Earth Science

A:

The main features of a volcano include a vent, a summit crater and a magma chamber. The vent is an opening through which volcanic material is erupted. Volcanoes can have more than one vent. The summit crater is the large concave opening that holds the central vent at the top of the volcano. The magma chamber is the large pool-like structure inside the volcano that holds the magma.

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  • What Are Man-Made Resources?

    Q: What Are Man-Made Resources?

    A: Man-made resources are items or substances that have value to human lives that do not occur in the natural world. Examples of man-made resources include plastic, paper, soda, sheet metal, rubber and brass. These contrast with natural resources, such as water, crops, sunlight, crude oil, wood and gold.
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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 Is Deforestation?

    Q: What Is Deforestation?

    A: Deforestation is clearing away woodlands to use the cleared land for other uses. Deforestation happens to all types of woodland, including jungle and rain forest. The land is often used for farming or urban development.
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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 Is a Grassland Ecosystem?

    Q: What Is a Grassland Ecosystem?

    A: A grassland ecosystem is the collection of plants, animals and micro-organisms that live within an environment where grasses are the primary form of vegetation. Examples of grassland ecosystems include the prairies of western North America, the Pampas of Argentina and the Russian steppes.
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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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  • Where Is Most of the Freshwater Found on Earth?

    Q: Where Is Most of the Freshwater Found on Earth?

    A: The majority of freshwater on earth is found in frozen glaciers and ice caps. This frozen water accounts for 68.7 percent of earth's freshwater, with 30.1 percent found in groundwater. Only 1.2 percent of fresh water is exposed to the surface of the planet.
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  • What Is a Physical Feature in Geography?

    Q: What Is a Physical Feature in Geography?

    A: Physical features in geography include bodies of water and landforms, for example, oceans, mountains, lakes, rivers, plateaus, plains, streams, hills, bays, gulfs, volcanoes, canyons, valleys and peninsulas are all various physical features. Anything that describes the Earth's topography is a physical feature.
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  • How Many Minutes of Daylight Do People Gain Each Day?

    Q: How Many Minutes of Daylight Do People Gain Each Day?

    A: In January, each day gains between 90 seconds and two minutes of daylight. In February, about two and a half minutes of daylight are added each day.
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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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  • How Do Glaciers Change the Landscape?

    Q: How Do Glaciers Change the Landscape?

    A: Glaciers alter the landscape through erosion of the soil and rocks over which they pass. This erosion process leaves a vertical-walled valley similar to an amphitheater at the glacier's sources, according to Reference.com. As they travel through V-shaped valleys, glaciers transform the valley into a U-shape, grinding away cliffs and the bases of slopes. If the ocean fills these valleys, they become fjords.
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  • How Does Altitude Affect Temperature?

    Q: How Does Altitude Affect Temperature?

    A: Air temperature decreases as altitude increases. Air is a mixture of gases, and at higher altitudes, air pressure decreases, which cools any gas. Air pressure on Earth is estimated to be about 14.7 pounds per square inch at sea level.
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  • How Are Rift Valleys Formed?

    Q: How Are Rift Valleys Formed?

    A: Rift valleys form when tectonic forces deep underground exert a pulling force on the terrain. In areas where this occurs, the land splits into a steep-walled valley with a flat floor. Rift valleys can be very narrow, especially early in their formation.
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  • What Are the Main Causes of Flooding?

    Q: What Are the Main Causes of Flooding?

    A: Heavy, consistent and prolonged rainfall coupled with the overflowing of rivers and other water channels is one of the main causes of flooding. As rainwater reaches and fills the river channels, the water spreads on the floodplain or the land next to the river and causes flooding.
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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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  • How Does the Sun Affect the Earth?

    Q: How Does the Sun Affect the Earth?

    A: The sun provides the Earth with energy in the form of heat, which it uses to warm the Earth's surface, oceans and atmosphere. The heat energy found in the atmosphere is one of the major components of the Earth's climate and climate change, according to Windows to the Universe.
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  • How Are Striations Formed?

    Q: How Are Striations Formed?

    A: Striations are a common feature of rocks that have once been overlain by a moving glacier. The scratches on the rock face are generally straight and all are oriented in the same direction, matching the downhill flow of the ice.
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  • Why Are Deserts Hot in the Day and Cold at Night?

    Q: Why Are Deserts Hot in the Day and Cold at Night?

    A: The heat that radiates from the sun and heats up the land begins to heat up the air and then escapes into the atmosphere due to the lack of clouds and humidity. This is the main reason that deserts can be hot during the day but cold during the night.
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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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  • How Many Volcanoes Does Hawai'i Have?

    Q: How Many Volcanoes Does Hawai'i Have?

    A: Hawai'i has seven primary volcanoes, out of which three are currently active. The eight primary islands that make up the state of Hawai'i are part of a series of volcanoes.
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  • What Is Considered Low Humidity?

    Q: What Is Considered Low Humidity?

    A: Any humidity of 30 percent or less is considered low and can be dangerous. Low humidity can cause breathing difficulties, discomfort and may damage a home's foundation.
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