(redirected from Land subsidence)
Also found in: Dictionary, Thesaurus, Medical.


lowering of a portion of the earth's crust. The subsidence of land areas over time has resulted in submergence by shallow seas (see oceansocean,
interconnected mass of saltwater covering 70.78% of the surface of the earth, often called the world ocean. It is subdivided into four (or five) major units that are separated from each other in most cases by the continental masses. See also oceanography.
..... Click the link for more information.
). Land subsidence can occur naturally or through human activity. Natural subsidence may occur when limestone, which is easily carved by underground water, collapses, leaving sink holes on the surface, such as in Florida. Earthquakes can also cause subsidence of the land because of the movement of faultsfault,
in geology, fracture in the earth's crust in which the rock on one side of the fracture has measurable movement in relation to the rock on the other side. Faults on other planets and satellites of the solar system also have been recognized.
..... Click the link for more information.
. Permafrost, or the permanently frozen ground in tundra regions, can subside during local warming trends, a phenomena called thermokarst. Oceanic crust produced at spreading ridges (see seafloor spreadingseafloor spreading,
theory of lithospheric evolution that holds that the ocean floors are spreading outward from vast underwater ridges. First proposed in the early 1960s by the American geologist Harry H.
..... Click the link for more information.
) subsides after cooling, as do calderas, the craterlike features at a volcano's peak. An atoll is a coralcoral,
small, sedentary marine animal, related to the sea anemone but characterized by a skeleton of horny or calcareous material. The skeleton itself is also called coral.
..... Click the link for more information.
 reef that forms a ring with no apparent central peak and may form when volcanic islands subside—an explanation first proposed by Charles Darwin. Human activity has contributed greatly to subsidence over the last few centuries. For example, withdrawal of oil from the field at Long Beach, California, beginning in 1936 resulted in subsidence at rates ranging from 0.5 to 2.0 ft (0.15–0.61 m) per yr in the center of the field. By 1962 the center of the oil field had subsided slightly over 27 ft (8.5 m), caused by the removal of fluid from the pore spaces in the underground rock, allowing the grains to compact. Similarly, withdrawal of groundwater through well pumping has resulted in subsidence in such cities as Mexico City, Houston, Tex., and Venice, Italy. Subsidence is also caused by the collapse of underground salt, ore, and coal mines.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



the compaction of soil owing to external stress or the soil’s own weight. It occurs in loess and loesslike deposits after artificial wetting and may result from thawing (thermal subsidence in frozen soils) and such dynamic actions as vibration subsidence. The soil’s surface may subside from a fraction of a centimeter to 2 meters. Subsidence may cause cracks on the surface and in the soil mass. If percolation of moisture in soils compacted by wetting occurs after subsidence, deformation of the soil is possible owing to leaching from the soil of water-soluble compounds.

The cause of subsidence in loess and loesslike deposits is insufficient compaction of the soil and accompanying loss of stability in particle bonding as a result of wetting. With soil of a given moisture content, a specific porosity corresponding to each degree of pressure decreases with increasing pressure. The bonds between particles in soil may keep it compact despite an increase in pressure caused by the weight of new deposits or of structures. This gives rise to a disparity between porosity and pressure, or a state of insufficient compaction. Subsidence also results from lowered stability of particle bonding in soil when loess is wetted by leakage from water pipes or when the groundwater level near a reservoir rises. Insufficient compaction of loess and loesslike deposits is characteristic of such arid semi-desert or steppe regions as those in Middle Asia, the Ukraine, the Northern Caucasus, China, Southern Central Europe, and the Mississippi basin. Thermal subsidence may occur in the permafrost zone.

The subsidence properties of loess and loesslike soils are studied in compression testing devices and by wetting trenches. The extent of the compaction of soil when wetted in relation to the original elevation of a soil sample is called the relative degree of subsidence and may vary from 0 to 0.1 or more. Subsidence may arise when the moisture content of soil increases to a certain level (initial moisture content of subsidence) or when pressure exceeds a certain level (initial pressure of subsidence). Conditions for construction on loess and loesslike soils are of two types: surface subsidence of less than 5 cm resulting from the weight of the wet ground itself, and surface subsidence of more than 5 cm. Different conditions require different construction measures.

Steps taken to control subsidence during construction include wetting of the ground, silicification, compaction, and firing. Structural measures are also taken, and the danger of water harming the foundations of structures is eliminated.


Denisov, N. Ia. Stroitel’nye svoistva lessa i lessovidnykh suglinkov, 2nd ed. Moscow, 1953.
Abelev, Iu. M., and M. Iu. Abelev. Osnovy proektirovaniia i stroitel’stva na prosadochnykh makroporistykh gruntakh, 2nd ed. Moscow, 1968.
Gil’man, Ia. D., and V. P. Anan’ev. Stroitel’nye svoistva lessovykh gruntov i proektirovanie osnovanii i fundamentov. Rostov-on-Don, 1971.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


A descending motion of air in the atmosphere, usually with the implication that the condition extends over a rather broad area.
(mining engineering)
A sinking down of a part of the earth's crust due to underground excavations.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


A sinking of an entire area, in contrast to the settlement of an individual structure.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.


A descending motion of air in the atmosphere over a broad area, as in polar regions.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
and Bi, H.: 2015, Land subsidence in the modern Yellow River Delta based on InSAR time series analysis.
In this study, a numerical model for a coupled one-dimensional multilayer aquifer system is developed to present the process of land subsidence due to hydraulic head variation in the pumped layer.
Environmental Impacts of Land Subsidence in Urban Areas of Indonesia [report].
The last 30-40 years have seen earthquakes, but also tsunamis, volcanic eruptions, floods and even land subsidence, a term not known in the past.
He warned: "That will cause land subsidence, which could have a big impact on construction and roads."
Furthermore, the earthquake caused widespread land subsidence, which has turned low-lying coastal lands into estuaries.
The sprawling cities by the sea - cities like Bangkok, Manila and Jakarta - face an increased risk of flooding thanks to the combined impacts of sea level rise, storm surge from intensified tropical cyclones and land subsidence. The ecological vulnerability of these cities is exacerbated by the fact that Asian cities are some of the most populous in the world and continue to grow at a staggering rate.
Land subsidence has increased the frequency and severity of infrastructure damage and flooding in the Houston-Galveston area.
20 ( ANI ): A recent study has revealed that rapid climatic changes, combined with increasing population, economic growth and land subsidence, could cause global flood losses worth 52 billion dollars by 2050.
According to recent environmental studies, there are "high levels of toxic gases, which pose an immediate health threat to residents, but also cause internal and surface combustion at the dump site leading to explosions, land subsidence, surface fires and other safety hazards.
In Bangkok, it anticipates a nearly two-fold increase in damage costs between 2008 and 2050 due to land subsidence. The city's subsidence is estimated by the Intergovernmental Panel on Climate Change at between 20 centimetres and 1.6 metres over the next 50 years, while sea-level rise in the upper Gulf of Thailand is projected to be between ten centimetres and one metre over the same period.