Earth's Interior

How thick is the crust, usually?

5 -40 kilometers thick

What does asthenes mean in greek?

weak

The inner core

a dense ball of solid metal

What is the rock like just beneath Earth's surface?

its cool

Where is crust thickest?Thinnest?

under high mountains and thinnest beneath the ocean.

How thick can the crust be?

up to 70 kilometers thick beneath mountains

Where and how deep is the deepest mine in the world?

A gold mine in South Africa, reaches a depth of 3.8 kilometers (that only scratches the surface)

When does the rock get warmer?

about 20 meters down

Which crust consists mostly of granite?

continental crust

Continental Crust

crust that forms the continents

Why is the inner core solid?

extreme pressure squeezes the atoms of iron and nickel so much that they cannot spread out and become liquid

How do scientists divide the mantle?

into layers based on the physical characteristics of those layers

The outer core

is a layer of molten metal that surrounds the inner core

Granite

is a rock that usually is a light color and has a coarse texture

The Crust

is the layer of rock that forms Earth's outer skin

What happens after this rapid rise of temperature?

it increases more slowly but steadily

Asthenosphere?

it is soft and can bend like plastic

The Lower Mantle

its beneath the asthenosphere and its solid-extends all the way to Earth's core

Seismograph

measures seismic waves

What is the crust called beneath the ocean?

oceanic crust

What other substances do scientists think are in the core?

oxygen, sulfur, and silicon

On average how thick is the lithosphere?

100 kilometers thick

Overall how thick is the mantle

3,000 kilometers

What is pressure a result of?

A force pressing on an area

Why is the part of the mantle just beneath the lithosphere less rigid than the rock above?

Because it is hotter and under increasing pressure

Why is it surprising that the outer core is liquid?

Because of the enormous pressure

Why does pressure increase the deeper you travel inside Earth?

Because the weight of the rock above the pressure increases

What do scientists think liquid in the outer core creates?

Earth's magnetic field

What happens 20 meters below the surface?

For every 40 meters you descend from that point, the temperature rises 1 Celsius degree

What is another way geologists obtain rocks from Earths interior?

Forces inside Earth sometimes blast rock to the surface from depths of more than 100 kilometers

How have geologists learned about Earth's inner structure?

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

What is the core mostly made of?

Iron and nickel

What does drilling into Earth do for geologists?

It brings up samples of rocks

How is Earth's surface changing?

It's surface has been lifted up, pushed down, bent, and broken

What is the crust like compared to the layer beneath it?

Much thinner

Basalt?

Oceanic rock that is dark with a fine texture

What is Earth's mantle made up of?

Rock that is very hot, but solid

What do earthquakes produce?

Seismic Waves

What indirect method do geologists rely on to find information about Earth's interior?

Seismic Waves

What does most of the current evidence suggest about both parts of the core?

That both contain iron and nickel

What have scientists learned from seismic waves?

That earths interior is made up of several layers

What is about 40 kilometers beneath the surface?

The Mantle

Characteristics of Earth's Crust

The crust is a layer of solid rock that includes both dry land and the ocean floor

What are the three main layers of Earth?

The crust, the mantle, and the core

Why can't geologists dig a whole to the center of the earth?

The extreme conditions in earths interior prevent exploration far below the surface

What are the two parts of the core?

The liquid outer core and the solid inner core

What is beneath the crust?

The solid material of the mantle, a layer of hot rock

Lithosphere?

The uppermost part of the mantle and the crust together form a rigid layer called the lithosphere

What are the characteristics of the crust, mantle, and core?

These layers vary greatly in size, composition, temperature, and pressure

Why are there high temperatures inside Earth?

They are a result of heat left over from the formation of the planet and also radioactive substances inside Earth release energy

How is the uppermost part of the mantle similar to the crust?

They are both solid

What do geologists do with the samples of rocks?

They can make inferences about conditions deep inside Earth

How do geologists study seismic waves?

They record the seismic waves and study how they travel through Earth. The speed of the seismic waves and the path they take reveal the structure of the planet

What can you find on the crust?

rocks and mountains. it also includes the soil and water that cover large parts of Earth's crust

What kind of rock does the ocean floor mostly consist of?

rocks such as basalt

What does lithos mean in greek?

stone

What happens when you use a compass?

the compass needle aligns with the lines of force in Earth's magnetic field