THE SINKHOLE

And it came to pass, as he had made an end of speaking all these words, that the ground clave asunder that was under them:And the earth opened her mouth, and swallowed them up, and their houses, and all the men that appertained unto Korah, and all their goods.They, and all that appertained to them, went down alive into the pit, and the earth closed upon them: and they perished from among the congregation.And all Israel that were round about them fled at the cry of them: for they said, Lest the earth swallow us up also.(Num.16:31-34)

A sinkhole, also known as a sink, snake hole, swallow hole, swallet, doline, or cenote, is a natural depression or hole in the Earth's surface caused by karst processes — for example, the chemical dissolution of carbonate rocks or suffosion processes in sandstone. Sinkholes may vary in size from 1 to 600 metres (3.3 to 2,000 ft) both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may be formed gradually or suddenly, and are found worldwide. The different terms for sinkholes are often used interchangeably.