What are sinkholes?
Perhaps you have walked past a large hole in the ground and wondered, “What natural disaster is this now?” Well, most likely, what you saw that looked very much as if a giant grabbed a handful of the ground for lunch is actually a sinkhole. Sinkholes are large holes in the ground which result when the surface of the ground collapses, creating a pit, sometimes a few feet deep but often massive with terrifying effects. These holes can even take down structures with them. A sinkhole can form gradually, but most times it is a sudden occurrence, as is usually the case with sinkholes in Florida. It can also be referred to as a swallet, cenote, or doline.
Causes of sinkholes
Sinkholes are usually caused naturally, but they can also be caused by human activities. Sinkholes in Florida are a very common occurrence and natural processes that may cause sinkholes include erosion and underground water. When water gathers in the subsurface of the ground and starts dissolving the soil and rocks, with no external surface drainage, there will be underground spaces which will eventually lead to a sudden collapse of the land surface. In regions called “karst terrain,” sinkholes are more likely to occur because the rocks in the land surface can easily be dissolved by the groundwater passing through them.
On the other hand, human activities like mining, drilling, construction, or broken drain pipes can cause the ground to give in, forming a sinkhole. When water from damaged drain pipes keep seeping into the subsurface, the rocks begin to dissolve and erode.
Types of sinkholes
There are three most common types of sinkholes, namely, Cover Collapse sinkholes, Solution sinkholes, and Cover Subsidence sinkholes.
Solution sinkholes can occur either gradually or suddenly. When the land surface is covered by a very thin layer of soil, water can easily drain into the lower surface, making it constantly exposed to erosion. With time, the previously solid foundation will become weak and collapse.
Cover Collapse sinkholes are the most popular and are usually the ones you hear of on the news. They form suddenly when the bedrock beneath the surface becomes weak due to erosion, to the extent that it cannot support the weight above it. Then, there will be a sudden collapse.
Cover Subsidence sinkholes form gradually and occur when the bedrock beneath the surface is made of rocks and soil that are not closely packed together, leaving spaces in between them. This type of sinkhole occurs when the hole forms on top of the soil, not above it.
Why are sinkholes so dangerous?
The problem with sinkholes is that when they occur, they usually do not go down alone, but take property, structures, shops, and human lives with them. Because they usually form over a long period of time only for them to appear suddenly, it is difficult to prevent them from happening. Sometimes, the ground may give in, taking down a whole house with it or destroying the structure built on it. The probability that a human will be involved is high because they can appear almost anywhere, even in the middle of the road.
Like most disasters caused by mother nature, sinkholes cannot easily be predicted; hence, prevention may not be effective. However, some signs may occur to indicate possible sinkhole activity. Some of these signs include cracks on foundation walls, wet areas around the foundation, nails popping or obvious low or sunken areas on the property. Upon noticing these signs, a structural engineer will need to inspect the house and issue a report that will include a remediation plan if necessary. In the event of a sinkhole appearing, the help of attorneys, contractors, and adjusters may need to be solicited as the only proven method of repairing a sinkhole is compaction grouting.
Some of the largest and most devastating sinkholes
Often sinkholes can be devastating to the human population, causing the destruction of property and the loss of lives. One of the largest sinkholes is Berezniki’s sinkhole. It is located in Soviet Russia and keeps getting worse each year. What’s more disturbing is that nothing can be done to stop it. It has reached a shocking depth of 200m and doesn’t look like it’s going to stop increasing in size and depth anytime soon.
In Guatemala City, a gigantic sinkhole appeared almost suddenly, and funny enough, it is quite a neat hole. Residents in the city had been hearing rumbles in the ground but had no idea a sinkhole was forming. When the ground caved in, 2 people were reported dead while over 1000 had to be evacuated from the hole.
Florida is actually one of the most common places prone to sinkholes. From all the sinkholes in Florida, one of the most shocking occurred in 1994 when a 15-story sinkhole tore open right under an 80-million-ton pile of toxic industrial waste. This waste contaminated 90% of Florida’s drinking water.
A more recent occurrence was in Daisetta, where a sinkhole started as just a 20-foot hole but grew to 900 feet within one day. It took down structures and vehicles with it.
How to prevent sinkholes
Nobody wants their house or property subsiding because of a sinkhole, but as sinkholes are often natural and appear suddenly, it is difficult to prevent them completely. However, there are certain preventive measures that can be applied as soon as signs are detected. Sinkholes cost a lot to repair (that’s for those that can be repaired), and so the best thing to do is to try to prevent them as much as possible. In terms of sinkholes caused by human activity, GPR scanning can be used to detect sinkhole formation so that damaged or leaking pipes can be replaced before a sinkhole is formed due to the continuous leaking of water into the subsurface of the ground. In essence, it is less costly to dig up sewer lines and replace them than to restore the sinkhole when it appears as well as the structures and vehicles destroyed. Not to talk of the possible loss of human lives that can never be replaced.
If you own a house or property, you also need to employ preventive measures, especially if your property is located in an area prone to sinkhole disasters like Florida. Here are some of the measures you can take to limit the threat of sinkholes to your property:
- Hire a building inspector to inspect your property and its surroundings
- Replace old or worn out pipes before they start leaking
- Hire a specialist to perform chemical grouting on small sinkholes beneath your property and compaction grouting on larger sinkholes
- Employ soil treatment accompanied by appropriate drainage control
Although sinkholes are mostly devastating, some turn out to be tourist attractions, and scientists love to investigate them. They can contain ecosystems, be turned into large water bodies, and even have their own weather. But yes, the disadvantages far outweigh the advantages. The destruction of property and loss of lives is definitely not worth a mere interesting spec and its mysteries. That is why here on www.sinkholestoppers.com, we connect attorneys, contractors, and adjusters to help stop sinkholes, so they don’t stop you.