Because earths crust is denser than the mantle
"True, the Seismic Waves change speed and direction when they encounter different materials."
The speed of seismic waves are affected by the type of material that the waves are traveling through. in other words (as an example): some type of waves can travel through rocks but not through liquids.
The Moho
In air, the seismic waves(P-wave) are simply sound waves, and travel with the speed of sound (approx. 335 m/s).
m to the o to the h to the o
The speed of the movement of the wave through the crust helps to work out the structure of the rocks below the surface of the earth. If the waves move slower the indication is that they are moving through a sedimentary type of rock such as sandstone. If the waves are moving more quickly that would indicate a more crystalline rock like granite..
Type of land surface, speed and volume of water.
The composition of the crust under continents consists mainly of granitic rocks (continental crust). We know this through seismic studies that measure the speed of seismic waves traveling through the crust, density measurements, and rock samples brought up from drilling and mountain-building processes.
"True, the Seismic Waves change speed and direction when they encounter different materials."
The speed of seismic waves from fastest to slowest is P waves (primary waves), S waves (secondary waves), and then surface waves. L waves are a type of surface wave, so they are generally slower than both P and S waves.
Continents can block the flow of surface currents, creating barriers that deflect the currents in different directions. They can also influence the direction and speed of currents by shaping the coastlines and creating deep ocean basins that can channel currents. Additionally, continents can impact the distribution of heat and moisture, which can affect the intensity and direction of surface currents.
they use vaginas
Continental drift occurs at a rate of about 2-5 centimeters per year, which is approximately the same speed at which fingernails grow. This movement is due to the slow spreading of tectonic plates beneath the Earth's surface. Over millions of years, this movement can lead to significant changes in the positions of continents.
Seismic wave studies have helped scientists determine the structure of Earth's interior by observing how these waves travel and get refracted or reflected by different layers beneath the surface. By analyzing the speed, direction, and behavior of seismic waves, scientists can infer the composition, density, and temperature of Earth's various layers, such as the crust, mantle, and core, providing valuable insights into the structure and dynamics of our planet's interior.
When seismic waves hit the Moho (Mohorovičić discontinuity), they can either be reflected back to the surface, refracted as they pass through the boundary, or converted into a different type of wave. This boundary separates the Earth's crust from the underlying mantle, resulting in changes in seismic wave behavior.
The three types of waves in order of speed are: P-waves (Primary waves) - fastest seismic waves, travel through solid and liquid. S-waves (Secondary waves) - slower than P-waves, can only travel through solid. Surface waves - slowest seismic waves, travel along Earth's surface causing most damage during earthquakes.
Seismic waves are waves that travel through the Earth or other elastic body2 to 8 kilometersThe primary factor is the composition of the rock that the wave travels through. Secondarily, temperature tends to lower the wave speed and pressure tends to increase the wave speed.