Scientists in Hawaii have captured rare images of blue flames burning from cracks in the pavement as Kilauea Volcano gushes fountains of lava in the background, offering insight into a new dimension in the volcano’s weeks-long eruption.

Volcanoes produce methane when hot lava buries and burns plants and trees. The gas flows through the ground and up through existing cracks.

“It’s very dramatic. It’s very eerie,” Jim Kauahikaua, a U.S. Geological Survey scientist, told reporters.

He said it was only the second time he’s ever seen blue flames during an eruption.

The methane can seep through cracks several feet away from the lava. It can also cause explosions when it’s ignited while trapped underground. These blasts can toss blocks of cooled lava several feet away, said Wendy Stovall, also a scientist at the Geological Survey.

Hawaii County has ordered about 2,000 people to evacuate from Leilani Estates and surrounding neighborhoods since the eruption began May 3.

The volcano has opened more than 20 vents in the ground that have released lava, sulfur dioxide and steam. The lava has been pouring down the flank of the volcano and into the ocean miles away.

The eruption has destroyed 50 buildings, including about two dozen homes. One person was seriously injured after being hit by a flying piece of lava.

Stovall said lava spatter from one vent was forming a wall that was helping protect the nearby Puna Geothermal Venture plant.

Lava from that vent was shooting farther into the air and producing the highest lava wall of all the vents, which was blocking molten rock from flowing north toward the plant.

Officials shut down PGV shortly after the eruption began, and on Tuesday finished stabilizing wells that bring up hot liquid and steam to feed a turbine generator. A team from the Hawaii Emergency Management Agency and the company continued Wednesday to plug the wells to make sure the fluid inside doesn’t move from one part of the well to the other, said Janet Snyder, a spokeswoman for Hawaii County.

Earlier this month officials removed a flammable gas called pentane from the plant to reduce the chance of explosions.