Visitors to Yellowstone National Park on Tuesday were treated to the eruption of a geyser which has been dormant for six years, which the park said unexpectedly ‘roared back to life’.
The Giantess geyser, which lies to the north of Old Faithful in Wyoming, shot water and steam an estimated 100-200 feet into the air.
Crowds of tourists gathered to watch the rare spectacle.
The Giantess geyser erupted on Tuesday for the first time in six years, to the surprise and delight of visitors to the park
A plume of steam shot up into the air, reaching an estimated top height of 200 feet. Crowds in the park were fascinated
‘It used to erupt more frequently in the past,’ said the USGS Volcanoes division.
‘The six-year gap between eruptions in the longest since at least the 80s, but it has had years-long dormant periods before.’
The last time the Giantess erupted was on January 29, 2014 – an eruption that lasted more than 40 hours.
The exact timing of Tuesday’s eruption was not given.
Prior to the 2014 eruption, it had not been active since 2011; the two years and 139 days of dormancy was the previous record.
The geyser before that had erupted two to six times a year.
‘Why geysers turn off and on is something that is not well understood,’ the USGS said.
‘They are very fragile systems.’
The geyser is pictured erupting in a pencil drawing by Reverend Samuel Manning, made around 1880
Yellowstone is home to around 500 geysers, according to the park website – the highest-concentration of geysers on Earth
The USGS, asked why the eruptions were erratic, said that geysers were ‘very fragile systems’ that were ‘not well understood’
There are more geysers in Yellowstone than anywhere else on Earth.
Yellowstone said the Giantess was ‘a volatile and well connected geyser’, within the vast crater of a volcano that makes up the park.
Its eruptions usually set off nearby geysers on the aptly named Geyser Hill, also north of Old Faithful, the park said.
Old Faithful is certainly the most famous of the 500 geysers in the park, and was named in 1870.
Old Faithful erupts every 35 to 120 minutes for 1.5 to five minutes.
Its maximum height ranges from 90 to 184 feet, the park says.