The noxious gas, normally emitted at risky levels only from the volcano's Halemaumau Crater, was seeping at a greater rate from the fissures in Leilani Estates, a residential area of about four square miles in the Big Island's Puna district.
The Hawaiian Volcano Observatory has advised of an explosive eruption at Kilauea summit that occurred at 4:17 a.m.
Civil Defense advises residents to protect themselves from ash fallout as more emissions are expected.
People play golf as an ash plume rises in the distance from the Kilauea volcano on Hawaii's Big Island in Hawaii Volcanoes National Park.
There's a lone webcam operating at the Hawaii Volcano Observatory's evacuated observation tower.
The United States Geological Survey has posted on social media a close-up look at a few scenes from vicinity of the Kilauea Volcano summit, shortly after the eruption went off. He's making sure the hundreds of evacuees that are using the shelter have food and a place to sleep, as well as any comfort they need during the stressful time.
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. "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".
Epic Lava tour operator John Tarson is an early-riser who was awake and says he only knew about it because an alert came in on his phone.
Another fissure has emerged on Hawaii's Kilauea volcano, bringing the total to 21, as authorities handed out protective masks and local officials warned that toxic ash and sulfur dioxide gas are the biggest health concerns for people near the mountain. The agency also closed a number of nearby schools due to elevated sulfur dioxide levels.
"With stratovolcanoes, when that lava reaches the surface, you get a very sudden expansion of that gas, and this generates a much more violent explosion", Malone said.
Scientists are predicting an eruption that shot ash almost 9 kilometres into the sky could be the first of a series of powerful explosions to rock Hawai'i's Kilauea volcano, reports SBS News.
The wind may carry the ash plume north toward Kau, Volcano, Mt. View, Kea'au and as far as Hilo.
The National Weather Service has issued an ashfall advisory until 12 p.m. HST, Hawaii County Civil Defense reported. At the same time, tourism is the island's biggest industry and people's livelihoods are dependent on visitors coming, he said.