PAHO, Hawaii (AP) — A geophysicist says a plume that’s rising from the Kilauea volcano summit on Hawaii’s Big Island does not contain as much ash as it did on Tuesday.

A woman takes a photo as an ash plume rises from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Volcano, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater 'has raised the potential for explosive eruptions' at the volcano. (Photo by Mario Tama/Getty Images)
A woman takes a photo as an ash plume rises from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Volcano, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater 'has raised the potential for explosive eruptions' at the volcano. (Photo by Mario Tama/Getty Images)
A woman holds her dog Tzippy at a golf course as an ash plume rises in the distance from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Hawaii Volcanoes National Park, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater 'has raised the potential for explosive eruptions' at the volcano. (Photo by Mario Tama/Getty Images)
A woman holds her dog Tzippy at a golf course as an ash plume rises in the distance from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Hawaii Volcanoes National Park, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater 'has raised the potential for explosive eruptions' at the volcano. (Photo by Mario Tama/Getty Images)

Mike Poland with the U.S. Geological Survey said Wednesday the plume seems to be made largely of rock dust. Because there’s little wind, the plume for the most part is rising vertically over the summit.

A family gathers at a golf course as an ash plume rises in the distance from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Hawaii Volcanoes National Park, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater 'has raised the potential for explosive eruptions' at the volcano. (Photo by Mario Tama/Getty Images)
A family gathers at a golf course as an ash plume rises in the distance from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Hawaii Volcanoes National Park, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater 'has raised the potential for explosive eruptions' at the volcano. (Photo by Mario Tama/Getty Images)

USGS scientists will not monitor the plume from a summit observatory because of fears of falling ash. Instead, they will operate from a backup command center at the University of Hawaii at Hilo. Warnings to pilots are still in place because of the plume that reached 12,000 feet (3,658 meters) Tuesday. The volcano has been spewing lava from fissures that opened up on its flanks for two weeks.

A man drives a golf cart at a golf course as an ash plume rises in the distance from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Hawaii Volcanoes National Park, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater Òhas raised the potential for explosive eruptionsÓ at the volcano. (Photo by Mario Tama/Getty Images)
A man drives a golf cart at a golf course as an ash plume rises in the distance from the Kilauea volcano on Hawaii's Big Island on May 15, 2018 in Hawaii Volcanoes National Park, Hawaii. The U.S. Geological Survey said a recent lowering of the lava lake at the volcano's Halemaumau crater Òhas raised the potential for explosive eruptionsÓ at the volcano. (Photo by Mario Tama/Getty Images)