Earth's Layers
What is the outermost layer of Earth called?
The Crust
What type of seismic wave is the fastest and travels through solids and liquids?
P-waves
What do we call the theory that explains how Earth’s lithospheric plates move?
Plate tectonics
What instrument do scientists use to measure seismic waves?
A Seismograph
If an earthquake happens, where would damage likely be the most severe?
Near the epicenter
What layer of Earth is made of semi-solid rock and allows for the movement of tectonic plates?
The mantle
What type of seismic wave moves side to side and only travels through solids?
S-Waves
What causes most earthquakes to occur?
The movement of tectonic plates along faults.
What scale is used to measure the magnitude of an earthquake?
The Richter Scale
How can studying seismic waves help predict the risk of earthquakes in a given area?
By analyzing past seismic activity and fault movement to assess future risks.
What is the innermost layer of the Earth, composed mainly of iron and nickel?
The Core
What happens to seismic waves as they move through different layers of the Earth?
They change speed and direction due to differences in density.
What is the point inside the Earth where an earthquake begins?
The focus
How do seismic waves help scientists determine the depth and boundaries of Earth’s layers?
Wave speeds and refractions indicate density and composition changes.
If a large earthquake occurs in California, why might it not be felt in Ohio?
Seismic energy weakens as it travels, and fault types affect energy transfer.
What is the difference between the inner and outer core?
he inner core is solid due to immense pressure, while the outer core is liquid.
Why can S-waves not travel through the outer core?
S-waves only move through solids, and the outer core is liquid
How does the movement at a convergent boundary affect seismic activity?
It causes powerful earthquakes and sometimes subduction zones, leading to deep-focus earthquakes.
What are seismic shadow zones, and what do they tell us about Earth’s interior?
Areas where certain waves don’t appear; they reveal the liquid outer core and wave refraction in different layers.
How do engineers use knowledge of seismic waves to design earthquake-resistant buildings?
By creating flexible structures that absorb wave energy and prevent collapse.
Scientists believe the mantle is solid but behaves like a fluid over long periods of time. How does this property impact the movement of tectonic plates and the formation of geological features?
The mantle’s convection currents drive plate movement, which leads to the formation of mountains, trenches, and volcanic activity.
Scientists use seismic waves to determine Earth’s interior structure. Explain how the differences in wave behavior provide evidence for the composition and state of matter of each layer.
P-waves travel through all layers but bend at boundaries, indicating density changes. S-waves disappear at the outer core, proving it is liquid. Wave speed variations confirm material composition.
Compare and contrast the effects of seismic activity at divergent and convergent plate boundaries. How do the characteristics of seismic waves differ in each setting?
Divergent boundaries produce shallow, less intense earthquakes due to tension forces, while convergent boundaries create deep, powerful earthquakes due to compression. Seismic waves at convergent zones travel farther and are stronger.
Suppose a powerful earthquake occurs in the Pacific Ocean. How would scientists use seismic data from different locations worldwide to determine the structure of Earth's interior?
By analyzing P-wave and S-wave arrival times at multiple locations, scientists identify shadow zones and infer layer composition, density, and phase changes.
You are a geologist studying a newly discovered planet with seismic activity. What methods and principles from Earth’s seismic studies would you use to determine the planet’s internal structure?
Use seismic waves to analyze speed, refraction, and shadow zones, apply knowledge of wave behavior to infer density and composition, and compare with Earth’s models to hypothesize layer structure.