Question

in san franciscos marina district in 1989, some fill underwent permanent deformation and settling, and some formed slurries as underground water and loose sediment flowed like a fluid in a process known as ______.
○ avulsion
○ liquefaction
○ slumping
○ creep

Explanation:

The question is about a geological process during an earthquake (1989 San Francisco event). Liquefaction is the process where saturated soil loses strength and behaves like a fluid due to seismic activity, matching the description of underground water and loose sediment flowing like a fluid. Avulsion is a river - related process, slumping is a mass - wasting event with a distinct movement, and creep is slow downhill movement of soil/rock, none of which fit the given description.

Answer:

B. liquefaction