Earth's Interior
This is the outermost layer of Earth where we live.
The crust
These are the fastest seismic waves and can travel through all states of matter.
P-waves or primary waves
In a system, this happens to the material that is less dense.
Rises
This theory describes that Earth's surface is divided into moving plates.
Plate tectonics
A natural hazard can become a disaster when it impacts this.
Human populations
This layer is made of solid rock but can flow slowly over time.
The mantle
These waves can only travel through solids.
S-waves or secondary waves
In a system, this happens to material that becomes cooler and more dense.
Sinks
At this type of boundary, plates move away from each other.
Divergent boundary
This factor determines how severely a population is affected by a natural hazard.
Vulnerability
This layer is liquid and responsible for generating Earth's magnetic field.
The outer core
This scientific instrument is used to measure and record seismic waves.
Seismometer
This process transfers heat through the movement of material.
Convection
This surface feature commonly forms at convergent oceanic-continental boundaries.
Volcanoes, Trenches, or Subduction zones
This technology gives populations seconds to minutes of warning before earthquakes arrive.
Early warning systems
This evidence from seismic waves proves the outer core is liquid.
S-waves do not travel through it
If two seismic stations record the same earthquake, the one that detects the waves earlier is located ____.
Closer
In Earth's mantle, convection is driven primarily by this energy source.
Heat from Earth's core or radioactive decay
This boundary type is mainly associated with frequent shallow earthquakes and no volcanic activity.
Transform boundary
This is the tradeoff people consider when living near tectonically active regions.
Risk versus reward
Scientists determined Earth has a layered structure by studying this type of wave data.
Seismic waves or seismograms
Scientists can determine that Earth has different layers because seismic waves change this as they travel through different materials.
Speed or direction
This relationship explains why iron sank toward the center of Earth early in its history.
Higher density materials sink while lower density materials rise
The age of the ocean floor increases as you move away from this feature.
Mid-ocean ridge
Wealthier and more developed countries often experience fewer fatalities from earthquakes because of this key factor.
Stronger infrastructure or being prepared