Land subsidence

Land subsidence is defined as the lowering of the land surface. Many different factors can cause the land surface to subside. Subsidence can occur rapidly due to a sinkhole or under ground mine collapse, or during a major earthquake. Subsidence can also take place slowly, becoming evident over a time span of many years. In either situation, subsidence can result in millions of dollars of damage. Find out more about causes of land subsidence by clicking on the links below.

picture of sinkhole

In 1811 and 1812, a series of strong earthquakes rattled northeastern Arkansas. These earthquakes initiated significant liquefaction that drastically changed the ground surface. Land subsidence was one of the major effects of these earthquakes. Large tracts of land subsided during the earthquakes and were flooded with water. Lakes such as Big Lake and St. Francis Lake formed in areas where the land surface has significantly subsided.

Land subsidence can occur in various ways during an earthquake. Movement that occurs along faults can be horizontal or vertical or have a component of both. As a result, a large area of land can subside drastically during an earthquake. Land subsidence can also be caused during liquefaction. Liquefaction can result in the settling and compacting of unconsolidated sediment in an event of a major earthquake. This can result in the lowering of the land surface.

swamp that was created after land subsidence after an earthquake

Land Subsidence Case Studies By County

Izard County

County Road 70 Karst Problems
Learn more »