Earth Science

A:

An active volcano is one that has had at least one eruption in the past 10,000 years. An active volcano can be dormant or erupting.

See Full Answer
Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • What Are Some Interesting Facts About Icebergs?

    Q: What Are Some Interesting Facts About Icebergs?

    A: Fresh water is turned into an iceberg by the splitting or calving of glaciers. Bergs also vary wildly in shape and can be steep or irregular with rounded or flat tops. Because wind and water erode them, they constantly shift shape.
    See Full Answer
    Filed Under:
  • What Are Some Interesting Facts About the Hubbard Glacier?

    Q: What Are Some Interesting Facts About the Hubbard Glacier?

    A: The Hubbard Glacier is the largest tidewater glacier in North America. A tidewater glacier is one that flows into the ocean. The glacier is approximately 7 miles wide at its foot and 76 miles long. These measurements are constantly changing as the Hubbard Glacier continues to grow and move forward.
    See Full Answer
    Filed Under:
  • What Is Collection in the Water Cycle?

    Q: What Is Collection in the Water Cycle?

    A: Collection refers to the process by which water gathers back into bodies of water such as rivers, lakes and oceans. This begins with precipitation, when water falls from the clouds in the form of rain, snow, sleet or hail. A lot of the time, precipitation falls directly into a body of water, but at other times, it soaks into the ground, where plants, people and animals end up drinking it as ground water. Most of the water will end up leaching back into bodies of water through the soil.
    See Full Answer
    Filed Under:
  • Can We Stop the Polar Ice Caps From Melting?

    Q: Can We Stop the Polar Ice Caps From Melting?

    A: Whether or not humankind can keep the polar ice caps from melting is a subject of great debate in which both side cite scientific studies that support their positions. The bulk of scientific and environmental organizations, however, believe that humans can slow or even halt the melting of polar ice caps and global warming by reducing the use of fossil fuels and other man-made chemicals.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • What Are Some Examples of Ductile Metals?

    Q: What Are Some Examples of Ductile Metals?

    A: Gold and platinum are the most ductile metals on the periodic table of elements. Metals like copper, iron, nickel, manganese, silver, iridium, osmium, tungsten, tantalum, hafnium, rhenium, tin and zirconium can be drawn into very long wires. An ounce of gold can be drawn into a wire 50 miles long.
    See Full Answer
    Filed Under:
  • What Are the Parts of a Wave?

    Q: What Are the Parts of a Wave?

    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.
    See Full Answer
    Filed Under:
  • How Do Glaciers Cause Erosion?

    Q: How Do Glaciers Cause Erosion?

    A: Glaciers erode the land in three primary ways: plucking, abrasion and freeze-thaw. All three manners of erosion combine to make glaciers one of the world’s most powerful agents of erosion.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • What Are the Water Cycle Steps, in Order?

    Q: What Are the Water Cycle Steps, in Order?

    A: In order, the steps of the water cycle are evaporation, condensation, sublimation, precipitation, transpiration, runoff and infiltration. Together, all of the steps help regulate the Earth’s water supply and climate.
    See Full Answer
    Filed Under:
  • Why Is a Pothole Called a Pothole?

    Q: Why Is a Pothole Called a Pothole?

    A: The word "pothole" can be split into two distinct morphemes. The first part being "pot," a word derived from Middle English that means "a deep hole," and the second part being "hole," which maintains the same meaning today, that is, a hollowness in the ground.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under:
  • 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.
    See Full Answer
    Filed Under: