Earth Science: Layers of the Earth

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the average thickness of the section that is composed mainly of basalt?

30-70 km (correct)

10-30 km

70-100 km

1-5 km

Which material is referred to as being thick and light in the context?

Metamorphic rock

Sedimentary rock

Basalt

Granite (correct)

What is the process described for the section that is being destroyed and replaced?

Erosion

Plate tectonics

Subduction (correct)

Continental drift

Which characteristic accurately describes the section that is thinner and heavier?

It is 6-10 km thick. Signup and view all the answers

Which layer of the Earth is known as the outermost shell?

Crust Signup and view all the answers

What characterizes the mantle layer of the Earth?

It contains molten rock. Signup and view all the answers

Which layer is located beneath the mantle?

Outer Core Signup and view all the answers

What is one of the two types of crusts present on Earth?

Oceanic Crust Signup and view all the answers

What is the approximate temperature at the core of the Earth?

5500°C Signup and view all the answers

What material is found in the mantle?

Magma Signup and view all the answers

How thick is the crust compared to the other layers?

Thinnest layer Signup and view all the answers

What term describes the molten rock found in the mantle?

Magma Signup and view all the answers

What does the Mercalli Scale measure?

The intensity of damage caused by an earthquake Signup and view all the answers

Which factors influence the reading of the Mercalli Scale?

The distance from the epicenter Signup and view all the answers

What is likely to happen to buildings in areas affected by higher Richter Scale readings?

They could collapse or suffer severe structural damage Signup and view all the answers

How is the Richter Scale commonly perceived in relation to earthquake detection?

It measures both the magnitude of an earthquake and its effects Signup and view all the answers

What kind of damage is generally associated with higher Richter Scale values?

Severe damage including landslides and building collapses Signup and view all the answers

What is the primary cause of plate movement on Earth?

Convection currents in the mantle Signup and view all the answers

What phenomenon occurs due to the movements of the Earth's plates?

Earthquakes Signup and view all the answers

Which type of plate boundary can experience earthquakes?

Any type of plate boundary Signup and view all the answers

What drives the convection currents in the Earth's mantle?

The heat from the Earth's core Signup and view all the answers

What happens during an earthquake?

The crust suddenly shakes and vibrates Signup and view all the answers

Which of the following is NOT a consequence of plate movement?

Increased atmospheric pressure Signup and view all the answers

What kind of movement do convection currents in the mantle cause?

They cause all types of plate movements Signup and view all the answers

Earthquakes are most likely to occur at which location?

Near plate boundaries Signup and view all the answers

How are new crustal formations created at divergent plate boundaries?

By volcanic eruptions filling the gaps with magma Signup and view all the answers

What is the Mid-Atlantic Ridge primarily known for?

An area of volcanic activity creating new oceanic crust Signup and view all the answers

Which statement accurately describes the age of the crust at divergent boundaries?

The crust is older further from the edge of the plates Signup and view all the answers

What occurs when two tectonic plates are moving apart?

Rift valleys are formed Signup and view all the answers

What is the primary substance that fills the gaps at divergent plate boundaries?

Hot magma Signup and view all the answers

Which of the following features is associated with the formation of islands?

Accumulation of lava from underwater volcanoes Signup and view all the answers

What drives the movement of tectonic plates?

Convection currents in the mantle Signup and view all the answers

What role does lava play in the formation of new crust during volcanic eruptions at plate boundaries?

It cools and solidifies to form new crust Signup and view all the answers

What is the function of a seismometer?

To detect and record earthquakes Signup and view all the answers

How does the Richter Scale measure earthquakes?

It measures the magnitude of an earthquake's power Signup and view all the answers

What effect does a magnitude 5 earthquake have compared to a magnitude 4 earthquake?

It is ten times more powerful than a magnitude 4 earthquake Signup and view all the answers

What primarily remains stationary during an earthquake when using a seismometer?

The mass attached to the seismometer Signup and view all the answers

What situation can a poorly built structure face during an earthquake?

It may suffer severe damage Signup and view all the answers

What is a significant effect of an earthquake on hanging objects?

They may swing due to vibrations Signup and view all the answers

What type of energy does a seismometer measure?

Energy waves emitted by earthquakes Signup and view all the answers

What level of the Richter Scale indicates low-magnitude earthquakes?

1 to 2 Signup and view all the answers

Study Notes

Earth Structure

Earth is made up of four layers: crust, mantle, outer core, and inner core.
The crust is the outermost layer, thin (a few kilometers thick), and floats on the mantle.
Molten rock in the mantle is called magma.
The layer beneath the mantle is the outer core, except for the solid inner core, where temperatures reach up to 5500°C.

Plate Tectonics

Continents are not static but move over time (continental drift).
Alfred Wegener proposed the theory of continental drift, suggesting all continents were once joined together in a supercontinent named Pangaea.
Pangaea existed around 240 million years ago
Evidence for continental drift includes fossils of ancient reptiles found in continents now separated by oceans, and plant fossils of tropical origins in places with colder climates.
Rocks also fit together as if they were once joined.
Plate boundaries are where plates meet.
Types of plate boundaries:
- Constructive: Plates move apart, magma rises, forms new crust (e.g., Mid-Atlantic Ridge, Iceland).
- Destructive: Oceanic plate is forced under the continental plate (subduction zone), creating volcanoes and earthquakes (e.g., Nazca and South American plates).
- Collision: Two continental plates collide, creating fold mountains (e.g., Himalayas, Alps).
- Conservative: Plates slide past each other, creating earthquakes (e.g., San Andreas Fault).
Convection currents in the Earth's mantle drive plate movement.
Hot magma rises and cools, sinking to cause currents.

Earthquakes

Earthquakes occur at plate boundaries.
Earthquakes are sudden shaking/vibrating of Earth's crust.
Seismic waves spread out from the focus, the point where the tension inside the Earth's crust is released.
The epicentre is directly above the focus.
Aftershocks are smaller earthquakes after the main quake, which can also cause damage.
The Richter Scale measures the magnitude (power) of an earthquake. (each scale is 10 times more powerful)
Ranges from 1 to 10.
The Mercalli scale measures earthquake intensity (damage caused)

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the different layers of the Earth, focusing on their composition, thickness, and characteristics. Questions cover topics such as the crust, mantle, and core, as well as seismic scales used to measure earthquakes. Test your knowledge on the fundamentals of Earth science and its geological features.