Soil liquefaction
Also called: Liquefaction · Topic: Natural Hazards and Disaster Management in India · NCERT: Class 11, Ch 6 "Natural Hazards and Disasters: Causes, Consequences and Management"; Class 11, Ch 3 "Interior of the Earth"
Meaning
Soil liquefaction happens when strong shaking makes loose, water-soaked sand lose its strength. During the shaking the sand grains lose their grip on each other, and the ground behaves like a liquid for a short time. Buildings on it tilt or sink. Sand boils, which are spouts of sand and water, burst up at the surface. Liquefaction is a key reason why buildings on soft, wet ground suffer more in earthquakes.
Example
During the Bhuj earthquake of 26 January 2001, the ground liquefied in parts of Kachchh, Gujarat, and sand boils appeared across the area.
Don't confuse with
- Land subsidence: this is the ground sinking slowly or suddenly because of mining, groundwater pumping or natural collapse, as in the Jharia coalfield. Liquefaction is caused by earthquake shaking and happens during the quake.