Throughout the Kilauea volcano’s 2,500-year-long history, it’s alternated between periods of gentle lava flows and explosive eruptions. Since 1983, it’s been stuck in a continuous, relatively peaceful state in which it slowly bubbles up lava. But on May 3, residents were forced to flee after a new fissure suddenly opened miles away from the volcano’s crater. A 6.9-magnitude earthquake hit the very next day, sending fluid basaltic rock gushing through a neighborhood that’s home to 2,000 people. And there’s a very real chance that it might not stop anytime soon.

Scientists don’t know how long it will take until the lava flow stabilizes. If it does, the evacuees could likely return home in two weeks. But history has shown that it might take much longer than that. As Hawaiian Volcano Observatory spokesperson Janet Babb told Reuters on Saturday, the eruptions from the new fissure could carry on “for weeks or months.” She said this event was similar to a 1955 Kilauea incident, in which the lava flow threatened people near the volcano for 88 days. After two more volcanic vents opened up on Tuesday, government officials warned that new areas would likely be evacuated, as the fissure system was slowly spreading eastward.

Lava moving down through the Leilani Estates on May 6.

It’s hard to say whether the eruption will intensify and continue because it’s not clear how much magma is ready to spew up and become lava. Kilauea is a shield volcano, which generally have high magma supply rates. As of now, scientists aren’t sure whether the newly opened fissures and increases in lava flow are being caused by an increase in magma supply, but they do know that as long as there’s magma in the system, it’s not going to stop.

“We really can’t peer through the ground and see it exactly in all its details and intricacies,” U.S. National Oceanic and Atmospheric Administration volcanologist Bill Chadwick, Ph.D., told NPR on Tuesday. “It could last days, weeks, years. All that’s possible. It’s hard to say, unfortunately.” The residents of Leilani Estates hoping to return home are, for now, stuck in limbo. Chadwick says that while a house might seem safe now, “it might be taken out by a lava flow five years from now if the eruption keeps going.”

In the meantime, all scientists can do is monitor flow rate as well as earthquake activity. On Tuesday, the United States Geological Survey announced: “Earthquake activity in the summit remains elevated. Many of these earthquakes are related to the ongoing subsidence of the summit area and earthquakes beneath the south flank of the volcano.” Its scientists plan on tracking earthquakes as well as gases filtering through cracks on the ground, key indicators of whether lava flow will increase.

The good news is that no deaths or major injuries have happened since Kilauea’s latest eruption, which experts credit to the efficiency of Hawaii’s Civil Defense agency.

Photos via USGS (1, 2)