California has its landslides, the Midwest its tornadoes, Florida its hurricanes, and New Jersey has...sinkholes. They’re sort of like your own personal earthquake. There are many famous sinkholes, both large and small. The largest in the world is the Qattara Depression west of Cairo, Egypt; it measures 80 kilometers by 120 kilometers. The famous cenotes of Mexico can also be considered sinkholes; the water-filled underground caverns are sometimes open to the surface, and dot the landscape of the state of Quintana Roo on the Yucatan Peninsula.
Sinkholes can occur naturally (as in the case of the Mexican cenotes) or be man-made. They are not uncommon in New Jersey, as well as some other areas of the United States including Florida, Texas, Alabama, Missouri, Tennessee, Pennsylvania, and Kentucky. As a matter of fact, just few years ago, a sinkhole swallowed up a warehouse and showroom in Kentucky filled with classic cars.
The danger of sinkholes is proportional to their size and location, of course. If a sinkhole opens up in a remote rural area with few man-made structures and sparse population, its impact is negligible; if one should occur in the middle of Main Street in a densely populated urban area, the damage can be catastrophic – even tragic.
What is a Sinkhole?
According to the website conserve-energy-future.com, naturally occurring sinkholes “occur due to erosion or underground water. They start developing a long time before they actually appear. The ground beneath our feet is not as much of a solid structure as we think it is. It’s made up of dirt, along with many rocks and minerals. There is water continually seeping in between the mud, rocks, and minerals, [making] its way down to the ground water reservoirs. As this happens, the water slowly erodes the rocks and minerals. Sometimes the flow of water increases to a point when it washes away the underground structure of the land. And when the structure becomes too weak to support the surface of the earth, it collapses and opens up a hole. This is how sinkholes are formed.”
Human activity can also contribute to the formation of sinkholes. “Activities like drilling, mining, construction, broken water or drain pipes, improperly compacted soil after excavation work, or even heavy traffic can result in small to large sinkholes,” according to the website. “Water from broken pipes can penetrate through mud and rocks and erode the ground underneath, causing sinkholes. Sometimes, heavy weight on soft soil can result in collapse...sinkholes can also form when the land surface is changed.”