A quake last Friday was measured at magnitude 6.9, the most powerful to hit the islands since 1975.
What will take a turn for the worse in terms of hazard is if hotter, fresher magma makes it to the surface, and that could be what is coming, said Hawaiian Volcano Observatory lead scientist Tina Neal.
Willie Nunn, the FEMA federal coordinating officer in the affected area, said that "additional designations may be made at a later date" depending on further damage assessments.
When you start seeing ferns go brown overnight, it's like, 'Wow, I gotta get out of here, ' he said. The observatory said that 15 fissures, which have emerged since May 3, have not produced any lava since Wednesday. If it falls below the water table, water will pour onto the lava, generating steam that will likely explode from the summit in a shower or rocks, ash and sulfur dioxide gases.
Hannique Ruder, a 65-year-old resident living in the Leilani Estates subdivision, walks past the mound of hardened lava while surveying the neighborhood Friday, May 11, 2018, near Pahoa, Hawaii.
Lava on Hawaii's Big Island has destroyed over 35 homes and other buildings.
In addition, Kilauea, one of the world's most active volcanoes, threatens to begin a series of explosive eruptions within days or weeks that could form huge clouds of volcanic smog, or vog, and hurl boulders as big as small cars.
The Hawaii National Guard is prepared, with only 90-minutes notice, to rescue some 2,000 people by ground convoy in troop-carrying vehicles and, if necessary, in Blackhawk or Chinook helicopters. Residents and officials remained concerned about potential explosions and toxic gas leaks from the plant's underground wells, which provide heat for electricity production. The recent volcanic activity in Hawaii has also caused countless earthquakes, including a magnitude 6.9 natural disaster on May 4m which was the strongest quake to strike Hawaii since 1975.
The Kilauea volcano has been erupting periodically for more than three decades. As a result, lava levels inside the volcano's main crater have been decreasing.
Scientists said they could not predict how long the current eruption would last.