Table of Contents
- 1 Do seismic waves follow a straight path?
- 2 What causes seismic waves to travel?
- 3 What is meant by a curve or bent path of a wave?
- 4 Why do seismic waves travel along curved paths through the mantle?
- 5 Why seismic waves follow curved paths inside the Earth?
- 6 What causes the bend effect in refraction?
- 7 How does refraction affect the speed of seismic waves?
- 8 Why does the amplitude of an earthquake decrease with distance?
Do seismic waves follow a straight path?
Seismic waves travel a curving path through the earth due to changes in composition, pressure, and temperature within the layers of the Earth. Seismic waves travel at different speeds through different materials.
What causes seismic waves to bend and change speed?
Figure 19.2a: P-waves generally bend outward as they travel through the mantle due to the increased density of mantle rocks with depth. When P-waves strike the outer core, however, they bend downward when traveling through the outer core and bend again when they leave. The bending of seismic waves is called refraction.
What causes seismic waves to travel?
Seismic waves are waves that travel through or over Earth. They are usually generated by movements of the Earth’s tectonic plates (earthquakes) but may also be caused by explosions, volcanoes and landslides.
Why do seismic waves follow curved paths inside Earth quizlet?
Why do seismic waves follow curved paths through the earth? Because the velocity of seismic waves generally increases with depth, and they travel faster when rock is stiffer or less compressible. The shadow zone is the area of the earth that s waves cannot pass through because they cannot pass through liquid.
What is meant by a curve or bent path of a wave?
Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or the bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves.
What causes seismic waves to reflect and refract within the earth?
When a wave encounters a change in material properties (seismic velocities and or density) its energy is split into reflected and refracted waves. Likewise, when an S-wave interacts with a boundary in rock properties, it too generates reflected and refracted P- and S-waves.
Why do seismic waves travel along curved paths through the mantle?
The waves are refracted as they travel through the Earth due to a change in density of the medium. This causes the waves to travel in curved paths. When the waves cross the boundary between two different layers, there is a sudden change in direction due to refraction.
What seismic wave travels horizontally?
There are two types of surface waves: Love and Rayleigh waves. Love waves move back and forth horizontally. Rayleigh waves cause both vertical and horizontal ground motion.
Why seismic waves follow curved paths inside the Earth?
Which of the following describes the curved path of seismic waves through the mantle quizlet?
Which of the following describes the curved path of seismic waves through the mantle? Waves are concave up because rock density increases with depth.
What causes the bend effect in refraction?
Light refracts whenever it travels at an angle into a substance with a different refractive index (optical density). This change of direction is caused by a change in speed. When light enters a more dense substance (higher refractive index), it ‘bends’ more towards the normal line.
Why do seismic waves travel a straight path?
If there were no changes with depth, seismic waves would travel a straight path to the other side of the Earth. But wave arrivals to distant seismic stations have taught us that there are layers. Seismic waves through the Earth follow the same laws of refraction and reflection as any other wave at interfaces.
How does refraction affect the speed of seismic waves?
Refraction has an important affect on waves that travel through Earth. In general, the seismic velocity in Earth increases with depth (there are some important exceptions to this trend) and refraction of waves causes the path followed by body waves to curve upward.
What happens when p and S waves travel through Earth?
The diagrams show what happens when P waves and S waves pass through the Earth. S waves cannot pass through the liquid outer core, but P waves can. The waves are refracted as they travel through the Earth due to a change in density of the medium. This causes the waves to travel in curved paths.
Why does the amplitude of an earthquake decrease with distance?
At farther distances the amplitude of the seismic waves decreases as the energy released by the earthquake spreads throughout a larger volume of Earth. Also with increasing distance from the earthquake, the waves are separated apart in time and dispersed because P, S, and surface waves travel at different speeds.