Earth science questions?

Some Earth Science questions that I'm stuck on .. please help! thanks=]





1. When a P or S wave encounters the different layers inside the earth, the earthquake wave is


a) reflected,


b) refracted,


c) scattered





2. The action of shear waves (S waves) is most similar to:


A) a line of parked cars hit by a moving car


B) Corks bobbing on the surface of water


C) throwing a baseball


D) stretching a rubber band





3. At a depth of about 25 km the earth's density increases sharply. This marks the interface between the lower density crust and the higher density mantle. This boundary is called ______ _______





4. The speed at which a seismic wave travels through the earth is a measure of the rock's density. This is not a perfect measure, however, because the wave's speed is:


A) constant within one type of rock at a given level


B) identical within one type of rock at any given level


C) constant in all types of rocks at the same level


D) affected by temperature and density

Earth science questions?
1) all three can happen, but most 'common', or at the most angles, the answer is refracted.





2) b. The example I usually give is shaking a slinky back and forth.





3) mohorviric discontinuity, or moho for short. It's about 6 km for ocean crust, and 30 km for continental crust.





4) d for sure!
Reply:Dear friend you can get answer for all your questions about earthquakes and Tsunami in my slide show URL. http://asia.pg.photos.yahoo.com/ph/quake


The primary wave gets refracted and the secondary wave get reflected when it reaches the surface of liquid and gets refracted when the density changes.The primary wave will travel at a speed of about 13 to 17 K/M per second and passes through all mediums. Moves the particles in the direction of its propagation. S wave travels at about half the speed of P wave. But the difference in the speed is almost 8 k/m per second. To find the distance of epicentre we need the difference of speed only. The reflection and refraction takes place at the surface of the earth after arrival of those body waves. The reflected and reflected waves namely L and R waves are called surface waves comes much behind the previous waves. Most dangerous waves The speed of the waves will be more if the density of the medium is heigh.
Reply:Read your textbook.