What is the process by which an earthquake's violent movement turns loose soil into liquid mud called?

The process by which an earthquake's violent movement turns loose soil into liquid mud is known as soil liquefaction. This phenomenon occurs when water-saturated soils lose their strength and stiffness due to the shaking of the ground during seismic activity. Essentially, the soil behaves more like a liquid than a solid, which can lead to significant ground failure and damage to structures. Soil liquefaction typically takes place in sandy or silty soils that retain significant amounts of water, where the increased pore water pressure during the shaking reduces the soil's effective stress, causing it to lose its bearing capacity.

In contrast, ground saturation refers to the condition where soil is filled with water, but it does not imply the loss of structure that liquefaction does. Earthflow is a type of mass movement that involves the slow, downhill flow of saturated soil, while mudslides occur as a result of excessive rainfall or rapid melting snow and involve the movement of wet soil and debris down slopes. Although these terms relate to ground movement and soil behavior, they do not specifically describe the unique mechanism of soil liquefaction triggered by seismic events.