Since Hawaii’s Kilauea Volcano first erupted on May 3, it has created several natural spectacles, from spewing giant rocks the size of refrigerators to emitting literal screams. Kilauea’s latest creation is sparking blue fire, which is every bit as dangerous as its prior nature-defying feats.

On Wednesday, the US Geological Survey (USGS) released an update on agency observations of the Kilauea Volcano, noting that the fissure system continues to produce robust eruptive activity in the Lower East Rift Zone. Fissure 22, among several other dangerous fissures, is producing fountains of lava that reach as far as the coast north of MacKenzie Park, creating blue flames in their wake.

“It’s very dramatic. It’s very eerie,” USGS scientist Jim Kauahikaua told CNN. These blue flames, much like when the eruption released toxic sulfur dioxide in the air, have to do with the gasses Kilauea is emitting into the atmosphere. When lava destroys plants and shrubs, methane gas is produced as a byproduct of burning vegetation. Methane can often seep into subsurface voids and will explode when heated, creating that signature blue flame.

Blue flames are signifiers of the growing vegetation casualties left in Kilauea’s wake. Methane from the fallen plants sits in the soil until heated by nearby lava, which is why the flames appear in cracks in the ground surrounded by lava streams.

The USGS observed the methane-infused blue flames in cracks on Kahukai Street in the Leilani Estates Subdivision this week and said it expects to see more of the ominous blue flames as Kilauea continues to ravage the surrounding vegetation. The lava is still “moving very vigorously” according to the USGS, meaning it’s slated to burn through even more vegetation and produce bursts of methane in various cracks in the soil.

In addition to Fissure 22, the most active fissures have been 19, 6, 5, and 23. Although Fissure 9 has not created new lava flows, it has already created blue flames of methane in road cracks. Expect to see more of these intermittent bursts of blue flames as fissures reach new plant life.