Water in Hawaii volcano may set off explosive eruptions

For the primary time in recorded historical past, a pond of water has been found contained in the summit crater of Hawaii’s Kilauea volcano, a growth that would sign a shift to a extra explosive section of future eruptions.

After every week of questions on a mysterious inexperienced patch on the backside of the volcano’s Halemaumau crater, the previous house of a famed lava lake, researchers confirmed the presence of water on Thursday, officers with the U.S. Geological Survey informed The Related Press on Friday.

“The query is what does this imply within the evolution of the volcano?” USGS scientist emeritus Don Swanson mentioned.

Halemaumau has by no means had water since written observations started, he mentioned, so the pond is uncommon.

Scientists aren’t precisely sure what is going to occur subsequent, however when lava interacts with water it might probably trigger explosive eruptions.

One chance is that lava may slowly warmth up the groundwater and finally create a brand new lava lake, Swanson mentioned. Lava may additionally work together with the water desk and create small explosions.

“The opposite chance is that magma rises quickly,” Swanson mentioned. “That would produce a bigger explosion.”

USGS officers harassed that there’s at the moment “no cause to assume hazards on the summit have elevated or decreased” due to the invention of water.

However Swanson mentioned in June that the presence of water might be a major change within the long-term exercise of the volcano.

Kilauea has a historical past of alternating between lengthy intervals of explosive eruptions and occasions of slower, so-called effusive phases.

Explosive intervals are precisely what they sound like, centuries of large explosions that ship sizzling particles racing down the hillsides and towering columns of rock and ash excessive into the environment.

Effusive intervals, which Kilauea has been in for about 200 years, are marked by slower, regular lava flows that — compared — trickle out of the bottom.

The subsequent explosive interval, researchers imagine, might be preceded by a large collapse of Kilauea’s caldera ground.

An eruption that was ongoing for greater than 30 years got here to a dramatic finish final yr when lava exploded from Kilauea’s flank and coated an enormous swath of land, destroying lots of of properties in one of many largest eruptions in latest historical past.

That eruption got here with a major drop of the caldera ground. Halemaumau crater collapsed almost 2,000 ft (600 meters) over the course of a number of months, however Swanson mentioned he would count on a bigger, “form of wholesale collapse of the caldera ground” to set off a chronic explosive interval.

“If it truly is a transition then there must be repeated collapses, ever-deepening the caldera ground, earlier than we’d get into considered one of these bigger scale occasions,” Swanson mentioned.

Swanson mentioned that whereas researchers have by no means noticed water on the caldera ground earlier than, there are Native Hawaiian chants that describe the presence of ponds showing simply earlier than explosive occasions.

“It is actually not scientific proof but it surely nonetheless enhances the interpretation,” Swanson mentioned.

Researchers have information going again about 2,500 years that reveals this transition between explosive and effusive levels.

“We all know from mapping the deposits and finding out them that there have been a number of of these (explosive) occasions between about 1,500 and 1,790 and several other occasions between about 200 B.C. and 1,000 A.D.,” Swanson mentioned. “Kilauea is the one volcano for which we have acknowledged these cycles to date and I feel that is as a result of it has been so intensively studied.”

These lengthy intervals are marked by massive explosions that happen each few a long time — and even centuries — with smaller explosions in between, Swanson mentioned. And whereas explosive eruptions do not usually function fast-moving lava flows or large fountains of molten rock, they’re nonetheless very harmful.

Swanson mentioned large explosive eruptions generally produce pyroclastic surges — partitions of sizzling air, ash and rock. In 1790 one such eruption killed numerous individuals at Kilauea’s caldera, Swanson mentioned.

“These surges can transfer at hurricane velocity throughout the panorama and they’re among the many most harmful sorts of eruptions,” he mentioned.

Swanson mentioned none of this can occur in a single day, and he hopes that fashionable monitoring methods will give the general public loads of warning.

“I have been stressing that the present exercise at Kilauea, or lack thereof, can go both method,” Swanson mentioned. “We will both return to what was occurring earlier than, or this might be the preamble to some extra vital change within the volcano that results in explosive exercise.”