Earth and Space

Earth and Space

Earth System - Structures of Earth

Structures of Earth

The Earth is divided into 4 major layers. Each layer is defined by the various properties of the materials that compose them.

Earth's 4 major layers

• Crust - the thin outer layer we see. It is made of cool, solid rock. It can either be oceanic crust or continental crust.

• Mantle - a rock that behaves similarly to modeling clay. It can move, but only very slowly. Temperatures range from 500°C to over 4,000°C (932°F to over 7,232°F).

• Outer core - very hot liquid iron and nickel. Temperatures range from 4,400°C to 6,100°C (7,952°F to 11,012°F).

• Inner core - solid, composed mostly of iron and some nickel. Even though it is very, very hot, the weight of all the rock above it causes the inner core to remain in a solid state.

Multiple Choice

Which layer is best described as liquid iron and nickel?

• inner core

• outer core

• mantle

• crust

Heat transfer through Earth's Subsystems.

• Heat Transfer - is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. 

• Conduction- the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

Multiple Choice

Which describes the difference between continental and oceanic crust chemical composition?

• continental crust has more SiO2 so it sinks

• continental crust has more Fe so it floats

• oceanic crust has more SiO2 so it floats

• oceanic crust has more Fe so it sinks

Heat transfer through Earth's Subsystems.

• Convection - the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.

• Radiation - the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization.

Multiple Choice

The inner core is a...

• solid

• liquid

• gas

^{Knowing about the layers of the Earth helps answer a few key geological questions.}

• Why are there oceans? Oceanic crust is made of basalt while continental crust is made of granite. The denser oceanic crust sits lower and sinks deeper into the mantle than continental crust, causing depressions that fill with water to create oceans.

• Why is the core so hot? The process of nuclear fission, the splitting of atomic nuclei of elements such as uranium, occurs in the core. This process releases heat. Then, it takes a long time for that heat to move via conduction through the inner core and via convection currents through the outer core and mantle.

Multiple Choice

The outer core is a...

• solid

• gas

• liquid

Multiple Choice

The lithosphere is ______ and the asthenosphere is _______.

• both brittle

• brittle, plastic/flexible

• plastic/flexible, brittle

• both plastic/flexible

Crust - the thin solid outer layer we see

Mantle - a rock that behaves similarly to modeling clay

Outer core - very hot liquid iron and nickel

Inner core - very hot solid, mostly iron

Multiple Choice

Which layer exists as a collection of tectonic plates?

• asthenosphere

• mantle

• lithosphere

• outer core

Multiple Choice

Which two layers have convection currents?

• asthenosphere & outer core

• asthenosphere & inner core

• lithosphere & outer core

• lithosphere & inner core

Multiple Choice

Convection currents in the ______ create Earth's magnetic field.

• asthenosphere

• inner core

• mantle

• outer core

Multiple Choice

Which two layers have convection currents?

• asthenosphere & outer core

• asthenosphere & inner core

• lithosphere & outer core

• lithosphere & inner core

Multiple Choice

Which two layers have convection currents?

• asthenosphere & outer core

• asthenosphere & inner core

• lithosphere & outer core

• lithosphere & inner core

Multiple Choice

The lithosphere is ______ and the asthenosphere is _______.

• both brittle

• brittle, plastic/flexible

• plastic/flexible, brittle

• both plastic/flexible

Multiple Choice

The outer core is a...

• solid

• gas

• liquid

Multiple Choice

The inner core is a...

• solid

• liquid

• gas

Multiple Choice

Which layer is best described as liquid iron and nickel?

• inner core

• outer core

• mantle

• crust

Multiple Choice

Which of the following represents physical layers of Earth?

• core, mantle, crust

• core, mantle, oceanic crust, continental crust

• inner core, outer core, mesosphere, asthenosphere, lithosphere

• inner core, outer core, mantle, oceanic crust, continental crust

Multiple Choice

What distinguishes chemical layers of Earth?

• the elements and compounds in each layer

• how rigid each layer is

• the thickness of each layer

• the temperature of each layer

Multiple Choice

What distinguishes physical layers of Earth?

• the elements and compounds in each layer

• how rigid each layer is

• the thickness of each layer

• the temperature of each layer