Tag Archives: Earth’s Crust

How does a seismograph measure earthquakes?

By means of a delicately hung weight on a fixed base, a seismograph traces a chart which records how powerful an earthquake is. When an earthquake occurs, the violent movement of the earth’s crust causes vibrations that spread out in all direction though the earth. To help detect and measure earthquakes, scientists have invented an …

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Why is the ocean salty?

Sea water contains all the natural elements that make up the minerals in the earth’s crust. The most common of the minerals found in the ocean is common table salt, which is mainly responsible for the salty taste of sea water.  In fact, the average gallon of seawater contains about a quarter of a pound …

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How were the mountain made?

Some high mountains are volcanoes.  Others were made in other ways.  Mountains are created by violent changes in the earth’s surface.  Deep under the earth great forces lift, wrinkle, and more that rocks that make up the earth’s crust. Huge blocks of rocks are pushed, tilted, raised or squeezed into great folds, much like a …

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How are rocks made?

Rocks are found almost everywhere.  Very small rocks are called sand.  Rocks bigger than sand have other names, like pebbles, or stone.  Big rocks are called boulders.  In fact, almost all the earth – the mountains and the ground itself – is made of rock. Rocks are made of minerals.  A few are made of …

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