6th Grade Homework Due Monday

Here is the information that goes in your “Layers of the Earth Book” for Earth Science (6th Grade)  Please make it neat and write clearly you may choose to write your facts as bullet points instead of sentences.  You can also look up additional facts on the internet & look in your notes to add to your book. These books will be collected on Monday. 

Inner CoreThe deepest layer is a solid iron ball, about 1,500 miles (2,400 kilometers) in diameter. Although this inner core is white hot, the pressure is so high the iron cannot melt.The iron isn’t pure—scientists believe it contains sulfur and nickel, plus smaller amounts of other elements. Estimates of its temperature vary, but it is probably somewhere between 9,000 and 13,000 degrees Fahrenheit (5,000 and 7,000 degrees Celsius).

Outer Core-Above the inner core is the outer core, a shell of liquid iron. This layer is cooler but still very hot, perhaps 7,200 to 9,000 degrees Fahrenheit (4,000 to 5,000 degrees Celsius). It too is composed mostly of iron, plus substantial amounts of sulfur and nickel. It creates the Earth’s magnetic field and is about 1,400 miles (2,300 kilometers) thick.

Lower Mantel-The next layer is the mantle. Many people think of this as lava, but it’s actually rock. The rock is so hot, however, that it flows under pressure, like road tar. This creates very slow-moving currents as hot rock rises from the depths and cooler rock descends.The mantle is about 1,800 miles. The lower manels’s chemical composition includes silicon, magnesium, and oxygen.

upper mantle The upper mantle makes up 10.3% of the Earth’s mass, extending a depth of 6-250 miles (10-400 kilometers).This layer is not completely made of solid minerals for scientists speculate that the asthenosphere could be partly liquid molten.and the lower mantle. The boundary between the two lies about 465 miles (750 kilometers) beneath the Earth’s surface.

The Crust-The crust is the outermost layer of the Earth. It is the familiar landscape on which we live: rocks, soil, and seabed. It ranges from about five miles (eight kilometers) thick beneath the oceans to an average of 25 miles (40 kilometers) thick beneath the continents.Currents within the mantle have broken the crust into blocks, called plates, which slowly move around, colliding to build mountains or rifting apart to form new seafloor.Continents are composed of relatively light blocks that float high on the mantle, like gigantic, slow-moving icebergs. Seafloor is made of a denser rock called basalt, which presses deeper into the mantle, producing basins that can fill with water.Except in the crust, the interior of the Earth cannot be studied by drilling holes to take samples. Instead, scientists map the interior by watching how seismic waves from earthquakes are bent, reflected, sped up, or delayed by the various layers.

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