• escarpment
    Wavy escarpment in Australia.

    Photograph by Uli Schnakenberg, MyShot

    Rupes
    Earth isn't the only place on which you'll find escarpments. Rupes, created by faulting, erosion, or the impact of a meteorite, are escarpments on other planets or moons. Rupes is the Latin word for cliff. There are rupes on Mercury, Mars, our own moon, and the rocky moons of other planets.

    An escarpment is an area of the Earth where elevation changes suddenly. Escarpment usually refers to the bottom of a cliff or a steep slope. (Scarp refers to the cliff itself.)

    Escarpments separate two level land surfaces. For example, an escarpment could be the area separating the lower parts of the coast from higher plateaus. An escarpment also usually indicates two different types of land, such as the area on a rocky beach where tall cliffs become rocky sand.

    One side of an escarpment could be rock from one geologic era, while the other side of the escarpment could be rock from a different geologic era.

    Escarpments are formed by one of two processes: erosion and faulting.

    Erosion creates an escarpment by wearing away rock through wind or water. One side of an escarpment may be eroded more than the other side. The result of this unequal erosion is a transition zone from one type of sedimentary rock to another. One example is the Niagara Escarpment, which runs in an arc from the U.S. state of New York, through the Canadian province of Ontario, and down to the U.S. state of Illinois. All along the Niagara Escarpment, hard, resistant rock sat on top of soft rock. As wind and water eroded the soft rock underneath, the hard rock tumbled down, creating cliffs and escarpments. The most dramatic example of this unequal erosion is the waterfalls at Niagara Falls.

    The other process by which escarpments are formed is faulting. Faulting is movement of the Earths top layer, or crust, along a crack called a fault. The same process often results in earthquakes. Faulting creates escarpments as it moves pieces of the Earth around. The Elgeyo Escarpment, part of Kenyas Great Rift Valley, was formed by faulting millions of years ago. The faulting that resulted in the Elgeyo Escarpment turned seabeds into nearly vertical cliffs.

    Escarpments are found on every continent, even Antarctica.

  • Term Part of Speech Definition Encyclopedic Entry
    beach Noun

    narrow strip of land that lies along a body of water.

    Encyclopedic Entry: beach
    cliff Noun

    steep wall of rock, earth, or ice.

    Encyclopedic Entry: cliff
    coast Noun

    edge of land along the sea or other large body of water.

    Encyclopedic Entry: coast
    continent Noun

    one of the seven main land masses on Earth.

    Encyclopedic Entry: continent
    crust Noun

    rocky outermost layer of Earth or other planet.

    Encyclopedic Entry: crust
    earthquake Noun

    the sudden shaking of Earth's crust caused by the release of energy along fault lines or from volcanic activity.

    elevation Noun

    height above or below sea level.

    Encyclopedic Entry: elevation
    erosion Noun

    act in which earth is worn away, often by water, wind, or ice.

    Encyclopedic Entry: erosion
    escarpment Noun

    cliff or steep rock that separates two level land surfaces.

    Encyclopedic Entry: escarpment
    fault Noun

    a crack in the Earth's crust where there has been movement.

    faulting Noun

    movement of rocks and tectonic plates beneath the Earth's surface.

    geologic era Noun

    one of 10 major periods in geologic history, each lasting several hundred million years. We are in the Cenozoic era.

    Great Rift Valley system Noun

    series of faults and other sites of tectonic activity stretching from southwestern Asia to the Horn of Africa.

    meteorite Noun

    type of rock that has crashed into Earth from outside the atmosphere.

    Encyclopedic Entry: meteorite
    moon Noun

    natural satellite of a planet.

    Encyclopedic Entry: moon
    planet Noun

    large, spherical celestial body that regularly rotates around a star.

    Encyclopedic Entry: planet
    plateau Noun

    large region that is higher than the surrounding area and relatively flat.

    Encyclopedic Entry: plateau
    province Noun

    division of a country larger than a town or county.

    Encyclopedic Entry: province
    rock Noun

    natural substance composed of solid mineral matter.

    rupes Plural Noun

    cliffs found on moons and on planets other than Earth.

    sand Noun

    small, loose grains of disintegrated rocks.

    scarp Noun

    steep cliff or line of cliffs.

    seabed Noun

    the floor of the ocean.

    sedimentary rock Noun

    rock formed from fragments of other rocks or the remains of plants or animals.

    transition zone Noun

    area in the Earth's interior between the upper mantle, near the Earth's crust, and the lower mantle, near the Earth's core.

    waterfall Noun

    flow of water descending steeply over a cliff. Also called a cascade.

    Encyclopedic Entry: waterfall
    wind Noun

    movement of air (from a high pressure zone to a low pressure zone) caused by the uneven heating of the Earth by the sun.

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