Authorities have warned residents to stay away from the neighborhoods evacuated, warning that toxic sulfur dioxide seeping out of almost two dozen cracks in the ground caused by the volcano could prove deadly.
The explosion came shortly after 4:00am (local time) after two weeks of volcanic activity that sent lava flows into neighbourhoods and destroyed dozens of homes. Join us in a conversation about world events, the newsgathering process or whatever aspect of the news universe you find interesting or important.
The staff at the volcano observatory has been evacuated as well.
"With ash eruptions occurring from Kilauea's summit this week, there is a threat of an even larger steam-driven violent explosion".
The immediate risk health risk comes from ash particles in the air, said Dr. Josh Green, a state senator who represents part of the Big Island, also called Hawai'i Island.
Their concern was that the sinking molten rock would create steam as it interacted with the water table and that the steam would then jet upward, hurling heavy rocks and ash into the sky in a phenomenon known as a phreatic eruption.
The US Geological Survey issued a red alert on Tuesday warning of an imminent major eruption. "Protect yourself from ash fallout". "I think it's going to be a series of explosions similar to the one that happened this morning, and that's based on what happened in 1924, which is really our only analog".
The USGS said, Depending on weather conditions, that the ash might fall as far as Hilo, 30 miles to the northeast.
A change in wind direction caused gas spewing from fissures to drift northwest towards Pahoa, prompting National guard troops to don gas masks at a nearby road intersection, according to a Reuters reporter.
"Tall but small", she said of Thursday's plume.
Kilauea volcano has been erupting continuously since 1983.
The new fissure was discovered at Leilani Estates, the neighborhood in Puna where the first new fissures were seen earlier this month when Kilauea suddenly became more active. The eventual eruptions generated ash clouds more than five miles (8 km) high and threw blocks weighing as much as 28,000 pounds (12,700 kg) out of the crater.
What is happening at Kilauea is fundamentally is dissimilar from that 1980 eruption, experts told.
"They said they slept through it".