What is subsidence hazard?

Subsidence hazards involve either the sudden collapse of the ground to form a depression or the slow subsidence or compaction of the sediments near the Earth’s surface.

What is a ground subsidence?

Definition. Subsidence is the mainly vertical downward displacement of the Earth’s surface generally due to insufficient support from beneath, a superimposed load, or a combination of both. It can arise from natural causes, human activities, or, often, by human activities destabilizing natural systems.

What are effects of ground subsidence?

Ground subsidence can affect the stability of pipelines, drains, and well casings. It can also cause the formation of ponds and cracks in the ground and, if the site is close to a populated area, can lead to instability of buildings [35].

What other hazard can be caused by subsidence?

Land subsidence generally results in substantial damage, including loss of ground surface altitude, cracking of buildings, failure of underground pipelines, increase of flood hazards etc.

What do you mean by subsidence?

Subsidence – sinking of the ground because of underground material movement—is most often caused by the removal of water, oil, natural gas, or mineral resources out of the ground by pumping, fracking, or mining activities.

What is an example of subsidence?

Slow subsidence occurs when the water within the sediment is slowly squeezed out because of overlying weight. The problem now is that sea levels are rising as glaciers melt and water expands due to global warming. An example of slow subsidence in the U.S. includes New Orleans, Louisiana.

What are an examples of subsidence?

Human processes that can cause subsidence include mining, natural gas removal, and overuse of groundwater. Natural processes that sometimes result in subsidence include the erosion of bedrock, earthquakes, the faulting (breaking) of bedrock, and the shifting of groundwater reservoirs.

Can subsidence be fixed?

Dealing with subsidence affecting your home is, unfortunately, never a quick fix. There is a process that you need to follow, which starts with spotting the first signs and getting a firm diagnosis of subsidence before you can move on to carrying out works to fix the problem and clearing up afterwards.

What is the result of subsidence?

Land subsidence—the loss of surface elevation due to removal of subsurface support—occurs in nearly every state in the United States. Subsidence is one of the most diverse forms of ground failure, ranging from small or local collapses to broad regional lowering of the earth’s surface.

How does subsidence affect weather?

If there is sufficient moisture present, rising air causes clouds to develop, which may eventually allow for precipitation. On the other hand, sinking air (subsidence) leads to generally fair weather with very few clouds and little to no rain. As the air sinks, the air compresses and warms.

What are the causes of subsidence?

What are some examples of areas that have been affected by subsidence?

Land subsidence caused by man-induced depressuring of underground reservoirs has occurred in at least nine urban areas in the United States. Significant efforts to control it have been made in three areas: Long Beach, California; Houston-Galveston, Texas; and Santa Clara Valley, California.

What causes the subsidence of the ground surface?

Subsidence is the sinking or settling of the ground surface. It can occur by a number of processes. Ground subsidence may result from the settlement of native low density soils, or the caving in of natural or man-made underground voids. Subsidence may occur gradually over many years as sags or depressions form on the ground surface.

What are the criteria for ground subsidence in Colorado?

The criteria for recognition of actual or potential ground subsidence conditions include a careful evaluation of all pertinent historic, geologic, and hydrologic factors or the area, and/or actual periodic measurements.

Which is an example of USGS land subsidence research?

Examples of research USGS does concerning land subsidence, sinkholes, and related science. The California Water Science Center has been involved in multiple studies simulating land subsidence associated with groundwater withdrawal. The simulations can be used to estimate the magnitude, location, and timing of subsidence.

Are there any subsidence hazards in Colorado Mines?

Potential subsidence hazards from underground mine working and shafts exist in many parts of Colorado. These include areas of past and present coal mining, “hard rock” mining areas, and undoubtedly others. Geologic conditions conducive to all of the basic types of subsidence described above exist in extensive areas of Colorado.