Planet Earth: Topics 4-7 Flashcards
Crust
The thin, outermost layer of the Earth
Mantle
The second layer of Earth, located between the crust and the core and made out of liquid rock
Outer Core
The third layer of Earth, located between the Mantle and the Inner Core. Composed of liquid iron and nickle. Very hot
Inner Core
The middle of Earth. Pressure from other layers forces this to be a solid ball. Very hot.
Continental Drift
A theory about the Earth’s structure. According to this theory, the continents have slowly changed their positions over time. The slow movement of continents
Sonar
A technology that bounces sound waves off an object to determine it’s distance from the source of the wave. SOund Navigation And Ranging.
Sea floor spreading
The process in which an ocean floor slowly increases in size over time because of the formation of new igneous rock along a fault
Plates
One of the large sections into which Earth’s crust is divided
Theory of Plate Tectonics
Theory suggesting that the Earth’s crust is divided into plates that interact with each other
Converging
Two or more plates colliding or coming together
Diverging
Two or more plates moving away from each other (or dividing)
Convection Currents
Flow resulting from the rise of warmer materials and the sinking of cooler materials.
Subduction Zones
A place on Earth’s crust where high pressure pushes one very large piece of rock below another.
Seismograph
Used to measure Earthquakes
Bedrock
The solid rock that lies beneath the soil and looser rocks
Richter Scale
Used to measure the strength of an Earthquake. Scale of 0 and can go as high as necessary.
Seismic waves
Energy waves that are released by an Earthquake and travel outward
Aftershocks
Smaller ground movements caused by seismic waves moving outward from the earthquakes focus
Primary Waves
The fastest moving of the three types of seismic waves that are produced by an earthquake. Can pass through solids, liquids, and gases.
Secondary Waves
The second fastest moving of the three types of seismic waves that are produced by an earthquake. Can pass through solids but not liquids or gases
Surface Waves
The slowest of the three types of seismic waves. Do the most damage
Focus
The source of primary and secondary earthquake waves. The place deep in the crust where the earthquake begins
Epicenter
The area on the surface of Earth that is directly above the focus of an earthquake. Source of surface waves
Normal Faults
A vertical fault in which rock moves downward. Tension pulls rocks apart. Causes shallow earthquakes usually on the sea floor
Reverse Faults
A vertical fault in which rock moves upward. Compression squeezes rock together. Forms a subduction zone.
Strike/Slip/or Transform Faults
Plates slide past each other. Top surface gets twisted.
Vents
An opening in Earth’s crust through which magma can escape, forming lava
Dormant
A stage when no eruption is occurring for a volcano
Anticline
An upfold of rock layers in sedimentary rock
Syncline
A downfold of rock layers in sedimentary rock
Thrust faulting
Low angle faulting of rock. Slabs of rock move over each other like shingles on a roof
Fault block mountains
Mountains formed by the process of thrust faulting
Complex Mountains
Mountains that are formed by a combined process of folding and faulting
Age of Mountains
young mountains have jagged tops. Old mountains have rounded tops.
