Chapter 2: The Interior of the Earth Flashcards
What is the crust made of?
Solid rock
What is the mantle made of?
Solid rock
What is the outer core made of?
Liquid iron
What is the inner core made of?
Solid iron
Which layer of the Earth is the thinnest?
The crust
Which layer of the Earth is the thickest?
The mantle
Shear waves are also called what?
Secondary waves (S waves)
Compressional waves are also called what?
Primary waves (P waves)
S waves are able to go through what?
Solids only.
P waves are able to go through what?
Solids, liquids, and gases.
Are S waves faster or slower?
What about P waves?
S waves are slower and P waves are faster.
What is a wave?
A wave is a motion that travels through a material and carries energy from one place to another.
What does refraction mean?
- Refraction is the deflection (or change in direction) of a ray of light or wave due to changes in its velocity as it passes from one medium to another.
- Refraction is also a change in direction that happen when something changes gradually rather than suddenly.
- Refraction is the change of wave’s speed/direction as it enters new materials due to changes in its velocity.
What is a seismic wave?
A seismic wave is a general term for all elastic waves produced by earthquakes or artificially through explosions (Syn: earthquake wave)
Define an earthquake.
An earthquake is a sudden motion or trembling in the Earth caused by the abrupt release of slowly accumulated strain.
What is a fault?
A fault is a fracture or fracture zone along which there has been displacement of one mass of rock relative to another, parallel to the fracture.
What is the core?
The core is the central part of the Earth, beginning at a depth of about 2,900 km, and consisting of iron-nickel alloy. It consists of mostly iron and a liquid outer core and solid inner core.
What is the crust?
The crust is the outermost layer of the Earth, composed of rock, representing less than 0.1% of the Earth’s total volume.
What is the mantle?
The mantle is the zone of the Earth beneath the crust and above the core. It is divided into the upper mantle and the lower mantle.
What is a seismograph?
A seismograph is an instrument that detects, magnifies, and records when seismic waves reach the surface.
What is the hydrosphere?
The hydrosphere is the part of the Earth system that includes all the planet’s water, including oceans, lakes, rivers, groundwater, ice, and water vapor.
How do earthquakes produce seismic waves?
Earthquakes produce seismic waves by vibrations caused by large masses of rock to sliding past each other or explosions caused by humans.
What is wave refraction?
Wave refraction is waves changing speeds in direction when entering new materials.
What is the focus of an earthquake?
The focus is where the earthquake starts.
How are earthquakes detected on the surface of the Earth?
Earthquakes are detected on the surface of the Earth using special instruments called seismographs.
How do scientists know the Earth’s mantle is solid?
Scientists know the Earth’s mantle is solid because S waves are able to go through the mantle and S waves only go through solids.
How do scientists know that the Earth’s core is made of a different material that that of the mantle?
Scientists know that the Earth’s core is made of a different material that that of the mantle because of the strong magnetic field Earth has, and S waves can’t go through the core.
What do waves carry with them when they travel?
When waves travel, they carry energy with them.
What is the Richter Scale?
What does a high number on the scale mean?
The Richter Scale is a way of measuring the magnitude of an earthquake using seismograph records.
A high number on the scale means that it’s capable of causing damage or it’s potentially very destructive.
What are two waves seismic waves can weaken?
They spread their energy over a larger and larger area as they move.
And they lose energy because they create friction as they move through the Earth.
What are shadow zones?
Shadow zones are zones where no S or P waves from a faraway earthquake don’t appear again at the surface and they show that there are places deep inside the Earth where there is an abrupt slowing of seismic-wave speeds.
How do scientists know that the outer core is probably liquid and not a gas or solid?
S waves can’t go through the core and S waves only go through solids, so it has to be liquid or gas and if it were made of gas the crust and mantle would collapse.
Shaking a material causes what?
Shaking a material causes vibrations.
When you do what, you make your vocal chords vibrate?
When you speak/talk/sing, you are making your vocal chords vibrate.
What happens during an earthquake?
During an earthquake, large masses of rock slide past each other, making powerful vibrations.
An earthquake over a magnitude of what is considered a major earthquake?
Any earthquake over a magnitude 7 is considered a major earthquake.
What do seismic waves do as they move through the Earth.
Seismic waves weaken as they move through Earth.
A motion that travels through a material and carries energy from one place to another is what?
A motion that travels through a material and carries energy from one place to another is a wave.
The order of the layers of the Earth is?
Crust, mantle, outer core, inner core.
