Week 8 – Earth’s Structure

Question 1

What is the Earth’s approximate depth (radius) from surface to core?

Answer 1

6400 +/- km

Question 2

What data and equipment are used to determine the structure & depth of the Earth’s layers.

Answer 2

Seismic Waves
P & S Waves
Both are seismographs

Question 3

Identify the layers of the Earth – be able to label them on a diagram.

Answer 3

1st layer: crust
2nd layer: mantle
3rd layer: core

Question 4

The three zones within the mantle:

Answer 4

mantle layers (top to bottom): lithosphere, asthenosphere “plastic,” mesosphere (lower mantle.”

Question 5

What happens to rock material’s temperature, pressure, and density as depth increases?

Answer 5

Increasing brittle strength (resistance to fracture) and decreasing ductile strength (resistance to plastic deformation).

Question 6

Identify the most common rock in the Oceanic crust, and the Continental crust.

Answer 6

oceanic crust: basalt
continental crust: granite

Question 7

Identify the process and cause of rock movement within the Mantle and how it affects the surface of the Earth.

Answer 7

Process: rising and subsiding
How it affects the surface: Convection

Question 8

What are the five properties that define what a mineral is?

Answer 8

1) Solid
2) Naturally formed in Nature
3) Inorganic (not made of carbon)
4) possess a specific chemical composition
5) Contain atoms arranged in a regular pattern to form solid crystals

Question 9

Define what a rock is.

Answer 9

A rock is a solid material composed of minerals

Question 10

What are the three major types of rocks?

Answer 10

Sedimentary
Metamorphic
Igneous

Question 11

Know the two igneous rock categories and the difference between magma and lava.

Answer 11

1) Plutonic (intrusive) rocks- rocks from magma that cool and solidify beneath the Earth’s surface (may be pushed up or exposed by erosion)
2) Volcanic (extrusive rocks- molten rock ejected onto the earth’s surface, solidifying quickly in the open air (lava)

Question 12

What is one common plutonic, igneous rock in Yosemite National Park?

Answer 12

Granite

Question 13

How are sedimentary rocks formed: what is sediment, and what causes strata in some sedimentary rocks?

Answer 13

Sediment is small particles of rock and debris or organic material deposited by water, wind, or ice. Sedimentary rocks are formed by sediment that is consolidated by the combination of pressure and cementation.

Question 14

What is a common type of sedimentary rock?

Answer 14

Sandstone

Question 15

What are metamorphic rocks, and explain the three ways they can form.

Answer 15

Metamorphic rocks were originally something else (igneous or sedimentary) but had drastically changed by massive forces of heat and/or pressure from within the Earth. It can be formed in three ways: contact metamorphism, regional metamorphism, or hydrothermal metamorphism.

Question 16

Know the Rock Cycle:
Magma and lava become igneous rock, and weathering/erosion of all rock (and organic material, like fossils/seashells) produces sedimentary rock. Subterranean heat and pressure convert igneous or sedimentary rock to metamorphic rock. Melting rock under heat/pressure produces magma.