Question 1
Felt earthquakes
usually last for ________.
◦ 10 to 60 seconds
◦ 1 to 10 minutes
◦ 1 to 10 seconds
◦ less than 1 second (they are instantaneous)
Question 2
Liquification, where normally solid material behaves more like a fluid during an earthquake, occurs because ________.
◦ friction from the vibrations melt rock and produce magmas
◦ pore spaces between particles in unconsolidated sediments close and displace fluids
◦ cracking in the rocks allows fluids to flow into the area and increase the amount of liquids in the subsurface
◦ rock particles dissolve and mix with the fluids in the subsurface to become a liquid