In the early hours of December 9th, the volcano known as Whakaari, or White Island off the northern coast of New Zealand erupted, killing several people.
Whakaari is New Zealand's most active volcano. It's also a popular tourist destination. And there were more than three dozen people on the island when the eruption happened.
Volcanic activity there is closely monitored, but there was no advanced warning about this eruption. This tragic event highlights just how hard it can be to predict volcanic eruptions and how much scientists still have to learn about the inner workings of volcanoes.
Jess Phoenix, known to many as VolcanoJess, is a geologist. She's also the executive director and co-founder of the nonprofit environmental science organization Blueprint Earth.
She says the Whakaari eruption was steam driven. It was not primarily a giant explosive event with lots of magma that many people associate with volcanic eruptions.
“This was something where pressure had been building up just beneath the surface of the volcano for many months. And essentially, it boiled the water that is present in the volcano's plumbing system. And when that happens, this this water gets so superheated and so pressurized that it essentially flashes to steam and it can move at supersonic speeds.”
The water that would have come out during the eruption would have been about 300 degrees Fahrenheit, Phoenix said .
While the volcano was monitored for changes, Jess says it’s actually extremely difficult to predict when a volcano will erupt.
“We can't actually predict eruptions at all. Prediction isn't a word that volcanologists use because prediction would imply that we could tell you when or how big an eruption would be, when in reality we're just trying to get better at forecasting eruptions, which is essentially saying that there is a likelihood of an eruption and what that likelihood might be.”
The latter is what volcanologists are working on, improving in the tricky and complicated science of volcano monitoring.