Nearly 9,000 people a day are touring Hawaii Volcanoes National Park on average this year, a 2.5% increase over last year, when the volcano's 25-year eruption was much more peaceful, said Cindy Orlando, the park's superintendent.
"Everybody's coming. I think they recognize they have an opportunity to participate and be here at a very historic time," Orlando said Thursday. "They're witnessing the creation of earth, and you can't experience that anywhere else in the world."
People in the park can see the plume of ash and sulfur dioxide rising from Halemaumau Crater, which spewed small blobs of lava that fell along its rim this week and exploded gas and gravel-size rocks on the summit last week -- the first such burst from Kilauea's main crater since 1924.
"It's unpredictable. The last several months have been extremely unusual, and perhaps the most exciting activity on Kilauea in decades," said geologist Tim Orr of the Hawaiian Volcano Observatory.
Outside the park along the southeast edge of the Big Island, county and park officials say, as many as 10,000 visitors in one day have come to see fresh lava collide with the ocean, creating a giant cloud of steam.
A new lookout point allows viewers to get about 600 feet from the lava flow.
So far, Hawaii's trade winds are pushing the plume to the southwest, toward the ocean, so the gas hasn't posed serious problems, state health officials say.
But emergency officials are preparing to evacuate the area in case the winds change. Inland areas have a scattered population of about 10,000, and highly concentrated levels of sulfur dioxide could pose serious health risks, especially to people with existing respiratory problems.
Most of the national park remains open, including the visitor center, Volcano House Hotel, Kilauea Military Camp, Volcano Art Center Gallery, Thurston Lava Tube, Devastation Trail, Chain of Craters Road, Petroglyph Trail and all backcountry campsites.
Closed areas include all trails leading to Halemaumau Crater and part of Crater Rim Drive near the ash-laden toxic gas plume.
The volcano has not given park rangers reason to believe that it's about to blow; there's no visible lava in the crater itself, little seismic activity and no surface swell, Orlando said.
"As long as the winds stay as they are, there is no danger," she said.
"The park is Hawaii's gift to the world, so we want to keep the area open as long as we can."