Liquefaction is:.a. flooding of coastal areas due to tectonic subsidence. b. a quicksand-like condition arising in some wet soils during earthquakes. c. flooding caused by tsunamis. d. flooding caused by dam failure resulting from an earthquake.

Answer is option B.

Liquefaction is a quicksand-like condition arising in some wet soils during earthquakes.

Explanation:

The saturated soil (the space between individual particles in this soil is completely filled with water) or partially saturated soil/sand loses the strength and stiffness and behaves like a liquid when it undergoes a sudden change in stress condition such as shaking during an earthquake or other rapid loadings on the soil particle. This phenomenon is called liquefaction. During earthquakes, liquefaction causes the buildings to sink.

The fine-grained soils such as sandy, silty, and gravelly soils, which are poorly drained are most susceptible to liquefaction. The soil loses its cohesive strength due to sudden water pressure. As a result, the soil gets softened, weak and it behaves like a viscous liquid as its solid properties get converted into liquid properties. Liquefaction also causes landslides and contributes to sand blows.