Author Question: Define and distinguish between the following: epicenter, focus, foreshock, aftershock. What will ... (Read 53 times)

Starlight · **on:** Jul 14, 2018

Define and distinguish between the following: epicenter, focus, foreshock, aftershock.

What will be an ideal response?

Question 2

Describe the creative forces and typical characteristics of the three major types of faults.

What will be an ideal response?

janeli · **Reply #1 on:** Jul 14, 2018

Answer to Question 1

The subsurface area where the motion of seismic waves is initiated along a fault plane is the focus (or hypocenter). The area at the surface directly above the focus is the epicenter. A foreshock is a quake that precedes the main shock. An aftershock occurs after the main shock, sharing the same general area of the epicenter.

Answer to Question 2

The three major types of fault are normal fault, reverse fault (thrust fault), and strike-slip fault. A normal fault is one in which the hanging wall moves downward relative to the footwall as a result of tension. A reverse fault is one in which the hanging wall moves upward relative to the footwall as a result of compression. A strike-slip fault is in which shear cause horizontal movement along a fault plane. All transform faults are a type of strike-slip fault. However, not all strike-slip faults are transform (since some occur at locations away from plate boundaries).