Science Chapter 1- section 1

What is the difference between the lithosphere and the asthenosphere? In which layer is each located.

After 40 kilometers you hit the mantle. Earths mantle is made up of rock that is very hot, but solid. Scientists divide the mantle into layers based on the physical characteristics of those Layers. Overall, the mantle is nearly 3,000 kilometers thick. Lithosphere is the uppermost part of the mantle and the crust together form a layer called the lithosphere. It is100 kilometers thick. "Litho" in Greek means "stone". That Asthenosphere, soft layer is underneath the lithosphere. This part is hotter and has a greater pressure. It is less rigid than the rock above and much softer, it is able to bend like plastic, but it is still a solid. In Greek "Asthenes" mean "week". Both the lithosphere and the Asthenosphere are found in the mantle.

How does temperature change inside earth.

At first the surrounding rock is cool. After you reach 20 meters deep, the rock becomes warmer. From then on for every 40 meters you descend the temperature increases by 1^C. This continues for several tens of kilometers. Then the increase becomes steady and slow until you reach the middle of the planet. High central temperatures are caused by heat left over from the formation of the planet. In addition, radioactive substances inside earth release energy which further heats the interior. Overall as you travel deeper into the earth the temperature increases.

What is Bassalt?

Bassalt is dark rock which has a fine texture. It makes up the oceanic crust.

Why do geologist consider the inner core and the outer core part of the same layer?

Both cores consist of the same materials, iron and nickel.

What is a limitation of studying a cave to learn about earths interior?

Even the deepest caves extend only a short distance into the earths crust.

Which type of crust, continental crust or oceanic crust is thickest? What is the composition of continental and oceanic crust.

Continental crust is the thickest. The continental crust is mostly granite, and the oceanic crust is mostly bassalt.

Why does temperature increase with depth?

Earth became very hot when it formed. Some of this heat remains. The decay of radioactive elements also contribute to heating Earths interior.

What are some ways that earth has changed over time?

Earths surface is constantly changing. Through out our planets long history, its surface has been lifted up, pushed does, bent and broken due to earthquakes, erosion, flooding, and glaciers. Thus Earth looks different than it did millons of years ago.

What is Granite?

Granite is a rock that is usually lightly colored and has a coarse texture. It makes up the continental crust.

Why does tock in the asthenosphere behave differently from the rock above?

It is hotter.

Classify each of the fallowing layers as liquid, solid, or solid but able to flow slowly.

Lithosphere- solid Asthenosphere- solid Lower mantle- solid Outer core- liquid Inner core- solid

Why does pressure increase with depth?

Pressure increases towards Earths center becuase more rock lies above the center.

What is pressure?

Pressure results from a force pressing on an area. Pressure increases with depth because of the weight of the rock above. This is a direct correlation.

How are seismic waves used to provide evidence about earths interior?

Seismic Waves are earthquakes occur, they produce seismic waves. They are able to tell the temperature and pressure of certain locations. This is an indirect method. Geologists record the seismic waves and study how they travel through earth. There speed helps reveal the structure of the planet. Seismic Waves have concluded that the earth is made out of several layers.

What characteristics does the asthenosphere have?

The asthenosphere is capable of flow.

Describe the Core.

The core is mostly made up of iron and nickel. It is made out of two layers, the inner and outer core. Together they are 3486 kilometers thick. The outer core is a layer of molten metal that surrounds the inner core. The inner cores extrem pressure prevents it from becoming a liquid.

Describe the Crust.

The crust is the layer of rock that forms on Earths outer skin. It includes both dry land and the ocean floor. On the ocean crust you can fing rocks, mountains, soils, and water that covers much of earths surface. You can relate the crust to the paper skin of an onion. The thickest part of the crust is under high mountains. There it can be up to 70 kilometers thick. The thinest part of the crust is found on the ocean floor. There it could be 5 to 40 kilometers thick. There are two types of crust. One is oceanic crust which is found beneath the ocean and made out of bassalt, the other is continental crust which forms continents and is made of granite.

Why is it difficult to determine earth's inner structure?

The earth is contently changing- surface has been lifted up, pushed down, bent and broken. This has happened through plate tectonics, earthquakes, volcanoes, erosions, flooding, and glaciers. The extreme conditions in the earth's interior prevent geologists from physically exploring it. The deepest part of the earth that geologists can explore is a mine in South Africa that is 3.8 kilometers deep. This only scratches the surface, as the center of the earth is 6,000 kilometers. Geologists have used two main types of evidence to learn about Earth's Interior: direct evidence from rock samples and indirect evidence from seismic waves.

How does the inner core differ from the outer core.

The inner core is solid; the outer core is liquid.

What characteristics does the lithosphere have?

The lithosphere is rigid. It behaves more like a brittle solid than does the asthenosphere below.

Describe the Mantle.

The mantel is found below the crust. It is a solid material made out of hot rock. Scientist divide the mantle into layers based on physical characteristics. Overall the mantle is nearly 3,000 kilometers thick.

List earth's three main layers.

The three main layers of Earth are the crust, the mantle, and the core; these layers vary greatly in size, composition, temperature, and pressure

Describe the Lithosphere.

The uppermost part of the mantle and the crust together form a layer called the lithosphere. It is 100 kilometers thick. Litho in greek means stone.

Why would a geologist study the inside of a cave?

To examine the materials below ground and determine processes that formed the cave.

Describe the Asthenosphere.

Under the lithosphere is the asthenosphere. This soft layer is hotter and has a greater pressure. The asthenosphere is less rigid than the rock above. It is also much softer and can "bend like plastic" but it is still solid. In Asthenes means week.

What is a Seismic Wave?

When an earthquake occurs it creates seismic waves. This is an indirect method of gathering information about the structure of earths planet by studying how they travel through earth. Scientist are able to infer earths inner structure as well as the many layers because of this method.