Massive 6-storey-deep sinkhole opens up on New Zealand farm
Scientists are excited after a new sinkhole appeared on a farm in North Island, New Zealand, exposing 60,000-year-old volcanic rock deposits. The sinkhole is as deep as four double-decker buses and almost the length of two football fields, according to Phys.org. It is expected that the fissure will continue to get bigger. The farm where the chasm appeared lies on the crater of a long-dormant volcano.
"This is pretty spectacular, it's a lot bigger than the ones I'd normally see," volcanologist Brad Scott told TVNZ. “What I see in the bottom of the hole is the original 60,000-year-old volcanic deposit that came out of this crater. Then there's a stack of about 10 to 12 metres of sediment sitting on top of it from lakes that have formed in this crater. The top three metres is volcanic ash."
Farmer Colin Tremain said that the fissure appeared overnight a few days ago. A worker attending to the cows discovered it early in the morning, almost riding his motorcycle into it. The sinkhole appeared after heavy rainfall struck near the town of Rotorua. It is believed that rainwater may have eroded underground limestone deposits over the course of thousands of years leading to the collapse which created a huge canyon 66 feet deep and 660 feet long.
The appearance of the sinkhole has not been much of a surprise for Tremain as new holes keep popping up on the farm, though the latest one is definitely the largest.
Speaking to RadioNZ, the farmer said: "(I'll) put a fence around it and forget about it, waste of time filling it in.”
New Zealand has a long and ancient history of volcanoes, the North Island region especially being peppered with both active and dormant volcanoes. Eruptions and their consequent geological upheavals have shaped the island nation’s geography since prehistoric times.