"As long as that supply is there, the eruption will continue", she said.
The update came as a window for residents of Leilani Estates to briefly return to their homes to gather essential items was about to end.
Lava continued to spew out of cracks in the ground Sunday night after the eruption of Hawaii's Kilauea volcano, which began last week, destroying at least 26 homes and forcing more than 1,700 people to evacuate.
Scientists said Kilauea was likely to release more lava through additional vents, but they were unable to predict exactly where. Spokeswoman Rhea Lee-Moku said power has been restored to about half of the customers, but sulfur gas levels in some areas are beyond what Hawaii Electric Light deems safe so they can not work in those places.
"The closest resort areas, in Kona and the Kohala Coast on the island of Hawaii's west side, are more than 100 miles away from where the lava flow is occurring and shielded by the massive mountains of Maunakea and Maunaloa".
The number of lava-venting fissures in the neighborhood grew overnight from eight to as many as 10, Stovall said, though some have quieted at various points.
Officials say 21 homes have now been destroyed in Hawaii by lava flowing from Kilauea volcano, based on an aerial survey by the fire department. Yesterday afternoon the FAA issued a Temporary Flight Restriction (TFR) for the area to prevent drones from interfering with first aid responders.
"Now we are just trying to make plans for the future", she said.
The woman, Amber Makuakane, told The Associated Press her three-bedroom house was right across from a fissure that had opened Friday. Lava flows from the volcano have covered 48 square miles (125 square km), according to the USGS.
A fellow teacher started a fundraising page to help Makuakane and her family rebuild.
Toxic sulfur dioxide gas spewing near the fissures is at lethal concentrations, said U.S. Geological Survey volcano scientist Wendy Stovall.
Snyder says it's all part of a little chain of events and that these "breakouts" are following a path.
One resident, Ikaika Marzo, told The Honolulu Star-Advertiser that lava fountains were shooting 150 feet into the air about 5:30 p.m. and that lava had spread over a 200-yard-wide area behind a house in Leilani Estates.
The Hawaii Fire Department reported "extremely unsafe air quality conditions due to high levels of sulfur dioxide gas in the evacuation area", civil defense officials said on Saturday.
Officials say some residents will be allowed to complete evacuation of pets, get medicine and grab vital documents.
Janet Babb, a spokeswoman for the observatory, said by telephone that the eruptions could carry on "for weeks or months".
Lava set trees ablaze and threatened homes as gas spewed out of cracks in the ground. The danger is of such magnitude that it warrants preemptive and protective action in order to provide for the safety, health and welfare of the residents of Leilani Estates and surrounding areas. Authorities ordered more than 1,700 residents to evacuate from there and nearby Lanipuna Gardens.