Earth Science

A:

Transverse waves have two parts: a crest, which is the highest point of the wave, and the trough, which is the lowest part of the wave. Longitudinal waves also have two parts: compression, which are areas of high molecular density, and rarefactions, which are areas of low molecular density.

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  • What causes global winds?

    Q: What causes global winds?

    A: Global winds refer to the pattern of air movement all around the globe, and they result from the fact that the Earth receives unequal heating from the sun. Not only does the tilt of the Earth's axis mean that different parts of the planet receive disparate amounts of sunlight, but the oceans and lands also heat at different rates. The imbalance in temperature makes heat move toward the poles, both in the wind and in ocean currents. When horizontal variances in air pressure take place as a result, wind occurs.
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  • What is the Earth's revolution?

    Q: What is the Earth's revolution?

    A: The Earth's revolution occurs in two different ways. The Earth revolves around the sun, and it also revolves, or rotates, on its own axis.
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  • What are the advantages and disadvantages of fires?

    Q: What are the advantages and disadvantages of fires?

    A: Fires can cause damage to property and homes, but they are also a crucial instrument that has helped man forge tools and keep predators at bay. Even though burns can cause severe injuries to the skin, fire has also helped man cook food.
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  • What are the characteristics of metamorphic rocks?

    Q: What are the characteristics of metamorphic rocks?

    A: The characteristics of metamorphic rock are that some contain layers and streaks of different colors and textures caused by different minerals. Other metamorphic rocks are more uniform in color and texture and have minerals arranged in parallel layers.
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  • What would happen if there were no trees on earth?

    Q: What would happen if there were no trees on earth?

    A: Life could not exist on Earth without trees because they produce most of the oxygen that humans and wildlife breathe. Trees absorb carbon dioxide from the atmosphere and release oxygen using the process of photosynthesis. There would also be no rain without trees, since trees absorb water from the soil and release it through evapotranspiration. Water vapor released through evapotranspiration is the major mechanism by which air is remoistened.
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  • Who discovered the chloroplast?

    Q: Who discovered the chloroplast?

    A: Russian botanist Konstantin Mereschkowsky was the first person to discover the chloroplast. His discovery was the result of his work with lichens. In 1905, he began arguing for the symbiotic origin of the chloroplast and nucleus.
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  • Why do natural disasters happen?

    Q: Why do natural disasters happen?

    A: There are many different causes for natural disasters; seismic activity, air pressure, ocean currents and soil erosion are the main causes. A natural disaster can cause damage to property, loss of life and effect the economy of the local area.
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  • What technologies are used to explore deserts?

    Q: What technologies are used to explore deserts?

    A: Technologies used to explore deserts include robotic rovers, satellites, online mapping software and image-processing programs. NASA scientists use robotic rovers to explore deserts to prepare for the desert-like terrain located on Mars and the moon.
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  • What is the composition of air?

    Q: What is the composition of air?

    A: Air is a gaseous substance that is composed primarily of nitrogen, oxygen and argon. The air in the atmosphere that surrounds the Earth is approximately 78 percent nitrogen, 21 percent oxygen and 1 percent argon, with the remainder made up of various other gases including neon, helium and hydrogen.
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  • What are different types of tornadoes?

    Q: What are different types of tornadoes?

    A: There are six different types of tornadoes. The most commonly recognized type is the supercell tornado, the type that causes massive destruction. A gustnado is the opposite; it is very weak. It causes leaves and other debris to swirl around on the ground during a storm.
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  • What is the frost line depth in New York City?

    Q: What is the frost line depth in New York City?

    A: The average frost line depth in New York City is 36 inches. The frost line is the average depth in which the ground water in soil usually freezes. This is also referred to as "frost depth" or "freezing depth."
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  • What is the average temperature of a swamp?

    Q: What is the average temperature of a swamp?

    A: The average temperature range of the world's swamps is between 15 C and 35 C. Swamps fall into two categories: swamp forests and shrub swamps. Bogs are not true swamps because they are not forested, but they are often mislabeled as such.
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  • Why is the Mississippi River important?

    Q: Why is the Mississippi River important?

    A: The Mississippi River is important due to its necessity in American commerce. Cities such as New Orleans, St. Louis and Minneapolis all get water from the river.
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  • What causes day and night?

    Q: What causes day and night?

    A: The Earth is constantly spinning on its axis, allowing sunlight to shine on different areas of the Earth at different times of the day, creating daytime when the Sun hits a specific area. When the Sun is not shining on a specific area of the Earth, it is nighttime. Since the Sun does not hit all of the Earth at the same time, it is daytime in some parts of the world, while it is nighttime in others.
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  • Can tornadoes be predicted?

    Q: Can tornadoes be predicted?

    A: While it is currently not possible to predict a tornado with certainty, organizations like the National Oceanic and Atmospheric Administration issue tornado watches and warnings to areas experiencing tornado-friendly weather conditions. A watch is issued when a tornado is likely to occur, while a warning indicates a more immediate threat.
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  • How does weathering change the Earth's surface?

    Q: How does weathering change the Earth's surface?

    A: Weathering constantly changes the earth's surface by wearing away exposed surfaces, smoothing rough areas of rocks and causing rock materials to break down in time. Weathering creates soil and happens due to ice, wind, water, salt, acids and changes in temperature.
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  • What is the difference between local winds and global winds?

    Q: What is the difference between local winds and global winds?

    A: The term global winds refers to the six major wind belts that encircle the globe. Local winds, however, are the winds, or breezes, that are stirred up by the temperatures and topographical features of a small region or area. This is especially true of coastal areas.
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  • What are types of natural calamities?

    Q: What are types of natural calamities?

    A: Types of natural calamities include hurricanes, earthquakes and tsunamis. Often, these calamities are connected such that one sets off another, as with earthquakes and tsunamis. Natural calamities are differentiated from human-made calamities, such as industrial accidents.
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  • Why does a compass always point north?

    Q: Why does a compass always point north?

    A: The earth's magnetic field causes a compass to point north, as compasses are powered by magnets. The magnets inside compasses are drawn to the magnetic North Pole, which is about 1,000 miles south of the actual North Pole. Therefore, even though a compass always points north, it does not always point toward the true north.
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  • What is the hardest metal on Earth?

    Q: What is the hardest metal on Earth?

    A: Maraging steel is the hardest metal on Earth. This steel is an alloy of nickel, cobalt and molybdenum. Most of the hardest metals are not naturally occurring; instead, they are man-made alloys.
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  • How do humans affect the ecosystem?

    Q: How do humans affect the ecosystem?

    A: Human activity affects ecosystems in a wide variety of ways, but it primarily does so through agriculture, habitat destruction, water use and fishing. Whenever humans enter a habitat, they tend to reshape it to fit their own needs, destroying the resources that other animals use, which drives them out. The overuse of water drains natural aquifers and alters the local water table, and pollution can negatively affect wildlife populations.
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