Sinkholes form seemingly out of nowhere, catching unsuspecting civilians off guard. It’s one of the only natural disasters capable of swallowing entire cars, houses and buildings. Sinkholes cause an enormous amount of property damage, as well as take lives and bury people within minutes. Despite insurance companies’ efforts to develop risk prediction methods for sinkholes, predicting them is not possible without expensive data collection tools.
The terrain on which you live has a huge impact on whether a sinkhole will form. Understanding the area in which you drive or live is useful in preparing for a sinkhole emergency. This guide provides you with pertinent information about sinkholes. Continue reading to learn how to prepare for this type of natural disaster and find evacuation strategies to stay safe during a sinkhole emergency.
Table of Contents
- What is a sinkhole?
- Levels of a Sinkhole
- Prep an Emergency Kit for a Sinkhole
- Reinforce Your Home for a Sinkhole
- Emergency Protocols and Exits for a Sinkhole
What is a sinkhole?
A sinkhole is a hole in the ground caused by the erosion of the earth below its surface. Some regions of the world have a layer of salt rock below the earth’s surface, which dissolves when too much water saturates the ground. A sinkhole’s size varies based on the amount of erosion and how long the subsurface crust has been breaking down.
Some sinkholes have a diameter as small as three feet, while others span upwards of 2,000 feet. They are most common in areas with high concentrations of limestone, gypsum and salt beds. Dissolution of these materials results in massive underground caves, even when surface levels appear to be fine.
Sinkholes are most dangerous when they form below apartment buildings, businesses, homes, parks and busy roads or highways. Sinkholes quickly expand to swallow entire buildings, cars, trees and anything standing on the surface. As a result, widespread injuries and deaths are common. Furthermore, a sinkhole causes irreparable property damage, rendering a plot of land useless for any type of construction.
Sinkhole events contaminate sources of clean drinking water, ruin sewage pipes, destroy underground electrical wires and damage other systems essential for modern comfort and daily living. Also affected are crops and farm animals, which often don’t survive the expansion of sinkholes.
Levels of a Sinkhole
There is currently no scale to measure the damage effects of a sinkhole, aside from financial costs of property damage and casualties. Below is a brief description of each major type of sinkhole.
Also referred to as “dissolution sinkholes,” this type forms when there is only a thin layer of grass and soil above the delicate limestone or brittle matter below the surface. The underlying bedrock slowly dissolves as it becomes saturated with water from rain and runoff. If it contains a lining of debris and other materials that block water from draining into deeper subsurface layers, the hole becomes a pond. These sinkholes develop slowly and are considered less dangerous than other sinkholes.
Cover Subsidence Sinkhole
Cover subsidence sinkholes occur where there is sand covering bedrock. Sand falls through the pores of the bedrock and slowly eats away at it, forming a depression that grows larger over time. Eventually, a buildup of this sand causes the earth’s surface to sink. Cover subsidence holes grow over time, much like a solution sinkhole.
Cover Collapse Sinkhole
Scientists consider cover collapse sinkholes to be the most dangerous type. In these cases, a layer of clay covers the underlying bedrock. Over time, water dissolves the bedrock that rests beneath the clay layer. This erosion results in several underground caverns, which grow into sizeable caves under the surface of the earth. Ultimately, the thin clay layer can no longer withstand the weight above and opens, swallowing any buildings, people or vehicles it was once supporting.
How to Prep an Emergency Kit for a Sinkhole
Sinkholes are not easily predicted. Often, citizens only have minutes to respond. It’s important to have an emergency kit readily available to help you and your family survive a sinkhole event.
Food is among the most important items to have in your sinkhole emergency kit. Have at least a three-day supply of non-perishable foods for each person in your household. Include a collection of food items you can eat straight out of the can or package. Examples of these foods include tuna, canned pork, sardines, ravioli, soups, beans, corn, peas, yams, ham, peanut butter, mushrooms and fruits.
Dried foods are other viable options, such as cashews, almonds, apricots, raisins, prunes, dates, peanuts, trail mix, chips, crackers, granola, granola bars and cereals.
Fresh fruits like apples, oranges and pears are edible for at least a week outside of the refrigerator.
Other food items like hard cheeses, preserved sausages and jerky do not spoil easily, so consider adding them to your emergency kit.
Keep at least one gallon of water for each person in your party per day for a minimum of three days. Use clean plastic bottles, gallon jugs, glass containers and buckets with lids to store your water. During an emergency, use half a gallon to hydrate per day, reserving the other half for bathing and sanitation purposes.
Include a few general supplies in your emergency kit, such as a battery-operated radio, flashlights, headlamps, matches, lighters, lanterns and extra batteries. Keep a manual can opener handy to access your food stores. A sharp utility knife, tool kit, shovel and sledge hammer are also important for performing quick repairs or modifications. Include a first-aid kit, over-the-counter pain medications and personal prescriptions. Don’t forget cash and your important personal documents, like birth certificates and insurance cards. Include a paper map of your area, a compass, duct tape, walkie-talkies and power bank for your cell phone.
Sinkhole-specific emergency items include:
- Dust mask
- Protective eyewear
Allow professional emergency responders to save those trapped under debris. However, if someone’s life is at stake, the items in your kit will assist you in helping.
If there is risk of the sinkhole becoming larger and burying the person under heavy debris, you may have to act quickly. It is never recommended to attempt to save anyone by yourself, as you could become trapped as well. A group of people working together is safer, but it’s not advised that you attempt this endeavor on your own. If you are not comfortable making rescue attempts or it is too dangerous to respond, wait for professionals to arrive.
How to Reinforce Your Home for a Sinkhole
To prepare for a sinkhole, check the base of your home for cracks in the foundation. Walk along the perimeter of your home and across your driveway. Examine all revealed fence posts and trees that were previously submerged.
Check your lawn for circle-shaped depressions, collections of soil and the formation of small ponds. Determine whether there are any ground openings. Take note of any plumbing or power issues, as this indicates damage to underground lines.
Inside, keep an eye out for any windows or doors that do not open or close as intended. This indicates the shifting of earth below, causing inconsistencies in the structure of your home. Cloudy water is another indication of a forming sinkhole. If you encounter any of the above issues, call an inspector to give you an expert assessment. Call your insurance company to file a claim and get the proper reinforcements completed.
Expert engineers may suggest a sinkhole-reinforced structure to help your home withstand one. In other cases, compaction grounding or void filling helps stop a developing sinkhole from reaching a catastrophic size. Otherwise, affix flexible pipe fittings where gas and water lines connect. These pipes are flexible enough to withstand minimal shifting, reducing the occurrence of fires, floods or explosions.
Emergency Protocols and Exits for a Sinkhole
If you see a large sinkhole forming on the street, try to see toward which direction it is opening. Get as far away from it as possible and call the police to notify authorities of the hazard. Listen for newscasts informing citizens of affected areas. Develop a working knowledge of your local area and drive away from the sinkhole spot.
Even though sinkholes cannot be predicted, your knowledge of the local area provides you with information about alternate routes and safe locations. If you are at home, listen for signs of sinkhole developments, such as:
- Trees and fences falling over.
- Cracks in the ground.
- Rustling of grass or leaves.
- Cracking sounds coming from your home’s foundation.
- Noises associated with the separation of walls and ceilings.
If you notice a large sinkhole forming under your home, notify your family members and evacuate immediately. Drive as far away from the sinkhole as possible. Do not escape to higher floors of your home, as this will only trap you within and make circumstances worse. Call 911 to inform them of the sinkhole. After reaching a safe distance, call as many of your neighbors to tell them to evacuate, too.
If you notice a small sinkhole forming on the street near your house, tape off the surrounding area and mark it with fluorescent traffic cones. Keep a distance from the sinkhole’s edges, as it may be larger than it appears. Taping it off keeps others from riding or walking over it, which often makes it bigger.
Call your local authorities to inform them of the issue. If the sinkhole is in your yard, tape it off and call your insurance company.
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