Land Subsidence

Causes

• Dissolution of Limestone: Subsidence frequently causes serious problems (such as caves) in karst terrains where the deterioration of limestone by subsurface fluid flow creates voids. This type of subsidence can result in sinkholes that can be hundreds of metres deep.
• Mining: Several subsurface mining methods, particularly those that purposefully cause the extracted void to collapse, such as pillar extraction, longwall mining, and any metalliferous mining method that includes "caving," such as "block caving" or "sub-level caving," can result in surface subsidence.
• Extraction of Petroleum and Natural Gas: If natural gas is extracted from a natural gas field, the field's initial ....