the North Pole and half toward the South Pole. As it moves along the top of the troposphere it cools. The cool air is dense and when it reaches a high-pressure zone it sinks to the g... | {
"Header 1": "GEOG 101",
"Header 2": "GLOBAL ATMOSPHERIC CIRCULATIONS",
"token_count": 1381,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The atmosphere is a mixture of nitrogen (78%), oxygen (21%), and other gases (1%) that surround Earth. High above the planet, the atmosphere becomes thinner until it gradually reaches space. It is divided into four layers, based on temperature, and two based on density. Most of the weather and clouds are found in the f... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 6 SUMMARY",
"token_count": 210,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
If someone across the country asks you what the weather is like today, you need to consider several factors. Air temperature, humidity, wind speed, the amount and types of clouds, and precipitation are all part of a thorough weather report. In this unit, you will learn about many of these features in more detail. Weath... | {
"Header 1": "GEOG 101",
"Header 2": "WEATHER & ATMOSPHERIC MOISTURE",
"token_count": 1975,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Where an air mass receives its characteristics of temperature and humidity is called the source region. Air masses are slowly pushed along by high-level winds when an air mass moves over a new region, it shares its temperature and humidity with that region. The temperature and humidity of a particular location depend p... | {
"Header 1": "GEOG 101",
"Header 2": "AIR MASSES",
"token_count": 1861,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Weather is experienced every day, but only some days experience extreme weather, such as storms. A storm's magnitude can vary immensely depending on whether they are composed of warm or cold air, originating off the ocean or off a continent, occurring in summer or winter, and many other factors. The effects of storms a... | {
"Header 1": "GEOG 101",
"Header 2": "TYPES OF EXTREME WEATHER",
"token_count": 2035,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The release of latent heat generates enormous amounts of energy, nearly the total annual electrical power consumption
of the United States from one storm. Hurricanes can also generate tornadoes. Hurricanes are strange phenomena because they are deadly monsters, yet have a gentle, but cold heart. The anatomy of a hurr... | {
"Header 1": "GEOG 101",
"Header 2": "TYPES OF EXTREME WEATHER",
"token_count": 604,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
People often confuse weather and climate; they are not identical. According to the American Meteorological Society (AMS), the weather is defined as the state of the atmosphere at some place and time, usually expressed in terms of temperature, air pressure, humidity, wind speed and direction, precipitation, and cloudine... | {
"Header 1": "GEOG 101",
"Header 2": "WEATHER VERSUS CLIMATE",
"token_count": 1277,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Weather, the state of the atmosphere at a particular place during a short period of time. It involves atmospheric phenomena such as temperature, humidity, precipitation (type and amount), air pressure, wind, and cloud cover.
An air mass is a large mass of air that has similar characteristics of temperature and humidi... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 7 SUMMARY",
"token_count": 392,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The best way to learn about Earth's crust would be to travel around the world, viewing minerals, rocks, and structures in a variety of places to see what they are and how they can be coaxed into telling Earth's story.
All matter is made of tiny particles. Protons, neutrons, and electrons form atoms that bond together... | {
"Header 1": "GEOG 101",
"Header 2": "MATERIALS OF EARTH'S CRUST",
"token_count": 868,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Minerals can be identified by their physical characteristics. The physical properties of minerals are related to their chemical composition and bonding. Some characteristics, such as a
mineral's hardness, are more useful for mineral identification. Color is readily observable and certainly obvious, but it is usually ... | {
"Header 1": "GEOG 101",
"Header 2": "BASIC MINERAL IDENTIFICATION",
"token_count": 2019,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
[Image](https://courses.lumenlearning.com/wmopen-geology/chapter/outcome-identifying-minerals/) is used under a [CC BY: Attribution](https://creativecommons.org/licenses/by/4.0/) license.*
Fracture is a break in a mineral that is not along a cleavage plane. Fracture is not always the same in the same mineral because ... | {
"Header 1": "GEOG 101",
"Header 2": "BASIC MINERAL IDENTIFICATION",
"token_count": 223,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
An atom has negatively charged electrons in orbit around its nucleus, which is composed of positively-charged protons and neutrons, which have no charge.
An atom that gains or loses electrons is an ion. Positively charged ions are cations, negatively charged ions are anions.
Minerals can be identified by their phys... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 8 SUMMARY",
"token_count": 362,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The rock components of the crust are slowly but constantly being changed from one form to another and the processes involved are summarized in the rock cycle. The rock cycle is driven by two forces:
- ➢ Earth's internal heat engine, which moves material around in the core and the mantle and leads to slow but signific... | {
"Header 1": "GEOG 101",
"Header 2": "THE ROCK CYCLE",
"token_count": 2024,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Others, such as pumice, contain holes where gas bubbles were trapped when the material was still hot and molten. The holes make pumice so light that it floats in water. The most common extrusive igneous rock is basalt, a rock that is especially common below the oceans.
*Figure 9.7 Clos... | {
"Header 1": "GEOG 101",
"Header 2": "THE ROCK CYCLE",
"token_count": 362,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Igneous rocks are classified according to how and where they formed, in other words, if they're plutonic or volcanic, and their mineral composition, describing the minerals they contain. The
mineral compositions of igneous rocks are usually described as being felsic, intermediate, mafic, or ultramafic.
As a mafic m... | {
"Header 1": "GEOG 101",
"Header 2": "COMPOSITION",
"token_count": 578,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Igneous rocks form either when they cool very slowly deep within the Earth or when magma cools rapidly at the Earth's surface. The composition of the magma will determine the minerals that will crystallize forming different types of igneous rocks.
Intrusive, or plutonic, igneous rock forms when magma is trapped deep ... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 9 SUMMARY",
"token_count": 358,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Transportation is the movement of sediments or dissolved ions from the site of erosion to a site of deposition; this can be by wind, flowing water, glacial ice, or mass movement down a slope. The deposition takes place where the conditions change enough so that sediments being transported can no longer be transported, ... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT ARE SEDIMENTARY ROCKS?",
"token_count": 2036,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
After this stage, the individual clasts are all touching one another. Cementation is the process of crystallization of minerals within the pores between the small clasts, and also at the points of contact between the larger clasts (sand size and larger). Depending on the pressure, temperature, and chemical conditions, ... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT ARE SEDIMENTARY ROCKS?",
"token_count": 967,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Whereas clastic sedimentary rocks are dominated by components that have been transported as solid clasts (clay, silt, sand, etc.), chemical sedimentary rocks are dominated by components that have been transported as ions in solution (Na<sup>+</sup> , Ca2+, HCO<sup>3</sup> – , etc.). There is some overlap between the tw... | {
"Header 1": "GEOG 101",
"Header 2": "CHEMICAL SEDIMENTARY ROCKS",
"token_count": 1471,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Through careful observation over the past few centuries, geologists have discovered that the accumulation of sediments and sedimentary rocks takes place according to some important geological principles, as follows:
- ➢ The principle of original horizontality states that sediments accumulate in essentially horizontal... | {
"Header 1": "GEOG 101",
"Header 2": "SEDIMENTARY STRUCTURES",
"token_count": 1269,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The word fossil comes from the Latin term *fossilis*, meaning "dug up." Fossils are formed when an organism is buried by water containing debris and minerals and through the effects of wind or gravity. Most fossils are found in sedimentary rocks. Fossils can also be found in metamorphic rock or rock that has been alter... | {
"Header 1": "GEOG 101",
"Header 2": "FOSSILS",
"token_count": 651,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Sedimentary clasts are classified based on their size, and variations in clast size have important implications for transportation and deposition. Clastic sedimentary rocks range from conglomerate to mudstone. Clast size, sorting, composition, and shape are important features that allow us to differentiate clastic rock... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 10 SUMMARY",
"token_count": 305,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
M is the change that takes place within a body of rock as a result of it being subjected to conditions that are different from those in which it formed. In most cases, but not all, this involves the rock being deeply buried beneath other rocks, where it is subjected to higher temperatures and pressures than those under... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT IS METAMORPHISM?",
"token_count": 1281,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
There are two main types of metamorphic rocks: those that are foliated because they have formed in an environment with either directed pressure or shear stress, and those that are not foliated because they have formed in an environment without directed pressure or relatively near the surface with very little pressure a... | {
"Header 1": "GEOG 101",
"Header 2": "CLASSIFICATION OF METAMORPHIC ROCKS",
"token_count": 1732,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
All of the important processes of metamorphism that we are familiar with can be directly related to geological processes caused by plate tectonics.
Most regional metamorphism takes place within continental crust. While rocks can be metamorphosed at depth in most areas, the potential for metamorphism is greatest in th... | {
"Header 1": "GEOG 101",
"Header 2": "PLATE TECTONICS & METAMORPHISM",
"token_count": 1671,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Metamorphism is controlled by five main factors: the composition of the parent rock, the temperature to which the rock is heated, the amount and type of pressure, the volumes and compositions of aqueous fluids that are present, and the amount of time available for metamorphic reactions to take place.
Metamorphic rock... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 11 SUMMARY",
"token_count": 290,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Weathering is what takes place when a body of rock is exposed to the weather, in other words, to the forces and conditions that exist at Earth's surface. Except for volcanic rocks and some sedimentary rocks, most rocks are formed at some depth within the crust. There they experience relatively constant temperature, hig... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT IS WEATHERING?",
"token_count": 1995,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
That process, which is fundamental to most chemical weathering, can be shown as follows:
$$H_2O + CO_2 \longrightarrow H_2CO_3$$
then $H_2CO_3 \longrightarrow H^+ + HCO_3^-$ , water + carbon dioxide $\longrightarrow$ carbonic acid then carbonic acid $\longrightarrow$ hydrogen ion + carbonate ion
Here we have w... | {
"Header 1": "GEOG 101",
"Header 2": "WHAT IS WEATHERING?",
"token_count": 1678,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Weathering is a key part of the process of the soil formation, and the soil is critical to our existence on Earth. In other words, we owe our existence to weathering, and we need to take care of our soil.
Many people refer to any loose material on Earth's surface as soil, but to earth scientists, soil is the material... | {
"Header 1": "GEOG 101",
"Header 2": "FORMATION OF SOIL",
"token_count": 1927,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Rocks weather when they are exposed to surface conditions, which in most cases are quite different from those at which they formed. The main processes of mechanical weathering include exfoliation, freeze-thaw, salt crystallization, and the effects of plant growth.
Chemical weathering takes place when minerals within ... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 12 SUMMARY",
"token_count": 362,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Before you can learn about plate tectonics, you need to know something about the layers that are found inside Earth. These layers are divided by composition into core, mantle, and crust or by mechanical properties into the lithosphere and asthenosphere. Scientists use information from earthquakes and computer modeling ... | {
"Header 1": "GEOG 101",
"Header 2": "SEEING EARTH'S INTERIOR",
"token_count": 765,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Core, mantle, and crust are divisions based on composition. The crust makes up less than 1%of Earth by mass, consisting of oceanic crust and continental crust is often more felsic rock. The mantle is hot and represents about 68% of Earth's mass. Finally, the core is mostly iron metal. The core makes up about 31% of the... | {
"Header 1": "GEOG 101",
"Header 2": "THE COMPOSITION & STRUCTURE OF EARTH",
"token_count": 1445,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The continental drift hypothesis was developed in the early part of the 20th century, mostly by Alfred Wegener. Wegener said that continents move around on Earth's surface and that they were once joined together as a single supercontinent. While Wegener was alive, scientists did not believe that the continents could mo... | {
"Header 1": "GEOG 101",
"Header 2": "THEORY OF CONTINENTAL DRIFT",
"token_count": 1314,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Puzzling new evidence came in the 1950s from studies on the Earth's magnetic history. Scientists used magnetometers, devices capable of measuring the magnetic field intensity, to look at the magnetic properties of rocks in many locations. Geologists noted important things about the magnetic polarity of different aged r... | {
"Header 1": "GEOG 101",
"Header 2": "THEORY OF CONTINENTAL DRIFT",
"Header 3": "**Magnetic Polarity on The Same Continent with Rocks of Different Ages**",
"token_count": 310,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
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Geologists noted that for rocks of the same age but on different continents, the little magnets pointed to different magnetic north poles. For example, 400-million-year-old magnetite in Europe pointed to a different north magnetic pole than the same-aged magnetite in North America. Around 250 million years ago, the nor... | {
"Header 1": "GEOG 101",
"Header 2": "THEORY OF CONTINENTAL DRIFT",
"Header 3": "**Magnetic Polarity on Different Continents with Rocks of The Same Age**",
"token_count": 221,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The discovery of magnetic striping naturally prompted more questions: How does the magnetic striping pattern form? And why are the stripes symmetrical around the crests of the mid-ocean ridges? These questions could not be answered without also knowing the significance of these ridges. In 1961, scientists began to theo... | {
"Header 1": "GEOG 101",
"Header 2": "SEAFLOOR SPREADING",
"token_count": 1114,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
When the concept of seafloor spreading came along, scientists recognized that it was the mechanism to explain how continents could move around Earth's surface. Scientific data and observation now allow us to merge the ideas of continental drift and seafloor spreading into the theory of plate tectonics. Seafloor and con... | {
"Header 1": "GEOG 101",
"Header 2": "EARTH'S TECTONIC PLATES",
"token_count": 2027,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Examples of mountain ranges created by this process are the Himalayan mountains as India is colliding with Asia, the Alps in Europe, and the Appalachian Mountains in the United States as the North American plate collided with the African plate when Pangea was forming. The Kashmir India ... | {
"Header 1": "GEOG 101",
"Header 2": "EARTH'S TECTONIC PLATES",
"token_count": 710,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The evidence for continental drift in the early 20th century included the matching of continental shapes on either side of the Atlantic and the geological and fossil matchups between continents that are now thousands of kilometers apart.
The established theories of global geology were permanentism and contractionism,... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 13 SUMMARY",
"token_count": 342,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Enormous slabs of lithosphere move unevenly over the planet's spherical surface, resulting in earthquakes. This chapter deals with two types of geological activity that occur because of plate tectonics: mountain building and earthquakes. First, we will consider what can happen to rocks when they are exposed to stress. ... | {
"Header 1": "GEOG 101",
"Header 2": "CAUSES & TYPES OF TECTONIC STRESS",
"token_count": 481,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
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Sedimentary rocks are important for deciphering the geologic history of a region because they follow certain rules. First, sedimentary rocks are formed with the oldest layers on the bottom and the youngest on top. Second, sediments are deposited horizontally, so sedimentary rock layers are originally horizontal, as are... | {
"Header 1": "GEOG 101",
"Header 2": "GEOLOGIC STRUCTURES",
"token_count": 1153,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Nearly 95% of all earthquakes take place along one of the three types of tectonic plate boundaries, but earthquakes do occur along all three types of plate boundaries. About 80% of all earthquakes strike around the Pacific Ocean basin because it is lined with convergent and transform boundaries. Called the Ring of Fire... | {
"Header 1": "GEOG 101",
"Header 2": "EARTHQUAKES & ZONES",
"token_count": 2036,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
|
| 9.0 – 9.9 | Great | Severe damage to most<br>buildings. | 1 per 5-50 years. |
| 10.0 OR OVER | Massive | Never recorded. | Never recorded... | {
"Header 1": "GEOG 101",
"Header 2": "EARTHQUAKES & ZONES",
"token_count": 1325,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
An earthquake is the shaking that results when a body of rock that has been deformed breaks and the two sides quickly slide past each other. The rupture is initiated at a point but quickly spreads across an area of a fault, via a series of aftershocks initiated by stress transfer. Episodic tremor and slip is a periodic... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 14 SUMMARY",
"token_count": 420,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
A volcano is any location where magma comes to the surface or has done so within the past several million years. This can include eruptions on the ocean floor (or even under the water of lake), where they are called subaqueous eruptions, or on land, where they are called subaerial eruptions. Not all volcanic eruptions ... | {
"Header 1": "GEOG 101",
"Header 2": "VOLCANISM",
"token_count": 1960,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The sizes and shapes of a typical shield, composite, and cinder cone volcanoes are compared in the table below, although, to be fair, Mauna Loa is the largest shield volcano on Earth; all others are smaller. Mauna Loa rises from the surrounding flat seafloor, and its diameter is in the order of 200 km. Its elevation is... | {
"Header 1": "GEOG 101",
"Header 2": "TYPES OF VOLCANOES",
"token_count": 2021,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
At Kilauea, the magma chamber appears to be several kilometers in diameter and is situated between 8 km and 11 km below the surface Although it is not a prominent mountain, Kilauea volcano has a large caldera in its summit area. A caldera is a volcanic crater that is more than 2 km in diameter; this one is 4 km long an... | {
"Header 1": "GEOG 101",
"Header 2": "TYPES OF VOLCANOES",
"token_count": 779,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
There are two classes of volcanic hazards, direct and indirect. Direct hazards are forces that directly kill or injure people or destroy property or wildlife habitat. Indirect hazards are volcanism-induced environmental changes that lead to distress, famine, or habitat destruction. Indirect effects of volcanism have ac... | {
"Header 1": "GEOG 101",
"Header 2": "VOLCANIC HAZARDS",
"token_count": 1312,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Volcanism is closely related to plate tectonics. Most volcanoes are associated with convergent plate boundaries (at subduction zones), and there is also a great deal of volcanic activity at divergent boundaries and areas of continental rifting. At convergent boundaries magma is formed where water from a subducting plat... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 15 SUMMARY",
"token_count": 476,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Most people love shorelines. They love panoramic ocean views, they love sandy beaches on crystal-clear lakes, they love to swim and surf and go out in boats, and they love watching the giant waves crash onto rocky shores. While an understanding of coastal processes isn't necessary for our enjoyment of coastal regions, ... | {
"Header 1": "GEOG 101",
"Header 2": "SHORELINES",
"token_count": 2027,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Longshore drift moves a tremendous amount of sediment along coasts (both oceans and large lakes) around the world.
*Figure 16.91 The Movement of Particles on a Beach as a Result of Swash and Backwash[. Image](https://opentextbc.ca/physicalgeology2ed/chapter/17-1-waves/) by Steven Earle[... | {
"Header 1": "GEOG 101",
"Header 2": "SHORELINES",
"token_count": 613,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Large waves crashing onto a shore bring a tremendous amount of energy that has a significant eroding & depositional effect, and several unique erosion & depositional features form on rocky & sandy shores.
#### **Erosional Landforms**
When waves approach an irregular shore, they are slowed down to varying degrees, d... | {
"Header 1": "GEOG 101",
"Header 2": "LANDFORMS OF COASTAL EROSION & DEPOSITION",
"token_count": 1646,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Sea-level change has been a feature on Earth for billions of years, and it has important implications for coastal processes and both erosional and depositional features. There are three main mechanisms of sea-level change, as described below.
Eustatic sea-level changes are global sea-level changes related either to c... | {
"Header 1": "GEOG 101",
"Header 2": "SEA-LEVEL CHANGE",
"token_count": 994,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
There are various modifications that we make in an attempt to influence beach processes for our purposes. Sometimes these changes are effective and may appear to be beneficial, although in most cases there are unintended negative consequences that we don't recognize until much later.
An example is at the beach near M... | {
"Header 1": "GEOG 101",
"Header 2": "HUMAN INTERFERENCE WITH SHORELINES",
"token_count": 707,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Waves form when the wind blows over water. The size of the waves depends on the wind speed, the area over which it is blowing, and time. The important parameters of a wave are its amplitude, wavelength, and speed. The water beneath a wave is disturbed to a depth of onehalf the wavelength, and a wave is slowed when it a... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 16 SUMMARY",
"token_count": 577,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Streams are the most important agents of erosion and transportation of sediments on Earth's surface. They are responsible for the creation of much of the topography that we see around us. They are also locations of great beauty and tranquility, and of course, they provide much of the water that is essential to our exis... | {
"Header 1": "GEOG 101",
"Header 2": "RIVERS",
"token_count": 614,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Freshwater in streams, ponds, and lakes is an extremely important part of the water cycle if only because of its importance to living creatures. Along with wetlands, these freshwater regions contain a tremendous variety of organisms. Streams are bodies of water that have a current; they are in constant motion. Geologis... | {
"Header 1": "GEOG 101",
"Header 2": "STREAMS & RIVERS",
"token_count": 1779,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Flowing water is a very important mechanism for both erosion and deposition. Water flow in a stream is primarily related to the stream's gradient, but it is also controlled by the geometry of the stream channel. Water flow velocity is decreased by friction along the stream bed, so it is slowest at the bottom and edges ... | {
"Header 1": "GEOG 101",
"Header 2": "STREAM EROSION & DEPOSITION",
"token_count": 2041,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The Owens River next to Lone Pine in California is a good example of this.
Old age streams are easily identified by their very low gradient, rich meanders, and a plethora of oxbow lakes and meander scars. The depositional process becomes more predominant and begins forming deltas, estuaries, levees, and distributarie... | {
"Header 1": "GEOG 101",
"Header 2": "STREAM EROSION & DEPOSITION",
"token_count": 256,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Water is stored for later use in natural water sources, such as groundwater aquifers, soil water, natural wetlands, and small artificial ponds, tanks and reservoirs behind major dams. Storing water invites a host of potential issues regardless of that water's intended purpose, including contamination through organic an... | {
"Header 1": "GEOG 101",
"Header 2": "WATER STORAGE",
"token_count": 2037,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
When coastal aquifers are overused, saltwater from the ocean may enter the aquifer, contaminating the aquifer and making it less useful for drinking and irrigation. Saltwater incursion is a problem in developed coastal regions, such as in Hawaii.
#### **Springs & Wells**
Groundwater meets the surface in a stream, a... | {
"Header 1": "GEOG 101",
"Header 2": "WATER STORAGE",
"token_count": 420,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Water is stored in the oceans, glacial ice, the ground, lakes, rivers, and the atmosphere. Its movement is powered by the sun and gravity.
All of the precipitation that falls within a drainage basin flows into the stream that drains that area. Stream drainage patterns are determined by the type of rock within the bas... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 17 SUMMARY",
"token_count": 288,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The entire solid surface of the Earth is subject to wind erosion. It is the balance between the driving force of the wind and the resistance of the surface that ultimately determines whether surface materials are detached and transported away.
The roughness length of the surface, a parameter based on the size and dis... | {
"Header 1": "GEOG 101",
"Header 2": "EROSIONAL FEATURES",
"token_count": 1103,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
A sand dune is an accumulation of loose sand grains piled up by the wind. Dunes are most likely to form where winds are strong and generally blow from the same direction. Some of the most extensive dune fields are found in the world's great deserts like the Sahara. The dune fields of these great sandy deserts are calle... | {
"Header 1": "GEOG 101",
"Header 2": "DEPOSITIONAL FEATURES & DUNE TYPES",
"token_count": 2039,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
When an alluvial fan is built by debris the flow, then it is referred to as the debris cone or colluvial fan.
*Figure 18.125 Alluvial Fan in Death Valley. [Image](https://upload.wikimedia.org/wikipedia/commons/f/fc/Alluvial_Fan.jpg) on Wikimedia Commons is in the Public Domain.*
Allu... | {
"Header 1": "GEOG 101",
"Header 2": "DEPOSITIONAL FEATURES & DUNE TYPES",
"token_count": 603,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
Rain does fall occasionally in deserts, and desert storms are often violent. A record 44 millimeters of rain once fell within 3 hours in the Sahara. Large Saharan storms may deliver up to 1 millimeter per minute. Normally dry stream channels, called arroyos or wadis, can quickly fill after heavy rains, and flash floods... | {
"Header 1": "GEOG 101",
"Header 2": "OTHER GEOMORPHIC ARID FEATURES",
"token_count": 1653,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The arid environment can be defined as one in which the amount of precipitation an area receives, divided by the amount, which is lost to evapotranspiration. The arid environment can be organized into three zones: hyper-arid, arid, and semi-arid. The zones are characterized by low annual precipitation.
Dunes are made... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 18 SUMMARY",
"token_count": 257,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
A glacier is a long-lasting body of ice (decades or more) that is large enough (at least tens of meters thick and at least hundreds of meters in extent) to move under its own weight. About 10% of Earth's land surface is currently covered with glacial ice, and although the vast majority of that is in Antarctica and Gree... | {
"Header 1": "GEOG 101",
"Header 2": "GLACIERS",
"token_count": 2020,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
These variations are attributed to subtle changes in Earth's orbital parameters (Milankovitch cycles), which are explained in more detail in this unit. Over the past million years, the glaciation cycles have been approximately 100,000 years.
*Figure 19.134 Foram Oxygen Isotope Record fo... | {
"Header 1": "GEOG 101",
"Header 2": "GLACIERS",
"token_count": 454,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
There are two main types of glaciers. Continental glaciers cover vast areas of land in extreme Polar Regions, including Antarctica and Greenland. Alpine glaciers, otherwise known as valley glaciers, originate on mountains, mostly in temperate and Polar Regions, but even in tropical regions if the mountains are high eno... | {
"Header 1": "GEOG 101",
"Header 2": "HOW GLACIERS WORK",
"token_count": 2042,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
In areas where there are differences in the strength of rocks, a glacier tends to erode the softer and weaker rock more effectively than the harder and stronger rock. Much of central and eastern Canada, which was completely covered by the huge Laurentide Ice Sheet at various times during the Pleistocene, has been erode... | {
"Header 1": "GEOG 101",
"Header 2": "HOW GLACIERS WORK",
"token_count": 2026,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
*Figure 19.148 A Depiction of the Various Types of Sediments Associated with Glaciation[. Image](https://opentextbc.ca/geology/chapter/16-4-glacial-deposition/) by Steven Earle[, CC](https://creativecommons.org/licenses/by/4.0/) [BY 4.0.](https://creativecommons.org/licenses/by/4.0/)*... | {
"Header 1": "GEOG 101",
"Header 2": "HOW GLACIERS WORK",
"token_count": 1135,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
There have been many glaciations in Earth's distant past, the oldest known starting around 2,400 Ma. The late Proterozoic "Snowball Earth" glaciations were thought to be sufficiently intense to affect the entire planet. The current glacial period is known as the Pleistocene Glaciation, and while it was much more intens... | {
"Header 1": "GEOG 101",
"Header 2": "UNIT 19 SUMMARY",
"token_count": 567,
"source_pdf": "datasets/websources/Geography_v1/Geography/GEOG101_version1.pdf"
} |
The aim of this book is to provide undergraduate students who are embarking upon Geography programs in universities throughout the world with a concise introduction to Human Geography.
It is my view that all students completing a three- or four-year program of study in Human Geography should emerge with an understand... | {
"Header 1": "**Preface**",
"Header 3": "For Whom This Book Is Written and Why",
"token_count": 1264,
"source_pdf": "datasets/websources/Geography_v1/Geography/human-geography_-a-concise-introduction-pdfdrive-.pdf"
} |
As you will discover in this book, Human Geography is a child of Western civilization and as such has developed thus far largely as a quintessential Western academic subject*.* In many ways, Human Geography continues to bear the stamp of its emergence in and through the rise of the West from the fifteenth century, its ... | {
"Header 1": "**Preface**",
"Header 3": "Locating Seminal Thinkers",
"token_count": 379,
"source_pdf": "datasets/websources/Geography_v1/Geography/human-geography_-a-concise-introduction-pdfdrive-.pdf"
} |
To assist instructors and students, this book has incorporated a number of learning supports. Use of these learning supports will help you to make the most of the book.
*Chapter Learning Objectives and Checklist Of Key Ideas*: To clarify for students the core points to be alert to, each chapter will begin with a box ... | {
"Header 1": "**Preface**",
"Header 3": "Learning Supports",
"token_count": 577,
"source_pdf": "datasets/websources/Geography_v1/Geography/human-geography_-a-concise-introduction-pdfdrive-.pdf"
} |
I have found from first-hand experience that not enough students show evidence of reading in their final examinations. This lament would appear to be widely shared; if I had a Dollar, Euro, Pound, Yuan, or Yen for every time I have heard colleagues from around the world complain that their students don't read enough, l... | {
"Header 1": "**Preface**",
"Header 3": "Finally … A Pre-departure Safety Briefing",
"token_count": 1164,
"source_pdf": "datasets/websources/Geography_v1/Geography/human-geography_-a-concise-introduction-pdfdrive-.pdf"
} |
In the twenty-first century humanity will be forced to confront a number of questions of epic significance. How many people will exist on planet earth in the year 2100 and where will these people live? Can the earth support continued population and economic growth? Is climate change really happening and what might its ... | {
"Header 1": "**A Concise Introduction to Human Geography**",
"Header 3": "Introduction",
"token_count": 432,
"source_pdf": "datasets/websources/Geography_v1/Geography/human-geography_-a-concise-introduction-pdfdrive-.pdf"
} |
Indulge your imagination for a second and try to visualize the sorts of people, places, and landscapes you might encounter were you to embark upon a whirlwind tour of the world. What do you see in your mind's eye? Try to imagine that you are now in some of those locations. What is your sense of the places you are visit... | {
"Header 1": "**A Concise Introduction to Human Geography**",
"Header 3": "Becoming Conscious of Your Geographical Imagination",
"token_count": 441,
"source_pdf": "datasets/websources/Geography_v1/Geography/human-geography_-a-concise-introduction-pdfdrive-.pdf"
} |
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