Dangerous levels of the toxic gas are rising from some fissures, or cracks in the ground caused by the volcano, Hawaii County officials said.
Officials warned residents to leave the area and get medical attention if they’re affected by the gas.
Since the Kilauea volcano erupted May 3, it’s been one nightmare after another for residents in the southeast part of the Big Island.
‘It sounded like hammers in the dryer’
Fissure 17 is the most active, shooting lava like a fountain and “sending spatter more than 100 feet into the air,” the Hawaiian Volcano Observatory said.
CNN’s Stephanie Elam said her heart started pounding as she approached one fissure.
“It sounded like hammers in the dryer,” she said. “The molten rock was such a deep vibrant orange that it looked technically altered. When the sulfur dioxide hit my lungs once, it took my breath away.”
“When you move to this volcano, or move to this island, you move into her house,” Bersamina said.
More eruptions could follow
Scorching lava has already swallowed dozens of homes and vehicles. So far, at least 37 structures have been destroyed, and counting.
The lava lake in the crater has been dropping since May 2, which increases the chances for a phreatic explosion.
USGS officials said a phreatic eruption could happen at Halemaumau crater at the top of the Kilauea volcano. And it could send ash plumes as far as 12 miles from the summit crater, the Hawaiian Volcano Observatory said.
But it will be difficult to warn residents who may be in the path of such an eruption.
Janet Babb, a geologist from the volcano observatory, said phreatic eruptions are “notoriously hard to forecast, and can occur with little or no warning.”
Scott McLean and Sara Weisfeldt reported from Pahoa, Hawaii. CNN’s Joe Sutton, Keith Allen and Chris Boyette contributed to this report.