Explore changes to Earth’s surface over time. Record any observations that help you answer the Guiding Question.

Question

1
This simulation shows a cross-section of Earth’s layers. Match each layer to its description.

Match answers from the answer bank with the items in the list. Use the arrow keys to select an answer and press space when you're ready to drag it to a new location. Then use the arrow keys to move the answer to a response area and press space to drop it.
Middle, thickest layer
Innermost layer
Outermost, thinnest layer
2
Next, locate the lithosphere in the simulation. Then, select the best definition of this area.

A
The hottest of all of Earth’s layers

B
The liquid layer directly beneath Earth’s crust

C
The crust plus the uppermost, solid part of the mantle

D
The mantle plus the innermost, liquid portion of the core
3
Now, select the third [] tool at the bottom of the simulation. What can you conclude from this indicator?

A
The mantle moves in random, unpredictable ways

B
Most of the mantle is liquid, swirling in a circular motion

C
The mantle moves so that the core and crust mix together

D
Mostof the mantle is made of solid rock that stays relatively still
4
Note the fault, or break, between two pieces of crust. Select the first [] tool at the bottom of the simulation. Then, fill in the blanks to complete the sentence. Not all answer choices will be used.

In this example, the two pieces of crust will move
each other at the fault, causing it to get
.

5
What other feature is visible at the fault?

A
Volcano

B
Ocean

C
Mountain

D
Atmosphere
6
In the simulation, the darker crust (near the fault) is new, “young” rock. Move forward through time, from 10 million years ago to 1 million years ago. As the amount of “young” rock changes, what can you conclude?

A
The Earth gets smaller as new crust is created

B
The entire crust gets replaced every million years

C
New rock is constantly being formed near the fault

D
Gravity causes rocks to fall in the gaps between pieces of crust
7
The mantle is often compared to a pot of boiling water. Hot, liquid rock “boils” to the top of the mantle, cools, and sinks. What energy source allows this to occur? (Hint: Use the thermometer tool at the bottom of the simulation.)

A
Heat from the Earth’s core

B
Human activity on Earth’s surface

C
Heat from sunlight that reaches the crust

D
Gravitational pull from Earth’s constant rotation

How To Use Models

Observation

Answer 1

Observations on Changes to Earth’s Surface Over Time

1. Matching Earth's Layers:

   • Middle, thickest layer: Mantle
   • Innermost layer: Core
   • Outermost, thinnest layer: Crust

2. Definition of Lithosphere:

   • The best definition of the lithosphere is C: The crust plus the uppermost, solid part of the mantle. This indicates that the lithosphere includes both the solid part of the Earth's crust and the solid upper mantle.

3. Conclusion from the Third Tool:

   • The observation indicates that D: Most of the mantle is made of solid rock that stays relatively still. This suggests that while there may be some movement, the majority of the mantle behaves as a solid over geological timescales.

4. Fault Observation:

   • In this example, the two pieces of crust will move past each other at the fault, causing it to get displaced. This illustrates how faults can disrupt the continuity of the Earth's crust.

5. Other Features Visible at the Fault:

   • The feature visible at the fault is C: Mountain. This implies that tectonic activity can result in mountain formation, particularly at fault lines.

6. Observation on Young Rock:

   • As the amount of “young” rock changes from 10 million years ago to 1 million years ago, the conclusion is C: New rock is constantly being formed near the fault. This suggests ongoing tectonic activity and the continuous generation of new crust.

7. Source of Energy for Mantle Movement:

   • The energy source that allows the mantle to act like a pot of boiling water is A: Heat from the Earth’s core. This internal heat drives the convection currents that facilitate mantle dynamics.

Summary of Observations

• The Earth's layers can be categorized into the thick mantle, the core, and the thin crust. The lithosphere consists of both the crust and the upper solid part of the mantle.
• Mantle behavior primarily involves rigid sections with limited movement, while faults in the crust can lead to significant displacement and the formation of mountains.
• Active tectonic processes lead to the formation of new rock at faults, demonstrating that Earth's surface is constantly changing due to geological activity.
• The movement of the mantle is fueled by heat from the Earth's core, contributing to convection currents and further influencing surface changes.

With these observations, we can better understand how the Earth's surface evolves over time, and how various processes contribute to this dynamic system.