Which of the following best describes a seismic gap?
A) Unusually quiet zones along typically active faults
B) A downdropped valley bound by normal faults
C) Faults that have not been active for several million years
D) An erosional valley that has developed in an inactive fault
Question 2
What information is needed to determine the distance from the focus of an earthquake to the seismic receiving station?
A) The velocity of the P and S waves
B) The amplitude of the seismic waves on a seismogram
C) The magnitude of the earthquake
D) The time interval between the P and S waves