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    Liquefaction is a phenomenon where saturated sand and silt take on the characteristics of a liquid during the intense shaking of an earthquake. The serious impact of liquefaction makes concrete buildings shift to other places or even like being swallowed into the earth all of sudden.

    Liquefaction takes place when a quake has increased water pressure in saturated soil and made particles in the soil lose contact with each other, making the soil - particularly sandy soil act like liquid. Liquefaction also happens in wet soils affected by seismic S waves (second waves). This waves caused ground vibrations during the earthquakes, especially in a poorly drained fine-grained soils such as sandy, muddy, and gravelly soils in a reclaimed area. The effect is like slapping soft muddy sand. Areas with shallow water tables and close to the sea or rivers are easily damaged by liquefaction too.

    Earthquake and soil experts say liquefaction is fairly common. It happened after the massive 9.0 magnitude quake hit eastern Japan in 2011 and numerous other earthquakes in recent years including the one in Palu and Donggala, Central Sulawesi.

What is mainly found in liquefaction process?