After a series of rainfalls, a chunk of ground recently opened up at a residence in Peshawar. It has been noted to range from 6-7 feet in diameter. No causalities have been reported. According to the residents, the sinkhole might have emerged due to the drilling done a year ago for building a dam.
Ranging from 10 to 12 feet in diameter, sinkholes have a capacity to expand to hundreds of feet in diameter. A geological process of erosion, sinkholes usually occur where soluble rock is present. These rocks may potentially be limestone, salt and gypsum.
Rainfall is one significant ingredient that can cause sinkholes to open up. This is because the rain water seeps through the soil absorbing carbon dioxide while reacting with decaying vegetation resulting in slightly acidic water. The water dissolves the soluble rocks and creates cracks and voids.
Sinkholes can also be man-made. According to USGS, sinkholes can be formed due to underground pumping, construction and development practice, sewage malfunctioning etc.
Sinkholes, though are non-frequent events today but their occurrence is likely to increase if proper measures are not taken. Geological Survey of Pakistan (GSP) should educate people and look into the matter and analyze the hazards these incidences can cause in future.