Gargantuan sinkhole surprises farm worker at sunrise in New Zealand

Last week, a worker on a farm in New Zealand was rounding up cows before sunrise when he noticed a massive sinkhole, almost falling into it while riding on his motorbike. But it wasn't until daylight that anyone realized how massive the sinkhole was - six stories deep and the length of two foot ball fields - thought to be the largest ever in New Zealand, according to Science Alert.

It looks more like a canyon than a sinkhole:

RAW VIDEO: See the massive sinkhole - six stories deep, two football fields long - that opened underneath a New Zealand farm. A volcanologist says it may have been growing underground for up to 100 years before recent heavy rain opened it up. https://t.co/LmtY2V4c7e pic.twitter.com/rxMXV2uEN4

- CBS Los Angeles (@CBSLA) May 4, 2018

The sinkhole, near the city of Rotorua in an area called Earthquake Flat, looks like it's been forming for up to 100 years. From Science Alert:

What is thought to be the largest known sinkhole in New Zealand has ripped open across a farm on NZ's North Island, revealing a gigantic cavernous void estimated to have been decades or even a century in the making...

"The largest I've seen prior to this would be about a third of the size of this, so this is really big," volcanologist Brad Scott from Kiwi geoscience firm GNS Science told AP...

According to Scott, the sinkhole could have been forming for up to 100 years, after decades of rainfall slowly eroded the farm's limestone rock foundations.

After a period of intensive rainfall at the end of April that lasted for about a week, the last of the rock's resistance gave way, opening up to reveal this jagged, 200-metre-long (656 ft) ravine that looks like something out of the movie 2012.

The sinkhole has been fenced off to keep farm stock - as well as motorbikes - from falling in.