Earth's Layers

Look at the model of Earth’s interior. How would you label each of Earth’s layers, starting with the innermost layer of Earth and moving toward the outermost layer?

• Outer core; inner core; crust; mantle

• Crust; mantle; inner core; outer core

• Mantle; crust; outer core; inner core

• Inner core; outer core; mantle; crust.

Answer explanation

The correct order of Earth's layers from innermost to outermost is: inner core, outer core, mantle, and crust. This reflects the structure of the Earth, with the inner core being solid and the crust being the outermost layer.

Mountains on Earth can be extremely tall, some reaching over 8 kilometers high. Which best describes the layer of Earth where mountains are found?

• Mountains are found in Earth’s mantle, which is the thickest layer of Earth with the most moderate temperatures.

• Mountains are found on Earth’s crust, which is the thickest layer of Earth with the coolest temperatures.

• Mountains are found on Earth’s mantle, which is the thinnest layer with an average temperature of 1000°C (1832°F).

• Mountains are found on Earth’s crust, which is the thinnest layer with the coolest temperatures.

Answer explanation

Mountains are found on Earth’s crust, which is the outermost layer. It is indeed the thinnest layer compared to the mantle and has relatively cooler temperatures, making this choice the most accurate.

Eduardo builds a model of Earth's layers. His model is composed of two thin layers, approximately 1.25 cm thick each, that represent Earth's crust and mantle. It then has one thick layer, approximately 4cm thick, to represent Earth's outer core. Finally, it has a solid metal ball to represent Earth's inner core. How should Eduard modify his model to accurately represent Earth’s layers?

• Eduard does not need to modify his model because it is already accurate.

• Eduard should make the layer that represents Earth’s crust thicker.

• Eduard should make the mantle thicker than all the other layers.

• Eduard should replace the solid metal ball with clay to better represent the inner core’s composition.

Answer explanation

Eduardo should make the mantle thicker than all the other layers because, in reality, the mantle is much thicker than both the crust and outer core, which is not accurately represented in his model.

Look at the image. The hot springs in this image are most likely heated by________________ . This layer of Earth is _________. Which correctly completes the paragraph?

• Magma in the mantle; approximately 3.000 kilometers thick and is made mostly of iron, magnesium, and silicon. It is dense, hot, and semi-solid.

• hot metals in Earth's inner core; a solid metal ball with a radius of 1,220 kilometers. It is extremely dense and made mostly of iron and nickel.

• magma in the mantle; a solid metal ball with a radius of 1,220 kilometers. It is extremely dense and made mostly of iron and nickel

• hot metals in Earths' inner core; approximately 3,000 kilometers thick and is made mostly of iron, magnesium, and silicon. It is dense, hot, and semi-solid.

Answer explanation

The hot springs are heated by magma in the mantle, which is approximately 3,000 kilometers thick and composed mainly of iron, magnesium, and silicon. This layer is dense, hot, and semi-solid, making it the correct choice.

Geologists use technology such as seismic waves to study Earth's interior, but imagine if you were able to take an actual trip to the center of Earth. Describe the various layers you would encounter as you move deeper through earth's layers. Your description should include information comparing the relative thickness and temperature of each layer.

Answer explanation

As you descend, you'd encounter the crust (thin, cool), the mantle (thick, hot), the outer core (liquid, very hot), and finally the inner core (solid, extremely hot). Temperatures rise significantly with depth.

Evaluate the model of Earth’s layers to determine whether it is an accurate representation. Describe which corrections you would make and why.

Answer explanation

The model of Earth's layers is generally accurate but oversimplified. I would correct the thickness and composition of the crust and mantle, and include the asthenosphere to better represent the dynamic nature of these layers.