A New Zealand farm worker says he was in for the surprise of a lifetime this week when he went to round up cows for milking and instead discovered a massive sinkhole that had opened up overnight in a field.
The sinkhole located near the North Island town of Rotorua is at least six stories deep and two football fields in length. It reportedly opened up after several days of heavy rain, the Associated Press reports.
Farm manager Colin Tremain said he didn’t realize just how massive the hole was until he went out at daybreak to survey the sinkhole.
Volcanologist Brad Scott told Newshub television that it is the largest sinkhole he has ever seen.
Scott noted that nine other sinkholes have opened up in the area in the past two years.
Sinkholes form from a combination of geology and weather. In areas like Florida where the rock below the land’s surface is easily dissolved by flowing groundwater, caverns that can lead to sinkholes form below the surface, collecting water and destabilizing the earth above, according to the United States Geological Survey.
Long bouts of rain can cause water to pool, leading to further destabilization, and in some instances, cataclysmic collapse.