PSCI 102 - Module 1 (Observation and Plate Tectonics Intro)

Earth’s interior is broadly divided by composition and depth intro what parts?

Crust, mantle, and core

The crust of the earth is primarily made of what types of rocks?

Igneous and metamorphic rocks

The remaining 5% of the crust is made up of what type of rock?

Sedimentary rock

Which interior part of the Earth typically holds different types of layers with same overall ultramafic composition?

Mantle

The upper mantle is mostly composed of what type of rock?

Peridotite

Peridotite is mostly composed of what?

Olivine and pyroxene

The rigid outer part of the Earth, including the crust and the mantle down to a depth about 100 kilometres is the:

Lithosphere

The part of the mantle from 100 to 200 kilometers below surface, within which the mantle material is close to its melting point, and usually weak is the:

Asthenosphere

This low seismic velocity zone, also called the prime layer, is within the basal 200 km of the mantle is the:

“D” layer

In between the mantle and the core is at a 2900 kilometer depth, is called the:

Core-mantle boundary

The core is composed of what type of periodic element?

Iron

Roughly how hot can the core of the Earth get?

3500° to 5000°C

The outer core is ____ while the inner core is ____

liquid; solid

Which part of the core is more hotter because the pressure is more greater at it’s depth?

Inner core

The major component of the Earth is the mantle

TRUE

The mantle makes up how much of the Earth’s volume?

82.5%

The core makes up how much of the Earth’s volume?

16.1%

The crust makes up how much of the Earth’s volume?

1.4%

What is the correct pattern of the Earth’s layers, starting from the centre of the Earth?

Inner solid core, outer liquid core, “D” layer, lower mantle, upper mantle, asthenosphere, lithospheric mantle, crust

The study of vibrations within the Earth is called:

Seismology

Which one of these examples IS not a causation of the vibrations of the Earth?

Stars

A seismic wave that travels through rock

Body waves

Unlike the surface waves on the ocean, body waves are transmitted through where?

The Earth’s materials

When hitting a large block of strong granite with a heavy sledgehammer, it will cause a compression that will transfer to the neighboring part of the rock and through the far side of the rock in a second. This is known as what kind of wave?

Compression wave

These waves push/pull particles parallel to wave travel, are faster, and can travel through solids and liquids. (E.g. such as using the Slinky toy)

Compression waves (P-waves)

These waves shake particles up and down, are slower, and only travel through solids and cause more damage. (E.g. such as shaking a rope):

Shear waves (S-waves)

The boundary between the crust and the mantle is named after this Croatian seismologist in 1909 that realized from a certain distance from and earthquake, two separate sets of seismic waves arrived at the seismic stations within a few seconds of each other. This boundary is called:

Mohorovicic discontinuity

People use data from seismometers and hundreds of earthquakes to create 2D or 3D images of the seismic properties of the part of the mantle. This technique is called:

Seismic tomography

Earth’s magnetic field is defined by the ____ and ____ Poles

North; South

In the direction of the northern hemisphere, the flow of the magnetic force move where?

Into the Earth

In the direction of the southern hemisphere, the flow of the magnetic force move where?

Out of the Earth

The force is ____ if it is by the North or South magnetic poles

vertical

The force is ____ if it is near the Equator of the Earth

horizontal

In-between the poles and the Equator, the force can be in any intermediate angle to the surface

TRUE

Earth’s magnetic field is generated within the ____ core

outer

How is Earth’s magnetic field generated?

Convective movement of liquid iron

The magnetic field is not stable over geological time

TRUE

Since the past 250 million years, there has not been any recorded magnetic field reversals

FALSE

In the magnetic field of the Earth, what happens during a reversal?

The Earth’s magnetic field becomes very complex