A massive sinkhole has opened up in Rotorua, New Zealand's North Island following a record-breaking rainfall on Sunday, April 30, 2018. The sinkhole is 200 m (656 feet) long, 30 m (98 feet) wide and 20 m (65 feet) deep. The hole is growing and is now threatening road access to the farm it formed on. Several fault lines run beneath the land the farm sits on.
Although sinkholes are common in this region due to its volcanic history, GNS Science volcanologist Bradley Scott said that he is amazed at its size after he visited the site on May 2.
"It is the largest I've seen. Prior to this would be about a third of the size of this, so this is really big," he said.
Scientists sent in drone into the hole for a closer inspection of the volcanic deposits which were exposed when the fissure opened up:
"What I see at the bottom of this hole is the original 60 000-year-old volcanic deposit that came out of this crater," Scott told 1 NEWS.
"Then there's a stack of about 10 to 12 meters [33 - 40 feet] of sediment sitting on top of it from lakes that have formed in this crater the top 3 meters [10 feet] is volcanic ash."
This is the ninth serious sinkhole - or tomo, as they're officially called - to form on this farm in recent years.
Farm manager Colin Tremain said the hole runs along a fault-line at the Tumunui farm and was discovered by one of the farm's staff, who went out to get the cows first thing on Monday morning.
The farm had 146 mm (5.7 inches) of rain over a 24 hour period on Sunday, April 30.
According to NIWA, Rotorua had its wettest hour on record with 51.8 mm (2 inches) of rain falling between 10:00 and 11:00 local time Sunday, with a total of 167.8 mm (6.6 inches) of rain falling between 04:00 on Saturday and 18:00 on Sunday.
The region saw a month's worth of rain in 24 hours on Sunday (more than 133 mm / 5.23 inches ) and the heaviest rain in more than 50 years.