MYSTERY WIRE (NEXSTAR) – Steamboat Geyser in Yellowstone National Park is the world’s tallest active geyser, known to rocket hot water and steam nearly 400 feet into the sky.

The geyser, which laid largely dormant for 34 years, has been erupting prolifically since 2018. From March 2018 to to the present, a whopping 129 eruptions have been recorded, dazzling — and stumping — scientists.

What’s to blame for the geyser’s reawakening? Scientists aren’t entirely sure, according to a study published Monday in the Proceedings of the National Academy of Sciences.

While the scientists remain altogether stumped by what’s causing the new active phase, they were able to rule out earthquakes, snowfall and precipitation, and they’ve yet to dismiss internal hydrothermal processes.

Ultimately, knowledge about geysers and how they work remains nebulous.

“It’s a field that not a lot of people are dedicated to studying,” said Mara H. Reed, the study’s lead author. “We really don’t know some basic things about how geysers work.”

One of the motivations to study geysers, Mara said, is that some of the physics can be analogue to volcanoes.

“If we can’t understand these basic questions about geysers, that’s a problem, and we really should be paying more attention to it,” she said.

While the lack of answers is unsatisfying, Reed said she’s lucky to just have witnessed the geyser erupt. Geyser watching, before being a professional pursuit, is an admittedly “niche” hobby of Reed’s.

Watching a geyser erupt, she said, “is just an entire experience. It’s this giant water column that’s rising up in front of you; it sounds like a freight train going by, and you have to shout to be heard by the people standing next to you.”

“The feeling of watching this massive geyser — it’s really exhilarating.”

Geyser eruptions are caused by a complicated process in which a magma chamber heats up water underground. Once the water touches the hot rock, it begins to rise to the surface, dissolving silica in the rock to form a constriction that contains the building pressure. As the hot water nears the surface, the pressure drops and the water erupts upward.