Types of Sinkholes

needs to do is to take a class about Geology or Meteorology to know why these

water fractures within the earth. Causing certain areas of the land to have an earthquake effect

The karst terrain which creates the geomorphic conditions for sinkholes is a broad topic in the field of geology, and encompasses the study of groundwater, drainage, chemical processes, and many other considerations. Essentially, karst regions are located where the rock below the earth can be dissolved by the acidic groundwater which percolates through it (The Science of Sinkholes). These areas are underlain by soluble rocks such as gypsum, limestone, and dolomite which typically react with carbonic acid (H2CO3) from groundwater to dissolve the rock. Presence of limestone is

Similar to a cave, a sinkhole begins by acidic water dissolving carbonate bedrock creating an underground void. If the void grows close enough to the surface, the structural integrity of the surface material will eventually give way and a sinkhole is formed. These depressions can range in size from a few square yards to over hundreds of acres. The depth of sinkholes can vary from shallow to hundreds of feet. Although there are nearly 16,000 verified sinkholes in the state, the MGS caution there are a great number which have not been reported or documented. Some sinkholes in Missouri are known to be a depth greater than 100 feet though no exact records concerning depths are maintained. Located in western Boone County, the largest known sinkhole in Missouri covers approximately 700 acres. If a sinkhole does occur, it is recommended that a registered geologist or professional engineer be consulted to assist in the stabilization of the sinkhole. Filling a sinkhole, referred to as remediation, generally consists of removing all soil materials down to the bedrock surface and filling it with size-graded material. Larger rocks should be used first with each successive layer consisting of gradually smaller grained material. Geotextile fabric covered by top soil will allow water

Soluble carbonate rocks under the surface and the collapse of old mines are common causes for sinkholes. Much of Alabama’s land is underlain by limestone, which is vulnerable to dissolution and leads to the formation of caves or sinkholes. The largest sinkhole recorded in the state developed near Calera in 1972 and was 325 feet long, 300 feet wide, and 120 feet deep. Northeast Alabama also suffers from earthquakes due to the state’s proximity to the Southern Appalachian Seismic Zone that runs along the Appalachian Mountains. The largest earthquake recorded occurred October 1916 at a 5.1 magnitude and spanned multiple states. The second largest earthquake in Alabama occurred October 24, 1997 at a 4.9 magnitude. In addition to sinkholes and earthquakes, the state suffers landslides due to rock strength. Most of the state is categorized as argillaceous rocks such as shales, clayey soil, and poorly compacted fills. A few areas are classified as weakly cemented rocks and soils such as sandy soils and poorly cemented sandstone. Though there are clusters of strongly cemented rocks, much of the state is included in the weaker categories. This means that they are more susceptible to landslides when earthquakes occur. (Geological Survey of

In this photo, you can see steel pipes coming out from under the road. These were installed as a form of drainage underneath the sea to sky highway to prevent damage to the road and flooding.

The majority of buildings in Afghanistan fall into the latter category. These buildings are especially dangerous because not only are they vulnerable to collapse, but the construction materials are heavy and cause severe injury or death when falling from modest

The excessive pumping of groundwater can create subsurface voids because of the lowering of the water table, which can lead to the development of sinkholes due to gravity and a loss of fluid-pressure support (Tihansky, 1999, p. 132). Waltham et al (2005) contend, “The most widespread cause of induced sinkholes is any form of water table decline, where the vertical drainage is quite literally drawn down to greater depths” (p. 165). In brief,

The United States Geological Survey (USGS, n.d.) defines a sinkhole as "an area of ground that has no natural external surface drainage--when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface." Sinkholes vary in size considerably: from a few feet in diameter and one foot of depth, to "hundreds of acres" wide and "more than 100 feet deep," (USGS, n.d.). Some sinkholes form naturally over time, but human intervention such as construction and development projects have been causing the rapid development of sinkholes in the state of Florida. These large-scale projects can have disastrous effects on the economy and environment, as well as public safety. Sinkholes are especially problematic when they occur suddenly, without warning, in urban areas (USGS, n.d.).

Sinkholes are pits in the ground that form where water gathers with no drainage. The water weakens the ground under the surface and any weight on the affected area will collapse the ground.

Within the state of New York, landslides are classified as the downward movement of a slope and materials under the force of gravity (New York State Hazard Mitigation Plan, 2008). This definition also includes: a wide range of ground movement, such as rock falls, deep slope failure, shallow debris flows, natural rock, soil or artificial fill (New York State Hazard Mitigation Plan, 2008). Depending on the size and location of the landslide, landslides can be dangerous (Hyndman and Hyndman 2014). There are three mechanisms that initiate landslides. One mechanism is too much water. When water is added to a slope, soil becomes saturated and pore water pressure increases causing a slope to slide. A second mechanism is cutting the toe and oversteepening of the base. Removal or addition of material at the bottom of a landslide increases steepness of a slope. A steeper slope is less stable, increasing the likeliness of a landslide to occur. The third mechanism is adding material to the top of a slope, this also helps creates steeper

Rapidly forming sinkholes are unusal, and can occur without warning. However, most sinkholes give warning signs before evolving into a much larger problem. If you suspect sinkhole activity on your property, inpsect your yard for small depressions. Additonal warning signs may include:

In the winter of 2013 a sinkhole took the life of Jeffrey Bush in Seffner, Florida. He was lying in bed when the ground collapsed beneath his bedroom. Death from sinkhole formation is rare, but sinkhole collapses are a common occurrence throughout the state of Florida (Brinkmann, 2013, p.1). Natural hazards, such as sinkholes, can detrimentally impact society and the environment. Indeed, sinkholes can reroute surface runoff into aquifers; cause structural damage to roads and buildings; drain wetlands; and as shown in the example above, have fatal consequences.

Sinkholes are pits in the ground. They form in areas where water sits. As the water drains into the ground it dissolves caverns, usually were the bedrock is poor and made of water-soluble rocks like salt and gypsum or carbonated rocks such as limestone or dolomite. Sinkholes, to some people, are known as swallow holes and shake holes. Most sinkholes form slowly but when they collapse they fall suddenly. Usually the sudden sinkholes swallow homes, people and cars. Sinkholes have swallowed up lots of things. They have reported

Gaps between two different sedimentary rocks, are called unconformities. These gaps usually happen when an old layer of sedimentary rock is covered by a new layer of sedimentary rock. They are called unconformities because they don’t conform the basic geological expectations. So, what are the expectations? The law of original horizontality states that layers of sedimentary rock called strata, should be laying down horizontally to the earth's surface, just like pages in a book. Where the layers mismatch and create a gap, that is called an unconformity.